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  • 1.
    Ansell, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Jedlinski, Adam
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Roberg, Karin
    Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping. Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science.
    Epidermal growth factor is a biomarker for poor cetuximab response in tongue cancer cells2016In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, Vol. 45, no 1, p. 9-16Article in journal (Refereed)
    Abstract [en]

    Background: Epidermal growth factor receptor (EGFR) is a target for treatment in tongue cancer. Here, EGFR ligands were evaluated for their potential uses as predictive biomarkers of cetuximab treatment response.

    Methods: In three tongue cancer cell lines the influences of epidermal growth factor (EGF), amphiregulin (AR), and epiregulin (EPR) on tumour cell proliferation and cetuximab response were evaluated by the addition of recombinant human (rh) proteins or the siRNA-mediated downregulation of endogenous ligand production.

    Results: EGF or AR downregulation suppressed the proliferation of all investigated cell lines. Furthermore, all cell lines displayed increased cetuximab resistance upon the addition of rhEGF, whereas EGF silencing resulted in an improved cetuximab response in one cell line.

    Conclusions: Our data suggest that EGF and AR are critical components of the EGFR signalling network required for full proliferative potential. Moreover, EGF is a potential predictive biomarker of poor cetuximab response and a possible treatment target.

  • 2.
    Ansell, Anna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Kankainen, M.
    Institute of Biomedicine, Medical Biochemistry and Developmental Biology, Genome-Scale Biology, Research Program, University of Helsinki, Helsinki, Finland.
    Jönsson, Jan-Ingvar
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Monni, O.
    Institute of Biomedicine, Medical Biochemistry and Developmental Biology, Genome-Scale Biology, Research Program, University of Helsinki, Helsinki, Finland.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Molecular cross-talk between head and neck squamous cell carcinoma cells and cancer-associated fibroblasts2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Cancer-associated fibroblasts (CAFs) are one of the main components of the tumor stroma and are known to increase tumor growth and stimulate  invasion and metastasis. Increasing evidence suggests that CAFs may also be an important determinant of the response to various treatments. In this study we aimed to characterize the molecular cross-talk between CAFs and head and neck squamous cell carcinoma (HNSCC) cells.

    HNSCC cell lines were co-cultured with their patient-matched CAFs for seven days, after which the gene expression of tumor cells was investigated by Affymetrix microarray. 58 protein coding genes were found to be differentially expressed (Q≤0.05) in tumor cells cocultured with CAFs when compared to tumor cells cultured alone. The top functions of these genes were cancer, cellular movement, and embryonic development as analyzed by Ingenuity Pathway Analysis. Nine genes were upregulated by ≥1.5-fold while the expression of 35 genes was found to be reduced by ≤ 0.67-fold. Several of the differentially expressed genes have been associated with epithelial-to-mesenchymal transition (EMT). The change in the expression of POSTN, GREM1, COL1A2, VIM, and MMP7 was verified by qPCR analysis. Moreover, the influence of CAFs on the proliferation, migration and cetuximab sensitivity of tumor cells was investigated, and was found to vary among the tumor cell-CAF pairs.

    In conclusion, we demonstrate that CAF-derived signals cause changes in the expression of multiple genes, several of which are associated with an EMT phenotype of tumor cells. Furthermore, CAFs modulate the proliferation, migration and cetuximab treatment response of tumor cells.

  • 3.
    Appelqvist, Hanna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Linderoth, Emma
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Antonsson, Bruno
    Geneva Research Centre, Switzerland .
    Steinfeld, Robert
    University of Medical Centre Gottingen, Germany .
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Lysosome-Mediated Apoptosis is Associated with Cathepsin D-Specific Processing of Bid at Phe24,Trp48, and Phe1832012In: Annals of Clinical and Laboratory Science, ISSN 0091-7370, E-ISSN 1550-8080, Vol. 42, no 3, p. 231-242Article in journal (Refereed)
    Abstract [en]

    Bax-mediated permeabilization of the outer mitochondrial membrane and release of apoptogenic factors into the cytosol are key events that occur during apoptosis. Likewise, apoptosis is associated with permeabilization of the lysosomal membrane and release of lysosomal cathepsins into the cytosol. This report identifies proteolytically active cathepsin D as an important component of apoptotic signaling following lysosomal membrane permeabilization in fibroblasts. Lysosome-mediated cell death is associated with degradation of Bax sequestering 14-3-3 proteins, cleavage of the Box activator Bid, and translocation of Box to mitochondria, all of which were cathepsin D-dependent. Processing of Bid could be reproduced by enforced lysosomal membrane permeabilization, using the lysosomotropic detergent O-methyl-serine dodecylamine hydrochloride (MSDH). We identified three cathepsin D-specific cleavage sites in Bid, Phe24, Trp48, and Phe183. Cathepsin D-cleaved Bid induced Bax-mediated release of cytochrome c from purified mitochondria, indicating that the fragments generated are functionally active. Moreover, apoptosis was associated with cytosolic acidification, thereby providing a more favorable environment for the cathepsin D-mediated cleavage of Bid. Our study suggests that cytosolic cathepsin D triggers Bax-mediated cytochrome c release by proteolytic activation of Bid.

