ABSTRACT
BACKGROUND: Histone demethylases LSD1, JHDM2A, and GASC1 have been suggested to function as androgen receptor co-activators, and to be involved in prostate cancer (PC) progression. We aim to identify genetic alterations and changes in expression of these genes in PC. METHODS: PC cell lines, xenografts as well as clinical specimens were screened for mutations using denaturating high-performance liquid chromatography and sequencing, and for expression alterations by using quantitative RT-PCR and immunohistochemistry. RESULTS: Only known single nucleotide polymorphisms, but no mutations, were found in these genes. JHDMA2 mRNA expression was slightly increased (P < 0.05) in PC compared with benign prostate hyperplasia (BPH), whereas the expression of GASC1 was slightly higher (P < 0.05) in castration-resistant PC (CRPC) compared with untreated PC or BPH. The mRNA expression of LSD1 was not altered in PC. The expression of LSD1 protein was somewhat, although not statistically significantly (P = 0.0521) lower in CRPC compared with untreated PC. In prostatectomy specimens, the level of LSD1 protein expression was associated with low pT-stage (P = 0.0402), but not with Gleason score or progression-free survival. CONCLUSIONS: As no genetic alterations and only very modest expression changes were found, it is unlikely that LSD1, JHDM2A, or GASC1 play a major role in the progression of PC.
Subject(s)
Adenocarcinoma/genetics , Histone Demethylases/genetics , Prostate/metabolism , Prostatic Neoplasms/genetics , Adenocarcinoma/metabolism , Cell Line, Tumor , Chromatography, High Pressure Liquid , Disease Progression , Genetic Predisposition to Disease/genetics , Histone Demethylases/metabolism , Humans , Immunohistochemistry , Jumonji Domain-Containing Histone Demethylases/genetics , Jumonji Domain-Containing Histone Demethylases/metabolism , Male , Mutation , Polymorphism, Single Nucleotide/genetics , Prostate/cytology , Prostatic Hyperplasia/genetics , Prostatic Hyperplasia/metabolism , Prostatic Neoplasms/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Statistics, Nonparametric , Tissue Array AnalysisABSTRACT
BACKGROUND: The critical role of the androgen receptor (AR) in the development of prostate cancer is well recognized. The transcriptional activity of AR is partly regulated by coregulatory proteins. It has been suggested that these coregulators could also be important in the progression of prostate cancer. The aim of this study was to identify coregulators whose expression is regulated by either the androgens and/or by the expression level of AR. METHODS: We used empty vector and AR cDNA-transfected LNCaP cells (LNCaP-pcDNA3.1, and LNCaP-ARhi, respectively), and grew them for 4 and 24 hours in the presence of dihydrotestosterone (DHT) at various concentrations. The expression of 25 AR coregulators (SRC1, TIF2, PIAS1, PIASx, ARIP4, BRCA1, beta-catenin, AIB3, AIB1, CBP, STAT1, NCoR1, AES, cyclin D1, p300, ARA24, LSD1, BAG1L, gelsolin, prohibitin, JMJD2C, JMJD1A, MAK, PAK6 and MAGE11) was then measured by using real-time quantitative RT-PCR (Q-RT-PCR). RESULTS: Five of the coregulators (AIB1, CBP, MAK, BRCA1 and beta-catenin) showed more than 2-fold induction and 5 others (cyclin D1, gelsolin, prohibitin, JMJD1A, and JMJD2C) less than 2-fold induction. Overexpression of AR did not affect the expression of the coregulators alone. However, overexpression of AR enhanced the DHT-stimulated expression of MAK, BRCA1, AIB1 and CBP and reduced the level of expression of beta-catenin, cyclinD1 and gelsolin. CONCLUSION: In conclusion, we identified 5 coactivators whose expression was induced by androgens suggesting that they could potentiate AR signaling. Overexpression of AR seems to sensitize cells for low levels of androgens.
