Study on the grade of malignancy and postoperative recurrence in hepatocellular carcinoma with special reference to molecular biological analysis

应用分子生物学方法检测了人肝细胞癌中常见的染色体13q、16q和17p的杂合性缺失(LOH)。我们还检测了与肿瘤转移相关的抗转移基因nm23H1、黏附分子、细胞黏附调节因子(CAR)和E-钙粘素(EC)的基因表达。最后，我们分析了这些因素与临床病理特征和DNA倍体类型的关系。我们的研究结果如下：1.随着肝癌分期的进展，CAR和EC基因的LOH频率，尤其是16Q染色体的LOH频率和nm23H1、Car、EC基因的低表达频率均增加；2.在16Q染色体LOH的肿瘤中，CAR和EC基因的低表达频率较高；3.在LOH包括16Q染色体且nm23H1、Car、EC表达降低的肿瘤中，门静脉侵袭、肝内转移、异倍体、MU…的频率均较高4.通过分析复发性肝癌切除标本中多结节癌与原发灶和复发灶的杂合性缺失(LOH)模式的差异，我们能够确定多中心的发生。这些研究表明，分子生物学分析对评价肝癌的恶性程度和诊断多中心的发生是非常有用的。结合微卫星标记的聚合酶链式反应(PCR)和逆转录聚合酶链式反应(RT-PCR)检测基因表达，我们可以分析极少量的标本，如针吸活检获得的标本，从而尝试对预后进行预先评估。由于这些基因改变发生在肝细胞癌的晚期，因此对其进行早期基因改变的研究具有重要意义。因此，我们计划在早期研究LOH，以确定这些染色体上新的肿瘤抑制基因，以及与遗传性非息肉病性结直肠癌患者中检测到的异常DNA修复基因的关系，后者导致肝癌的发生和发展。较少

Using the molecular biological methods, we examined the loss of heterozygosity (LOH) on chromosomes 13q, 16q and 17p, which are frequently detected in human hepatocellular carcinoma (HCC). We also examined the gene expression of antimetastatic gene, nm23H1, adhesion molecules, cell adhesion regulator (CAR) and E-cadherin (EC) which are associated with cancer metastasis. Finally, we analyzed the relationships between these factors and clinicopathological features and DNA ploidy pattern. Our results were as follows ;1.The frequency of LOH,especially 16q chromosome and reduced expression of nm23H1, CAR,EC gene were increased along with the progression of the Stage of HCC.2.CAR and EC genes also existed on 16q chromosome and their frequency of reduced expression was higher in those tumors with LOH of 16q chromosome.3.In tumors with 2 and more LOH,including 16q chromosome, and reduced expression of nm23H1, CAR,EC,the frequency of portal vein invasion, intrahepatic metasstasis, aneuploid, mu … More ltiple intrahepatic recurrence, and extrahepatic metastasis were high.4.We were able to confirm the multicentric occurence of HCC by analysing the differences of LOH pattern of tumors of multinodular HCC and primary and recurrent tumors in the resected specimens of recurrent HCC.Thsese investigations demonstrated that molecular biological analysis was very useful to evaluate the grade of malignancy and diagnose muticentric occurence in HCC.With polymerase chain reaction (PCR) method with microsatellite marker for LOH and reverse transcriptase PCR (RT-PCR) method for gene expression, we can analyze a very small amount of sample, such as those obtained by needle biopsy, and thus, try to evaluate the prognosis preoeratively. As these genetic alteration occures in the late stage of HCC,it is important to investigate the genetic alteration in the early stage. Thus we plan to study the LOH in the early stage to identify new tumor suppressor genes on these chromosomes, and the relationship with abnormal DNA repair genes, detected in those who had hereditary nonpolyposis colorectal cancer, which causes carcinogenesis and progression of HCC. Less