  • 4.
    Dabrosin, Charlotta
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Johansson, Ann-Charlotte
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Pathology.
    Öllinger, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Pathology. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Decreased secretion of Cathepsin D in breast cancer in vivo by tamoxifen: Mediated by the mannose-6-phosphate/IGF-II receptor?2004In: Breast Cancer Research and Treatment, ISSN 0167-6806, E-ISSN 1573-7217, Vol. 85, no 3, p. 229-238Article in journal (Refereed)
    Abstract [en]

    The lysosomal protease Catliepsin D (Cath D) is associated with increased invasiveness and metastasis in breast cancer. Both estrogen and tamoxifen have been reported to increase Cath D, which seems to contradict the efficacy of tamoxifen as an adjuvant for estrogen dependent breast cancer. Cath D is bioactive in the extracellular space but very little is known about hormonal regulation of secreted Cath D in vivo. In this study we used microdialysis to sample the extracellular fluid in estrogen receptor positive MCF-7 tumors in nude mice. We show that tamoxifen in combination with estradiol decreased secreted Cath D compared with estradiol treatment only in solid tumors in situ. Cell culture of MCF-7 cells revealed that estradiol and tamoxifen increased intracellular proteolytic activity of Cath D in a similar fashion whereas secretion of Cath D was increased by estradiol and inhibited by tamoxifen. Immunofluorescence showed that estradiol located Cath D to the cell surface, while tamoxifen accumulated Cath D to dense lysosomes in perinuclear regions. Moreover, tamoxifen increased the intracellular transporter of Cath D, the mannose 6-phosphate/IGF-II receptor (M6P/IGF2R). In contrast, estradiol decreased the levels of this receptor. Thus, secretion of Cath D is hormone dependent and may be mediated by altered expression of the M6P/IGF2R. Our results highlight the importance of measurements of proteins in all compartments where they are biological active and show that microdialysis is a viable technique for sampling of Cath D in vivo.

  • 5.
    Farnebo, Lovisa
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Jedlinski, Adam
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Ansell, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Thunell, Lena
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Grenman, Reidar
    University of Turku.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Proteins and single nucleotide polymorphisms involved in apoptosis, growth control, and DNA repair predict cisplatin sensitivity in head and neck cancer cell lines2009In: International Journal of Molecular Medicine, ISSN 1107-3756, E-ISSN 1791-244X, Vol. 24, no 4, p. 549-556Article in journal (Refereed)
    Abstract [en]

    The present study was undertaken to evaluate the possibility of using a panel of proteins and single nucleotide polymorphisms (SNPs) involved in apoptosis, growth control, and DNA repair as predictive markers for cisplatin sensitivity. For this purpose the intrinsic cisplatin sensitivity (ICS) was determined in 39 cell lines derived from squamous cell carcinomas of the head and neck using a colony-forming assay. In these cell lines and in normal oral keratinocytes (NOK), the expression of epidermal growth factor receptor (EGFR), Hsp70, Bax, Bcl-2, Bcl-XL, survivin, and COX-2 was determined. Moreover, the p53, MDM2, FGFR4, XPC, XPD, XRCC1, and XRCC3 genes were analyzed for the presence of specific single nucleotide polymorphisms (SNPs). Pearsons correlation test showed that EGFR was the only protein that was significantly correlated to the ICS (r=0.388, p=0.015). The combination of EGFR, Hsp70, Bax, and Bcl-2 gave the strongest correlation (r=0.566, p andlt;= 0.001), whereas Bax alone had the second highest influence on the ICS. Furthermore, all four SNPs within genes involved in DNA repair, i.e. XPC, XPD, XRCC1, and XRCC3, tended to influence the ICS. In order to find the combination of factors, on both protein and gene levels, with the highest correlation to ICS, a multivariate statistical calculation was performed. Our results indicate that SNPs in DNA repair genes (XRCC3(241) and XPD751) influence the ICS and together with the expression of EGFR, Hsp70, Bax, and Bcl-2, they could predict the cisplatin sensitivity of head and neck cancer cell lines (r=0.614, p andlt;= 0.001).

  • 6.
    Farnebo, Lovisa
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Jerhammar, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Ceder, Rebecca
    Institute of Environmental Medicine, Division of Biochemical Toxicology and Experimental Cancer Research, Karolinska Institute, Stockholm, Sweden.
    Grafström, Roland C
    Institute of Environmental Medicine, Division of Biochemical Toxicology and Experimental Cancer Research, Karolinska Institute, Stockholm, Sweden.
    Vainikka, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Thunell, Lena
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Grénman, Reidar
    Medical Biochemistry, University of Turku, Finland.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Combining factors on protein and gene level to predict radioresponse in head and neck cancer cell lines2011In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, Vol. 40, no 10, p. 739-746Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Radiotherapy is the main therapy for head and neck squamous cell carcinoma (HNSCC); however, treatment resistance and local recurrence are significant problems, highlighting the need for predictive markers. In this study, we evaluated selected proteins, mutations, and single nucleotide polymorphisms (SNPs) involved in apoptosis, cell proliferation, and DNA repair alone or combined as predictive markers for radioresponse in 42 HNSCC cell lines.

