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  • 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.
    Ahnström Waltersson, Marie
    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, 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.
    Fornander, Tommy
    Department of Cytology, Karolinska University Hospital, SE-104 01 Stockholm, Sweden.
    Skoog, Lambert
    Department of Cytology, Karolinska University Hospital, SE-104 01 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.
    miR-206 expression is downregulated in cyclin D1 amplified breast tumoursManuscript (preprint) (Other academic)
    Abstract [en]

    Amplification in the 11q13 region has been found in around 15% of all breast cancers and is strongly correlated with oestrogen receptor (ER) positive tumours. We have previously found that amplification of at least one of the genes PAK1 or CCND1 is associated with decreased recurrencefree survival among ER+ patients. Other genes in the amplicon might also contribute to this effect and situated close to CCND1 are the FGF-3, -4 and - 19 genes. The FGF-4 protein has been shown to inhibit the expression of the ERα regulator miR-206 in chicken embryo. In this study we analysed 23 tumours with and 27 tumours without previously detected 11q13 amplification to explore if 11q13 amplification is associated with decreased levels of miR-206 and if miR-206 is associated with ER expression. Using real-time PCR, we found that miR-206 expression was inversely correlated to CCND1 and 11q13 amplification (P=0.016 and P=0.022 respectively). Tumours with low miR-206 expression had higher levels of ERα than tumours with intermediate and high expression (P=0.043). We conclude that miR-206 might be an important regulator of the ERα. Our finding that low mir-206 is associated with CCND1 amplification and thereby also FGF-4 amplification points towards the possibility of a miR-206 regulator, FGF-4 or another FGF, present in the amplicon.

  • 3.
    Bojmar, Linda
    et al.
    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.
    Ellegård, Sander
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Olsson, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Björnsson, Bergthor
    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 Surgery in Linköping.
    Hallböök, Olof
    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 Surgery in Linköping.
    Larsson, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. 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.
    Sandström, Per
    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 Surgery in Linköping.
    The Role of MicroRNA-200 in Progression of Human Colorectal and Breast Cancer2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 12, p. 84815-Article in journal (Refereed)
    Abstract [en]

    The role of the epithelial-mesenchymal transition (EMT) in cancer has been studied extensively in vitro, but involvement of the EMT in tumorigenesis in vivo is largely unknown. We investigated the potential of microRNAs as clinical markers and analyzed participation of the EMT-associated microRNA-200 ZEB E-cadherin pathway in cancer progression. Expression of the microRNA-200 family was quantified by real-time RT-PCR analysis of fresh-frozen and microdissected formalin-fixed paraffin-embedded primary colorectal tumors, normal colon mucosa, and matched liver metastases. MicroRNA expression was validated by in situ hybridization and after in vitro culture of the malignant cells. To assess EMT as a predictive marker, factors considered relevant in colorectal cancer were investigated in 98 primary breast tumors from a treatment-randomized study. Associations between the studied EMTmarkers were found in primary breast tumors and in colorectal liver metastases. MicroRNA-200 expression in epithelial cells was lower in malignant mucosa than in normal mucosa, and was also decreased in metastatic compared to non-metastatic colorectal cancer. Low microRNA-200 expression in colorectal liver metastases was associated with bad prognosis. In breast cancer, low levels of microRNA-200 were related to reduced survival and high expression of microRNA-200 was predictive of benefit from radiotheraphy. MicroRNA-200 was associated with ER positive status, and inversely correlated to HER2 and overactivation of the PI3K/AKT pathway, that was associated with high ZEB1 mRNA expression. Our findings suggest that the stability of microRNAs makes them suitable as clinical markers and that the EMT-related microRNA-200 - ZEB - E-cadherin signaling pathway is connected to established clinical characteristics and can give useful prognostic and treatment-predictive information in progressive breast and colorectal cancers.

  • 4.
    Bojmar, Linda
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Zhang, Haiying
    Children’s Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children’s Health, Meyer Cancer Center, Weill Cornell Medical College, New York, USA.
    Costa da Silva, Bruno
    Children’s Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children’s Health, Meyer Cancer Center, Weill Cornell Medical College, New York, USA.
    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.
    Olsson, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Vincent, Theresa
    Departments of Physiology and Biophysics and Cell and Developmental Biology, Weill Cornell Medical College, New York, USA / Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
    Larsson, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    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.
    Lyden, David
    Children’s Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children’s Health, Meyer Cancer Center, Weill Cornell Medical College, New York, USA.
    Sandström, Per
    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 Surgery in Linköping.
    miR-18a is regulated between progressive compartments of cancers, and incorporated in exosomes with the potential of creating premetastatic niches and predict cancer outcome2015Manuscript (preprint) (Other academic)
    Abstract [en]

