TERE1, a novel gene affecting growth regulation in prostate carcinoma

Recently, we isolated a ubiquitously expressed gene designated TERE1, which has a significant effect on the growth regulation in bladder cancer. The TERE1 gene maps to chromosome 1p36.11-1p36.33 between the micro-satellite markers D1S2667 and D1S434, a chromosome locus that has been identified by loss of heterozygosity studies as a site of a putative tumor suppressor gene or genes for multiple tumor types including prostate carcinoma. The expression of the TERE1 transcript and protein was examined in a series of thirty microdissected prostate tumors by semi-quantitative RT/PCR and immunohistochemistry. There was a significant 61% decrease in the TERE1 transcript in prostate carcinoma (CaP) and a distinct loss of the TERE1 protein in metstatic prostate. Though a loss of heterozygosity at chromosome 1p36 was found in 25% of these prostate tumors, there appeared to be no TERE1 mutations present in these tumor samples. Induced TERE1 expression after transduction or transfection of TERE1 constructs into two prostate carcinoma (LNCaP and PC-3) cell lines significantly decreased proliferation up to 80% with a significant increase in the number of cells in G1. Serum factors but not DHT (dihydrotestosterone) appear to regulate the amount of TERE1 protein in the androgen responsive LNCaP cell line. Additionally, we have identified by microarray analysis various growth regulatory genes that are down-regulated or up-regulated in TERE1-transduced PC-3 cells. Altogether, these data suggest that TERE1 maybe significant in prostate cancer growth regulation and the down regulation or absence of TERE1 may be an important component of the phenotype of advanced disease.