D-TMPP: a novel androgen-regulated gene preferentially expressed in prostate and prostate cancer that is the first characterized member of an eukaryotic gene family.

Background: The understanding of the molecular biology of the prostate and the process of prostate carcinogenesis is brought forward by the identification and characterization of new genes specifically expressed in prostate tissue. The encoded proteins may, in addition, provide novel diagnostic and therapeutic tools in prostate carcinoma (PCa). Here, we identify the novel gene Dresden-transmembrane protein of the prostate (D-TMPP) that is overexpressed in human prostate and prostate cancer.

Methods: Proceeding from a prostate-specific expressed sequence tag identified with an Affymetrix chip-based expression database, the full-length cDNA of the novel gene was isolated from prostate tissue. The potential protein-coding function of the open reading frame (ORF) was tested by in vitro transcription-coupled translation and recombinant expression in transfected prostate cancer cells. The expression pattern of D-TMPP in malignant and nonmalignant tissues and tumor cell lines was analyzed by hybridization of a radioactively labeled cDNA probe with a multiple tissue expression array and by a quantitative real-time PCR assay.

Results: The D-TMPP-mRNA encodes a putative seven-span transmembrane protein of 883 amino acids and is selectively overexpressed in prostate tissue. D-TMPP represents the first cloned and characterized transcript of a family of eukaryotic genes. D-TMPP transcripts were detected in all analyzed pairs (n = 25) of malignant and nonmalignant prostate tissues. In the androgen-dependent PCa cell line LNCaP, D-TMPP was upregulated by methyltrienolone.

Conclusions: We describe the novel prostate-restricted molecule D-TMPP widely expressed in prostate cancer tissues.