liu.seSearch for publications in DiVA
Change search
Refine search result
1 - 21 of 21
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aguilar, Helena
    et al.
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Urruticoechea, Ander
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Halonen, Pasi
    The Netherlands Cancer Institute, Amsterdam.
    Kiyotani, Kazuma
    Center for Genomic Medicine, RIKEN, Yokohama, Japan.
    Mushiroda, Taisei
    Center for Genomic Medicine, RIKEN, Yokohama, Japan.
    Barril, Xavier
    University of Barcelona, Catalonia, Spain.
    Serra-Musach, Jordi
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Islam, Abul
    University of Dhaka, Bangladesh.
    Caizzi, Livia
    Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain.
    Di Croce, Luciano
    Centre for Genomic Regulation (CRG), Barcelona, Catalonia, Spain.
    Nevedomskaya, Ekaterina
    The Netherlands Cancer Institute, Amsterdam.
    Zwart, Wilbert
    The Netherlands Cancer Institute, Amsterdam.
    Bostner, Josefine
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Karlsson, Elin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Fornander, Tommy
    Karolinska University Hospital, Stockholm South General Hospital, Sweden.
    Sgroi, Dennis C
    Massachusetts General Hospital, Boston, USA.
    Garcia-Mata, Rafael
    University of North Carolina at Chapel Hill, USA.
    Jansen, Maurice Phm
    Cancer Institute, Rotterdam, The Netherlands.
    García, Nadia
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Bonifaci, Núria
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Climent, Fina
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Soler, María Teresa
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Rodríguez-Vida, Alejo
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Gil, Miguel
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Brunet, Joan
    Hospital Josep Trueta, Girona, Catalonia, Spain.
    Martrat, Griselda
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Gómez-Baldó, Laia
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Extremera, Ana I
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Figueras, Agnes
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Balart, Josep
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Clarke, Robert
    Georgetown University Medical Center, Washington, DC, USA.
    Burnstein, Kerry L
    University of Miami, Miller School of Medicine, Miami, FL, USA.
    Carlson, Kathryn E
    University of Illinois, Urbana, USA.
    Katzenellenbogen, John A
    University of Illinois, Urbana, USA.
    Vizoso, Miguel
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Esteller, Manel
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain .
    Villanueva, Alberto
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    Rodríguez-Peña, Ana B
    CSIC-University of Salamanca, Spain.
    Bustelo, Xosé R
    CSIC-University of Salamanca, Spain.
    Nakamura, Yusuke
    University of Tokyo, Japan.
    Zembutsu, Hitoshi
    University of Tokyo, Japan.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Beijersbergen, Roderick L
    The Netherlands Cancer Institute, Amsterdam .
    Pujana, Miguel Angel
    L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain.
    VAV3 mediates resistance to breast cancer endocrine therapy2014In: Breast Cancer Research, ISSN 1465-5411, E-ISSN 1465-542X, Vol. 16, no 3, p. R53-Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: Endocrine therapies targeting cell proliferation and survival mediated by estrogen receptor alpha (ERalpha) are among the most effective systemic treatments for ERalpha-positive breast cancer. However, most tumors initially responsive to these therapies acquire resistance through mechanisms that involve ERalpha transcriptional regulatory plasticity. Here, we identify VAV3 as a critical component in this process.

    METHODS: A cell-based chemical compound screen was carried out to identify therapeutic strategies against resistance to endocrine therapy. Binding to ERalpha was evaluated by molecular docking analyses, an agonist fluoligand assay, and short-hairpin (sh) RNA-mediated protein depletion. Microarray analyses were performed to identify altered gene expression. Western blot of signaling and proliferation markers and shRNA-mediated protein depletion in viability and clonogenic assays were performed to delineate the role of VAV3. Genetic variation in VAV3 was assessed for association with the response to tamoxifen. Immunohistochemical analyses of VAV3 were carried out to determine the association with therapy response and different tumor markers. An analysis of gene expression association with drug sensitivity was carried out to identify a potential therapeutic approach based on differential VAV3 expression.

    RESULTS: The compound YC-1 was found to comparatively reduce the viability of cell models of acquired resistance. This effect was probably not due to activation of its canonical target (soluble guanylyl cyclase) but instead a result of binding to ERalpha. VAV3 was selectively reduced upon exposure to YC-1 or ERalpha depletion and, accordingly, VAV3 depletion comparatively reduced the viability of cell models of acquired resistance. In the clinical scenario, germline variation in VAV3 was associated with response to tamoxifen in Japanese breast cancer patients (rs10494071 combined P value = 8.4 x 10-4). The allele association combined with gene expression analyses indicated that low VAV3 expression predicts better clinical outcome. Conversely, high nuclear VAV3 expression in tumor cells was associated with poorer endocrine therapy response. Based on VAV3 expression levels and the response to erlotinib in cancer cell lines, targeting EGFR signaling may be a promising therapeutic strategy.

    CONCLUSIONS: This study proposes VAV3 as a biomarker and rationale signaling target to prevent and/or overcome resistance to endocrine therapy in breast cancer.

  • 2.
    Bostner, Josefine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Karlsson, Elin
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Bivik, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Inflammation Medicine. Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Franzén, Hanna
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Konstantinell, Aelita
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Fornander, Tommy
    Karolinska University Hospital, Sweden .
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    S6 kinase signaling and tamoxifen response in breast cancer cells and in two randomized breast cancer cohorts2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Detecting signals in the mammalian target of rapamycin (mTOR), and the estrogen receptor (ER) pathways for prediction of treatment response may be a future clinical tool in primary breast cancer. Here, we investigated the validity and value of the mTOR targets p70-S6 kinase (S6K) 1 and 2 as biomarkers for tamoxifen sensitivity in vitro and in two independent tamoxifen randomized postmenopausal breast cancer cohorts. In addition, the prognostic value of the S6Ks was evaluated. A simultaneous knockdown of the S6Ks in ER-positive breast cancer cells resulted in G1 arrest, and tamoxifen-induced G1 arrest was in part S6K1+S6K2 dependent, suggesting separate roles in proliferation and in tamoxifen response. We found S6K1 to correlate with HER2 and cytoplasmic Akt activity, whereas S6K2 and phosphorylated S6K were closer connected with ER positivity, low proliferation and nucleic p-Akt. Treatment prediction and prognosis were evaluated by immunohistochemical staining. Nuclear accumulation of S6K1 was indicative of a reduced tamoxifen treatment effect, compared with a significant benefit from tamoxifen treatment in patients without tumor S6K1 nuclear accumulation. Patients with a combination of S6K1 nuclear accumulation and S6K2 cytoplasmic accumulation in the tumor cells had no tamoxifen benefit. Also, S6K1 and S6K2 activation, indicated by p-S6K-t389 expression, was associated with low benefit from tamoxifen compared with untreated patients. In addition, high protein expression of S6K1, independent of localization, predicted worse prognosis. This was not evident for variations in S6K2 or p-S6K-t389 expression.