    METHODS: The expression of epidermal growth factor receptor, survivin, Bax, Bcl-2, Bcl-XL, cyclooxygenase-2, and heat shock protein 70 was analyzed by ELISA. Furthermore, mutations and SNPs in the p53 gene as well as SNPs in the MDM2, XRCC1, and XRCC3 genes were analyzed for their relation to radioresponse. To enable the evaluation of the predictive value of several factors combined, each cell line was allocated points based on the number of negative points (NNP) system, and the NNP sum was correlated with radioresponse.

    RESULTS: Survivin was the only factor that alone was significantly correlated with the intrinsic radiosensitivity (r=0.36, p=0.02). The combination of survivin, Bax, Bcl-2, Bcl-XL, cyclooxygenase-2, and the p53 Arg72Pro polymorphism was found to most strongly correlate with radioresponse (r=0.553, p<0.001).

    CONCLUSION: These data indicate that the intrinsic radiosensitivity of 42 HNSCC cell lines can be predicted by a panel of factors on both the protein and gene levels. Moreover, among the investigated factors, survivin was the most promising biomarker of radioresponse.

  • 7.
    Jedlinski, Adam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    Ansell, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    EGFR status and EGFR ligand expression influence the treatment response of head and neck cancer cell lines2013In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, Vol. 42, no 1, p. 26-36Article in journal (Refereed)
    Abstract [en]

    Background: Combination treatment (chemoradiotherapy) is the standard treatment for locally advanced head and neck squamous cell carcinoma (HNSCC); however, treatment resistance and local recurrence are significant problems. A high level of epidermal growth factor receptor (EGFR) has been associated with a more aggressive phenotype as well as decreased responsiveness to radio- or chemotherapy. We examined the role of EGFR status and EGFR ligand expression for the treatment response. Methods: Intrinsic sensitivity to radiotherapy, cisplatin, and cetuximab treatments was investigated in 25 HNSCC cell lines. EGFR gene copy number, mRNA and protein expression, EGFR and Akt phosphorylation status, and mRNA expression of the EGFR ligands were analyzed using quantitative PCR and ELISA and assessed for their impact on treatment sensitivity. Results: Different treatment modalities yielded great diversity in outcome; of note, cetuximab treatment stimulated growth in one cell line. When treatments were combined primarily additive effects were observed. While radioresistance tended to be associated with a high level of phosphorylated EGFR (pEGFR; P = 0.09), cetuximab-resistant cells had low levels of pEGFR (P = 0.13). The three most cetuximab-sensitive cell lines had high EGFR gene copy numbers. Furthermore, cetuximab treatment response was significantly correlated with epiregulin mRNA expression (r = -0.408, P = 0.043). Cisplatin-resistant tumor cells expressed significantly lower levels of EGFR protein (P = 0.04) compared to cisplatin-sensitive cells and tended to have lower levels of phosphorylated Akt (pAkt; P = 0.13) and lower expression levels of amphiregulin (P = 0.18). Conclusions: Epidermal growth factor receptor status and ligand expression influence the treatment sensitivity of HNSCC cells and may be useful as predictive markers.

  • 8.
    Jedlinski, Adam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Garvin, Stina
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Clinical pathology.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience. Linköping University, Faculty of Medicine and Health Sciences.
    Edqvist, Per-Henrik
    Uppsala University, Uppsala, Sweden.
    Pontén, Fredrik
    Uppsala University, Uppsala, Sweden.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    Cetuximab sensitivity of head and neck squamous cell carcinoma xenografts is associated with treatment-induced reduction of EGFR, pEGFR, and pSrc2017In: Journal of Oral Pathology & Medicine, ISSN 0904-2512, E-ISSN 1600-0714, no 9, p. 717-724Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The aim of this study was to validate in vitro drug sensitivity testing of head and neck squamous cell carcinoma (HNSCC)cell lines in an in vivo xenograft model, and to identify treatment-induced changes in the EGFR signaling pathway that could be used as markersfor cetuximab treatment response.

    METHODS: The in vitro cetuximab sensitivity of two HNSCC cell lines, UT-SCC-14 and UTSCC-45, was assessed using a crystal violet assay. In order to determine the corresponding in vivo sensitivity, UT-SCC-14 and UT-SCC-45 xenografts were generated in female BALB/c (nu/nu) nude mice. Mice were given three injections of intraperitoneal cetuximab or PBS and the tumor volume was recorded continuously. The expression of epidermal growth factor receptor (EGFR), phosphorylated EGFR (pEGFR), phosphorylated Src (pSrc), and Ki67 was investigated by immunohistochemistry.

