Catalytic cleavage of the androgen-regulated TMPRSS2 protease results in its secretion by prostate and prostate cancer epithelia.

We identified TMPRSS2 as a gene that is down-regulated in androgen-independent prostate cancer xenograft tissue derived from a bone metastasis. Using specific monoclonal antibodies, we show that the TMPRSS2-encoded serine protease is expressed as a Mr 70,000 full-length form and a cleaved Mr 32,000 protease domain. Mutation of Ser-441 in the catalytic triad shows that the proteolytic cleavage is dependent on catalytic activity, suggesting that it occurs as a result of autocleavage. Mutational analysis reveals the cleavage site to be at Arg-255. A consequence of autocatalytic cleavage is the secretion of the protease domain into the media by TMPRSS2-expressing prostate cancer cells and into the sera of prostate tumor-bearing mice. Immunohistochemical analysis of clinical specimens demonstrates the highest expression of TMPRSS2 at the apical side of prostate and prostate cancer secretory epithelia and within the lumen of the glands. Similar luminal staining was detected in colon cancer samples. Expression was also seen in colon and pancreas, with little to no expression detected in seven additional normal tissues. These data demonstrate that TMPRSS2 is a secreted protease that is highly expressed in prostate and prostate cancer, making it a potential target for cancer therapy and diagnosis.

[1]  S. Goldenberg,et al.  Effects of intermittent androgen suppression on androgen‐dependent tumors. Apoptosis and serum prostate‐specific antigen , 1993, Cancer.

[2]  D. Peehl,et al.  Biological effects of prostate specific antigen as an insulin-like growth factor binding protein-3 protease. , 1994, The Journal of endocrinology.

[3]  G. Yousef,et al.  Prostase/KLK-L1 is a new member of the human kallikrein gene family, is expressed in prostate and breast tissues, and is hormonally regulated. , 1999, Cancer research.

[4]  G W Becker,et al.  Growth regulation of prostatic stromal cells by prostate-specific antigen. , 1999, Journal of the National Cancer Institute.

[5]  K. Kurachi,et al.  A novel trypsin-like serine protease (hepsin) with a putative transmembrane domain expressed by human liver and hepatoma cells. , 1988, Biochemistry.

[6]  R. Hubert,et al.  STEAP: a prostate-specific cell-surface antigen highly expressed in human prostate tumors. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[7]  Aaron P. Campbell,et al.  Suppression subtractive hybridization: a method for generating differentially regulated or tissue-specific cDNA probes and libraries. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[8]  K. Shigemasa,et al.  Hepsin, a cell surface serine protease identified in hepatoma cells, is overexpressed in ovarian cancer. , 1997, Cancer research.

[9]  K. Pienta,et al.  Parathyroid hormone-related protein as a growth regulator of prostate carcinoma. , 1999, Cancer research.

[10]  A. Belldegrun,et al.  Evidence for clonal outgrowth of androgen-independent prostate cancer cells from androgen-dependent tumors through a two-step process. , 1999, Cancer research.

[11]  K. A. Klein,et al.  Progression of metastatic human prostate cancer to androgen independence in immunodeficient SCID mice , 1997, Nature Medicine.

[12]  G. Duchesne,et al.  Androgens and prostate cancer: biology, pathology and hormonal therapy. , 1997, European journal of cancer.

[13]  Noah Craft,et al.  A mechanism for hormone-independent prostate cancer through modulation of androgen receptor signaling by the HER-2/neu tyrosine kinase , 1999, Nature Medicine.

[14]  P. Cohen,et al.  Role of insulin‐like growth factors and their binding proteins in growth control and carcinogenesis , 2000, Journal of cellular physiology.

[15]  L. Hood,et al.  Molecular cloning and characterization of prostase, an androgen-regulated serine protease with prostate-restricted expression. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[16]  M. Peitsch,et al.  Cloning of the TMPRSS2 gene, which encodes a novel serine protease with transmembrane, LDLRA, and SRCR domains and maps to 21q22.3. , 1997, Genomics.

[17]  O. Witte,et al.  BCR first exon sequences specifically activate the BCR/ABL tyrosine kinase oncogene of Philadelphia chromosome-positive human leukemias , 1991, Molecular and cellular biology.

[18]  K. Kurachi,et al.  Hepsin, a cell membrane-associated protease. Characterization, tissue distribution, and gene localization. , 1991, The Journal of biological chemistry.

[19]  D. Wolf,et al.  Transcriptional regulation of prostate kallikrein-like genes by androgen. , 1992, Molecular endocrinology.

[20]  S. Yeh,et al.  From HER2/Neu signal cascade to androgen receptor and its coactivators: a novel pathway by induction of androgen target genes through MAP kinase in prostate cancer cells. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[21]  K. Burnstein,et al.  Androgenic up-regulation of androgen receptor cDNA expression in androgen-independent prostate cancer cells , 1996, Steroids.

[22]  T. Vu,et al.  Identification and Cloning of the Membrane-associated Serine Protease, Hepsin, from Mouse Preimplantation Embryos* , 1997, The Journal of Biological Chemistry.

[23]  L. Hood,et al.  Prostate-localized and androgen-regulated expression of the membrane-bound serine protease TMPRSS2. , 1999, Cancer research.

[24]  L. Chung,et al.  Osteomimetic properties of prostate cancer cells: A hypothesis supporting the predilection of prostate cancer metastasis and growth in the bone environment , 1999, The Prostate.

[25]  C. Wilson,et al.  Androgen Receptor Gene Expression in Human Prostate Carcinoma Cell Lines1 , 1990 .