CGA gene (coding for the alpha subunit of glycoprotein hormones) overexpression in ER alpha-positive prostate tumors.
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 alpha subunit of glycoprotein hormones as a new ER alpha-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.


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 ER alpha normal expression (P = 0.016), but not with ER beta or androgen receptor (AR) expression status.


CONCLUSIONS
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.
Laboratoire de Génétique Moléculaire-UPRES JE 2195, Faculté des Sciences Pharmaceutiques et Biologiques de Paris, Université René Descartes-Paris V, 4 Avenue de l'Observatoire, F-75006 Paris, France.
Ivan
I
Bièche
Alain
A
Latil
Béatrice
B
Parfait
Dominique
D
Vidaud
Ingrid
I
Laurendeau
Rosette
R
Lidereau
Olivier
O
Cussenot
Michel
M
Vidaud
D001943:Breast Neoplasms / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006023:Glycoproteins / Q000096:biosynthesis*; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011960:Receptors, Estrogen / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D006023:Glycoproteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen