Expressions of angiogeneic factors in choroidal melanoma

Abstract

Background Angiogenesis is an essential event for the growth and mobility of malignant tumors,but there is little literature about the effects of anoxia and angiogenesis-related factors on angiogenesis in choroidal melanoma.Objective The aim of this study was to investigate the expression of angiogeneic factors such as hypoxia inducible factor-1α(HIF-1α),inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),and vascular endothelial growth factor(VEGF)in choroidal melanoma and their clinical significance.Methods The specimens from 44 cases of choroidal melanoma and 16 cases of eyelid nevi identified by pathology were collected.Immunohistochemistry SP was used to examine the expression of HIF-1α,iNOS,COX-2 and VEGF in the samples.The expression of HIF-1 α,iNOS,COX-2 and VEGF in tumors with different sizes,different pathological types and different growth patterns was evaluated.The correlations among these four proteins in tumor growth and development were assessed.Results The expression of HIF-1α,iNOS,COX-2 and VEGF in choroidal melanoma were significantly higher than those in the eyelid nevi group(x2 =6.58,4.105,8.350,13.240,P＜0.05).The expression of VEGF was associated with tumor size(x2 =9.389,P＜0.05),but not associated with pathological types(x2 =1.186,P＞0.05)and infiltration depth(x2 =5.398,P＞ 0.05).The expression of HIF-1α was associated with tumor size(x2=8.664,P＜0.05)and pathological type(x2=6.622,P ＜ 0.05),but not associated with infiltration depth(x2=4.914,P＞0.05).The expression of iNOS was associated with tumor size(x2 =8.609,P＜0.05),but was not associated withpathological type(x2 =4.789,P＞0.05)and infiltration depth(x2 =4.309,P＞0.05).The expression of COX-2 was associated with tumor size(x2 =7.320,P＜0.05),but was not associated with pathological type(x2 =2.772,P＞0.05)and infiltration depth(x2 =2.103,P＞0.05).The expression of HIF-1 α,iNOS,and COX-2 were significantly correlated with the expression of VEGF(r =0.943,1.000,0.986,P ＜ 0.05).The expression of COX-2 was significantly correlated with the expression of iNOS(r =0.986,P＜0.05).The expression of HIF-1 α was significantly associated with the expression of COX-2(r=0.986,P＜O.05).The expression of HIF-1α was significantly associated with the expression of iNOS(r=0.943,P＜0.05).Conclusions The expressions of the HIF-1 α,iNOS,COX-2 and VEGF protein are up-regulated in choroidal melanoma.They may play important roles in the angiogenesis of the choroidal melanoma.Assessment of the expression of HIF-1α,iNOS and COX-2 may be useful for the diagnosis and therapy of choroidal melanoma. Key words: Choroidal melanoma; Angiogenesis; Hypoxia inducible factor-1α; Inducible nitric oxide synthase; Cyclooxygenase-2