【摘要】 目的观察肝细胞癌(HCC)中甲基化相关沉默目标-1(TMS1)、DNA甲基转移酶1(DNMT1)和DNA甲基化结构域2(MBD2)蛋白的表达情况,及TMS1基因启动子的甲基化情况,探讨3个基因的关系及临床诊断意义。方法采用免疫组织化学法(IHC)检测48例肝癌组织和48例对照肝组织中TMS1、MBD2和DNMT1蛋白表达水平的变化。采用甲基化特异性PCR(MSP)检测34例HCC患者、26例乙型肝炎患者和23例健康者血清中的TMS1基因甲基化情况。结果肝癌组织、正常肝组织中TMS1的阳性表达率分别为26.08%、97.92%,MBD2分别为18.75%、80.00%;DNMT1分别为77.08%、32.25%,TMS1、MBD2在肝癌组织中的阳性表达率均低于正常肝组织,而DNMT1阳性表达率高于正常肝组织,差异均有统计学意义(P<0.05)。TMS1、MBD2与DNMT1的表达均呈负相关(P<0.05)。TMS1蛋白表达水平与年龄、性别无相关性,而与肿瘤的TNM分期和分化程度相关(P<0.05)。HCC组、乙型肝炎组、健康者组TMS1基因甲基化检出率为70.6%、50.0%和0.0%,差异均有统计学意义(P<0.05)。HCC组、乙型肝炎组的甲基化检出率明显高于健康者组,并随着肿瘤分级、分期的增加而升高。结论 TMS1高甲基化可能是肝组织癌变的早期事件,TMS1、MBD2和DNMT1蛋白异常表达在HCC的发生、发展等过程中起着重要的作用,三者可作为肝癌早期诊断和判断预后的新生物学指标,并可成为HCC治疗的新靶点。更多还原

【Abstract】 Objective To observe the expression of methylation related silent target 1(TMS1),DNA methyltransferase 1(DNMT1)and methyl CpG binding domain protein 2(MBD2),and the methylation of the TMS1 gene promoter,in hepatocellular carcinoma(HCC),and to investigate the relationship between the three genes and the clinical diagnostic significance.Methods The protein expression of TMS1,MBD2 and DNMT1 in 48 cases of HCC tissues and 48 case of normal tissues were detected by immunohistochemistry(IHC);the methylation status of TMS1 gene in serum of 34 patients with HCC,26 patients with hepatitis B and 23 healthy controls were analyzed by methylation specific polymerase chain reaction(MSP).Results The positive rates of TMS1 expression in HCC tissues and normal tissues were 26.08% and 97.92%,respectively;the positive rate of MBD2 expression were 18.75%and 80.00%,respectively;the positive rate of expression were 77.08 % and 32.25%,respectively.The positive rates of TMS1 and MBD2 expression in HCC tissues were significantly lower than those in the normal tissues,and DNMT1 expression was higer than that in the normal tissues,and the difference was statistically significant(P<0.05).The expression TMS1 and MBD2 were negatively correlated with DNMT1(P<0.05).TMS1 protein expression was associated with TNM stage and tumor differentiation but not associated with the age and gender(P<0.05).The methylation detection rates of TMS1 gene in HCC group,hepatitis B group and healthy group were 70.6%,50.0%and 0.0%,respectively,and the differences were statistically significant(P<0.05).The methylation detection rate of HCC group and hepatitis b group was obviously higher than the normal group,which aggravated with the increase of tumor grade and stage.Conclusion TMS1 hypermethylation may be an early event in the carcinogenesis of liver tissue,the abnormal expression of TMS1,MBD2 and DNMT1 proteins plays an important role in the occurrence and the development of HCC,which can be used as new molecular markers for the early diagnosis and prognosis of HCC,and become the new targets for the treatment of HCC.更多还原