    RESULTS: The treatment sensitive UT-SCC-14 cells were found to have an intrinsic cetuximab sensitivity (ICmabS) of 0.15 whereas the ICmabS of the insensitive cell line UT-SCC-45 was 0.78. The corresponding size ratio between untreated and cetuximab treated xenografts was 0.22 and 0.83 for UT-SCC-14 and UT-SCC-45, respectively. UT-SCC-14 cells had a higher baseline expression of pEGFR as compared to UT-SCC-45. Furthermore, in UT-SCC-14 xenografts there was a decrease in EGFR, pEGFR and pSrc upon cetuximab treatment. In contrast, a slight cetuximab-induced increase in EGFR, pEGFR and pSrc was observed in treatment-resistant UT-SCC-45 xenografts.

    CONCLUSIONS: The in vitro treatment sensitivity was reproduced in the in vivo model and cetuximab sensitivity was found to associate with a treatment-induced reduction in pEGFR and pSrc.

  • 9.
    Jerhammar, Fredrik
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Not Found:Linkoping Univ, Fac Hlth Sci, Dept Clin and Expt Med, Div Otorhinolaryngol and Head and Neck Surg, Linkoping, Sweden .
    Ceder, Rebecca
    Karolinska Institute, Sweden .
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Jansson, Agneta
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Grafstrom, Roland C.
    Karolinska Institute, Sweden VTT Technical Research Centre Finland, Finland .
    Söderkvist, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuroscience. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Otorhinolaryngology in Linköping.
    YAP1 is a potential biomarker for cetuximab resistance in head and neck cancer2014In: Oral Oncology, ISSN 1368-8375, E-ISSN 1879-0593, Vol. 50, no 9, p. 832-839Article in journal (Refereed)
    Abstract [en]

    Objectives: Targeted therapy against the epidermal growth factor receptor (EGFR) only variably represents a therapeutic advance in head and neck squamous cell carcinoma (HNSCC). This study addresses the need of biomarkers of treatment response to the EGFR-targeting antibody cetuximab (Erbitux (R)). Materials and Methods: The intrinsic cetuximab sensitivity of HNSCC cell lines was assessed by a crystal violet assay. Gene copy number analysis of five resistant and five sensitive cell lines was performed using the Affymetrix SNP 6.0 platform. Quantitative real-time PCR was used for verification of selected copy number alterations and assessment of mRNA expression. The functional importance of the findings on the gene and mRNA level was investigated employing siRNA technology. The data was statistically evaluated using Mann-Whitney U-test and Spearmans correlation test. Results: Analysis of the intrinsic cetuximab sensitivity of 32 HNSCC cell lines characterized five and nine lines as cetuximab sensitive or resistant, respectively. Gene copy number analysis of five resistant versus five sensitive cell lines identified 39 amplified protein-coding genes, including YAP1, in the genomic regions 11q22.1 or 5p13-15. Assessment using qPCR verified that YAP1 amplification associated with cetuximab resistance. Amplification of YAP1 correlated to higher mRNA levels, and RNA knockdown resulted in increased cetuximab sensitivity. Assessment of several independent clinical data sets in the public domain confirmed YAP1 amplifications in multiple tumor types including HNSCC, along with highly differential expression in a subset of HNSCC patients. Conclusion: Taken together, we provide evidence that YAP1 could represent a novel biomarker gene of cetuximab resistance in HNSCC cell lines.

  • 10.
    Jerhammar, Fredrik
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Jansson, Agneta
    Linköping University, Department of Clinical and Experimental Medicine, Oncology. Linköping University, Faculty of Health Sciences.
    Welander, Jenny
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Söderkvist, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    YAP1 Gene Amplification is a Marker for Cetuximab Resistance in Head and Neck CancerManuscript (preprint) (Other academic)
    Abstract [en]

    The epidermal growth factor receptor (EGFR) is commonly overexpressed in head and neck squamous cell carcinomas (HNSCC). The monoclonal antibody cetuximab (Erbitux®) inhibits its signaling and has been approved for treatment of HNSCC. However, since many patients do not benefit from cetuximab treatment, predictive biomarkers of cetuximab response are required. The present study aims at finding novel markers of cetuximab resistance.

    The intrinsic cetuximab sensitivity of 35 HNSCC cell lines was determined, and revealed a great variation in the response between cell lines. Five cell lines (14%) were cetuximab sensitive, and 12 (34%) were resistant. Interestingly, two cell lines proliferated after cetuximab treatment.

    10 cell lines (five cetuximab sensitive and five cetuximab resistant) were selected for gene copy number array analysis on the Affymetrix SNP 6.0 platform. 39 protein coding genes were amplified in cetuximab resistant cells and normal in sensitive cells, all present on genomic regions 11q22.1 or 5p13-15. Five genes were selected for quantitative PCR  verification, namely, YAP1 and TRPC6 (11q22.1) and PDCD6, TPPP, and PTGER4 (5p13-15). An extended panel of totally 10 cetuximab resistant and 10 sensitive cell lines verified that YAP1 amplified cells are cetuximab resistant.

    YAP1 gene amplification was highly correlated to the YAP1 mRNA expression, which was significantly higher in cetuximab resistant cells than in sensitive. YAP1 downregulation resulted in increased cetuximab sensitivity in one of two cetuximab resistant cell lines investigated and growth inhibition in another. We conclude that YAP1 is a marker for cetuximab resistance in head and neck cancer.