    The ultimate cause of death for many cancer patients is the spread of the cancer via metastasis. Even so, there are still a lack of knowledge regarding the metastasis process. This study was performed to investigate the role of metastamirs in exosomes and their metastatic patterns. We used the well-established isogeneic murine cancer model of low metastatic 67NR cells, mimicking luminal/basal breast tumors, and highly metastatic 4T1 cells with characteristics of basal breast  tumors. We studied the exosomal properties and pre-metastatic effects in this metastasis model and compared human materials and exosomes of several other tumor types. Our data clearly demonstrated that exosomes from the highly metastatic cells home to the metastatic organs of their parental cells whereas exosomes from cells with low metastatic potential mostly located to lymph nodes. The exosome protein cargos also resembled their parental cells and potentially affects their target organs, and cells, differently. Furthermore, the exosomes from the highly metastatic cells had a more pronounced effect on tumor growth and pre-metastatic changes than the low metastatic exosomes. The microRNA-18a, a predictor of metastasis, was present to a higher extent in metastatic exosomes as compared to low metastatic exosomes, and altered the tumor progressive properties. Our findings support the role of exomirs as important players in the metastatic process, the value as biomarkers and potential therapeutic targets.

  • 5.
    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.

  • 6.
    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.

  • 7.
    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, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Pandiyan, Muneeswaran J.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Westman, Hanna
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Skoog, Lambert
    Stockholm S Gen Hospital, Sweden .
    Fornander, Tommy
    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.
    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.
    Activation of Akt, mTOR, and the estrogen receptor as a signature to predict tamoxifen treatment benefit2013In: Breast Cancer Research and Treatment, ISSN 0167-6806, E-ISSN 1573-7217, Vol. 137, no 2, p. 397-406Article in journal (Refereed)
    Abstract [en]

    The frequent alterations of the PI3K/Akt/mTOR-growth signaling pathway are proposed mechanisms for resistance to endocrine therapy in breast cancer, partly through regulation of estrogen receptor alpha (ER) activity. Reliable biomarkers for treatment prediction are required for improved individualized treatment. We performed a retrospective immunohistochemical analysis of primary tumors from 912 postmenopausal patients with node-negative breast cancer, randomized to either tamoxifen or no adjuvant treatment. Phosphorylated (p) Akt-serine (s) 473, p-mTOR-s2448, and ER phosphorylations-s167 and -s305 were evaluated as potential biomarkers of prognosis and tamoxifen treatment efficacy. High expression of p-mTOR indicated a reduced response to tamoxifen, most pronounced in the ER+/progesterone receptor (PgR) + subgroup (tamoxifen vs. no tamoxifen: hazard ratio (HR), 0.86; 95 % confidence interval (CI), 0.31-2.38; P = 0.78), whereas low p-mTOR expression predicted tamoxifen benefit (HR, 0.29; 95 % CI, 0.18-0.49; P = 0.000002). In addition, nuclear p-Akt-s473 as well as p-ER at -s167 and/or -s305 showed interaction with tamoxifen efficacy with borderline statistical significance. A combination score of positive pathway markers including p-Akt, p-mTOR, and p-ER showed significant association with tamoxifen benefit (test for interaction; P = 0.029). Cross-talk between growth signaling pathways and ER-signaling has been proposed to affect tamoxifen response in hormone receptor-positive breast cancer. The results support this hypothesis, as an overactive pathway was significantly associated with reduced response to tamoxifen. A clinical pre-treatment test for cross-talk markers would be a step toward individualized adjuvant endocrine treatment with or without the addition of PI3K/Akt/mTOR pathway inhibitors.

  • 8.
    Karlsson, Elin
    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.
    Clinical potential of the mTOR effectors S6K1, S6K2 and 4EBP1 in breast cancer2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The prognosis of patients diagnosed with breast cancer has been considerably improved in the latest 25 years, as a result of continuous development of diagnostics and treatment regimens. Though, tumour diseases, for woman mainly lung cancer and breast cancer, still constitute of the most common causes of death in developed countries, following heart diseases. A future utopia is to develop more individualised therapy strategies, to further increase breast cancer survival, but also to decrease  the risk of severe side-effects of unnecessary treatments.

    Normal mammary gland development is regulated by a complex interplay between growth factors and hormones, mainly oestrogen and progesterone, in different cell types. Breast cancer origin and progression is assumed to result from an imbalance in this interplay, leading to the so called “Hallmarks of cancer”, including unlimited cellular proliferation. A central hub in the regulation of proliferation is the intracellular mTOR signalling pathway. Antioestrogen therapy is widely used in breast cancer clinics, however resistance towards this treatment is a remaining problem, and overactivation of mTOR may be one reason behind. A new treatment regimen constituting a combination of mTOR inhibitors with endocrine therapy was recently clinically approved for advanced breast cancers. Although significant benefit for this combination treatment is evident for some patients, counteracting feedback mechanisms are assumed to diminish the effects.