    In conclusion, the mTOR targeted kinases S6K1 and S6K2 interfere with proliferation and response to tamoxifen. Monitoring their activity andintracellular localization may provide biomarkers for breast cancer treatment, allowing for identification of a group of patients less likely tobenefit from tamoxifen and thus in need of an alternative or additional treatment.

  • 3.
    Bostner, Josefine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Elin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Bivik Eding, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Franzén, Hanna
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Konstantinell, Aelita
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Fornander, Tommy
    Karolinska University Hospital, Sweden.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    S6 kinase signaling: tamoxifen response and prognostic indication in two breast cancer cohorts2015In: Endocrine-Related Cancer, ISSN 1351-0088, E-ISSN 1479-6821, Vol. 22, no 3, p. 331-343Article in journal (Refereed)
    Abstract [en]

    Detection of signals in the mammalian target of rapamycin (mTOR) and the estrogen receptor (ER) pathways may be a future clinical tool for the prediction of adjuvant treatment response in primary breast cancer. Using immunohistological staining, we investigated the value of the mTOR targets p70-S6 kinase (S6K) 1 and 2 as biomarkers for tamoxifen benefit in two independent clinical trials comparing adjuvant tamoxifen with no tamoxifen or 5 years versus 2 years of tamoxifen treatment. In addition, the prognostic value of the S6Ks was evaluated. We found that S6K1 correlated with proliferation, HER2 status, and cytoplasmic AKT activity, whereas high protein expression levels of S6K2 and phosphorylated (p) S6K were more common in ER-positive, and low-proliferative tumors with pAKT-s473 localized to the nucelus. Nuclear accumulation of S6K1 was indicative of a reduced tamoxifen effect (hazard ratio (HR): 1.07, 95% CI: 0.53-2.81, P=0.84), compared with a significant benefit from tamoxifen treatment in patients without tumor S6K1 nuclear accumulation (HR: 0.42, 95% CI: 0.29-0.62, Pless than0.00001). Also S6K1 and S6K2 activation, indicated by pS6K-t389 expression, was associated with low benefit from tamoxifen (HR: 0.97, 95% CI: 0.50-1.87, P=0.92). In addition, high protein expression of S6K1, independent of localization, predicted worse prognosis in a multivariate analysis, P=0.00041 (cytoplasm), P=0.016 (nucleus). In conclusion, the mTOR-activated kinases S6K1 and S6K2 interfere with proliferation and response to tamoxifen. Monitoring their activity and intracellular localization may provide biomarkers for breast cancer treatment, allowing the identification of a group of patients less likely to benefit from tamoxifen and thus in need of an alternative or additional targeted treatment.

  • 4.
    Ellegård, Sander
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Veenstra, Cynthia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Pérez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Fagerström, Victor
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology. Department of Surgery, Kalmar Hospital, Kalmar.
    Garsjo, Jon
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Gert, Krista
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Sundquist, Marie
    Department of Surgery, Kalmar Hospital, Kalmar.
    Malmström, Annika
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Wingren, Sten
    Department of Clinical Medicine, School of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Elander, Nils
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Hallbeck, Anna-Lotta
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    ERBB2 and PTPN2 gene copy numbers as prognostic factors in HER2-positive metastatic breast cancer treated with trastuzumab2019In: Oncology Letters, ISSN 1792-1074, E-ISSN 1792-1082, Vol. 17, no 3, p. 3371-3381Article in journal (Refereed)
    Abstract [en]

    Trastuzumab has markedly improved the treatment and long-term prognosis of patients with HER2-positive breast cancer. A frequent clinical challenge in patients with relapsing and/or metastatic disease is de novo or acquired trastuzumab resistance, and to date no predictive biomarkers for palliative trastuzumab have been established. In the present study, the prognostic values of factors involved in the HER2-associated PI3K/Akt signalling pathway were explored. The first 46 consecutive patients treated at the Department of Oncology, Linkoping University Hospital between 2000 and 2007 with trastuzumab for HER2-positive metastatic breast cancer were retrospectively included. The gene copy number variation and protein expression of several components of the PI3K/Akt pathway were assessed in the tumour tissue and biopsy samples using droplet digital polymerase chain reaction and immunohistochemistry. Patients with tumours displaying a high-grade ERBB2 (HER2) amplification level of amp;gt;= 6 copies had a significantly improved overall survival hazard ratio [(HR)=0.4; 95%, confidence interval (CI): 0.2-0.9] and progression-free survival (HR=0.3; 95% CI: 0.1-0.7) compared with patients with tumours harbouring fewer ERBB2 copies. High-grade ERBB2 amplification was significantly associated with the development of central nervous system metastases during palliative treatment. Copy gain (amp;gt;= 3 copies) of the gene encoding the tyrosine phosphatase PTPN2 was associated with a shorter overall survival (HR=2.0; 95% CI: 1.0-4.0) and shorter progression-free survival (HR=2.1; 95% CI: 1.0-4.1). In conclusion, high ERBB2 amplification level is a potential positive prognostic factor in trastuzumab-treated HER2-positive metastatic breast cancer, whereas PTPN2 gain is a potential negative prognostic factor. Further studies are warranted on the role of PTPN2 in HER2 signalling.

  • 5.
    Falivelli, Giulia
    et al.
    Sanford-Burnham Medical Research Institute, San Diego, California, USA / Department Pharmacology, University of Bologna, Bologna, Italy.
    Lisabeth, Erika Mathes
    Sanford-Burnham Medical Research Institute, San Diego, California, USA.
    Rubio de la Torre, Elena
    Sanford-Burnham Medical Research Institute, San Diego, California, USA.
    Perez-Tenorio, Gizeh
    Sanford-Burnham Medical Research Institute, San Diego, California, USA.
    Tosato, Giovanna
    Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
    Salvucci, Ombretta
    Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
    Pasquale, Elena B
    Sanford-Burnham Medical Research Institute, San Diego, California, USA / Department of Pathology, University of California San Diego, San Diego, California, USA.
    Attenuation of eph receptor kinase activation in cancer cells by coexpressed ephrin ligands2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 11, p. e81445-Article in journal (Refereed)
    Abstract [en]

    The Eph receptor tyrosine kinases mediate juxtacrine signals by interacting "in trans" with ligands anchored to the surface of neighboring cells via a GPI-anchor (ephrin-As) or a transmembrane segment (ephrin-Bs), which leads to receptor clustering and increased kinase activity. Additionally, soluble forms of the ephrin-A ligands released from the cell surface by matrix metalloproteases can also activate EphA receptor signaling. Besides these trans interactions, recent studies have revealed that Eph receptors and ephrins coexpressed in neurons can also engage in lateral "cis" associations that attenuate receptor activation by ephrins in trans with critical functional consequences. Despite the importance of the Eph/ephrin system in tumorigenesis, Eph receptor-ephrin cis interactions have not been previously investigated in cancer cells. Here we show that in cancer cells, coexpressed ephrin-A3 can inhibit the ability of EphA2 and EphA3 to bind ephrins in trans and become activated, while ephrin-B2 can inhibit not only EphB4 but also EphA3. The cis inhibition of EphA3 by ephrin-B2 implies that in some cases ephrins that cannot activate a particular Eph receptor in trans can nevertheless inhibit its signaling ability through cis association. We also found that an EphA3 mutation identified in lung cancer enhances cis interaction with ephrin-A3. These results suggest a novel mechanism that may contribute to cancer pathogenesis by attenuating the tumor suppressing effects of Eph receptor signaling pathways activated by ephrins in trans.