  • 11.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Lysosomal Membrane Permeabilization: A Cellular Suicide Stragegy2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the last decade, a tremendous gain in knowledge concerning the molecular events of apoptosis signaling and execution has been achieved.

    The aim of this thesis was to clarify the role of lysosomal membrane permeabilization and lysosomal proteases, cathepsins, in signaling for apoptosis. We identified cathepsin D as an important factor in staurosporine-induced human fibroblast cell death. After release to the cytosol, cathepsin D promoted mitochondrial release of cytochrome c by proteolytic activation of Bid. Cathepsin D-mediated cleavage of Bid generated two fragments with the apparent molecular mass of 15 and 19 kDa. By sequence analysis, three cathepsin D-specific cleavage sites, Phe24, Trp48, and Phe183, were identified. Moreover, we investigated the mechanism by which cathepsins escape the lysosomal compartment, and found that Bax is translocated from the cytosol to lysosomes upon staurosporine treatment. In agreement with these data, recombinant Bax triggered release of cathepsins from isolated rat liver lysosomes. Conceivably, the Bcl-2 family of proteins may govern release of pro-apoptotic factors from both lysosomes and mitochondria. The importance of lysosomal cathepsins in apoptosis signaling was studied also in oral squamous cell carcinoma cells following exposure to the redox-cycling drug naphthazarin or agonistic anti-Fas antibodies. In this experimental system, cathepsins were released to the cytosol, however, inhibition of neither cathepsin D, nor cysteine cathepsin activity suppressed cell death. Interestingly, cysteine cathepsins still appeared to be involved in activation of the caspase cascade. Cathepsins are often overexpressed and secreted by cancer cells, and it has been reported that extracellular cathepsins promote tumor growth and metastasis. Here, we propose that cathepsin B secreted from cancer cells may suppress cancer cell death by shedding of the Fas death receptor.

    Defects in the regulation of apoptosis contribute to a wide variety of diseases, such as cancer, neurodegeneration and autoimmunity. Increased knowledge of the molecular details of apoptosis could lead to novel, more effective, treatments for these illnesses. This thesis emphasizes the importance of the lysosomal death pathway, which is a promising target for future therapeutic intervention.

    List of papers
    1. Cathepsin D mediates cytochrome c release and caspase activation in human fibroblast apoptosis induced by staurosporine
    Open this publication in new window or tab >>Cathepsin D mediates cytochrome c release and caspase activation in human fibroblast apoptosis induced by staurosporine
    2003 (English)In: Cell Death and Differentiation, ISSN 1350-9047, Vol. 10, no 11, p. 1253-1259Article in journal (Refereed) Published
    Abstract [en]

    There is increasing evidence that proteases other than caspases, for example, the lysosomal cathepsins B, D and L, are involved in apoptotic cell death. In the present study, we present data that suggest a role for cathepsin D in staurosporine-induced apoptosis in human foreskin fibroblasts. Cathepsin D and cytochrome c were detected partially released to the cytosol after exposure to 0.1 µM staurosporine for 1 h. After 4 h, activation of caspase-9 and -3 was initiated and later caspase-8 activation and a decrease in full-length Bid were detected. Pretreatment of cells with the cathepsin D inhibitor, pepstatin A, prevented cytochrome c release and caspase activation, and delayed cell death. These results imply that cytosolic cathepsin D is a key mediator in staurosporine-induced apoptosis. Analysis of the relative sequence of apoptotic events indicates that, in this cell type, cathepsin D acts upstream of cytochrome c release and caspase activation.

    Keywords
    apoptosis, caspases, cathepsin D, cytochrome c, fibroblasts, lysosomes
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13200 (URN)10.1038/sj.cdd.4401290 (DOI)
    Available from: 2008-04-17 Created: 2008-04-17 Last updated: 2017-08-30
    2. Lysosomal membrane permeabilization during apoptosis: Involvement of Bax?
    Open this publication in new window or tab >>Lysosomal membrane permeabilization during apoptosis: Involvement of Bax?
    Show others...
    2005 (English)In: International journal of experimental pathology (Print), ISSN 0959-9673, E-ISSN 1365-2613, Vol. 86, no 5, p. 309-321Article in journal (Refereed) Published
    Abstract [en]

    Bcl-2 family members have long been known to control permeabilization of the mitochondrial membrane during apoptosis, but involvement of these proteins in lysosomal membrane permeabilization (LMP) was not considered until recently. The aim of this study was to investigate the mechanism underlying the release of lysosomal proteases to the cytosol seen during apoptosis, with special emphasis on the role of Bax. In human fibroblasts, exposed to the apoptosis-inducing drug staurosporine (STS), the release of the lysosomal protease cathepsin D to the cytosol was observed by immunocytochemistry. In response to STS treatment, there was a shift in Bax immunostaining from a diffuse to a punctate pattern. Confocal microscopy showed co-localization of Bax with both lysosomes and mitochondria in dying cells. Presence of Bax at the lysosomal membrane was confirmed by immuno-electron microscopy. Furthermore, when recombinant Bax was incubated with pure lysosomal fractions, Bax inserted into the lysosomal membrane and induced the release of lysosomal enzymes. Thus, we suggest that Bax is a mediator of LMP, possibly promoting the release of lysosomal enzymes to the cytosol during apoptosis.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2005
    Keywords
    Bax, cathepsins, lysosomes, lysosomal membrane permeabilization, mitochondria
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13201 (URN)10.1111/j.0959-9673.2005.00442.x (DOI)
    Note

    The previous status of this article was Manuscript and the working title was Insertion of Bax into lysosomal membranes promotes release of lysosomal proteases during apoptosis.

