Involvement of neutral endopeptidase in neoplastic progression
Cornell University, Итак, New York, United States Biochimica et Biophysica Acta
(Impact Factor: 4.66).
09/2005; 1751(1):52-9. DOI: 10.1016/j.bbapap.2004.11.001
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.
Available from: diagnosticpathology.biomedcentral.com
- "The molecular mechanism of these effects induced by CD10 is associated with the cleavage and inactivation of fibroblast growth factor 2 (FGF2)  or direct binding with PTEN, leading to the enhancement of stability and activity, which result in the inhibition of the Akt pathway . These inhibitory effects on cell migration and proliferation allow CD10 to prevent the aggressive behavior of tumor cells [10, 26]. Therefore, we assume that CD10 expression in the NEC component has an anti-cancer effect by retaining the expression of PTEN, which leads to decreased phosphorylated Akt expression. "
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ABSTRACT: Endometrial mixed carcinoma with the neuroendocrine carcinoma (NEC) component is rare and is believed to have a poor prognosis. CD10 expression is reported to be a favorable prognostic marker for some tumors such as B-lymphoblastic leukemia/lymphoma, but unfavorable for others. Here, we report the case of a 33-year-old woman diagnosed with endometrial mixed carcinoma with the NEC component expressing CD10 who showed a favorable outcome.
The patient presented with lumbago and brownish discharge from the genitals. Imaging modalities revealed a large exophytic mass in the uterine corpus, and a small one in the uterine cervix. Radical hysterectomy with bilateral salpingo-oophorectomy was performed. Microscopic examination of the endometrial and cervical masses revealed that the NEC component accounted for the maximum area in both masses. However, small areas in both lesions showed well differentiated endometrioid adenocarcinoma (WDEA) components, and histological transition between the two components was also observed. In addition to CD56 and synaptophysin expression, the NEC component was positive for CD10 but negative for estrogen receptor (ER), progesterone receptor (PgR), and carcinoembryonic antigen (CEA). In contrast, the WDEA component expressed both ER and PgR, but neither CD10 nor neuroendocrine markers were demonstrated. The CD10 and neuroendocrine markers clearly distinguished between the NEC and WDEA components. Furthermore, retained expression of phosphatase and tensin homolog (PTEN) and weak phosphorylated Akt expression were found, which were assumed to suppress the aggressive behavior of the tumor. The patient received postoperative chemotherapy and has survived without recurrence for 6 years after the operation.
This is the first case of endometrial mixed carcinoma with the NEC component expressing CD10 that showed a long survival.
Available from: PubMed Central
- "Neutral endopeptidase (NEP) is a zinc-dependent, cell surface metallopeptidase that is involved in the cleavage and inactivation of certain peptide hormones and is important for signal transduction, including transduction of enkephalins, bombesin, and substrate P.5,6 Under nonpathological conditions, NEP is widely distributed in the epithelial cells of the kidney, liver, stomach, intestine, breast, lung, and prostate gland.7 Under pathological conditions, NEP has been demonstrated to play a crucial role in migration, survival, and apoptosis of various cancer cells.8 NEPs’ diagnostic and prognostic values were originally discovered in acute lymphoblastic leukemia with elaboration of rabbit antisera against leukemic cells.9 "
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ABSTRACT: The aim of this study was to investigate the relationship between the expression of neutral endopeptidase (NEP) and dipeptidyl peptidase IV (DPP IV) proteins, and the clinical significance of the two proteins in patients with intrahepatic cholangiocarcinomas (IHCC).
Expression patterns and subcellular localizations of NEP and DPP IV proteins in 186 primary IHCC and 60 noncancerous liver tissue specimens were detected by immunohistochemistry.
Both the expression of NEP and DPP IV proteins in IHCC tissues were significantly higher than those in noncancerous liver tissues (both P<0.001). Of 186 patients with IHCC, 128 (68.82%) highly expressed both NEP and DPP IV proteins. In addition, the coexpression of NEP and DPP IV proteins was significantly associated with advanced tumor stage (P=0.009), positive lymph node metastasis (P=0.016) and distant metastasis (P=0.013), and the presence of recurrence (P=0.027). Moreover, Kaplan-Meier analysis showed that IHCC patients with high NEP expression, high DPP IV expression, and combined overexpression of NEP and DPP IV proteins all had poorer overall survival and early recurrence after surgery. Furthermore, Cox analysis suggested that NEP expression, DPP IV expression, and combined expression of NEP and DPP IV proteins were all independent prognostic markers for overall survival and recurrence-free survival in patients with IHCC.
Our data suggest, for the first time, that both the expression of NEP and DPP IV proteins may be upregulated in human IHCC tissues and the combined expression of NEP and DPP IV proteins may play important roles in progression and prognosis of patients with IHCC.
Available from: Andrea Olschewski
- "MME, which is identical to common acute leukemia antigen (CALLA), is a 90–110 kDa zinc binding cell surface peptidase, which cleaves small peptides, such as atrial natriuretic peptide, substance P, endothelin-1, and bombesin (for review see [46,47]). It also possesses elastase activity . "
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ABSTRACT: Hypoxia-induced genes are potential targets in cancer therapy. Responses to hypoxia have been extensively studied in vitro, however, they may differ in vivo due to the specific tumor microenvironment. In this study gene expression profiles were obtained from fresh human lung cancer tissue fragments cultured ex vivo under different oxygen concentrations in order to study responses to hypoxia in a model that mimics human lung cancer in vivo.
Non-small cell lung cancer (NSCLC) fragments from altogether 70 patients were maintained ex vivo in normoxia or hypoxia in short-term culture. Viability, apoptosis rates and tissue hypoxia were assessed. Gene expression profiles were studied using Affymetrix GeneChip 1.0 ST microarrays.
Apoptosis rates were comparable in normoxia and hypoxia despite different oxygenation levels, suggesting adaptation of tumor cells to hypoxia. Gene expression profiles in hypoxic compared to normoxic fragments largely overlapped with published hypoxia-signatures. While most of these genes were up-regulated by hypoxia also in NSCLC cell lines, membrane metallo-endopeptidase (MME, neprilysin, CD10) expression was not increased in hypoxia in NSCLC cell lines, but in carcinoma-associated fibroblasts isolated from non-small cell lung cancers. High MME expression was significantly associated with poor overall survival in 342 NSCLC patients in a meta-analysis of published microarray datasets.
The novel ex vivo model allowed for the first time to analyze hypoxia-regulated gene expression in preserved human lung cancer tissue. Gene expression profiles in human hypoxic lung cancer tissue overlapped with hypoxia-signatures from cancer cell lines, however, the elastase MME was identified as a novel hypoxia-induced gene in lung cancer. Due to the lack of hypoxia effects on MME expression in NSCLC cell lines in contrast to carcinoma-associated fibroblasts, a direct up-regulation of stroma fibroblast MME expression under hypoxia might contribute to enhanced aggressiveness of hypoxic cancers.
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