  • 6.
    Fohlin, Helena
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Health and Developmental Care, Regional Cancer Center South East Sweden.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Fornander, Tommy
    Karolinska University Hospital, Sweden.
    Skoog, Lambert
    Karolinska University Hospital, Sweden.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Carstensen, John
    Linköping University, Department of Medical and Health Sciences, Health and Society. Linköping University, Faculty of Health Sciences.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Akt2 expression is associated with good long-term prognosis in oestrogen receptor positive breast cancer2013In: European Journal of Cancer, ISSN 0959-8049, E-ISSN 1879-0852, Vol. 49, no 6, p. 1196-1204Article in journal (Refereed)
    Abstract [en]

    Introduction

    Akt is a signalling modulator for many cellular processes, including metabolism, cell proliferation, cell survival and cell growth. Three isoforms of Akt have been identified, but only a few studies have concerned the isoform-specific roles in the prognosis of breast cancer patients. The aim of this study was to investigate the prognostic value of v-akt murine thymoma viral oncogene homologue 1 (Akt1) and v-akt murine thymoma viral oncogene homologue 2 (Akt2) in oestrogen receptor positive (ER+) and oestrogen receptor negative (ER–) breast cancer with long-term follow-up.

    Material and methods

    The expression of Akt in tumour tissue was analysed with immunohistochemistry in a cohort of 272 postmenopausal patients with stage II breast cancer. The median follow-up time was 19 years. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using the Cox’s proportional hazards model.

    Results

    The risk of distant recurrence was reduced for patients with ER+ tumours expressing Akt2 compared to patients with no Akt2 expression (HR = 0.49, 95% CI 0.29–0.82, p = 0.007). When adjusting for important clinical tumour characteristics and treatment, Akt2 was still an independent prognostic factor (HR = 0.38, 95% CI 0.21–0.68, p = 0.001) and the association remained long-term. The prognostic value of Akt2 increased with higher oestrogen receptor levels from no effect among patients with ER– tumours to 68% risk reduction for the group with high ER-levels (P for trend = 0.042). Akt1 showed no significant prognostic information.

    Conclusion

    Our results indicate that Akt2 expression is associated with a lower distant recurrence rate for patients with ER+ tumours and that this association remains long-term. The prognostic value of Akt2 increases with higher oestrogen receptor expression, motivating further mechanistic studies on the role of Akt2 in ER+ breast cancer.

  • 7.
    Husa, Anna-Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. St Anna Kinderkrebsforsch eV, Austria.
    Magic, Zeljana
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Larsson, Malin
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Fornander, Tommy
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    EPH/ephrin profile and EPHB2 expression predicts patient survival in breast cancer2016In: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 7, no 16, p. 21362-21380Article in journal (Refereed)
    Abstract [en]

    The EPH and ephrins function as both receptor and ligands and the output on their complex signaling is currently investigated in cancer. Previous work shows that some EPH family members have clinical value in breast cancer, suggesting that this family could be a source of novel clinical targets. Here we quantified the mRNA expression levels of EPH receptors and their ligands, ephrins, in 65 node positive breast cancer samples by RT-PCR with TaqMan (R) Micro Fluidics Cards Microarray. Upon hierarchical clustering of the mRNA expression levels, we identified a subgroup of patients with high expression, and poor clinical outcome. EPHA2, EPHA4, EFNB1, EFNB2, EPHB2 and EPHB6 were significantly correlated with the cluster groups and particularly EPHB2 was an independent prognostic factor in multivariate analysis and in four public databases. The EPHB2 protein expression was also analyzed by immunohistochemistry in paraffin embedded material (cohort 2). EPHB2 was detected in the membrane and cytoplasmic cell compartments and there was an inverse correlation between membranous and cytoplasmic EPHB2. Membranous EPHB2 predicted longer breast cancer survival in both univariate and multivariate analysis while cytoplasmic EPHB2 indicated shorter breast cancer survival in univariate analysis. Concluding: the EPH/EFN cluster analysis revealed that high EPH/EFN mRNA expression is an independent prognostic factor for poor survival. Especially EPHB2 predicted poor breast cancer survival in several materials and EPHB2 protein expression has also prognostic value depending on cell localization.

  • 8.
    Karlsson, E
    et al.
    Karolinska University Hospital.
    Waltersson, M A
    Karolinska University Hospital.
    Bostner, Josefine
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Fornander, T
    Karolinska University Hospital.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Comprehensive Genomic and Transcriptomic Analysis of the 11q13 Amplicon in Breast Cancer in CANCER RESEARCH, vol 69, issue 24, pp 820S-821S2009In: CANCER RESEARCH, 2009, Vol. 69, no 24, p. 820S-821SConference paper (Refereed)
    Abstract [en]

    n/a

  • 9.
    Karlsson, Elin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Ahnström, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Bostner, Josefine
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Hallbeck, Anna-Lotta
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    High-Resolution Genomic Analysis of the 11q13 Amplicon in Breast Cancers Identifies Synergy with 8p12 Amplification, Involving the mTOR Targets S6K2 and 4EBP12011In: Genes, Chromosomes and Cancer, ISSN 1045-2257, E-ISSN 1098-2264, Vol. 50, no 10, p. 775-787Article in journal (Refereed)
    Abstract [en]

    The chromosomal region 11q13 is amplified in 15-20% of breast cancers; an event not only associated with estrogen receptor (ER) expression but also implicated in resistance to endocrine therapy. Coamplifications of the 11q13 and 8p12 regions are common, suggesting synergy between the amplicons. The aim was to identify candidate oncogenes in the 11q13 region based on recurrent amplification patterns and correlations to mRNA expression levels. Furthermore, the 11q13/8p12 coamplification and its prognostic value, was evaluated at the DNA and the mRNA levels. Affymetrix 250K NspI arrays were used for whole-genome screening of DNA copy number changes in 29 breast tumors. To identify amplicon cores at 11q13 and 8p12, genomic identification of significant targets in cancer (GISTIC) was applied. The mRNA expression levels of candidate oncogenes in the amplicons [ RAD9A, RPS6KB2 (S6K2), CCND1, FGF19, FGF4, FGF3, PAK1, GAB2 (11q13); EIF4EBP1 (4EBP1), PPAPDC1B, and FGFR1 (8p12)] were evaluated using real-time PCR. Resulting data revealed three main amplification cores at 11q13. ER expression was associated with the central 11q13 amplification core, encompassing CCND1, whereas 8p12 amplification/gene expression correlated to S6K2 in a proximal 11q13 core. Amplification of 8p12 and high expression of 4EBP1 or FGFR1 was associated with a poor outcome in the group. In conclusion, single nucleotide polymorphism arrays have enabled mapping of the 11q13 amplicon in breast tumors with high resolution. A proximal 11q13 core including S6K2 was identified as involved in the coamplification/coexpression with 8p12, suggesting synergy between the mTOR targets S6K2 and 4EBP1 in breast cancer development and progression.