    Available from: 2008-04-17 Created: 2008-04-17 Last updated: 2017-12-13Bibliographically approved
    3. Cathepsin D-mediated processing of Bid at Phe24, Trp48, and Phe183
    Open this publication in new window or tab >>Cathepsin D-mediated processing of Bid at Phe24, Trp48, and Phe183
    Show others...
    2008 (English)In: International Journal of Experimental PathologyArticle in journal (Refereed) Submitted
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13202 (URN)
    Available from: 2008-04-17 Created: 2008-04-17 Last updated: 2017-08-30
    4. Role of lysosomal cathepsins in naphthazarin- and Fas-induced apoptosis in oral squamous cell carcinoma cells
    Open this publication in new window or tab >>Role of lysosomal cathepsins in naphthazarin- and Fas-induced apoptosis in oral squamous cell carcinoma cells
    2006 (English)In: Acta Oto-Laryngologica, ISSN 0001-6489, Vol. 126, no 1, p. 70-81Article in journal (Refereed) Published
    Abstract [en]

    Conclusion. Intracellular cysteine cathepsins are pro-apoptotic factors involved in activation of caspases in two oral squamous cell carcinoma (SCC) cell lines.

    Objective. To study the possible involvement of lysosomal cathepsins in oral SCC cell apoptosis.

    Material and methods. Apoptosis was induced in the two human oral SCC cell lines UT-SCC-20A and UT-SCC-24A using naphthazarin or anti-Fas antibodies, and was studied by analysis of caspase activity and nuclear morphology. Involvement of lysosomal cathepsins was investigated using the cysteine cathepsin inhibitor z-FA-FMK and the cathepsin D inhibitor pepstatin A. The amounts of cellular and soluble Fas death receptor were determined by ELISA.

    Results. Release of cathepsins from the lysosomes to the cytosol was observed early in apoptosis. Cysteine cathepsins were found to be involved in activation of caspases in response to treatment with naphthazarin or anti-Fas antibodies, but inhibition of cysteine cathepsin activity was not sufficient to prevent cell death. Moreover, inhibition of cysteine cathepsin activity resulted in increased expression of the Fas death receptor, suggesting involvement of extracellular cysteine cathepsins in death receptor shedding.

    Keywords
    Caspases; cathepsin D; cell death; cysteine cathepsins; Fas death receptor; lysosomes; shedding; soluble Fas
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13203 (URN)10.1080/00016480510043422 (DOI)
    Available from: 2008-04-17 Created: 2008-04-17 Last updated: 2009-05-20
  • 12.
    Johansson, Ann-Charlotte
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Ansell, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Jerhammar, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Bradic Lindh, Maja
    Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    Grenman, Reidar
    Turku University Hospital, Finland University of Turku, Finland .
    Munck-Wikland, Eva
    Karolinska University Hospital, Sweden .
    Ostman, Arne
    Karolinska Institute, Sweden .
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    Cancer-Associated Fibroblasts Induce Matrix Metalloproteinase-Mediated Cetuximab Resistance in Head and Neck Squamous Cell Carcinoma Cells2012In: Molecular Cancer Research, ISSN 1541-7786, E-ISSN 1557-3125, Vol. 10, no 9, p. 1158-1168Article in journal (Refereed)
    Abstract [en]

    A growing body of evidence suggests that components of the tumor microenvironment, including cancer-associated fibroblasts (CAF), may modulate the treatment sensitivity of tumor cells. Here, we investigated the possible influence of CAFs on the sensitivity of head and neck squamous cell carcinoma (HNSCC) cell lines to cetuximab, an antagonistic epidermal growth factor receptor (EGFR) antibody. Cetuximab treatment caused a reduction in the proliferation rate of HNSCC cell lines, whereas the growth of HNSCC-derived CAF cultures was unaffected. When tumor cells were cocultured with CAFs in a transwell system, the cetuximab-induced growth inhibition was reduced, and a complete protection from growth inhibition was observed in one of the tumor cell lines investigated. Media that had been conditioned by CAFs offered protection from cetuximab treatment in a concentration-dependent manner, suggesting that the resistance to treatment was mediated by CAF-derived soluble factors. The coculture of HNSCC cell lines with CAFs resulted in an elevated expression of matrix metalloproteinase-1 (MMP-1) in both the tumor cells and CAFs. Moreover, the CAF-induced resistance was partly abolished by the presence of an MMP inhibitor. However, CAFs treated with siRNA targeting MMP-1 still protected tumor cells from cetuximab treatment, suggesting that several MMPs may cooperate to facilitate resistance or that the protective effect is mediated by another member of the MMP family. These results identify a novel CAF-dependent modulation of cetuximab sensitivity and suggest that inhibiting MMPs may improve the effects of EGFR-targeted therapy.

