| MMPs( Matrix metalloproteinases ) are a band of Zn2+ dependent endopep-tides and can degrade extracell matrix (ECM). Among which MMP2 and MMP9 are very important because they can degrade basement membrane by degrading type IV collagen. The degradation of basement membrane is very crucial for tumor invasion metastasis and angiogenesis. CD34 was primarily regarded as he-mopoietic stem cell antigen , but at present it was the most sensitive vessel marker . our study aimed to discuss the expression of MMP2 and MMP9 in renal cell carcinoma (RCC) and the relationship between the expression of MMP2,MMP9 and MVD.Materials and MethodsThis study included 38 patients with RCC who underwent radical nephrecto-my from 1998 to 2002 in our hospital. Twenty four patients were male and fourteen patients were female. There are 16 stage I cases, 12 stage II cases ,7 stage III cases and 3 stage IV cases according to ROBSON pathological staging and 11 grade I cases, 20 grade II cases and 7 grade III cases according to Fuhrman' s grading system. And there are 8 normal kidney tissues for contrast. The expression of MMP2, MMP9 and CD34 was detected immunohistochemically and counted the MVD value. Then we studied the relationship between the expressionof MMP2,MMP9 and MVD value and the tumor clinical and pathological character.ResultsThe expression of MMP2, MMP9 mainly lies in cytoplasma. There was a positive relationship between the expression of MMP9 and tumor stage and grade. The MVD value in tumor tissue s was much higher than in normal kidney tissues and was positively related to the tumor stage and grade. Furthermore, the expression of MMP9 in tumor tissues was positively associated with the MVD val-ue.DiscussionA lot of study indicated that the ability of tumor invation and metastasis was closely associated with its ability of inducing the production of proteinase to degrade the ECM and basement membrane. Among these proteinases MMPs are most important because they can degrade almost all the components in ECM and basement membrane. So far we have found at least 16 kinds of MMPs which are different in their moleculler weight and properts. The first barrier to tumor invasion is basement membrane which was mainly consist of type IV collagen. Because MMP2 and MMP9 can degrade type IV collagen , gelatin and fibronectin, they are closely associated with tumor invasion, metastasis and angiogenesis. Angiogenesis is very essential for tumor invasion and metastasis because newly -born vessels not only provide tumor cells with nutrients but also act as important pathes for further invasion. It was reported that MVD value was closely related to invasion and metastasis of RCC and may be one of the objective markers re-fleting the biological action of RCCs.Regression analysis of Spearman correlation coefficient demonstrated that a significant positive relationship between the expression of MMP9 and the tumor stage and grade. The positive expression mainly lies in the tumor area and a-round. Increased activity of MMP9 was noted in high stage and high grade groups. Therefore MMP9 may be involved in the invasion and metastasis of RCC, which is in accordance with other studies. In some recent investigations,MMP9 may be responsible for tumor angiogenesis as a member of angiogenic factors. There are also researches indicating that the expression of MMP9 was related to angiogenesis in breast cancer, but there is no similar report in RCC. The present study demonstrated that the expression of MMP9 also increased where the MVD value is high. The MVD value was higher in high MMP9 expression group then in low group, (r =0. 558,p <0. 001). The mechanism of MMP9 as angiogenic factors may be that it promotes the release and migation of vascular endothelia cell from the basement membrane by degrading vascular basement membrane and extracellular matrix, but the accurate mechanism is still needed further study. The significant relationship between the expression of MMP9 and MVD value showed that to some extent MMP9 maybe promote th... |
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