  • 10.
    Karlsson, Elin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Pérez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Amin, Risul
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Bostner, Josefine
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Skoog, Lambert
    Department of Pathology and Cytology, Karolinska University Hospital, Solna, Stockholm, Sweden.
    Fornander, Tommy
    Department of Oncology, Karolinska University Hospital, Stockholm South General Hospital, Stockholm, Sweden .
    Sgroi, Dennis C
    Department of Pathology, Molecular Pathology Research Unit, Massachusetts General Hospital, Boston, USA.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Hallbeck, Anna-Lotta
    Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology. Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    The mTOR effectors 4EBP1 and S6K2 are frequently coexpressed, and associated with a poor prognosis and endocrine resistance in breast cancer: a retrospective study including patients from the randomised Stockholm tamoxifen trials.2013In: Breast Cancer Research, ISSN 1465-5411, E-ISSN 1465-542X, Vol. 15, no 5, p. R96-Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: mTOR and its downstream effectors the 4E-binding protein 1 (4EBP1) and the p70 ribosomal S6 kinases (S6K1 and S6K2) are frequently upregulated in breast cancer, and assumed to be driving forces in tumourigenesis, in close connection with oestrogen receptor (ER) networks. Here, we investigated these factors as clinical markers in five different cohorts of breast cancer patients.

    METHODS: The prognostic significance of 4EBP1, S6K1 and S6K2 mRNA expression was assessed with real-time PCR in 93 tumours from the treatment randomised Stockholm trials, encompassing postmenopausal patients enrolled between 1976 and 1990. Three publicly available breast cancer cohorts were used to confirm the results. Furthermore, the predictive values of 4EBP1 and p4EBP1_S65 protein expression for both prognosis and endocrine treatment benefit were assessed by immunohistochemical analysis of 912 node-negative breast cancers from the Stockholm trials.

    RESULTS: S6K2 and 4EBP1 mRNA expression levels showed significant correlation and were associated with a poor outcome in all cohorts investigated. 4EBP1 protein was confirmed as an independent prognostic factor, especially in progesterone receptor (PgR)-expressing cancers. 4EBP1 protein expression was also associated with a poor response to endocrine treatment in the ER/PgR positive group. Cross-talk to genomic as well as non-genomic ER/PgR signalling may be involved and the results further support a combination of ER and mTOR signalling targeted therapies.

    CONCLUSION: This study suggests S6K2 and 4EBP1 as important factors for breast tumourigenesis, interplaying with hormone receptor signalling. We propose S6K2 and 4EBP1 as new potential clinical markers for prognosis and endocrine therapy response in breast cancer.

  • 11.
    Karlsson, Elin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Veenstra, Cynthia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Emin, Shad
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Dutta, Chhanda
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Fornander, Tommy
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Loss of protein tyrosine phosphatase, non-receptor type 2 is associated with activation of AKT and tamoxifen resistance in breast cancer2015In: Breast Cancer Research and Treatment, ISSN 0167-6806, E-ISSN 1573-7217, Vol. 153, no 1, p. 31-40Article in journal (Refereed)
    Abstract [en]

    Breast cancer is a heterogeneous disease and new clinical markers are needed to individualise disease management and therapy further. Alterations in the PI3K/AKT pathway, mainly PIK3CA mutations, have been shown frequently especially in the luminal breast cancer subtypes, suggesting a cross-talk between ER and PI3K/AKT. Aberrant PI3K/AKT signalling has been connected to poor response to anti-oestrogen therapies. In vitro studies have shown protein tyrosine phosphatase, non-receptor type 2 (PTPN2) as a previously unknown negative regulator of the PI3K/AKT pathway. Here, we evaluate possible genomic alterations in the PTPN2 gene and its potential as a new prognostic and treatment predictive marker for endocrine therapy benefit in breast cancer. PTPN2 gene copy number was assessed by real-time PCR in 215 tumour samples from a treatment randomised study consisting of postmenopausal patients diagnosed with stage II breast cancer 1976-1990. Corresponding mRNA expression levels of PTPN2 were evaluated in 86 available samples by the same methodology. Gene copy loss of PTPN2 was detected in 16 % (34/215) of the tumours and this was significantly correlated with lower levels of PTPN2 mRNA. PTPN2 gene loss and lower mRNA levels were associated with activation of AKT and a poor prognosis. Furthermore, PTPN2 gene loss was a significant predictive marker of poor benefit from tamoxifen treatment. In conclusion, genomic loss of PTPN2 may be a previously unknown mechanism of PI3K/AKT upregulation in breast cancer. PTPN2 status is a potential new clinical marker of endocrine treatment benefit which could guide further individualised therapies in breast cancer.

  • 12.
    Miller, Todd W
    et al.
    Vanderbilt University.
    Narasanna, Archana
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Gonzalez-Angulo, Ana M
    University of Texas.
    Hennessy, Bryan T
    University of Texas.
    Mills, Gordon B
    University of Texas.
    Kennedy, J Phillip
    Vanderbilt University.
    Lindsley, Craig W
    Vanderbilt University.
    Arteaga, Carlos L
    Vanderbilt University.
    Loss of Phosphatase and Tensin Homologue Deleted on Chromosome 10 Engages ErbB3 and Insulin-Like Growth Factor-I Receptor Signaling to Promote Antiestrogen Resistance in Breast Cancer2009In: CANCER RESEARCH, ISSN 0008-5472, Vol. 69, no 10, p. 4192-4201Article in journal (Refereed)
    Abstract [en]

    Knockdown of the tumor suppressor phosphatase Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) with shRNA in three estrogen receptor (ER)-positive breast cancer cell lines resulted in increased phosphatidylinositol-3 kinase (PI3K) and AKT activities, resistance to tamoxifen and fulvestrant, and hormone-independent growth. PTEN knockdown induced the up-regulation of ER transcriptional activity in MCF-7 cells but decreased ER protein levels and transcriptional activity in T47D and MDA-361 cells. Tamoxifen and fulvestrant treatment inhibited estradiol-induced Ell transcriptional activity in all shPTEN cell lines but did not abrogate the increased cell proliferation induced by PTEN knockdown. PTEN knockdown increased basal and ligand-induced activation of the insulin-like growth factor-I (IGF-I) and ErbB3 receptor tyrosine kinases, and prolonged the association of the p85 PI3K subunit with the IGF-I receptor (IGF-IR) effector insulin receptor substrate-1 and with ErbB3, implicating VITA in the modulation of Signaling upstream of PI3K. Consistent with these data, PTEN levels inversely correlated with levels of tyrosine-phosphorylated IGF-IR in tissue lysate arrays of primary breast cancers. Inhibition of IGF-IR and/or ErbB2-mediated activation of ErbB3 with tyrosine kinase inhibitors restored hormone dependence and the growth inhibitory effect of tamoxifen and fulvestrant. oil shPTEN cells, suggesting that cotargeting both Ell and receptor tyrosine kinase pathways holds promise for the treatment of patients with ER+, PTEN-deficient breast cancers.

