Characterization of BCAR4, a novel oncogene causing endocrine resistance in human breast cancer cells

Resistance to the antiestrogen tamoxifen remains a major problem in the management of estrogen receptor‐positive breast cancer. Knowledge on the resistance mechanisms is needed to develop more effective therapies. Breast cancer antiestrogen resistance 4 (BCAR4) was identified in a functional screen for genes involved in tamoxifen resistance. BCAR4 is expressed in 27% of primary breast tumors. In patients treated with tamoxifen for metastized disease high BCAR4 mRNA levels are associated with reduced clinical benefit and progression‐free survival. Regarding tumor aggressiveness high BCAR4 mRNA levels are associated with a shorter metastasis free survival and overall survival. In the present study, we investigated the role of BCAR4 in endocrine resistance. Forced expression of BCAR4 in human ZR‐75‐1 and MCF7 breast cancer cells resulted in cell proliferation in the absence of estrogen and in the presence of various antiestrogens. Inhibition of estrogen receptor 1 (ESR1) expression with small interfering RNA (siRNA), implied that the BCAR4‐induced mechanism of resistance is independent of ESR1. Highly conserved BCAR4 homologues of rhesus monkey, green monkey, and the less conserved common marmoset gene induced tamoxifen‐resistant cell proliferation, in contrast to the distant BCAR4 homologues of bovine and rabbit. Injection of BCAR4‐expressing ZR‐75‐1 cells into nude mice resulted in rapidly growing tumors. In silico analysis showed that BCAR4 mRNA is highly expressed in human placenta and oocyte, and absent in other normal tissues. In conclusion, BCAR4 is a strong transforming gene causing estrogen‐independent growth and antiestrogen resistance, and induces tumor formation in vivo. Due to its restricted expression, BCAR4 may be a good target for treating antiestrogen‐resistant breast cancer. J. Cell. Physiol. 226: 1741–1749, 2011. © 2010 Wiley‐Liss, Inc.

[1]  J. Foekens,et al.  Prediction of relapse and survival in breast cancer patients by pS2 protein status. , 1990, Cancer research.

[2]  J. Foekens,et al.  Induction of estrogen independence of ZR-75-1 human breast cancer cells by epigenetic alterations. , 1994, Molecular endocrinology.

[3]  R. Levine,et al.  Pathogenesis of preeclampsia. , 2010, Annual review of pathology.

[4]  F. Gandolfi,et al.  The maternal legacy to the embryo: cytoplasmic components and their effects on early development. , 2001, Theriogenology.

[5]  Osborne Ck,et al.  Tamoxifen in the Treatment of Breast Cancer , 1998 .

[6]  M Baum,et al.  First results from the International Breast Cancer Intervention Study (IBIS-I): a randomised prevention trial , 2002, The Lancet.

[7]  C K Redmond,et al.  Tamoxifen for prevention of breast cancer: report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study. , 1999, Journal of the National Cancer Institute.

[8]  C. Osborne,et al.  Comparison of estrogen receptor DNA binding in untreated and acquired antiestrogen-resistant human breast tumors. , 1997, Cancer research.

[9]  Peter Braude,et al.  Human gene expression first occurs between the four- and eight-cell stages of preimplantation development , 1988, Nature.

[10]  J. Foekens,et al.  Prognostic factors in human primary breast cancer: Comparison of c-myc and HER2/neu amplification , 1992, The Journal of Steroid Biochemistry and Molecular Biology.

[11]  J. Foekens,et al.  Relevance of BCAR4 in tamoxifen resistance and tumour aggressiveness of human breast cancer , 2010, British Journal of Cancer.

[12]  R. Schiff,et al.  Resistance to endocrine therapy in breast cancer: exploiting estrogen receptor/growth factor signaling crosstalk. , 2006, Endocrine-related cancer.

[13]  W. McGuire,et al.  Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene. , 1987, Science.

[14]  A. Thor,et al.  Downregulation of erbB3 abrogates erbB2‐mediated tamoxifen resistance in breast cancer cells , 2007, International journal of cancer.

[15]  S. Legha,et al.  Tamoxifen in the treatment of breast cancer. , 1988, Annals of internal medicine.

