Matsubara T, Funabiki T, Jinno O, Sakurai Y, Hasegawa S, Imazu H, Ochiai M
Department of Surgery, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan.
J Hepatobiliary Pancreat Surg. 1999;6(3):286-93. doi: 10.1007/s005340050120.
To investigate the molecular mechanisms of the high incidence of carcinogenesis in the biliary epithelium of patients with pancreaticobiliary maljunction, we examined p53 gene mutations, loss of heterozygosity of p53, and overexpression of p53 gene product in the cancerous and noncancerous biliary epithelium of 27 patients with pancreaticobiliary maljunction. Mutations of the p53 gene were examined by polymerase chain reaction-single strand conformation polymorphism and a direct sequencing method. Loss of heterozygosity of the p53 gene was determined using a double-targeted fluorescence in situ hybridization method. Expression of p53 gene product was examined using immunohistochemical staining. Mutations of the p53 gene were found in 4 of 5 biliary carcinomas (80%) and in 10 of 26 noncancerous biliary lesions (38.5%). Point mutations of the p53 gene were detected at codons 207, 212, and 217 on exons 5 through 8. The incidence of p53 gene mutations on exons 5, 6, 7, and 8 was 12. 9%, 36.4%, 0.0%, and 13.8%, respectively. Loss of heterozygosity of p53 was shown in 72% of the cells obtained from the cancerous lesion, and in an average of 14% obtained from the noncancerous lesions. Overexpression of p53 protein was found in 57.1% of carcinoma, and in 31.3% of the noncancerous lesions. These results suggest that p53 gene mutations are involved in the carcinogenesis of biliary epithelium in patients with pancreaticobiliary maljunction.
为了探究胰胆管合流异常患者胆管上皮细胞癌变发生率高的分子机制，我们检测了27例胰胆管合流异常患者癌性和非癌性胆管上皮细胞中的p53基因突变、p53杂合性缺失以及p53基因产物的过表达情况。采用聚合酶链反应-单链构象多态性和直接测序法检测p53基因突变。使用双靶点荧光原位杂交法测定p53基因的杂合性缺失。采用免疫组织化学染色检测p53基因产物的表达。在5例胆管癌中有4例（80%）发现p53基因突变，在26例非癌性胆管病变中有10例（38.5%）发现该突变。在第5至8外显子的第207、212和217密码子处检测到p53基因的点突变。第5、6、7和8外显子的p53基因突变发生率分别为12.9%、36.4%、0.0%和13.8%。在癌性病变获得的细胞中有72%显示p53杂合性缺失，在非癌性病变获得的细胞中平均有14%显示该缺失。在57.1%的癌组织以及31.3%的非癌性病变中发现p53蛋白过表达。这些结果表明，p53基因突变参与了胰胆管合流异常患者胆管上皮细胞的癌变过程。