    The work presented in this thesis focuses on the genes S6K1, S6K2 and 4EBP1 which are main effectors of the intracellular mTOR signalling pathway and thereby secondary targets of the mTOR inhibitors. Our results suggests that the gene amplification status, expression levels of the corresponding mRNA and protein of S6K1, S6K2 and 4EBP1 as well as their cellular localisation may be used to predict breast cancer outcome and the benefit from antioestrogen treatments. These factors are indicated to play separate roles in different subtypes of breast cancer, and specific targeting of S6K1 and S6K2 may be valuable in different tumour subtypes, and in comparison to present day’s mTOR inhibitors, further promote individualised therapies, and thereby increase breast cancer survival.

    List of papers
    1. Clinical potential of the mTOR targets S6K1 and S6K2 in breast cancer
    Open this publication in new window or tab >>Clinical potential of the mTOR targets S6K1 and S6K2 in breast cancer
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    2011 (English)In: Breast Cancer Research and Treatment, ISSN 0167-6806, E-ISSN 1573-7217, Vol. 128, no 3, p. 713-723Article in journal (Refereed) Published
    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.

    Place, publisher, year, edition, pages
    Springer Science Business Media, 2011
    Keywords
    mTOR; S6 kinase; 17q21-23; 11q13; Gene amplification; Tamoxifen response
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-69784 (URN)10.1007/s10549-010-1058-x (DOI)000292557100013 ()
    Note
    The original publication is available at www.springerlink.com: Gizeh Perez-Tenorio, Elin Karlsson, Marie Ahnström, Birgit Olsson, Birgitta Holmlund, Bo Nordenskjöld, Tommy Fornander, Lambert Skoog and Olle Stål, Clinical potential of the mTOR targets S6K1 and S6K2 in breast cancer, 2011, Breast Cancer Research and Treatment, (128), 3, 713-723. http://dx.doi.org/10.1007/s10549-010-1058-x Copyright: Springer Science Business Media http://www.springerlink.com/Available from: 2011-08-10 Created: 2011-08-08 Last updated: 2017-12-08
    2. High-Resolution Genomic Analysis of the 11q13 Amplicon in Breast Cancers Identifies Synergy with 8p12 Amplification, Involving the mTOR Targets S6K2 and 4EBP1
    Open this publication in new window or tab >>High-Resolution Genomic Analysis of the 11q13 Amplicon in Breast Cancers Identifies Synergy with 8p12 Amplification, Involving the mTOR Targets S6K2 and 4EBP1
    Show others...
    2011 (English)In: Genes, Chromosomes and Cancer, ISSN 1045-2257, E-ISSN 1098-2264, Vol. 50, no 10, p. 775-787Article in journal (Refereed) Published
    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.

    Place, publisher, year, edition, pages
    Wiley-Blackwell, 2011
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-70514 (URN)10.1002/gcc.20900 (DOI)000294177300003 ()
    Note

    Funding Agencies|Swedish Cancer Foundation||Swedish Research Council||

    Available from: 2011-09-12 Created: 2011-09-12 Last updated: 2017-12-08
    3. 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.
    Open this publication in new window or tab >>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.
    Show others...
    2013 (English)In: Breast Cancer Research, ISSN 1465-5411, E-ISSN 1465-542X, Vol. 15, no 5, p. R96-Article in journal (Refereed) Published
    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.

    Place, publisher, year, edition, pages
    BioMed Central, 2013
    Keywords
    mTOR; S6 kinase; 17q21-23; 11q13; Gene amplification; Tamoxifen response
    National Category
    Cancer and Oncology
    Identifiers
    urn:nbn:se:liu:diva-104178 (URN)10.1186/bcr3557 (DOI)000329763800024 ()24131622 (PubMedID)
    Available from: 2014-02-10 Created: 2014-02-10 Last updated: 2017-12-06Bibliographically approved
    4. Revealing Different Roles of the mTOR-Targets S6K1 and S6K2 in Breast Cancer by Expression Profiling and Structural Analysis
    Open this publication in new window or tab >>Revealing Different Roles of the mTOR-Targets S6K1 and S6K2 in Breast Cancer by Expression Profiling and Structural Analysis
    Show others...
    2015 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 12, p. e0145013-Article in journal (Refereed) Published
    Abstract [en]

    Background

    The AKT/mTORC1/S6K pathway is frequently overstimulated in breast cancer, constituting a promising therapeutic target. The benefit from mTOR inhibitors varies, likely as a consequence of tumour heterogeneity, and upregulation of several compensatory feed-back mechanisms. The mTORC1 downstream effectors S6K1, S6K2, and 4EBP1 are amplified and overexpressed in breast cancer, associated with a poor outcome and divergent endocrine treatment benefit. S6K1 and S6K2 share high sequence homology, but evidence of partly distinct biological functions is emerging. The aim of this work was to explore possible different roles and treatment target potentials of S6K1 and S6K2 in breast cancer.

