| There are two isoforms of cyclooxygenase which catalyze the conversion of arachidonic acid to prostaglandins, cyclooxygenase-1 and cyclooxygenase-2. COX-1 is constitutively expressed to serve noble purposes in housekeeping such as protecting the stomach from ulcers and regulating renal blood flow, whereas COX-2 is inducible by a variety of inflammatory mediators, cytokines, hormones and tumor promoters so to produce excessive PGs and cause redness, swelling , pain and fever. Classical nonsteroidal anti-inflammation drugs(NSAIDs) inhibit both COX-1 and COX-2. Epidemiological studies have demonstrated regular administration of NSAIDs could reduce risk of developing colon cancer and other types of cancer. Most of the studies attributed the anti-tumor effect of NSAIDs to their ability to inhibit the function of COX-2, which is achieved by inhibiting the proliferation, inducing the apoptosis, controlling the differentiation and inhibiting the invasion of the tumor cells. Little is done about the relationship between NSAIDs and angiogenesis. Therefore, This research was designed to study the relationship between COX-2 and angiogenesis and invasiveness in human transitional cell carcinoma(TCC) from three aspects: The relationship between COX-2'expression and invasive state and microvessel density (MVD) in TCC specimens; TCC cell line EJ were transfected by cox-2 gene plasmid or mock plasmid and named as EJ-COX2 and mock-EJ respectively, their invasive ability , endothelial migration ability, expression levels of VEGF,uPA and MMP-2 were compared under various drug concentrations of dual COX inhibitor indomethacin and selective COX-2 inhibitor NS-398;Also, the transfected cell lines were inoculated into nude mice , the MVD ,the related factors in the xenografts were compared between mock-EJ and EJ-COX2 with or without treatment by indomethacin. The main results are listed following:1. The relationship between COX-2'expression and invasive state and microvessel density (MVD) in 50 TCC specimens were analyzed by IHC of COX-2 and â…§ factor, the data suggested that:(1) COX-2 expression was significantly related to the invasive state of tumors, it only expressed in invasive TCC and positively correlated to the invasive stages. Non-invasive TCC had no expression of COX-2;(2) MVD was significantly increased in invasive TCC and positively correlated to the invasive stages, it had little difference between non-invasive TCC of every grade.(3) MVD was significantly increased in COX-2 positive TCC.There had a positive correlation between MVD and COX-2 expression ratio.2.The relationship between COX-2'expression and invasive ability, angiogenic ablity, expression levels of VEGF,uPA and MMP-2 were compared beteen mock-EJ and EJ-COX2 under various drug concentrations of indomethacin and NS-398 by methods of transfection, invasion assay, endothelial cell migration assay, RT-PCR and Western blot, the results indicated that:(1) COX-2 could stimulate the growth of EJ-COX2, indomethacin and NS-398 could inhibit the growth of EJ-COX2.(2) COX-2 promoted the invasive ability of EJ-COX2, indomethacin and NS-398 could inhibit the growth of EJ-COX2; Indomethacin but not NS-398 blocked the migration of mock-EJ.(3) COX-2 promoted the migration ability of ECV304 cocultured with EJ-COX2, indomethacin and NS-398 could inhibit the endothelial migration cocultured with EJ-COX2 in a dose-dependent manner; Indomethacin but not NS-398 blocked the endothelial migration cocultured with mock-EJ. So it seemed the NS-398 inhibited angiogenesis through the tumor cells but indomethacin functioned through both the tumor cells and endothelial cells. (4) COX-2 stimulated the expression of VEGF,uPA and MMP-2 in EJ-COX2, indomethacin and NS-398 could inhibit their expression in a dose-dependent manner. Therefore, we can conclude that COX-2 overexpressed in EJ-COX2 stimulated tumor cells' invasive and angiogenic ability by activation of VEGF, uPA and MMP-2.3. The angiogenetic ability was studied in nude mice by inoculating E...
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