肝癌缺失基因在胃癌中的表达及启动子甲基化

Expression of tumor suppressor gene DLC-1 in human gastric cancer tissues and methylation of promoter

目的探讨肝癌缺失基因(DLC1)与胃癌及其临床分期、分化程度等关系,DLC1mRNA表达与启动子甲基化的关系。方法用半定量逆转录聚合酶链反应方法检测34例原发性胃癌及癌旁正常组织中DLC1mRNA表达;用甲基化特异聚合酶链反应法(MSP)检测启动子甲基化。结果正常组织中DLC1mRNA均正常表达,胃癌组织DLC1mRNA低表达或表达缺失;正常组织0.62±0.11,胃癌组织0.24±0.17,差异有统计学意义(P<0.01)。DLC1mRNA表达与淋巴结转移和肿瘤分化程度有关,与性别、肿瘤大小和临床分期无关。正常组织中未发现DLC1基因启动子甲基化;胃癌组织中DLC1启动子甲基化阳性12例,甲基化率35.3%。启动子甲基化与无甲基化患者间DLC1mRNA表达差异有统计学意义(P<0.01)。结论DLC1与胃癌存在明显相关性,是重要的抑癌基因。启动子甲基化与DLC1mRNA表达抑制密切相关,可能是影响DLC1在胃癌中低表达的最主要因素,DLC1是胃癌甲基化谱中主要成员。

Objective To study the expression of DLC-1 in gastric cancer and its clinical significance;To evaluate methylation of promoter of gastric cancer related gene DLC-1 and explore the association of methylation and the expression of DLC-1 mRNA.Methods The expression of DLC-1 mRNA was detected by semi-quantitative RT-PCR in 34 patients who underwent operation for gastric cancer.Promoter methylation of gene DLC-1 was examined by methylation specific polymerase chain reaction (MSP).[WT5”HZ]Results DLC-1 mRNA was low-expressed in gastric cancer specimens although it was also expressed in normal gastic specimens.The results of semi-quantitative RT-PCR analysis showed the expression of DLC-1 mRNA was 0.62± 0.11 in normal tissues and 0.24± 0.17 in cancer respectively (P< 0.01).The levels of DLC-1 expression were correlated with malignancy of cancer and lymph node metastasis,but had no relationship with size,gender and clinical stage.In 34 gastric cancer tissues,12 had DLC-1 gene promoter methylation,and the rate of methylation was 35.3%.In normal tissues near by cancer,no methylation of promoter for DLC-1 was found either.Conclusion[WT5”BZ] The expression of DLC-1 was closely correlated with gastric cancer.Methylation of promoter may be the main factor influencing DLC-1 mRNA to express only,and DLC-1 is the main member in the methylation table of gastric cancer.