| Bladder cancer is the most common malignancy of the urinary tract, and the fourth or fifth leading cause of cancerrelated death of men in Wester industrialied countries. The prognosis of patients with advanced bladder cancer is still extremely poor despite recent therapeutic advances, such as improved surgical techniques and perioperative combination chemotherapy. Therefore, future improvement in the survival rate of patients with bladder cancer might be possible through the development of novel indicator or therapeutic strstegies.ln recent years, there are ample studies about COX-2 in Euro-American and America and Japan, especially about the relationship with COX-2 and the formation of tumor. Non-steroid anti-inflammatory drugs(NSAIDs) including aspirin and piroxicam, which are candidate chemopreventive agents active against the development of colon cancer, havechemo-preventive potential against rat urinary bladder carcinogens induced by N-butyl-N-(4-hydro-xybutyl)nitroamine, The chemo preventive mechanisms of NSAIDs remain to be elucidated in detail, but have been postulated to involve their abilities to inhibit cyclooxy -genase(COX) activity. COX catalyzes the synthesis of prostaglandin's from arachidonic acid. There are two isoforms of COX: one is constitutively expressed (COX-l)and other is inducible (COX-2). COX-1 is a constitutively expressed gene in many tissues, and levels of this protein do not fluctuate in response to stimuli. COX-2 is induced by pathologic stimuli, such as inflammation, various growth factors, and cytokines produced by tumor cells. Multiple lines of evidence suggest that COX-2 is important in carcinogen sis, and COX-2 is up-regulated in transformed cells. COX-2 also may be involved in certain features of tumor aggressiveness such as invasion and metastasis. Over expression of COX-2 confers invasive ability on tumor cells in vitro by activating metal- oproteinase,which is a prerequisite for tumor invasion. Furthermore, over expression of COX-2 increases production of variable proangiogenic factors including vascular endothelial growth factor. Recently, many studies have reported on the relation between the malignant potential of neoplasm and tumor angiogenesis. Vascular endothelial growth factor (VEGF) is one of these angiogenic factors, and is known to play a crucial role in the formation of neovasculature. VEGF expression is correlated significantly with tumor vascularity and a marker for tumorangiogenesis. The current study indicate that expression of COX-2 contributes to angiogenesis in tumor, This action is probably related to the production of angiogenic factors VEGF modulated by COX-2. Recently cox-2 overexpression has been reported in human colon cancer and colorectal carcinoma and gastric carcinoma. And the over expression of COX-2 and VEGF have also been reported in human transitional cell carcinoma of bladder .However, There are few reports about the expression of COX-2 and VEGF in human transitional cell carcinoma of bladder and its relationship with the formation of microvessels and their clinical significance and the prognosis value in transitional cell carcinoma of bladder.Materials and Methods: In the current study, expression of COX-2 ,VEGF and MVC were detected by immunohistochemical method(S-p method) in 68 specimens of transitional cell carcinoma of bladder(Histologic grades were classified into there groups,Grades1,2and Grade3,Local invasion was classified into two groups, pTis~T1 and pT2-4, 26 including metastatic lymph nodes, 14 including vascular invasion) and in 10 normal bladder mucosa as control, the relationship among the expression of COX-2, VEGF and microvessel count (MVC) were studied and their clinical significance in transitional cell carcinoma of bladder were evaluatedResults: 1. COX-2 was positive in 43 specimens(63.2%)while was negative in all controls and VEGF was positive in 31 specimens(45.6%) while was negative in all controls . 2. The expression of COX-2 and VEGF iscorrelated (rs=0. 637, x2=27. 566, P<0. 01). And the positive rates... |
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