Androgen receptor expression predicts breast cancer survival: the role of genetic and epigenetic events

BMC Cancer

Melissa A Brown³  Susan J Clark²  Glenn D Francis¹  Sarah Wagner¹  Sandra Stein¹  Kathryn Salkield³  Peter J Bailey³  Juliet D French³  Shalima S Nair²  Stacey L Edwards³  Kate M Peters³ 

[1]Department of Pathology, Princess Alexandra Hospital, Queensland Woolloongabba, 4102 Queensland, Australia

[2]Epigenetics Group, Garvan Institute of Medical Research, Sydney 2010, NSW, Australia

[3]School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia 4072 Queensland, Australia

关键词: MiRNA;    Regulatory mutation;    Promoter methylation;    Gene regulation;    Breast cancer;    Prognostic biomarker;    Androgen receptor;   

Others  :  1080475
DOI  :  10.1186/1471-2407-12-132

 received in 2011-12-07, accepted in 2012-04-02,  发布年份 2012

【 摘 要 】

Background

Breast cancer outcome, including response to therapy, risk of metastasis and survival, is difficult to predict using currently available methods, highlighting the urgent need for more informative biomarkers. Androgen receptor (AR) has been implicated in breast carcinogenesis however its potential to be an informative biomarker has yet to be fully explored. In this study, AR protein levels were determined in a cohort of 73 Grade III invasive breast ductal adenocarcinomas.

Methods

The levels of Androgen receptor protein in a cohort of breast tumour samples was determined by immunohistochemistry and the results were compared with clinical characteristics, including survival. The role of defects in the regulation of Androgen receptor gene expression were examined by mutation and methylation screening of the 5' end of the gene, reporter assays of the 5' and 3' end of the AR gene, and searching for miRNAs that may regulate AR gene expression.

Results

AR was expressed in 56% of tumours and expression was significantly inversely associated with 10-year survival (P = 0.004). An investigation into the mechanisms responsible for the loss of AR expression revealed that hypermethylation of the AR promoter is associated with loss of AR expression in breast cancer cells but not in primary breast tumours. In AR negative breast tumours, mutation screening identified the same mutation (T105A) in the 5'UTR of two AR negative breast cancer patients but not reported in the normal human population. Reporter assay analysis of this mutation however found no evidence for a negative impact on AR 5'UTR activity. The role of miR-124 in regulating AR expression was also investigated, however no evidence for this was found.

Conclusion

This study highlights the potential for AR expression to be an informative biomarker for breast cancer survival and sets the scene for a more comprehensive investigation of the molecular basis of this phenomenon.

