The Study Of The Relationship Between The Expression Of COX-2 And Lymphangiogenesis In Renal Clear Cell Carcinoma

ObjectiveTo investigate the expression of cyclo-oxygenase-2(COX-2) and vascular endothelial growth factor-c(VEGF-C) in renal clear cell carcinoma(RCC) and the correlation of the COX-2 with lymphangiogenesis.Materials and Methods40 renal clear cell carcinoma and 10 normal kidney tissues were selected, which were resected in the Department of Urology, Beijing Friendship Hospital,from 2002 to 2006. There were 29 males and 11 females, aged from 42 to 87 years old. All the patients didn't receive any radiotherapy and chemotherapy before operation. According to the Robson's classification criterion, 10 cases were of grade I,10 cases were of grade II and the others were of grade III-IV.(1) Immunohistochemical staining was used to evaluate the expression of COX-2,VEGF-C and it's receptor,VEGFR-3 in 40 cases with RCC,which had been comfirmed by phthological examination,and 10 cases in normal renal tissue.(2) The positive rate of COX-2 and VEGF-C was observed under optical microscope. lymphatic vessels density(LVD) in or around the tumor was counted;the average OD value(optical density value) of the COX-2 and VEGF-C in tumor was measured by the software of IPP(Image-Pro Plus);the correlation of the averageOD value of COX-2,VEGF-C and the LVD was analyzed.Results(1) The positive rate of COX-2 in 40 cases was 80 % while COX-2 was not found in normal cerebral tissues.The expression of COX-2 did not correlate with sex, age, the diameter of tumor and clinical stage(p>0.05).(2) The rate of positive expression of VEGF-C in RCC was 37.5%,which was higher compared to 10% in control column(p<0.05). The expression of VEGF-C in cases in clinical stageâ…¢andâ…£was higher compared to clinical stageâ… andâ…¡(p=0.004,p<0.01).The expression of VEGF-C in cases with metastasis was higher compared to the cases without metastasis(p=0.042,p<0.05). The expression of VEGF-C did not correlate with sex, age, the diameter of tumor (p>0.05).(3) The LVD in cases of clinical stageâ…¢andâ…£was higher compared to clinical stageâ…¡(p=0.017,p<0.05)and stageâ… (p=0.02,p<0.05).The LVD in metastasis cases was higher compared to cases without metastasis( p=0.033,p<0.05).(4) The expression of COX-2 was positively correlated with VEGF-C(r=0.612,p=0.026).The expression of VEGF-C was positively correlated with LVD(r=0.718,p=0.003).Conclusions(1) The expression of COX-2 and VEGF-C was high in RCC and the expression of COX-2 was positively correlated with VEGF-C.(2) The expression of COX-2 in RCC was an early event and it maybe promote the lymphangiogenesis by inducing VEGF-C expression and leaded to metastasis.