SV40大T抗原在人脑肿瘤中的表达

Expression of SV40 large tumor antigen in human brain tumors

目的 探讨 SV40早期区域基因编码产物大 T抗原(Tag)的表达及与抑癌蛋白 p5 3,p Rb的相互作用在人脑肿瘤发生发展中的意义 .方法 采用免疫共沉淀结合银染色及Western印迹法检测 6 5例人脑肿瘤及 8例正常人脑组织中Tag的表达 ,并对 18例和 15例 Tag阳性瘤组织分别检测Tag- p5 3和 Tag- p Rb复合物的形成 .结果 SV40 Tag在人脑肿瘤中广泛表达 ,阳性率为 6 6 % (4 3/ 6 5 ) ,而 8例正常人脑组织均无 Tag表达 ,二者差异显著 (P<0 .0 5 ) ;分别检测 18例和 15例 Tag阳性瘤组织 ,均发现 Tag可与 p5 3,p Rb形成特异性复合物 .结论 SV40 Tag的表达与人脑肿瘤的发生有一定关系 ;SV40 Tag与 p5 3,p Rb形成特异性复合物并导致其失活 ,可能是 SV40致人脑肿瘤发生的一个重要机制 .

AIM To study the expression of SV40 early region gene coding product, the large tumor antigen (Tag), and its interaction with tumor suppressors p53 and pRb in human brain tumorigenesis. METHODS Tag was investi-gated by immunoprecipitation followed by silver staining and Western blot in 65 cases of human brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-pRb complexes were screened by immunoprecipitation and Western blot in 18 and 15 Tag positive tumor tissues respectively. RESULTS SV40 Tag was expressed generally in human brain tumors with a positive rate 66% (43/65), while in 8 normal brain tissues Tag was negative in all cases. There was a significant difference between them (P<0.05). Tag-p53 complex was detected in all of 18 Tag positive tumors, and Tag-pRb complex was positive in all of the 15 Tag positive tumors. CONCLUSION SV40 Tag expression is associated with human brain tumorigenesis. The inactivation of p53 and pRb due to the formation of Tag-p53 and Tag-pRb complexes might possibly be an important mechanism in the pathogenesis of human brain tumors.