【 授权许可】

   
2012 Peters et al; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Sorlie T, Perou CM, Tibshirani R, Aas T, Geisler S, Johnsen H, Hastie T, Eisen MB, van de Rijn M, Jeffrey SS, et al.: Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications. Proc Natl Acad Sci USA 2001, 98(19):10869-10874.
• [2]Rakha EA, Reis-Filho JS, Ellis IO: Combinatorial biomarker expression in breast cancer. Breast Cancer Res Treat 2010, 120(2):293-308.
• [3]Yeh S, Hu YC, Wang PH, Xie C, Xu Q, Tsai MY, Dong Z, Wang RS, Lee TH, Chang C: Abnormal mammary gland development and growth retardation in female mice and MCF7 breast cancer cells lacking androgen receptor. J Exp Med 2003, 198(12):1899-1908.
• [4]Liao DJ, Dickson RB: Roles of androgens in the development, growth, and carcinogenesis of the mammary gland. J Steroid Biochem Mol Biol 2002, 80(2):175-189.
• [5]Li S, Han B, Liu G, Ouellet J, Labrie F, Pelletier G: Immunocytochemical localization of sex steroid hormone receptors in normal human mammary gland. J Histochem Cytochem 2010, 58(6):509-515.
• [6]Doane AS, Danso M, Lal P, Donaton M, Zhang L, Hudis C, Gerald WL: An estrogen receptor-negative breast cancer subset characterized by a hormonally regulated transcriptional program and response to androgen. Oncogene 2006, 25(28):3994-4008.
• [7]Birrell SN, Bentel JM, Hickey TE, Ricciardelli C, Weger MA, Horsfall DJ, Tilley WD: Androgens induce divergent proliferative responses in human breast cancer cell lines. J Steroid Biochem Mol Biol 1995, 52(5):459-467.
• [8]Ni M, Chen Y, Lim E, Wimberly H, Bailey ST, Imai Y, Rimm DL, Liu XS, Brown M: Targeting androgen receptor in estrogen receptor-negative breast cancer. Cancer Cell 2011, 20:119-131.
• [9]Agoff SN, Swanson PE, Linden H, Hawes SE, Lawton TJ: Androgen receptor expression in estrogen receptor-negative breast cancer. Immunohistochemical, clinical, and prognostic associations. Am J Clin Pathol 2003, 120(5):725-731.
• [10]Gonzalez-Angulo AM, Stemke-Hale K, Palla SL, Carey M, Agarwal R, Meric-Berstam F, Traina TA, Hudis C, Hortobagyi GN, Gerald WL, et al.: Androgen receptor levels and association with PIK3CA mutations and prognosis in breast cancer. Clin Cancer Res 2009, 15(7):2472-2478.
• [11]Faber PW, van Rooij HC, van der Korput HA, Baarends WM, Brinkmann AO, Grootegoed JA, Trapman J: Characterization of the human androgen receptor transcription unit. J Biol Chem 1991, 266(17):10743-10749.
• [12]Faber PW, van Rooij HC, Schipper HJ, Brinkmann AO, Trapman J: Two different, overlapping pathways of transcription initiation are active on the TATA-less human androgen receptor promoter. The role of Sp1. J Biol Chem 1993, 268(13):9296-9301.
• [13]Chen S, Supakar PC, Vellanoweth RL, Song CS, Chatterjee B, Roy AK: Functional role of a conformationally flexible homopurine/homopyrimidine domain of the androgen receptor gene promoter interacting with Sp1 and a pyrimidine single strand DNA-binding protein. Mol Endocrinol 1997, 11(1):3-15.
• [14]Takane KK, McPhaul MJ: Functional analysis of the human androgen receptor promoter. Mol Cell Endocrinol 1996, 119(1):83-93.
• [15]Mizokami A, Yeh SY, Chang C: Identification of 3',5'-cyclic adenosine monophosphate response element and other cis-acting elements in the human androgen receptor gene promoter. Mol Endocrinol 1994, 8(1):77-88.
• [16]Kinoshita H, Shi Y, Sandefur C, Meisner LF, Chang C, Choon A, Reznikoff CR, Bova GS, Friedl A, Jarrard DF: Methylation of the androgen receptor minimal promoter silences transcription in human prostate cancer. Cancer Res 2000, 60(13):3623-3630.
• [17]Waltering KK, Wallen MJ, Tammela TL, Vessella RL, Visakorpi T: Mutation screening of the androgen receptor promoter and untranslated regions in prostate cancer. Prostate 2006, 66(15):1585-1591.
• [18]Crocitto LE, Henderson BE, Coetzee GA: Identification of two germline point mutations in the 5'UTR of the androgen receptor gene in men with prostate cancer. J Urol 1997, 158(4):1599-1601.
