title: Involvement of neutral endopeptidase in neoplastic progression.
abstract: Neutral endopeptidase 24.11 (NEP) is a 90-110 kDa cell surface cell surface peptidase that is normally expressed by numerous tissues, including prostate, kidney, intestine, endometrium, adrenal glands and lung. This enzyme cleaves peptide bonds on the amino side of hydrophobic amino acids and inactivates a variety of physiologically active peptides, including atrial natriuretic factor, substance P, bradykinin, oxytocin, Leu- and Met-enkephalins, neurotensin, bombesin, endothelin-1, and bombesin-like peptides. NEP reduces the local concentration of peptide available for receptor binding and signal transduction. Loss or decreases in NEP expression have been reported in a variety of malignancies. Reduced NEP may promote peptide-mediated proliferation by allowing accumulation of higher peptide concentrations at the cell surface, and facilitate the development or progression of neoplasia. We have used prostate cancer as model in which to study the involvement of NEP in malignancy. Using a variety of experimental approaches, including recombinant NEP, cell lines expressing wild-type and mutant NEP protein, and cell lines expressing NEP protein with a mutated cytoplasmic domain, we have examined the effects of NEP on cell migration and cell survival. We have shown that the effects of NEP are mediated by its ability to catalytically inactivate substrates such as bombesin and endothelin-1, but also through direct protein-protein interaction with other protein such as Lyn kinase [which associates with the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) resulting in NEP-Lyn-PI3-K protein complex], ezrin/radixin/moesin (ERM) proteins, and the PTEN tumor suppressor protein. We review the mechanisms of NEP's tumor suppressive action and how NEP loss contributes to tumor progression.
authors.affiliation: Department of Urology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sumitomo
authors.forename: Ruoqian
authors.initials: R
authors.lastname: Shen
authors.forename: David M
authors.initials: DM
authors.lastname: Nanus
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D000081247:CSK Tyrosine-Protein Kinase; D002465:Cell Movement / Q000187:drug effects; D004789:Enzyme Activation; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D022001:Focal Adhesions / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D008297:Male; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D015260:Neprilysin / Q000502:physiology*; D025581:Neurofibromin 2 / Q000378:metabolism; D051059:PTEN Phosphohydrolase; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000503:physiopathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D019061:src-Family Kinases
chemical_list: D018960:Hyaluronan Receptors; D025581:Neurofibromin 2; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D025521:Tumor Suppressor Proteins; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019061:src-Family Kinases; C000631346:CSK protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D015260:Neprilysin; D013755:Tetradecanoylphorbol Acetate