  • 13.
    Perez-Tenorio, Gizeh
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Berglund, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Esguerra Merca, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Rutqvist, Lars Erik
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Skoog, Lambert
    Institutionen för cytology, Karolinska Hospital, Stockholm, Sweden.
    Stål , Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Cytoplasmic p21WAF1/CIP1 correlates with Akt activation and poor response to tamoxifen in breast cancer2006In: International Journal of Oncology, ISSN 1019-6439, Vol. 28, no 5, p. 1031-1042Article in journal (Refereed)
    Abstract [en]

    P21WAF1/Cip1 (p21) translocates to the cytoplasm inducing cell cycle progression and survival upon Akt/PKB activation. We studied whether heregulin beta1 (HRGbeta1), that activates the PI3K/Akt and MAPK pathways, also misallocates p21. We also explored whether HRGbeta1 interferes with the effects of tamoxifen. The clinical material studied helped us to clarify whether p21 was associated with phosphorylated Akt, recurrence-free survival and response to tamoxifen. MCF-7 cells treated with HRGbeta1 -/+ E2 were analyzed by flow cytometry to observe how the different compounds affected tamoxifen-induced cell cycle arrest and apoptosis. Total cell lysate and nuclear and cytoplasmic fractions were used to detect p21, phospho-Akt and other proteins by Western blotting. Immunofluorescence was used to visualize p21+ cells upon HRGbeta1 and E2 stimulation. The localization of p21 in breast cancer was studied by immunohistochemistry in frozen tumor sections from 280 patients. In MCF-7 we found that HRGbeta1 counteracted the inhibition of p21 expression by tamoxifen and caused p21 cytoplasmic accumulation. HRGbeta1 partially counteracted the cytostatic effect of tamoxifen but abrogated its cytotoxic effect. The clinical material revealed that nuclear p21 (P=0.022) and cytoplasmic p21 (P=0.00001) were associated with phospho-Akt. Based on p21 cell location, we identified 3 subgroups of ER+ patients: the p21N+/C- group for whom tamoxifen was needed otherwise the survival was poor (P=0.0082), the p21N+/C+ or p21N-/C- group, that responded to tamoxifen (P=0.034), and the p21C+/N- group, that might not benefit from this treatment (P=0.7). In conclusion, HRGbeta1 inhibits tamoxifen-induced apoptosis, contributes to p21 cytoplasmic expression while the cellular localization of p21 interacts with the benefit from tamoxifen treatment.

  • 14.
    Perez-Tenorio, Gizeh
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Karlsson, Elin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Oncology.
    Ahnström, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Holmlund, Birgitta
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Fornander, Tommy
    Karolinska University Hospital, Department Oncol, S-11883 Stockholm, Sweden.
    Skoog, Lambert
    Karolinska University Hospital, Department Pathol and Cytol, S-17176 Stockholm, Sweden.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology UHL.
    Clinical potential of the mTOR targets S6K1 and S6K2 in breast cancer2011In: Breast Cancer Research and Treatment, ISSN 0167-6806, E-ISSN 1573-7217, Vol. 128, no 3, p. 713-723Article in journal (Refereed)
    Abstract [en]

    The mammalian target of rapamycin (mTOR) and its substrates S6K1 and S6K2 regulate cell growth, proliferation, and metabolism through translational control. RPS6KB1 (S6K1) and RPS6KB2 (S6K2) are situated in the commonly amplified 17q21-23 and 11q13 regions. S6K1 amplification and protein overexpression have earlier been associated with a worse outcome in breast cancer, but information regarding S6K2 is scarce. The aim of this study was to evaluate the prognostic and treatment predictive relevance of S6K1/S6K2 gene amplification, as well as S6K2 protein expression in breast cancer. S6K1/S6K2 gene copy number was determined by real-time PCR in 207 stage II breast tumors and S6K2 protein expression was investigated by immunohistochemistry in 792 node-negative breast cancers. S6K1 amplification/gain was detected in 10.7%/21.4% and S6K2 amplification/gain in 4.3%/21.3% of the tumors. S6K2 protein was detected in the nucleus (38%) and cytoplasm (76%) of the tumor cells. S6K1 amplification was significantly associated with HER2 gene amplification and protein expression. S6K2 amplification correlated significantly with high S6K2 mRNA levels, ER+ status and CCND1 amplification. S6K1 and S6K2 gene amplification was associated with a worse prognosis independent of HER2 and CCND1. S6K2 gain and nuclear S6K2 expression was related to an improved benefit from tamoxifen among patients with ER+, respectively ER+/PgR+ tumors. In the ER+/PgR- subgroup, nuclear S6K2 rather indicated decreased tamoxifen responsiveness. S6K1 amplification predicted reduced benefit from radiotherapy. This is the first study showing that S6K2 amplification and overexpression, like S6K1 amplification, have prognostic and treatment predictive significance in breast cancer.

  • 15.
    Perez-Tenorio, Gizeh
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Karlsson, Elin
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Ahnström Waltersson, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Holmlund, Birgitta
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Fornander, Tommy
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Skoog, Lambert
    Department of Cytology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Clinical Value of RPS6KB1 and RPS6KB2 Gene Amplification in Postmenopausal Breast Cancer2008Article in journal (Refereed)
    Abstract [en]

    The mammalian target of rapamycin (mTOR) and its substrates the ribosomal S6 kinases (S6K)1 and 2 integrate nutrient and hormonal/growth factor mediated signals and are implicated indiabetes, obesity and cancer. The genes encoding S6K1 (RPS6KB1) and S6K2 (RPS6KB2) aresituated close to well known amplicons but information regarding its expression and clinicalvalue is scarce. In this study we quantified RPS6KB1/2 gene copy number, establishedassociations with other clinical factors and explored their clinical value in breast cancer. RPS6KB1/2 copy number was determined by fast real-time PCR in 207 breast tumors.RPS6KB1 was amplified (≥ 4 copies) in 10.7% (22/206) and RPS6KB2 in 4.3% (9/207) of thetumors. Amplification of RPS6KB1 was associated with HER2 gene amplification (P=0.025)and protein expression (P=0.014) while RPS6KB2 correlated with ER+ status (P=0.046) and CCND1 amplification (P<0.00001). In a multivariate analysis, both genes were independentprognostic factors indicating higher risk to develop recurrences. In terms of loco regionalcontrol, amplification of the RPS6KB1 gene predicted less response to radiotherapy (P=0.035) while RPS6KB2 gene copy gain (≥ 3 copies) indicated increased benefit from tamoxifen (P=0.03) among ER+ patients. S6K1/2 gene amplification could be used as an indicator oftherapy response among postmenopausal breast cancer patients.