• [19]Cox DG, Blanche H, Pearce CL, Calle EE, Colditz GA, Pike MC, Albanes D, Allen NE, Amiano P, Berglund G, et al.: A comprehensive analysis of the androgen receptor gene and risk of breast cancer: results from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3). Breast Cancer Res 2006, 8(5):R54. BioMed Central Full Text
• [20]Kyndi M, Sorensen FB, Knudsen H, Overgaard M, Nielsen HM, Andersen J, Overgaard J: Tissue microarrays compared with whole sections and biochemical analyses. A subgroup analysis of DBCG 82 b&c. Acta Oncol 2008, 47(4):591-599.
• [21]Karlsson C, Bodin L, Piehl-Aulin K, Karlsson MG: Tissue Microarray Validation: A Methodologic Study with Special Reference to Lung Cancer. Cancer Epidemiology Biomarkers & Prevention 2009, 18:2014-2021.
• [22]Castellano I, Allia E, Accortanzo V, Vandone AM, Chiusa L, Arisio R, Durando A, Donadio M, Bussolati G, Coates AS, et al.: Androgen receptor expression is a significant prognostic factor in estrogen receptor positive breast cancers. Breast Cancer Res Treat 2010.
• [23]Bryan RM, Mercer RJ, Bennett RC, Rennie GC, Lie TH, Morgan FJ: Androgen receptors in breast cancer. Cancer 1984, 54(11):2436-2440.
• [24]Park S, Koo JS, Kim MS, Park HS, Lee JS, Kim SI, Park BW, Lee KS: Androgen receptor expression is significantly associated with better outcomes in estrogen receptor-positive breast cancers. Ann Oncol 2011.
• [25]Jarrard DF, Kinoshita H, Shi Y, Sandefur C, Hoff D, Meisner LF, Chang C, Herman JG, Isaacs WB, Nassif N: Methylation of the androgen receptor promoter CpG island is associated with loss of androgen receptor expression in prostate cancer cells. Cancer Res 1998, 58(23):5310-5314.
• [26]Coolen MW, Statham AL, Gardiner-Garden M, Clark SJ: Genomic profiling of CpG methylation and allelic specificity using quantitative high-throughput mass spectrometry: critical evaluation and improvements. Nucleic Acids Res 2007, 35(18):e119.
• [27]Yeap BB, Wilce JA, Leedman PJ: The androgen receptor mRNA. Bioessays 2004, 26(6):672-682.
• [28]Hurst DR, Edmonds MD, Welch DR: Metastamir: the field of metastasis-regulatory microRNA is spreading. Cancer Research 2009, 69(19):7495-7498.
• [29]Valastyan S, Benaich N, Chang A, Reinhardt F, Weinberg RA: Concomitant suppression of three target genes can explain the impact of a microRNA on metastasis. Genes Dev 2009, 23(22):2592-2597.
• [30]Sikand K, Slaibi JE, Singh R, Slane SD, Shukla GC: miR 488* inhibits androgen receptor expression in prostate carcinoma cells. Int J Cancer 2010.
• [31]Neve RM, Chin K, Fridlyand J, Yeh J, Baehner FL, Fevr T, Clark L, Bayani N, Coppe JP, Tong F, et al.: A collection of breast cancer cell lines for the study of functionally distinct cancer subtypes. Cancer Cell 2006, 10(6):515-527.
• [32]Francis GD, Jones MA, Beadle GF, Stein SR: Bright-field in situ hybridization for HER2 gene amplification in breast cancer using tissue microarrays: correlation between chromogenic (CISH) and automated silver-enhanced (SISH) methods with patient outcome. Diagn Mol Pathol 2009, 18:88-95.
• [33]Wojdacz TK, Hansen LL, Dobrovic A: A new approach to primer design for the control of PCR bias in methylation studies. BMC Res Notes 2008, 1:54. BioMed Central Full Text
• [34]Korhonen J, Martinmäki P, Pizzi CPR, Ukkonen E: MOODS: fast search for position weight matrix matches in DNA sequences. Bioinformatics 2009, 25:3181-3182.
• [35]Bryne JC, Valen E, Tang MH, Marstrand T, Winther O, da Piedade I, Krogh A, Lenhard B, Sandelin A: JASPAR, the open access database of transcription factor-binding profiles: new content and tools in the 2008 update. Nucleic Acids Res 2008, 36:102-106.
• [36]Miranda KC, Huynh T, Tay Y, Ang YS, Tam WL, Thomson AM, Lim B, Rigoutsos I: A pattern-based method for the identification of MicroRNA binding sites and their corresponding heteroduplexes. Cell 2006, 126(6):1203-1217.
• [37]Lewis BP, Burge CB, Bartel DP: Conserved seed pairing, often flanked by adenosines, indicates that thousands of human genes are microRNA targets. Cell 2005, 120(1):15-20.