Hypoxia-Induced TPM2 Methylation is Associated with Chemoresistance and Poor Prognosis in Breast Cancer

Background/Aims: Tropomyosin-2 (TPM2) plays important roles in functions of the cytoskeleton, such as cytokinesis, vesicle transport, cell proliferation, migration and apoptosis,and these functions imply that TPM2 also plays a role in cancer development. Indeed, it has been shown that TPM2 plays a critical role in some cancers. However, the role of TPM2 in breast cancer is still poorly characterized. Thus, we explored the role of TPM2 in breast cancer. Methods: We analysed TPM2 expression and its correlation with the clinicopathological features in breast cancer. Then, we examined the influence of hypoxia on TPM2 expression and methylation status using bisulfite sequencing PCR. Furthermore, we performed TPM2-mediated migration and invasion assays in the context of hypoxia and examined changes in matrix metalloproteinase-2 (MMP2) expression. Finally, we detected the influence of TPM2 on survival and chemotherapy drug sensitivity. Results: We found that TPM2 expression is down-regulated in breast cancer cells compared to that in normal breast cells. The data from TCGA supported these results. Promoter methylation of TPM2, which could be induced by hypoxia, was responsible for its low expression. Hypoxia might regulate cell invasiveness partly by TPM2 down-regulation-mediated changes of MMP2 expression. Importantly, low TPM2 expression was correlated with lymph node metastasis (P=0.031), tumour node metastasis stage (P=0.01), histological grade (P=0.037), and shorter overall survival (P=0.028). Univariate and multivariate analyses indicated that TPM2 was an independent predictor in breast cancer patients. Paclitaxel chemotherapy did not benefit patients with low TPM2 expression (P<0.0001). TPM2 knockdown significantly reduced cell sensitivity to paclitaxel. Conclusion: TPM2 is a potential novel tumour suppressor gene in breast cancer. TPM2 is associated with poor survival and chemoresistance to paclitaxel in breast cancer, and TPM2 may represent a promising therapeutic gene target for breast cancer patients with chemoresistance.

[1]  A. Ray,et al.  A phase I trial of azacitidine and nanoparticle albumin bound paclitaxel in patients with advanced or metastatic solid tumors. , 2017, Oncotarget.

[2]  W. Qiu,et al.  Kaempferol Modulates DNA Methylation and Downregulates DNMT3B in Bladder Cancer , 2017, Cellular Physiology and Biochemistry.

[3]  Wei Shi,et al.  Lower Expression of SPRY4 Predicts a Poor Prognosis and Regulates Cell Proliferation in Colorectal Cancer , 2016, Cellular Physiology and Biochemistry.

[4]  T. Xiao,et al.  iTRAQ-based quantitative analysis of cancer-derived secretory proteome reveals TPM2 as a potential diagnostic biomarker of colorectal cancer , 2016, Frontiers of Medicine.

[5]  Bram Boeckx,et al.  Tumor hypoxia causes DNA hypermethylation by reducing TET activity , 2016, Nature.

[6]  W. Grady,et al.  Epigenetic silencing of TPM2 contributes to colorectal cancer progression upon RhoA activation , 2016, Tumor Biology.

[7]  J. Chen,et al.  MicroRNAs as Regulators of Cisplatin Resistance in Lung Cancer , 2015, Cellular Physiology and Biochemistry.

[8]  A. Jemal,et al.  Cancer statistics: Breast cancer in situ , 2015, CA: a cancer journal for clinicians.

[9]  Zhenyu Xiao,et al.  The SIRT 3 Expression Profile is Associated with Pathological and Clinical Outcomes in Human Breast Cancer Patients , 2014, Cellular Physiology and Biochemistry.

[10]  J. Geng,et al.  IGF2R Expression is Associated with the Chemotherapy Response and Prognosis of Patients with Advanced NSCLC , 2014, Cellular Physiology and Biochemistry.

[11]  B. Han,et al.  Notch 3 Protein, not its Gene Polymorphism, is Associated with the Chemotherapy Response and Prognosis of Advanced NSCLC Patients , 2014, Cellular Physiology and Biochemistry.

[12]  Denis Wirtz,et al.  Hypoxia and the extracellular matrix: drivers of tumour metastasis , 2014, Nature Reviews Cancer.

[13]  C. Perou,et al.  Personalizing the treatment of women with early breast cancer: highlights of the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013 , 2013, Annals of oncology : official journal of the European Society for Medical Oncology.

[14]  Tong Liu,et al.  Dysregulated expression of Slug, vimentin, and E‐cadherin correlates with poor clinical outcome in patients with basal‐like breast cancer , 2013, Journal of surgical oncology.

[15]  Jesper Nylandsted,et al.  Identification of Cytoskeleton-Associated Proteins Essential for Lysosomal Stability and Survival of Human Cancer Cells , 2012, PloS one.

[16]  K. Patterson,et al.  DNA Methylation: Bisulphite Modification and Analysis , 2011, Journal of visualized experiments : JoVE.

[17]  Charles M. Perou,et al.  Ki67 Index, HER2 Status, and Prognosis of Patients With Luminal B Breast Cancer , 2009, Journal of the National Cancer Institute.

[18]  O. Olopade,et al.  Advances in Breast Cancer: Pathways to Personalized Medicine , 2008, Clinical Cancer Research.

