CGA Gene (Coding for the α Subunit of Glycoprotein Hormones) Overexpression in ERα-Positive Prostate Tumors

Abstract Objective: The precise role of estrogen, estrogen receptor (ER) and ER -responsive genes in prostate carcinogenesis is unclear. Paradoxically, estrogens and antiestrogens are used in the treatment of advanced metastatic prostate cancers. Recently, we identified CGA gene coding for the α subunit of glycoprotein hormones as a new ERα -responsive gene in human breast cancer cells. The aim of this study was to explore the role of CGA in the second major hormone-related cancer, i.e. prostate cancer. Patients and Methods: We quantified CGA mRNA in nine cases of benign prostatic hyperplasia (BPH) and 23 sporadic prostate tumors (TP) by using a real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Results: CGA overexpression (>10 S.D. above the mean in normal prostate tissues (NP)) was observed in 39% of the TP (ranging from 4.4 to 174.5 times the level in NP) and in none of the BPH samples. CGA overexpression was not accompanied by overexpression of the CGB , LHB , TSHB or FSHB genes to produce ectopic glycoprotein hormones. CGA gene overexpression correlated with ERα normal expression ( P =0.016), but not with ERβ or androgen receptor ( AR ) expression status. Conclusion: These results point to CGA gene as a member of a novel dysregulated pathway in prostate cancer. CGA should therefore be considered for investigation as possible novel molecular marker in clinical applications and as possible new potential therapeutic target.