  • 16.
    Pérez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Alterations in the PI3K/AKT Signaling Pathway and Response to Adjuvant Treatment in Breast Cancer2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    (PI3K)/AKT signaling pathway could be a cause of therapeutic resistance in breast cancer. The PI3K/AKT pathway controls cell proliferation, cell growth and survival, and its members include oncogenes and tumor suppressor genes. Alterations in this pathway are frequent in cancer. In this thesis, we aimed to study the biological significance of some of these alterations in a tumor context as well as their clinical value. PIK3CA gene, encoding the PI3K catalytic subunit, was examined for mutations. The tumor suppressor PTEN, that counteracts PI3Kmediated effects, was studied at the protein level whereas amplification of RPS6KB1 (S6K1) and RPS6KB2 (S6K2) genes, encoding two substrates of the mammalian target of rapamycin (mTOR) acting downstream PI3K/AKT, was also inspected. AKT phosphorylation or activation (pAKT) was determined by immunohistochemistry. Other factors related with this pathway, such as HER-2, heregulin (HRG) β1, the cell cycle inhibitor p21WAF1/CIP1, the pro-apoptotic factor Bcl-2, and cyclin D1,  were also considered. These studies were perfomed in two patient materials consisting of premenopausal patients that received endocrine treatment (paper I) and postmenopausal patients randomized to receive radiotherapy (RT) or chemotherapy (CMF) in combination with tamoxifen (Tam) or no endocrine treatment (papers II-IV). In the first material, we found that pAKT indicated higher risk of distant recurrence among endocrine treated patients. In the second material HRGβ1 induced accumulation cytoplasmic p21 in vitro and pAKT was associated with cytoplasmic p21 in the tumors. In addition, p21 cellular location identified subgroups of ER+ patients with different responses to tamoxifen. Other alterations such as PIK3CA mutations and PTEN loss were positively associated in this material. PIK3CA mutations lowered the risk for local recurrences while PTEN loss conferred radiosensitivity as a single variable or combined with mutated PIK3CA. PIK3CA mutations and/or PTEN loss was associated with lower S-phase (SPF). Nevertheless, among patients with low proliferating tumors, these alterations predicted higher risk of recurrence in contrast to those with high proliferating tumors. Finally, we found amplification of the S6K1 and S6K2 genes. S6K2 amplification was associated with cyclin D1 gene amplification, predicted poor recurrence-free survival and breast cancer death, and indicated benefit from tamoxifen. On the other hand, S6K1 amplification was associated with HER-2 amplification/overexpression, indicated higher risk of recurrence and was a predictor of poor response to radiotherapy. These results indicate the potential of this pathway as therapeutic source.

     

    List of papers
    1. Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients
    Open this publication in new window or tab >>Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients
    2002 (English)In: British Journal of Cancer, ISSN 0007-0920, E-ISSN 1532-1827, Vol. 86, no 4, p. 540-545Article in journal (Refereed) Published
    Abstract [en]

    Akt/PKB is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin β1 and Bcl-2 was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged < 50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P = 0.001) and the presence of heregulin β1-expressing stromal cells (P = 0.017). Neither Akt-1 nor pAkt was related with other factors Turnout cells-derived heregulin β1 was found mainly in oestrogen receptor negative (P = 0.026) and node negative (P = 0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P = 0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer

    Keywords
    Breast cancer, endocrine treatment, Akt, PKB, erbB-2, hergulin ß1
    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-15031 (URN)10.1038/sj.bjc.6600126 (DOI)
    Available from: 2008-10-10 Created: 2008-10-10 Last updated: 2017-12-11
    2. Cytoplasmic p21WAF1/CIP1 correlates with Akt activation and poor response to tamoxifen in breast cancer
    Open this publication in new window or tab >>Cytoplasmic p21WAF1/CIP1 correlates with Akt activation and poor response to tamoxifen in breast cancer
    Show others...
    2006 (English)In: International Journal of Oncology, ISSN 1019-6439, Vol. 28, no 5, p. 1031-1042Article in journal (Refereed) Published
    Abstract [en]

    P21WAF1/Cip1 (p21) translocates to the cytoplasm inducing cell cycle progression and survival upon Akt/PKB activation. We studied whether heregulin beta1 (HRGbeta1), that activates the PI3K/Akt and MAPK pathways, also misallocates p21. We also explored whether HRGbeta1 interferes with the effects of tamoxifen. The clinical material studied helped us to clarify whether p21 was associated with phosphorylated Akt, recurrence-free survival and response to tamoxifen. MCF-7 cells treated with HRGbeta1 -/+ E2 were analyzed by flow cytometry to observe how the different compounds affected tamoxifen-induced cell cycle arrest and apoptosis. Total cell lysate and nuclear and cytoplasmic fractions were used to detect p21, phospho-Akt and other proteins by Western blotting. Immunofluorescence was used to visualize p21+ cells upon HRGbeta1 and E2 stimulation. The localization of p21 in breast cancer was studied by immunohistochemistry in frozen tumor sections from 280 patients. In MCF-7 we found that HRGbeta1 counteracted the inhibition of p21 expression by tamoxifen and caused p21 cytoplasmic accumulation. HRGbeta1 partially counteracted the cytostatic effect of tamoxifen but abrogated its cytotoxic effect. The clinical material revealed that nuclear p21 (P=0.022) and cytoplasmic p21 (P=0.00001) were associated with phospho-Akt. Based on p21 cell location, we identified 3 subgroups of ER+ patients: the p21N+/C- group for whom tamoxifen was needed otherwise the survival was poor (P=0.0082), the p21N+/C+ or p21N-/C- group, that responded to tamoxifen (P=0.034), and the p21C+/N- group, that might not benefit from this treatment (P=0.7). In conclusion, HRGbeta1 inhibits tamoxifen-induced apoptosis, contributes to p21 cytoplasmic expression while the cellular localization of p21 interacts with the benefit from tamoxifen treatment.

