Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The extra-enzymic function of cell-surface adenosine deaminase (ADA), an enzyme mainly localized in the cytosol but also found on the cell surface of monocytes, B cells and T cells, has lately been the subject of numerous studies. Cell-surface ADA is able to transduce co-stimulatory signals in T cells via its interaction with CD26, an integral membrane protein that acts as ADA-binding protein. The aim of the present study was to explore whether ADA-CD26 interaction plays a role in the adhesion of lymphocyte cells to human epithelial cells. To meet this aim, different lymphocyte cell lines (Jurkat and CEM T) expressing endogenous, or overexpressing human, CD26 protein were tested in adhesion assays to monolayers of colon adenocarcinoma human epithelial cells, Caco-2, which express high levels of cell-surface ADA. Interestingly, the adhesion of Jurkat and CEM T cells to a monolayer of Caco-2 cells was greatly dependent on CD26. An increase by 50% in the cell-to-cell adhesion was found in cells containing higher levels of CD26. Incubation with an anti-CD26 antibody raised against the ADA-binding site or with exogenous ADA resulted in a significant reduction (50-70%) of T-cell adhesion to monolayers of epithelial cells. The role of ADA-CD26 interaction in the lymphocyte-epithelial cell adhesion appears to be mediated by CD26 molecules that are not interacting with endogenous ADA (ADA-free CD26), since SKW6.4 (B cells) that express more cell-surface ADA showed lower adhesion than T cells. Adhesion stimulated by CD26 and ADA is mediated by T cell lymphocyte function-associated antigen. A role for ADA-CD26 interaction in cell-to-cell adhesion was confirmed further in integrin activation assays. FACS analysis revealed a higher expression of activated integrins on T cell lines in the presence of increasing amounts of exogenous ADA. Taken together, these results suggest that the ADA-CD26 interaction on the cell surface has a role in lymphocyte-epithelial cell adhesion.
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PMID:Regulation of epithelial and lymphocyte cell adhesion by adenosine deaminase-CD26 interaction. 1177 92

Previous studies have shown epidermal growth factor (EGF) facilitate peritoneal membrane healing by augmenting cell adhesion and migration. The objective of this study was to show the effect of sustained and local administration of EGF on peritoneal adhesion. Fourty-two rats were divided into six groups: control 7 and 14, gelatin 7 and 14, and EGF 7 and 14. Adhesions were created by scraping the cecum with mesh gause followed by application of absolute alcohol and placement of silk suture in the parietal peritoneum. The anterior walls of the intestines were covered with 5 x 5 cm unloaded, and EGF loaded gelatin films in the gelatin and EGF groups, respectively. The rats were killed on days 7 and 14 to assess the adhesion occurring, and for biochemical examination. The mean adhesion grades of EGF groups were significantly lower than in the other groups (P < 0.008). The mean adenosine deaminase (ADA) measurements of EGF 7 group were lower than in the gelatin 7 and control 7 groups but the difference was not significant (P > 0.008). The mean ADA measurements in the 14 days groups were as follows: control 14 < EGF 14 < gelatin 14 groups. The mean ADA measurements between 14 days groups did not significantly differ from each other (P > 0.008). The mean hydroxyproline measurements did not differ among the groups (P > 0.008). EGF decreased intestinal adhesion in our study. EGF has important roles in DNA synthesis and cell proliferation. Further studies are required to determine the exact mechanism by which EGF lowers the efficiency of intestinal adhesion.
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PMID:Reduction of peritoneal adhesions by sustained and local administration of epidermal growth factor. 1798 34

The blossom of immunotherapy in melanoma highlights the need to delineate mechanisms of immune resistance. Recently, we have demonstrated that the RNA editing protein, adenosine deaminase acting on RNA-1 (ADAR1) is down-regulated during metastatic transition of melanoma, which enhances melanoma cell proliferation and tumorigenicity. Here we investigate the role of ADAR1 in melanoma immune resistance.Importantly, knockdown of ADAR1 in human melanoma cells induces resistance to tumor infiltrating lymphocytes in a cell contact-dependent mechanism. We show that ADAR1, in an editing-independent manner, regulates the biogenesis of miR-222 at the transcription level and thereby Intercellular Adhesion Molecule 1 (ICAM1) expression, which consequently affects melanoma immune resistance. ADAR1 thus has a novel, pivotal, role in cancer immune resistance. Corroborating with these results, the expression of miR-222 in melanoma tissue specimens was significantly higher in patients who had no clinical benefit from treatment with ipilimumab as compared to patients that responded clinically, suggesting that miR-222 could function as a biomarker for the prediction of response to ipilimumab.These results provide not only novel insights on melanoma immune resistance, but also pave the way to the development of innovative personalized tools to enable optimal drug selection and treatment.
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PMID:A novel immune resistance mechanism of melanoma cells controlled by the ADAR1 enzyme. 2633 62