title: Molecular cloning and characterization of STAMP1, a highly prostate-specific six transmembrane protein that is overexpressed in prostate cancer.
abstract: We have identified a novel gene, six transmembrane protein of prostate 1 (STAMP1), which is largely specific to prostate for expression and is predicted to code for a 490-amino acid six transmembrane protein. Using a form of STAMP1 labeled with green fluorescent protein in quantitative time-lapse and immunofluorescence confocal microscopy, we show that STAMP1 is localized to the Golgi complex, predominantly to the trans-Golgi network, and to the plasma membrane. STAMP1 also localizes to vesicular tubular structures in the cytosol and colocalizes with the early endosome antigen 1 (EEA1), suggesting that it may be involved in the secretory/endocytic pathways. STAMP1 is highly expressed in the androgen-sensitive, androgen receptor-positive prostate cancer cell line LNCaP, but not in androgen receptor-negative prostate cancer cell lines PC-3 and DU145. Furthermore, STAMP1 expression is significantly lower in the androgen-dependent human prostate xenograft CWR22 compared with the relapsed derivative CWR22R, suggesting that its expression may be deregulated during prostate cancer progression. Consistent with this notion, in situ analysis of human prostate cancer specimens indicated that STAMP1 is expressed exclusively in the epithelial cells of the prostate and its expression is significantly increased in prostate tumors compared with normal glands. Taken together, these data suggest that STAMP1 may have an important role in the normal prostate cell as well as in prostate cancer progression.
authors.affiliation: Department of Biology and the Biotechnology Centre of Oslo, University of Oslo, Postboks 1050 Blindern, 0316 Oslo, Norway.
authors.forename: Kemal S
authors.initials: KS
authors.lastname: Korkmaz
authors.forename: Cem
authors.initials: C
authors.lastname: Elbi
authors.forename: Ceren G
authors.initials: CG
authors.lastname: Korkmaz
authors.forename: Massimo
authors.initials: M
authors.lastname: Loda
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Hager
authors.forename: Fahri
authors.initials: F
authors.lastname: Saatcioglu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D018450:Disease Progression; D011992:Endosomes / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D009368:Neoplasm Transplantation; D010088:Oxidoreductases; D010957:Plasmids / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D018076:DNA, Complementary; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D010088:Oxidoreductases; C467741:STEAP2 protein, human