[19]  M. Gamulin,et al.  Immunohistochemical Analysis of ER, PR, HER-2, CK 5/6, p63 and EGFR Antigen Expression in Medullary Breast Cancer , 2008, Tumori.

[20]  F. de Longueville,et al.  Hypoxia induces protection against etoposide-induced apoptosis: molecular profiling of changes in gene expression and transcription factor activity , 2008, Molecular Cancer.

[21]  G. O'Neill,et al.  Tropomyosins as interpreters of the signalling environment to regulate the local cytoskeleton. , 2008, Seminars in cancer biology.

[22]  H. Harputluoglu,et al.  Demographic, clinical, and pathological characteristics of Turkish triple-negative breast cancer patients: single center experience. , 2007, Annals of oncology : official journal of the European Society for Medical Oncology.

[23]  Suzanne Schubbert,et al.  Hyperactive Ras in developmental disorders and cancer , 2007, Nature Reviews Cancer.

[24]  W. Jones,et al.  DNA methylation-dependent silencing of CST6 in human breast cancer cell lines , 2006, Laboratory Investigation.

[25]  Jun Yao,et al.  Distinct epigenetic changes in the stromal cells of breast cancers , 2005, Nature Genetics.

[26]  Nicole S. Bryce,et al.  Tissue-specific Tropomyosin Isoform Composition , 2005, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[27]  J. Rao,et al.  Microfilament actin remodeling as a potential target for cancer drug development. , 2004, Current cancer drug targets.

[28]  Douglas N Robinson,et al.  Mechanics and regulation of cytokinesis. , 2004, Current opinion in cell biology.

[29]  G. Borisy,et al.  Cell Migration: Integrating Signals from Front to Back , 2003, Science.

[30]  J. Herman,et al.  Gene silencing in cancer in association with promoter hypermethylation. , 2003, The New England journal of medicine.

[31]  M. Willingham,et al.  Loss of expression of tropomyosin-1, a novel class II tumor suppressor that induces anoikis, in primary breast tumors , 2003, Oncogene.

[32]  Hung Chiang,et al.  Interobserver reproducibility of Her-2/neu protein overexpression in invasive breast carcinoma using the DAKO HercepTest. , 2002, American journal of clinical pathology.

[33]  C. Der,et al.  Opposing Roles of the Extracellular Signal-Regulated Kinase and p38 Mitogen-Activated Protein Kinase Cascades in Ras-Mediated Downregulation of Tropomyosin , 2002, Molecular and Cellular Biology.

[34]  E. Jonasch,et al.  Radicicol suppresses transformation and restores tropomyosin-2 expression in both ras- and MEK-transformed cells without inhibiting the Raf/MEK/ERK signaling cascade. , 2001, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[35]  D. Helfman,et al.  Cytoskeletal changes in cell transformation and tumorigenesis. , 2001, Current opinion in genetics & development.

[36]  T. Chauncey.  Drug resistance mechanisms in acute leukemia , 2001, Current opinion in oncology.

[37]  E. Jonasch,et al.  Ras- and Raf-induced Down-modulation of Non-muscle Tropomyosin Are MEK-independent* , 1998, The Journal of Biological Chemistry.

[38]  G. Auer,et al.  Down-regulation of tropomyosin-2 expression in c-Jun-transformed rat fibroblasts involves induction of a MEK1-dependent autocrine loop. , 1998, Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research.

[39]  M. Jordan,et al.  Microtubules and actin filaments: dynamic targets for cancer chemotherapy. , 1998, Current opinion in cell biology.

[40]  J. Mier,et al.  Tropomyosin-2 cDNA lacking the 3' untranslated region riboregulator induces growth inhibition of v-Ki-ras-transformed fibroblasts. , 1997, Molecular biology of the cell.

[41]  D. Helfman,et al.  Forced expression of tropomyosin 2 or 3 in v-Ki-ras-transformed fibroblasts results in distinct phenotypic effects. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[42]  J. Herman,et al.  Methylation-specific PCR: a novel PCR assay for methylation status of CpG islands. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[43]  H. Kato,et al.  Expression of tropomyosin isoforms in benign and malignant human breast lesions. , 1996, British Journal of Cancer.

[44]  D. Helfman,et al.  Functional properties of non-muscle tropomyosin isoforms. , 1994, Current opinion in cell biology.

[45]  D. Murphy,et al.  The mechanism of equilibrium binding of microtubule-associated protein 2 to microtubules. Binding is a multi-phasic process and exhibits positive cooperativity. , 1993, The Journal of biological chemistry.

[46]  R. Winn,et al.  Phase II study of taxol in patients with untreated advanced non-small-cell lung cancer. , 1993, Journal of the National Cancer Institute.

[47]  Peter A. Jones,et al.  Epigenetics in cancer. , 2010, Carcinogenesis.

[48]  G. O'Neill,et al.  Tropomyosin-based regulation of the actin cytoskeleton in time and space. , 2008, Physiological reviews.

[49]  M. Gimona,et al.  Adhesions that mediate invasion. , 2006, The international journal of biochemistry & cell biology.

[50]  E. Friederich,et al.  The actin cytoskeleton as a therapeutic target: state of the art and future directions. , 2003, Progress in cell cycle research.

[51]  J. Lin,et al.  Tropomyosin isoforms in nonmuscle cells. , 1997, International review of cytology.