胰腺癌组织中人音猬因子相互作用蛋白基因CpG岛甲基化分析

CpG methylation analysis of human hedgehog interacting protein gene in pancreatic cancer

目的研究胰腺癌组织中人音猬因子相互作用蛋白(HHIP)基因CpG岛甲基化状态,探索胰腺癌早期诊断的检测方法。方法在30例胰腺癌(PCa组)及其癌旁组织(CAT组)和13例慢性胰腺炎(CP组)组织中,分别应用定量逆转录-聚合酶链反应(RT-PCR)、巢式甲基化特异性聚合酶链反应(NMSP)和基因克隆测序的方法检测HHIPmRNA表达及其CpG岛甲基化状况。结果PCa组的HHIPmRNA表达为2.042±1.412,显著低于CAT组的3.710±3.488及CP组的4.485±2.434(P值分别<0.05、0.01),后两组间的差异无统计学意义(P>0.05)。PCa组的甲基化阳性率为43.3%(13/30),显著高于CP组的7.7%(1/13)及CAT组的0(P值分别<0.05、0.01),后两组间的差异无统计学意义(P>0.05)。PCa组中多个CG位点发生甲基化,而CP组中大部分及CAT组中的CG位点未发生甲基化。结论胰腺癌组织中HHIP基因CpG岛呈现高甲基化的状态,可能与胰腺癌的发生相关。

Objective To investigate the CpG island methylation status of human hedgehog interacting protein（HHIP） gene in pancreatic cancer tissues, in an attempt to search for new molecular markers for the early diagnosis of pancreatic carcinoma（PCa）. Methods The mRNA expression and methylation status of HHIP gene were examined by RT-PCR, NMSP, cloning and sequencing in 30 pancreatic carcinoma tissues and the matched adjacent tissues, and 13 chronic pancreatitis tissues（CP）. Results The relative quantification （RQ） of HHIP expression in pancreatic carcinoma tissues （2. 042±1. 412） was significantly lower than those in the cancer adjacent tissues （3.710±3. 488） and the chronic pancreatic tissues （4. 485±2. 434, P〈0.01 or 0.05）, with no significant difference found between CAT and CP tissues. NMSP showed that the methylation rates in POa, CAT and CP tissues were 43.3% （13/30）, 0% （0/30） and 7.7% （1/13）, respectively, with that of POa tissue significantly higher than those of CAT and CP（P〈0.05）. Methylation was observed in several CG sites in PCa tissues, while it was not observed in most OAT and CP tissues. Conclusion CpG islands of HHIP gene is hypermethylated in PCa, suggesting the hypermethylation of HHIP gene might be associated with the tumorigenesis of pancreatic carcinoma.