  • 13.
    Johansson, Ann-Charlotte
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Appelqvist, Hanna
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Nilsson, Cathrine
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Kågedal, Katarina
    Linköping University, Department of Neuroscience and Locomotion, Pathology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Regulation of apoptosis-associated lysosomal membrane permeabilization2010In: APOPTOSIS, ISSN 1360-8185, Vol. 15, no 5, p. 527-540Article in journal (Refereed)
    Abstract [en]

    Lysosomal membrane permeabilization (LMP) occurs in response to a large variety of cell death stimuli causing release of cathepsins from the lysosomal lumen into the cytosol where they participate in apoptosis signaling. In some settings, apoptosis induction is dependent on an early release of cathepsins, while under other circumstances LMP occurs late in the cell death process and contributes to amplification of the death signal. The mechanism underlying LMP is still incompletely understood; however, a growing body of evidence suggests that LMP may be governed by several distinct mechanisms that are likely engaged in a death stimulus- and cell-type-dependent fashion. In this review, factors contributing to permeabilization of the lysosomal membrane including reactive oxygen species, lysosomal membrane lipid composition, proteases, p53, and Bcl-2 family proteins, are described. Potential mechanisms to safeguard lysosomal integrity and confer resistance to lysosome-dependent cell death are also discussed.

  • 14.
    Johansson, Ann-Charlotte
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Mild, Hanna
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Nilsson, Cathrine
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Antonsson, Bruno
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Cathepsin D-mediated processing of Bid at Phe24, Trp48, and Phe1832008In: International Journal of Experimental PathologyArticle in journal (Refereed)
  • 15.
    Johansson, Ann-Charlotte
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Norberg-Spaak, Lena
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences.
    Role of lysosomal cathepsins in naphthazarin- and Fas-induced apoptosis in oral squamous cell carcinoma cells2006In: Acta Oto-Laryngologica, ISSN 0001-6489, Vol. 126, no 1, p. 70-81Article in journal (Refereed)
    Abstract [en]

    Conclusion. Intracellular cysteine cathepsins are pro-apoptotic factors involved in activation of caspases in two oral squamous cell carcinoma (SCC) cell lines.

    Objective. To study the possible involvement of lysosomal cathepsins in oral SCC cell apoptosis.

    Material and methods. Apoptosis was induced in the two human oral SCC cell lines UT-SCC-20A and UT-SCC-24A using naphthazarin or anti-Fas antibodies, and was studied by analysis of caspase activity and nuclear morphology. Involvement of lysosomal cathepsins was investigated using the cysteine cathepsin inhibitor z-FA-FMK and the cathepsin D inhibitor pepstatin A. The amounts of cellular and soluble Fas death receptor were determined by ELISA.

    Results. Release of cathepsins from the lysosomes to the cytosol was observed early in apoptosis. Cysteine cathepsins were found to be involved in activation of caspases in response to treatment with naphthazarin or anti-Fas antibodies, but inhibition of cysteine cathepsin activity was not sufficient to prevent cell death. Moreover, inhibition of cysteine cathepsin activity resulted in increased expression of the Fas death receptor, suggesting involvement of extracellular cysteine cathepsins in death receptor shedding.

  • 16.
    Johansson, Ann-Charlotte
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Steen, Håkan
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Cathepsin D mediates cytochrome c release and caspase activation in human fibroblast apoptosis induced by staurosporine2003In: Cell Death and Differentiation, ISSN 1350-9047, Vol. 10, no 11, p. 1253-1259Article in journal (Refereed)
    Abstract [en]

    There is increasing evidence that proteases other than caspases, for example, the lysosomal cathepsins B, D and L, are involved in apoptotic cell death. In the present study, we present data that suggest a role for cathepsin D in staurosporine-induced apoptosis in human foreskin fibroblasts. Cathepsin D and cytochrome c were detected partially released to the cytosol after exposure to 0.1 µM staurosporine for 1 h. After 4 h, activation of caspase-9 and -3 was initiated and later caspase-8 activation and a decrease in full-length Bid were detected. Pretreatment of cells with the cathepsin D inhibitor, pepstatin A, prevented cytochrome c release and caspase activation, and delayed cell death. These results imply that cytosolic cathepsin D is a key mediator in staurosporine-induced apoptosis. Analysis of the relative sequence of apoptotic events indicates that, in this cell type, cathepsin D acts upstream of cytochrome c release and caspase activation.