[16]  M. Dowsett,et al.  HER-2 amplification impedes the antiproliferative effects of hormone therapy in estrogen receptor-positive primary breast cancer. , 2001, Cancer research.

[17]  Hans Clevers,et al.  Distinct gene mutation profiles among luminal-type and basal-type breast cancer cell lines , 2010, Breast Cancer Research and Treatment.

[18]  J. Veldscholte,et al.  Identification of a novel breast‐cancer‐anti‐estrogen‐resistance (BCAR2) locus by cell‐fusion‐mediated gene transfer in human breast‐cancer cells , 1997, International journal of cancer.

[19]  J. Robertson,et al.  Oestrogen receptor: a stable phenotype in breast cancer. , 1996, British Journal of Cancer.

[20]  N. Hynes,et al.  The ErbB receptors and their role in cancer progression. , 2003, Experimental cell research.

[21]  O. Shaker,et al.  Pathogenesis of preeclampsia , 2013, Human & experimental toxicology.

[22]  Lambert C. J. Dorssers,et al.  The substrate domain of BCAR1 is essential for anti-estrogen-resistant proliferation of human breast cancer cells , 2010, Breast Cancer Research and Treatment.

[23]  M. Smid,et al.  Breast cancer oestrogen independence mediated by BCAR1 or BCAR3 genes is transmitted through mechanisms distinct from the oestrogen receptor signalling pathway or the epidermal growth factor receptor signalling pathway , 2004, Breast Cancer Research.

[24]  Simak Ali,et al.  Regulation of ERBB2 by oestrogen receptor–PAX2 determines response to tamoxifen , 2008, Nature.

[25]  A. Harris,et al.  c-erbB-2 protein overexpression in breast cancer is a risk factor in patients with involved and uninvolved lymph nodes. , 1991, British Journal of Cancer.

[26]  Michael Kofler,et al.  The crystal structure of a truncated ErbB2 ectodomain reveals an active conformation, poised to interact with other ErbB receptors. , 2003, Molecular cell.

[27]  Alexander F Schier,et al.  The Maternal-Zygotic Transition: Death and Birth of RNAs , 2007, Science.

[28]  P. Mermillod,et al.  Differential regulation of abundance and deadenylation of maternal transcripts during bovine oocyte maturation in vitro and in vivo , 2007, BMC Developmental Biology.

[29]  S. Sleijfer,et al.  Selective recruitment of breast cancer anti-estrogen resistance genes and relevance for breast cancer progression and tamoxifen therapy response. , 2010, Endocrine-related cancer.

[30]  Minetta C. Liu,et al.  Antiestrogen resistance in breast cancer and the role of estrogen receptor signaling , 2003, Oncogene.

[31]  Mieke Timmermans,et al.  How ADAM-9 and ADAM-11 Differentially From Estrogen Receptor Predict Response to Tamoxifen Treatment in Patients with Recurrent Breast Cancer: a Retrospective Study , 2005, Clinical Cancer Research.

[32]  Jorge S Reis-Filho,et al.  The contribution of gene expression profiling to breast cancer classification, prognostication and prediction: a retrospective of the last decade , 2010, The Journal of pathology.

[33]  J. Foekens,et al.  Prognostic value of PS2 and cathepsin D in 710 human primary breast tumors: multivariate analysis. , 1993, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[34]  D. Horsfall,et al.  Clinical significance of HER-2/neu oncogene amplification in primary breast cancer. The South Australian Breast Cancer Study Group. , 1993, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[35]  M. Smid,et al.  Functional identification of genes causing estrogen independence of human breast cancer cells , 2009, Breast Cancer Research and Treatment.

[36]  A. Rajkovic,et al.  Identification of expressed sequence tags preferentially expressed in human placentas by in silico subtraction , 2003, Prenatal diagnosis.

[37]  J. Foekens,et al.  Oncogene amplification and prognosis in breast cancer: relationship with systemic treatment. , 1995, Gene.

[38]  S. Kansra,et al.  Differential effects of estrogen receptor antagonists on pituitary lactotroph proliferation and prolactin release , 2005, Molecular and Cellular Endocrinology.