    Materials and methods

    Whole-genome expression profiles were compared for breast tumours expressing high levels of S6K1, S6K2 or 4EBP1, using public datasets, as well as after in vitro siRNA downregulation of S6K1 and/or S6K2 in ZR751 breast cancer cells. In silico homology modelling of the S6K2 kinase domain was used to evaluate its possible structural divergences to S6K1.

    Results

    Genome expression profiles were highly different in S6K1 and S6K2 high tumours, whereas S6K2 and 4EBP1 profiles showed significant overlaps, both correlated to genes involved in cell cycle progression, among these the master regulator E2F1. S6K2 and 4EBP1 were inversely associated with IGF1 levels, and their prognostic value was shown to be restricted to tumours positive for IGFR and/or HER2. In vitro, S6K1 and S6K2 silencing resulted in upregulation of genes in the mTORC1 and mTORC2 complexes. Isoform-specific silencing also showed distinct patterns, e.g. S6K2 downregulation lead to upregulation of several cell cycle associated genes. Structural analyses of the S6K2 kinase domain showed unique structure patterns, deviating from those of S6K1, facilitating the development of isoform-specific inhibitors. Our data support emerging proposals of distinct biological features of S6K1 and S6K2, suggesting their importance as separate oncogenes and clinical markers, where specific targeting in different breast cancer subtypes could facilitate further individualised therapies.

    Place, publisher, year, edition, pages
    Public Library Science, 2015
    National Category
    Clinical Medicine Biological Sciences Chemical Sciences
    Identifiers
    urn:nbn:se:liu:diva-124494 (URN)10.1371/journal.pone.0145013 (DOI)000367092600042 ()26698305 (PubMedID)
    Note

    At the time for thesis presentation publication was in status: Manuscript

    Funding Agencies|Swedish Research Council [2012-5136, 2007-3475]; Swedish Cancer Foundation; LiU Cancer; LiU Cancer Foundation

    Available from: 2016-02-02 Created: 2016-02-01 Last updated: 2017-11-30Bibliographically approved
  • 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 Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Magic, Ivana
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering. Region Östergötland, 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 Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Oncology.
    Dyrager, Christine
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lysholm, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Hallbeck, Anna-Lotta
    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.
    Lundström, Patrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Revealing Different Roles of the mTOR-Targets S6K1 and S6K2 in Breast Cancer by Expression Profiling and Structural Analysis2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 12, p. e0145013-Article in journal (Refereed)
    Abstract [en]

    Background

    The AKT/mTORC1/S6K pathway is frequently overstimulated in breast cancer, constituting a promising therapeutic target. The benefit from mTOR inhibitors varies, likely as a consequence of tumour heterogeneity, and upregulation of several compensatory feed-back mechanisms. The mTORC1 downstream effectors S6K1, S6K2, and 4EBP1 are amplified and overexpressed in breast cancer, associated with a poor outcome and divergent endocrine treatment benefit. S6K1 and S6K2 share high sequence homology, but evidence of partly distinct biological functions is emerging. The aim of this work was to explore possible different roles and treatment target potentials of S6K1 and S6K2 in breast cancer.

    Materials and methods

    Whole-genome expression profiles were compared for breast tumours expressing high levels of S6K1, S6K2 or 4EBP1, using public datasets, as well as after in vitro siRNA downregulation of S6K1 and/or S6K2 in ZR751 breast cancer cells. In silico homology modelling of the S6K2 kinase domain was used to evaluate its possible structural divergences to S6K1.

    Results

    Genome expression profiles were highly different in S6K1 and S6K2 high tumours, whereas S6K2 and 4EBP1 profiles showed significant overlaps, both correlated to genes involved in cell cycle progression, among these the master regulator E2F1. S6K2 and 4EBP1 were inversely associated with IGF1 levels, and their prognostic value was shown to be restricted to tumours positive for IGFR and/or HER2. In vitro, S6K1 and S6K2 silencing resulted in upregulation of genes in the mTORC1 and mTORC2 complexes. Isoform-specific silencing also showed distinct patterns, e.g. S6K2 downregulation lead to upregulation of several cell cycle associated genes. Structural analyses of the S6K2 kinase domain showed unique structure patterns, deviating from those of S6K1, facilitating the development of isoform-specific inhibitors. Our data support emerging proposals of distinct biological features of S6K1 and S6K2, suggesting their importance as separate oncogenes and clinical markers, where specific targeting in different breast cancer subtypes could facilitate further individualised therapies.

  • 11.
    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.

  • 12.
    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.

  • 13.
    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.

  • 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, 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.

  • 15.
    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.

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