MUC2基因甲基化在胰腺癌细胞株、胰腺癌患者外周血中的检测及意义

Methylation status of MUC2 gene in pancreatic carcinoma cell lines and peripheral blood of pancreatic carcinoma patients

目的检测MUC2基因在胰腺癌细胞株、胰腺癌患者外周血中的甲基化情况，探讨MUC2基因甲基化对胰腺癌早期诊断的价值。方法收集长海医院消化内科实验室保存的人胰腺癌细胞系SW1990、ASPC、PANC1、BxPC3、PaTu8988、CFPAC1及40例胰腺癌、15例慢性胰腺炎患者和25例正常对照者外周血标本，应用甲基化敏感性限制性内切酶（methylation-sensitive restriction endonuclease，MS-RE）为基础的PCR法检测MUC2基因甲基化。结果人胰腺癌细胞系PANCl、BxPC3、PaTu8988未发生MUC2基因甲基化；ASPC、CFPAC1、SW1990胰腺癌细胞系发生MUC2基因甲基化。外周血标本中，40例胰腺癌标本甲基化率为40．0％（16例），15例慢性胰腺炎无甲基化，25例正常对照甲基化率4．0％（1例）。胰腺癌与慢性胰腺炎、正常对照之间的甲基化率有显著差异（P〈0．01）。外周血标本MUC2基因启动子CpG岛甲基化检测诊断胰腺癌的敏感性为40％、特异性为97．5％、诊断准确性68．8％、阳性预测值94．1％、阴性预测值61．9％。结论用甲基化限制性酶切PCR法对外周血进行MUC2基因启动子区高甲基化检测可望成为新的胰腺癌诊断的重要实验室辅助手段。

Objective To analyze the methylation status of MUC2 gene in pancreatic carcinoma cell lines and peripheral blood of pancreatic carcinoma patients, and to explore the role of MUC2 methylation in the early diagnosis of pancreatic carcinoma. Methods Human pancreatic cancer cell lines of SW1990, ASPC, PANC1, BxPC3, PaTu8988 and CFPAC1, and 40 peripheral blood samples of pancreatie earcinoma patients, 15 cases of chronic pancreatitis, 25 cases of normal controls were collected, and the methylation status of MUC2 gene was detected by methylation sensitive restriction endonuclease PCR. Results MUC2 methylation was not detected in PANC1, BxPC3, PaTu8988, but was detected in ASPC, CFPAC1, SW1990. Among the peripheral blood samples, the rate of methylation in pancreatic cancer was 40.0% （n = 16）, in chronic pancreatitis was 0% , in normal controls was 4.0% （ n = 1 ） , and the difference among the three groups was statistically significant （ P 〈 0.01 ）. The methylation of MUC2 gene CpG islands for the diagnosis of pancreatic carcinoma had a sensitivity of 40% , specificity of 97.5% , accuracy of 68.8% , positive predictive value of 94.1% and negative predictive value of 61.9%. Conclusions The detection of MUC2 hypermethylation in peripheral blood samples may be an potential marker for early diagnosis of pancreatic carcinoma.