[39]  J. Foekens,et al.  Ectopic expression of epidermal growth factor receptors induces hormone independence in ZR-75-1 human breast cancer cells. , 1992, Cancer research.

[40]  V. Speirs,et al.  New perspectives into the biological and clinical relevance of oestrogen receptors in the human breast , 2007, The Journal of pathology.

[41]  A. Giordano,et al.  Molecular Mechanism and Clinical Implications of Endocrine Therapy Resistance in Breast Cancer , 2010, Oncology.

[42]  L. Dorssers,et al.  Functional Screen for Genes Responsible for Tamoxifen Resistance in Human Breast Cancer Cells , 2006, Molecular Cancer Research.

[43]  C K Osborne,et al.  Estrogen receptor status by immunohistochemistry is superior to the ligand-binding assay for predicting response to adjuvant endocrine therapy in breast cancer. , 1999, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[44]  Mike Clarke,et al.  Tamoxifen for early breast cancer: an overview of the randomised trials , 1998, The Lancet.

[45]  W. Gradishar.  Safety Considerations of Adjuvant Therapy in Early Breast Cancer in Postmenopausal Women , 2005, Oncology.

[46]  Robert L. Sutherland,et al.  Biological determinants of endocrine resistance in breast cancer , 2009, Nature Reviews Cancer.

[47]  René Bernards,et al.  New tools for functional mammalian cancer genetics , 2003, Nature Reviews Cancer.

[48]  T. Agthoven,et al.  Induction of antiestrogen resistance in human breast cancer cells by random insertional mutagenesis using defective retroviruses: identification of bcar-1, a common integration site. , 1993, Molecular endocrinology.

[49]  H. Lane,et al.  ERBB Receptors and Cancer: The Complexity of Targeted Inhibitors , 2005, Nature Reviews Cancer.

[50]  S. Sleijfer,et al.  Relevance of breast cancer antiestrogen resistance genes in human breast cancer progression and tamoxifen resistance. , 2009, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[51]  Handan Can,et al.  The transcriptome of human oocytes , 2006, Proceedings of the National Academy of Sciences.

[52]  L. Vreede,et al.  Identification of BCAR3 by a random search for genes involved in antiestrogen resistance of human breast cancer cells , 1998, The EMBO journal.

[53]  J. Baselga,et al.  Novel anticancer targets: revisiting ERBB2 and discovering ERBB3 , 2009, Nature Reviews Cancer.

[54]  W. McGuire,et al.  Estrogen control of progesterone receptor in human breast cancer. Correlation with nuclear processing of estrogen receptor. , 1978, The Journal of biological chemistry.

[55]  R. Riggins,et al.  Pathways to tamoxifen resistance. , 2007, Cancer letters.

[56]  P. Boyle,et al.  Italian randomized trial among women with hysterectomy: tamoxifen and hormone-dependent breast cancer in high-risk women. , 2003, Journal of the National Cancer Institute.

[57]  G. Hampton,et al.  Aromatase inhibitors—Gene discovery , 2007, The Journal of Steroid Biochemistry and Molecular Biology.

[58]  H. Kurahashi,et al.  Microarray analysis of differentially expressed fetal genes in placental tissue derived from early and late onset severe pre-eclampsia. , 2007, Placenta.

[59]  D. Cameron,et al.  Estrogen-regulated gene expression predicts response to endocrine therapy in patients with ovarian cancer. , 2007, Gynecologic oncology.

[60]  J. Cairns,et al.  Relationship between c-erbB-2 protein product expression and response to endocrine therapy in advanced breast cancer. , 1992, British Journal of Cancer.

[61]  P. Chambon,et al.  Cloning of cDNA sequences of hormone-regulated genes from the MCF-7 human breast cancer cell line. , 1982, Nucleic acids research.

[62]  A. Mikheev,et al.  Profiling Gene Expression in Human Placentae of Different Gestational Ages: An OPRU* Network and UW SCOR Study , 2008, Reproductive Sciences.

[63]  J. Kere,et al.  Distinct sets of developmentally regulated genes that are expressed by human oocytes and human embryonic stem cells. , 2007, Fertility and sterility.