ObjectiveTo determine the frequency and type of p16 gene homozygous deletion and mutation with the progression of human gastric carcinogenesis.MethodsPCR （polymerase chain reaction），SSCP (single strand conformation polymorphism) and DNA sequencing were performed on 50 operative tissues, which included 7 early gastric cancer and 43 advanced gastric cancer. In this group there were 36 male and 14 female patients aged 35 to 68,which included 30 welldifferetiated adenocarcinoma and 20 poordifferentiated carcinoma; 19 patients with lymph node metastases.ResultsTotal mutation frequency of p16 gene was 8.00%(4/50), including 14.29%(1/7) of early cancer and 7.00%(3/43) of advanced cancer，there was no significant difference between early and advanced cancer （P＞0.05）. In addition, p16 gene mutation was not related to site，location，grade of tumor differentiation and lymph node metastases, respectively. Total deletion frequency of p16 gene was 16.00%(8/50), of which 18.60%(8/43) was detected in advanced cancer, but no cases in early cancers. There was a significant difference between early and advanced cancer （P＜0.05）, and frequency p16 gene homozygous deletion was related to grade of tumor differentiation and lymph node metastases, respectively. Direct DNA sequencing displayed that 4 point mutations detected in 99,125,433,441 base, there were 3 missense mutation and 1 samesense mutation, no deletion or insertion was found. Conclusionp16 gene mutation is an early event in gastric carcinogenesis，it helps early diagnosis of human gastric carcinoma. p16 gene homozygous deletion is a late event in gastric carcinogenesis，it might relate to metastases and recurrence of gastric cancer.
【Abstract】Objective To demonstrate the role of p16 protein and Rb protein in the formation and progression and their relationship in thyroid carcinoma. Methods p16 and Rb from 46 patients with thyroid cancer were detected by SP immunohistochemistry. Results In thyroid carcinoma,the p16 positive rate was decreased with the decline of differentiation. There was an inverse correlation between the rates of p16 positive expression and involvement of lymph node,clinical stage and prognosis index.The Rb protein was not present in any cases as a nucleus staining. Conclusion The p16 gene is likely to play an important role in the genesis and malignant progression of thyroid carcinoma,while the Rb gene is not .
目的研究p16基因甲基化在乳腺癌中的分布情况，并探讨其与乳腺癌发生、发展的关系。方法采用甲基化特异的PCR技术检测四川省肿瘤医院乳腺科2008年3～9月期间收治的38例原发性乳腺癌组织及距离肿瘤＞5 cm以远的正常乳腺组织中p16基因启动子区CpG岛甲基化频率。结果乳腺癌组织中p16基因启动子区CpG岛甲基化频率〔31.6%（12/38）〕明显高于其正常乳腺组织〔5.3%（2/38）〕，差异有统计学意义（P=0.003）。有淋巴结转移的乳腺癌患者中p16基因甲基化频率〔45.5%（10/22）〕高于无淋巴结转移患者〔12.5%（2/16）〕，差异有统计学意义（P=0.044）。结论p16基因启动子区CpG岛甲基化可能在乳腺癌发生、发展过程中起着重要作用。