A highly conserved protein secreted by the prostate cancer cell line PC-3 is expressed in benign and malignant prostate tissue.

Research output: Contribution to journalArticle


In this study we characterize a novel gene on human chromosome 9 and its translation product, PC3-secreted microprotein (PSMP). The gene contains three exons that encode a protein of 139 amino acid residues, including a predicted signal peptide of 36 residues. The molecule is homologous to P-microseminoprotein (MSP), a protein of unknown function, secreted at high concentration by the prostate gland. These two proteins have only 23% sequence identity, but their common origin is revealed by a preserved pattern of Cys residues. In contrast to IMSP, which shows poor conservation between species, PSMP is very conserved. High transcript levels were detected in the prostate cancer cell line PC-3. Antiserum raised against PSMP detected a protein with an apparent molecular mass of 18 kDa in culture medium conditioned by PC-3 cells, but in cell lysates the antiserum also recognized a molecular species of 16 kDa, suggesting that PSMP undergoes post-translational modification. Xeno-grafted PC-3 cell tumors in athymic nude mice showed strong staining for both PSMP protein and mRNA. Studies on human prostate cancer specimens showed immunohistochemical staining of both tumor and benign glandular cells. Our results suggest that PSMP is an important protein with significance in prostate cancer.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology


  • semen, trachea, gene, homology, evolution
Original languageEnglish
Pages (from-to)289-295
JournalBiological Chemistry
Issue number3
Publication statusPublished - 2007
Publication categoryResearch

Bibliographic note

Department affilation moved from v1000588 (Tumour Biology, Malmö) to v1000562 (Department of Translational Medicine) on 2016-01-18 14:39:31.