    Keywords
    PI3K, heregulin ß1, cell cycle, cell survival
    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-15032 (URN)16596219 (PubMedID)
    Available from: 2008-10-10 Created: 2008-10-10 Last updated: 2017-12-11Bibliographically approved
    3. PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer
    Open this publication in new window or tab >>PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer
    Show others...
    2007 (English)In: Clinical Cancer Research, ISSN 1078-0432, E-ISSN 1557-3265, Vol. 13, no 12, p. 3577-3584Article in journal (Refereed) Published
    Abstract [en]

    Purpose: The phosphatidylinositol 3'-kinase/Akt pathway is frequently altered in breast cancer. PTEN, a phosphatase that opposes the effect of phosphatidylinositol 3'-kinase, can be mutated or lost, whereas the PIK3CA gene is mutated. These have been proposed as alternative mechanisms, and their clinicalpathology significance is under discussion. In this study, we aimed to explore whether PIK3CA mutations and PTEN loss are mutually exclusive mechanisms, correlate with other known clinicopathologic markers, or have clinical implication in breast cancer.

    Experimental Design: Exons 9 and 20 of the PIK3CA gene were analyzed in 270 breast tumors, and mutations were detected by single-stranded conformational analysis followed by sequencing. The expression of PTEN was evaluated by immunohistochemistry in 201 tumors.

    Results: PIK3CA mutations were found in 24% of the tumors and associated with estrogen receptor(+) status, small size, negative HER2 status, high Akt1, and high cyclin D1 protein expression. PTEN was negative in 37% of the cases and PTEN loss was associated with PIK3CA mutations (P = 0.0024). Tumors presenting PTEN loss or both alterations were often estrogen receptor(+), small in size, and HER2(-). PIK3CA mutations predicted for longer local recurrence-free survival. Moreover, PTEN loss by itself or combined with mutated PIK3CA tended to confer radiosensitivity. In addition, the patients with high S-phase fraction had longer recurrence-free survival if they carried mutations in the PIK3CA gene and/or had lost PTEN, whereas the same alterations were associated with shorter recurrence-free survival among patients with low S-phase fraction.

    Conclusions: PIK3CA mutations and PTEN loss were not mutually exclusive events and associated with similar prognostic factors.

    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-15041 (URN)10.1158/1078-0432.CCR-06-1609 (DOI)17575221 (PubMedID)
    Available from: 2008-10-13 Created: 2008-10-13 Last updated: 2017-12-11
    4. Clinical Value of RPS6KB1 and RPS6KB2 Gene Amplification in Postmenopausal Breast Cancer
    Open this publication in new window or tab >>Clinical Value of RPS6KB1 and RPS6KB2 Gene Amplification in Postmenopausal Breast Cancer
    Show others...
    2008 (English)Article in journal (Refereed) Submitted
    Abstract [en]

    The mammalian target of rapamycin (mTOR) and its substrates the ribosomal S6 kinases (S6K)1 and 2 integrate nutrient and hormonal/growth factor mediated signals and are implicated indiabetes, obesity and cancer. The genes encoding S6K1 (RPS6KB1) and S6K2 (RPS6KB2) aresituated close to well known amplicons but information regarding its expression and clinicalvalue is scarce. In this study we quantified RPS6KB1/2 gene copy number, establishedassociations with other clinical factors and explored their clinical value in breast cancer. RPS6KB1/2 copy number was determined by fast real-time PCR in 207 breast tumors.RPS6KB1 was amplified (≥ 4 copies) in 10.7% (22/206) and RPS6KB2 in 4.3% (9/207) of thetumors. Amplification of RPS6KB1 was associated with HER2 gene amplification (P=0.025)and protein expression (P=0.014) while RPS6KB2 correlated with ER+ status (P=0.046) and CCND1 amplification (P<0.00001). In a multivariate analysis, both genes were independentprognostic factors indicating higher risk to develop recurrences. In terms of loco regionalcontrol, amplification of the RPS6KB1 gene predicted less response to radiotherapy (P=0.035) while RPS6KB2 gene copy gain (≥ 3 copies) indicated increased benefit from tamoxifen (P=0.03) among ER+ patients. S6K1/2 gene amplification could be used as an indicator oftherapy response among postmenopausal breast cancer patients.

    Keywords
    PI3K, AKT, mTOR, CCND1, HER2, ER, Tamoxifen
    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-15042 (URN)
    Available from: 2008-10-13 Created: 2008-10-13 Last updated: 2009-04-09
  • 17.
    Pérez-Tenorio, Gizeh
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Alkhori, Liza
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Ahnstro Waltersson, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Rutqvist, Lars Erik
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Skoog, Lambert
    Institutionen för Cytology, Karolinska Hospital, Stockholm, Sweden.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    PIK3CA mutations and PTEN loss correlate with similar prognostic factors and are not mutually exclusive in breast cancer2007In: Clinical Cancer Research, ISSN 1078-0432, E-ISSN 1557-3265, Vol. 13, no 12, p. 3577-3584Article in journal (Refereed)
    Abstract [en]

    Purpose: The phosphatidylinositol 3'-kinase/Akt pathway is frequently altered in breast cancer. PTEN, a phosphatase that opposes the effect of phosphatidylinositol 3'-kinase, can be mutated or lost, whereas the PIK3CA gene is mutated. These have been proposed as alternative mechanisms, and their clinicalpathology significance is under discussion. In this study, we aimed to explore whether PIK3CA mutations and PTEN loss are mutually exclusive mechanisms, correlate with other known clinicopathologic markers, or have clinical implication in breast cancer.

    Experimental Design: Exons 9 and 20 of the PIK3CA gene were analyzed in 270 breast tumors, and mutations were detected by single-stranded conformational analysis followed by sequencing. The expression of PTEN was evaluated by immunohistochemistry in 201 tumors.

    Results: PIK3CA mutations were found in 24% of the tumors and associated with estrogen receptor(+) status, small size, negative HER2 status, high Akt1, and high cyclin D1 protein expression. PTEN was negative in 37% of the cases and PTEN loss was associated with PIK3CA mutations (P = 0.0024). Tumors presenting PTEN loss or both alterations were often estrogen receptor(+), small in size, and HER2(-). PIK3CA mutations predicted for longer local recurrence-free survival. Moreover, PTEN loss by itself or combined with mutated PIK3CA tended to confer radiosensitivity. In addition, the patients with high S-phase fraction had longer recurrence-free survival if they carried mutations in the PIK3CA gene and/or had lost PTEN, whereas the same alterations were associated with shorter recurrence-free survival among patients with low S-phase fraction.

    Conclusions: PIK3CA mutations and PTEN loss were not mutually exclusive events and associated with similar prognostic factors.

