胃癌中Cav-1的异常表达及其调控机制  

Abnormal expression and its regulation mechanism of Cav-1 gene in gastric cancer

作　　者：郭艳丽[1] 周珍[1] 郭炜[1] 邝钢[1] 杨植彬[1] 董稚明[1] 

机构地区：[1]河北医科大学第四医院病理研究室,石家庄050011

出　　处：《临床与实验病理学杂志》2015年第3期255-259,共5页Chinese Journal of Clinical and Experimental Pathology

基　　金：河北自然科学基金(H2013206315);河北省医学科学研究重点课题计划(20130543)

摘　　要：目的检测胃癌(gastric cancer,GC)细胞系及其组织标本中小凹蛋白-1(Cav-1)的表达,并探讨基因甲基化对Cav-1表达的影响。方法应用甲基化特异性PCR(methylation specific PCR,MSP)技术检测胃癌细胞株(AGS、MKN45、BGC-823)及104例胃癌及相应癌旁组织中Cav-1基因的甲基化状态,应用RT-PCR技术检测胃癌细胞株中Cav-1 mRNA的表达,应用免疫组化法检测胃癌组织中Cav-1的表达。结果甲基化抑制剂5-aza-2’-deoxycytidine(5-Aza-Dc)处理细胞株后,AGS中Cav-1mRNA由阴性表达恢复为阳性表达,MKN45及BGC-823中Cav-1 mRNA在处理前后均呈阳性;用组蛋白去乙酰化酶抑制剂曲古抑菌素A(trichostatin A,TSA)分别处理3株细胞,处理前后Cav-1 mRNA表达均无明显变化。MSP检测结果显示,AGS细胞株可扩增出甲基化条带,5-Aza-Dc处理后,甲基化条带消失,MKKN45及BGC-823处理前后均无甲基化条带扩出。胃癌组织中Cav-1基因甲基化率为29.8%(31/104),明显高于癌旁组织(P=0.000);癌组织中Cav-1基因高甲基化与患者淋巴结转移及上消化道肿瘤家族史(upper gastrointestinal cancers,UGIC)相关(P<0.05),与病理分级及临床分期无关(P>0.05);胃癌组织中Cav-1的阳性率为51.9%(54/104),明显低于癌旁组织,差异有统计学意义(P=0.000),且癌组织中Cav-1表达与其基因高甲基化状态明显相关(P=0.000)。结论 Cav-1在胃癌组织中表达下调,并且基因启动子区Cp G岛的高甲基化状态可能是引起其表达下调的机制之一。Purpose To investigate the expression of Cav-1 in gastric cancer （GC） cell lines and GC samples, and to analyze the pos- sible effect of gene methylation in expression of Cav-1. Methods Methylation specific PCR （MSP） method was applied to examine the CpG methylation of the Car-1 promoter in GC cell lines （ AGS, MKN45, BGC-823 ） and 104 samples of GC and corresponding ad- jacent tissues. RT-PCR method was applied to examine the mRNA expression in GC cell lines. IHC were applied to examine the pro- tein expression of Cav-1 in the GC tissues. Results The expression level of Car-1 mRNA was obviously increased after treated with 5- aza-2＇-deoxycytidine （5-Aza-Dc, a demethylation agent） in AGS cell line. We detected the positive expression of Cav-1 gene in MKN45 and BGC-823 cell lines before and after treated with 5-Aza-Dc. The level of Cav-1 mRNA expression was no any change in AGS, MKN45 and BGC-823 cell lines treated with trichostatin A （TSA）. MSP results showed that it can be amplified methylated bands in AGS cell line, and the methylated bands disappeared after treated with 5-Aza-Dc. MKN45 and BGC-823 cell lines were no any methylated bands amplified before and after treatment. The methylation frequency of Cav-1 gene was 29.8% （31/104） , which was significantly higher than that in adjacent tissues （ P = 0. 000 ）. Furthermore, Cav-1 gene hypermethylation status was correlated with lymph node metastasis and family history of upper gastrointestinal cancers （ UGIC ） , but not with pathological grade and clinical stage （P 〉 O. 05 ）. The positive frequency of Cav-1 expression was 51.9% （54/104） in GC, which was significantly lower than that in adja- cent tissues （P = O. 000）. The expression of Cav-1 was correlated with the frequency of gene methylation in GC tissues （P = 0. 000）. Conclusion The expression of Cav-1 was reduced in GC tissues and the gene hyermethylation may be one of the mechanisms causing Cav-1 gene silencing.

关 键 词：胃肿瘤 小凹蛋白-1 基因甲基化 

分 类 号：R735.2[医药卫生—肿瘤]