  • 17.
    Kågedal, Katarina
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Heimlich, Gerd
    Institute for Medical Microbiology, Immunology and Hygiene, University of Köln, Köln, Germany.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Wang, Nancy S.
    Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
    Jürgensmeier, Juliane M.
    Institute for Medical Microbiology, Immunology and Hygiene, University of Köln, Köln, Germany.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Lysosomal membrane permeabilization during apoptosis: Involvement of Bax?2005In: International journal of experimental pathology (Print), ISSN 0959-9673, E-ISSN 1365-2613, Vol. 86, no 5, p. 309-321Article in journal (Refereed)
    Abstract [en]

    Bcl-2 family members have long been known to control permeabilization of the mitochondrial membrane during apoptosis, but involvement of these proteins in lysosomal membrane permeabilization (LMP) was not considered until recently. The aim of this study was to investigate the mechanism underlying the release of lysosomal proteases to the cytosol seen during apoptosis, with special emphasis on the role of Bax. In human fibroblasts, exposed to the apoptosis-inducing drug staurosporine (STS), the release of the lysosomal protease cathepsin D to the cytosol was observed by immunocytochemistry. In response to STS treatment, there was a shift in Bax immunostaining from a diffuse to a punctate pattern. Confocal microscopy showed co-localization of Bax with both lysosomes and mitochondria in dying cells. Presence of Bax at the lysosomal membrane was confirmed by immuno-electron microscopy. Furthermore, when recombinant Bax was incubated with pure lysosomal fractions, Bax inserted into the lysosomal membrane and induced the release of lysosomal enzymes. Thus, we suggest that Bax is a mediator of LMP, possibly promoting the release of lysosomal enzymes to the cytosol during apoptosis.

  • 18.
    La Fleur, Linnea
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology. Linköping University, Faculty of Health Sciences.
    Roberg, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of ENT - Head and Neck Surgery UHL.
    A CD44(high)/EGFR(low) Subpopulation within Head and Neck Cancer Cell Lines Shows an Epithelial-Mesenchymal Transition Phenotype and Resistance to Treatment2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 9Article in journal (Refereed)
    Abstract [en]

    Mortality in head and neck squamous cell carcinoma (HNSCC) is high due to emergence of therapy resistance which results in local and regional recurrences that may have their origin in resistant cancer stem cells (CSCs) or cells with an epithelial-mesenchymal transition (EMT) phenotype. In the present study, we investigate the possibility of using the cell surface expression of CD44 and epidermal growth factor receptor (EGFR), both of which have been used as stem cell markers, to identify subpopulations within HNSCC cell lines that differ with respect to phenotype and treatment sensitivity. Three subpopulations, consisting of CD44(high)/EGFR(low), CD44(high)/EGFR(high) and CD44(low) cells, respectively, were collected by fluorescence-activated cell sorting. The CD44(high)/EGFR(low) population showed a spindle-shaped EMT-like morphology, while the CD44(low) population was dominated by cobblestone-shaped cells. The CD44(high)/EGFR(low) population was enriched with cells in G0/G1 and showed a relatively low proliferation rate and a high plating efficiency. Using a real time PCR array, 27 genes, of which 14 were related to an EMT phenotype and two with stemness, were found to be differentially expressed in CD44(high)/EGFR(low) cells in comparison to CD44(low) cells. Moreover, CD44(high)/EGFR(low) cells showed a low sensitivity to radiation, cisplatin, cetuximab and gefitinib, and a high sensitivity to dasatinib relative to its CD44(high)/EGFR(high) and CD44(low) counterparts. In conclusion, our results show that the combination of CD44 (high) and EGFR (low) cell surface expression can be used to identify a treatment resistant subpopulation with an EMT phenotype in HNSCC cell lines.

  • 19.
    Nilsson, Cathrine
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Uno
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Johansson, Ann-Charlotte
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Kågedal, Katarina
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Experimental Pathology . Linköping University, Faculty of Health Sciences.
    Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells2006In: Apoptosis (London), ISSN 1360-8185, E-ISSN 1573-675X, Vol. 11, no 7, p. 1149-1159Article in journal (Refereed)
    Abstract [en]

    Apoptosis is often associated with acidification of the cytosol and since loss of lysosomal proton gradient and release of lysosomal content are early events during apoptosis, we investigated if the lysosomal compartment could contribute to cytosolic acidification. After exposure of U937 cells to tumor necrosis factor-α, three populations; healthy, pre-apoptotic, and apoptotic cells, were identified by flow cytometry. These populations were investigated regarding intra-cellular pH and apoptosis-associated events. There was a drop in cytosolic pH from 7.2 ± 0.1 in healthy cells to 6.8 ± 0.1 in pre-apoptotic, caspase-negative cells. In apoptotic, caspase-positive cells, the pH was further decreased to 5.7 ± 0.04. The cytosolic acidification was not affected by addition of specific inhibitors towards caspases or the mitochondrial F0F1-ATPase. In parallel to the cytosolic acidification, a rise in lysosomal pH from 4.3 ± 0.3, in the healthy population, to 4.8 ± 0.3 and 5.5 ± 0.3 in the pre-apoptotic- and apoptotic populations, respectively, was detected. In addition, lysosomal membrane permeability increased as detected as release of cathepsin D from lysosomes to the cytosol in pre-apoptotic and apoptotic cells. We, thus, suggest that lysosomal proton release is the cause of the cytosolic acidification of U937 cells exposed to TNF-α.

1 - 19 of 19
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