肝细胞癌4号染色体微卫星变异的研究

Features of micro satellite alterations on chromosome 4 in hepatocellular carcinoma

目的 探讨肝细胞癌(HCC)微卫星变异的特点及其与临床病理的相关性。方法 应用聚合酶链反应-简单重复序列多态性方法,对56例患者HCC中4号染色体上10个微卫星的杂合性缺失(LOH)、微卫星不稳定性(MSI)和等位基因失衡(AI)3种变异特征进行检测。结果 56例HCC中,LOH的频率为71.4％(40/56),D4S426的LOH率最高为61.0％,其次为D4S1534(53.7％)。D4S406基因座,血清乙型肝炎表面抗原阳性患者的LOH频率高于阴性者[76.9％(20/26)与12.5％(2/16),x^2=13.999,P<0.01];在D4S426、D4S1615和D4S1652基因座,EdmondsonⅢ、Ⅳ级的LOH明显高于Edmondson Ⅰ、Ⅱ级[76.7％(23/30)与18.2％(2/11),x^2=9.242、P<0.01;53.8％(14/26)与16.7％(2/12),P<0.05;60.7％(17/28)与18.2％(2/11),P<0.051;D4S2921基因座,肝内转移者的LOH显著高于无肝内转移者[63.6％(21/33)与18.2％(2/11),x^2=5.132,P<0.05]。MSI的频率为8.9％(5/56);AI的频率为26.8％(15/56)。结论 HCC 4号染色体微卫星变异形式以LOH为主,提示LOH路径在HCC的发生和发展过程中起主要作用,MSI路径的作用次之。

Objective To study the features of micro satellite alterations and their association with clinicopatho-logical characteristics of hepatocellular carcinoma (HCC). Methods Ten high-polymorphic micro satellite markers on chromosome 4 were selected to be detected for loss of heterozygosity (LOH), micro satellite instability (MSI) and allelic imbalance (AI) in 56 HCC using PCR-simple sequence length polymorphism (PCR-SSLP) analysis. Results LOH was found in 40 of 56 HCC (71.4%) on at least 1 locus, the top two loci were D4S426 (61%), D4S1534 (53.7%). LOH on D4S406 was significantly higher in cases with positive serum HBsAg than in those with negative HBsAg. Similarly, LOH on D4S1538 occurred more frequently in patients with HBsAg negative than those with HBsAg positive [76.9 % (20/26) vs 12.5% (2/16), x2= 13.999, P < 0.01]. LOH on D4S426, D4S1615 and D4S165 were more frequent in poorly or moderately differentiated HCC than in well-differentiated HCC [76.7% (23/30) vs 18.2% (2/11), x2= 9.242, P < 0.01; 53.8% (14/26) vs 16.7% (2/12), P < 0.05; 60.7% (17/28) vs 18.2% (2/11), P<0.01]. LOH on loci D4S2921 was more frequently detected in tumors with intrahepatic metastasis than in those without [63.6% (21/33) vs 18.2% (2/11), x2= 5.132, P < 0.01]. MSI was found in 8.9% (5/56) cases. AI was found in 26.8% (15/56) of all cases examined. Conclusion Frequent micro satellite alterations on chromosome 4 were existed in HCC. LOH, which represents tumor suppressor gene pathway, plays a more important role in hepatocarcinogenesis of HCC; MSI, representing mismatch repair gene pathway, arranges as the next.