大肠癌P21、P53蛋白表达和K-ras基因、p53基因突变研究

Expression of P21, P53 Protein and Mutation of K -ras Gene, p53 Gene in Colo rectal Carcinoma

采用免疫组化技术和PCR-SSCP技术对高、中、低分化大肠腺癌、癌旁粘膜、正常粘膜及大肠腺瘤型息肉的P21、P53蛋白表达和K-ras基因、p53基因突变进行了检测,检测结果高、中、低分化大肠腺癌、癌旁粘膜、正常粘膜和大肠腺瘤型息肉六组P21蛋白表达阳性率分别为57.5％、62.5％、75％、13.3％、6.7％、50％,p53蛋白表达阳性率分别为30％、37.5％、50％、4.4％、22％、33.3％,K-ras基因突变率分别为32.5％、37.5％、62.5％、2.2％、0％、16.7％,p53基因突变率分别为22.5％、25％、37.5％、0％、0％、0％.结果表明大肠腺癌P21、P53蛋白表达比大肠腺瘤增多,但增加不显著(P>0.05), 二组均比癌旁粘膜和正常粘膜P21、P53蛋白表达阳性率高(P<0.01);大肠腺癌K-ras基因和p53基因突变率比大肠腺瘤、癌旁粘膜和正常粘膜组显著增加(P<0.01);高、中、低分化大肠癌各组中,随恶性程度增加,P21、P53蛋白表达增加,K-ras基因和p53基因突变率增加,但均不显著(P>0.05).说明K-ras基因、p53基因突变及其蛋白表达产物P21、P53在细胞癌变、癌细胞恶性表型维持中起重要作用。

P21, P53 protein expression and K - ras, p53 gene mutation was detected by ABC immunohistochemistry and PCR-SSCP silver staining technigue respectively in well - differentiated, moderately differentiated, poorly differentiated colorectal carcinoma, adjacent mucosa, normal mucosa and adenomatous polyps. The results showed P21, P53 protein expression in colorectal carcinoma was increased not significantly compared with those in colorectal adenoma, but significantly higher than those in adjacent mucosa and normal mucosa. K -ras gene and p53 gene mutation was found to correlate with P21, P53 protein expression. The poor differentiated in tumor progression was accompanied by P21, P53 protein overexpression and K -ras, p53 gene frequently mutaion, but the difference is not significant (P>0.05). Overall these indicated that K -ras gene, p53 gene mutation and P21, P53 protein expression may play an important role during colorectal carcinogenesis.