人肝癌p57^(kip2)基因表达缺失与杂合性缺失的关系研究

The Relationship between the Loss of Heterozygosity and Loss of Expression of p57^(kip2) mRNA

目的通过对p57kip2 mRNA表达水平下降的人体肝癌进行杂合性缺失研究,探讨肝癌发生有关基因调控的分子机制.方法对人肝细胞肝癌及癌周肝组织各30例,正常肝组织对照20例,共80例标本,采用原位杂交检测p57kip2 mRNA的表达,并运用PCR—聚丙烯酰胺凝胶电泳—银染法和基因分型对30例肝癌组织及其癌周肝硬化组织p57kip2基因所在染色体区域的10个微卫星位点(D11S1397,D11S1318,D11S4046,D11S922,THO1,D11S2359,D11S1760,D11S1338,D11S569和D11S1397)进行杂合性缺失检测.同时分析了p57kip2 mRNA表达与杂合性缺失之间的关系.结果原位分子杂交检测正常肝组织未见p57kip2 mRNA表达,癌周肝硬化组与肝癌组阳性表达率均为26.7%(8/30).杂合性缺失检测结果显示在10个微卫星位点中,仅有TH01(7/30,23.3%)、D11S2359(5/30,16.6%)和D11S569(1/30,3.3%)3个位点有杂合性缺失;p57kip2mRNA和蛋白表达缺失主要与TH01位点相关.结论p57kip2 mRNA和蛋白表达异常提示其可能在原发性肝癌的发生发展中起重要作用.与p57kip2基因同一区域的10个微卫星位点不是p57kip2基因LOH和MSI的频发位点,但p57kip2 mRNA表达缺失与TH01位点的杂合性缺失相关.

Objective To explore the molecular mechanism of gene regulation in hepatocarcinogenesis by studying the loss of heterozygosity （LOH） of p57^kip2 gene in loss of p57^kip2 gene expression of human hepatoeellular carcinoma （HCC）. Methods The expression of p57^kip2 mRNA was detected by in situ hybridization （ISH） in 30 eases of pericaneerous cirrhosis and HCC. LOH of ten mierosatellite loci （D11S1397, D11S1318, D11S4046, D11S922, THO1, D11S2359, D11S1760, D11S1338, D11S569and D11S1397） were deteeted where the p57^kip2 gene was located in the area of 11p15.5 to 11p15.1 by using PCR-Polyacrylamide gel electrophoresis silver staining method in 30 cases of HCC. Then, the PCR products were genotyped to confirm the results of LOH. The relationship between LOH and the loss of expression of p57^kip2 mRNA was analyzed. Results ISH study showed that there was no expression of p57^kip2 mRNA in normal liver tissue. Expressions of mRNA both in pericancerous cirrhosis and hepatocellular carcinoma were 26.67% （8/30）. LOH detection showed that LOH was identified only by TH01 （7/30, 23.3%） . D11S2359 （5/30, 16.6%） and D11S569 （1/30, 3.3%） in 30 cases on ten microsatellite loci. But the loss of expression of p57^kip2 mRNA and protein mainly related to the LOH of TH01. Conclusions Abnormal expression of p57^kip2 may play a role in the development of hepatocellular carcinoma. The loss of p57^kip2 mRNA expression may be related to the LOP of TH1.