  • 18.
    Pérez-Tenorio, Gizeh
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Members of the Southeast Sweden Breast Cancer Group,
    Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients2002In: British Journal of Cancer, ISSN 0007-0920, E-ISSN 1532-1827, Vol. 86, no 4, p. 540-545Article in journal (Refereed)
    Abstract [en]

    Akt/PKB is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin β1 and Bcl-2 was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged < 50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P = 0.001) and the presence of heregulin β1-expressing stromal cells (P = 0.017). Neither Akt-1 nor pAkt was related with other factors Turnout cells-derived heregulin β1 was found mainly in oestrogen receptor negative (P = 0.026) and node negative (P = 0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P = 0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer

  • 19.
    Stål, Olle
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Åkerberg, Lind
    Olsson, Birgit
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Skoog, Lambert
    Division of Cytology, Karolinska Hospital, Stockholm, Sweden .
    Rutqvist, Lars
    Department of Oncology, Huddinge University Hospital, Stockholm, Sweden .
    Akt kinases in breast cancer and the results of adjuvant therapy2003In: Breast Cancer Research, ISSN 1465-5411, E-ISSN 1465-542X, Vol. 5, no 2, p. R37-R44Article in journal (Refereed)
    Abstract [en]

    Background

    The serine/threonine kinase Akt, or protein kinase B, has recently been a focus of interest because of its activity to inhibit apoptosis. It mediates cell survival by acting as a transducer of signals from growth factor receptors that activate phosphatidylinositol 3-kinase.

    Methods

    We analysed the expression of the isoforms Akt1 and Akt2 as well as phosphorylated Akt (pAkt) by immunohistochemistry in frozen tumour samples from 280 postmenopausal patients who participated in a randomised trial comparing cyclophosphamide–methotrexate–5-fluorouracil chemotherapy and postoperative radiotherapy. The patients were simultaneously randomised to tamoxifen or to no endocrine treatment.

    Results

    Marked staining was found in 24% of the tumours for Akt1, but in only 4% for Akt2. A low frequency of Akt2-positive cells (1–10%) was observed in another 26% of the tumours. pAkt was significantly associated with both Akt1 and Akt2 expression. Overexpression of erbB2 correlated significantly with pAkt (P = 0.0028). The benefit from tamoxifen was analysed in oestrogen receptor (ER)-positive patients. Patients with a negative status of Akt (no overexpression of Akt1, Akt2 or pAkt) showed significant benefit from tamoxifen. The relative rate of distant recurrence, with versus without tamoxifen, was 0.44 (95% confidence interval [CI], 0.25–0.79) for ER+/Akt1- patients, while it was 0.72 (95% CI, 0.34–1.53) for ER+/Akt1+ patients. The difference in rate ratio did not reach statistical significance. The rate of locoregional recurrence was significantly decreased with radiotherapy versus chemotherapy for Akt-negative patients (rate ratio, 0.23; 95% CI, 0.08–0.67; P = 0.0074), while no benefit was evident for the Akt-positive subgroup (rate ratio, 0.77; 95% CI, 0.31–1.9; P = 0.58). The interaction between Akt and the efficacy of radiotherapy was significant in multivariate analysis (P = 0.042).

    Conclusion

    Activation of the Akt pathway is correlated with erbB2 overexpression in breast cancer. The results suggest that Akt may predict the local control benefit from radiotherapy.

  • 20.
    Söderlund Leifler, Karin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences.
    Pérez-Tenorio, Gizeh
    Linköping University, Department of Biomedicine and Surgery. Linköping University, Faculty of Health Sciences.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Oncology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Activation of the phosphatidylinositol 3-kinase/Akt pathway prevents radiation-induced apoptosis in breast cancer cells2005In: International Journal of Oncology, ISSN 1019-6439, Vol. 26, no 1, p. 25-32Article in journal (Refereed)
    Abstract [en]

    Radiotherapy is widely used in the treatment of breast cancer and reduces the risk of loco-regional recurrence. Overexpression of the erbB2 receptor occurs in 20-30% of all breast cancers, and seems to be involved in chemotherapeutic resistance of breast cancer cells and radioresistance of lung cancer cells. The hypothesis of this study was that erbB2 confers resistance to radiation-induced apoptosis in breast cancer cells through the phosphatidylinositol 3-kinase (PI3-K)/Akt signalling pathway. Two human breast cancer cell lines were used, BT-474 and MCF-7. BT-474 cells overexpress erbB2 and have mutated p53, while MCF-7 have normal expression of erbB2 and functional p53. The cells were treated with the PI3-K inhibitor wortmannin or the erbB receptor ligand heregulin-ß1, which is expressed by both malignant and stromal cells in vivo. After pharmacological treatment, the cells were irradiated with 10 Gy gamma-radiation. Consistent with the p53 status in the cell lines, gamma-radiation caused G1 arrest in MCF-7 cells, but not in BT-474 cells. 10 Gy gamma-radiation increased apoptosis by on an average 76% (95% CI, 44-109%) in MCF-7. Treatment of MCF-7 with heregulin-ß1 decreased apoptosis by 66% (95% CI, 48-84%) compared to the untreated controls. In BT-474 cells, wortmannin in combination with radiation resulted in 119% (95% CI, 76-161%) more apoptosis compared to wortmannin alone, whereas radiation alone resulted in 45% (95% CI, 15-75%) increased apoptosis. This radiosensitising effect was not seen in MCF-7. Furthermore, transfection of MCF-7 cells with constitutively active Akt made the cells more resistant against apoptosis. Taken together, our results support the hypothesis that the erbB2/PI3-K/Akt signalling pathway is involved in resistance to radiation-induced apoptosis in breast cancer cells in which this signalling pathway is overstimulated.

  • 21.
    Veenstra, Cynthia
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Perez-Tenorio, Gizeh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Stelling, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Elin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Mirwani Mirwani, Sanam
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Nordenskjöld, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Fornander, Tommy
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden.
    Stål, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Met and its ligand HGF are associated with clinical outcome in breast cancer2016In: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 7, no 24, p. 37145-37159Article in journal (Refereed)
    Abstract [en]

    Few biomarkers exist to predict radiotherapy response in breast cancer. In vitro studies suggest a role for Met and its ligand HGF. To study this suggested role, MET and HGF gene copy numbers were determined by droplet digital PCR in tumours from 205 pre-menopausal and 184 post-menopausal patients, both cohorts randomised to receive either chemo-or radiotherapy. MET amplification was found in 8% of the patients in both cohorts and HGF amplification in 7% and 6% of the patients in the pre-and post-menopausal cohort, respectively. Met, phosphorylated Met (pMet), and HGF protein expression was determined by immunohistochemistry in the premenopausal cohort. Met, pMet, and HGF was expressed in 33%, 53%, and 49% of the tumours, respectively. MET amplification was associated with increased risk of distant recurrence for patients receiving chemotherapy. For the pre-menopausal patients, expression of cytoplasmic pMet and HGF significantly predicted benefit from radiotherapy in terms of loco-regional recurrence. Similar trends were seen for MET and HGF copy gain. In the post-menopausal cohort, no significant association of benefit from radiotherapy with neither genes nor proteins was found. The present results do not support that inhibition of Met prior to radiotherapy would be favourable for pre-menopausal breast cancer, as previously suggested.

1 - 21 of 21
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf