Molecular biological analysis of a development and progression of hepatocellular carcinoma to establish a rational treatment for it

我们的实验目标是：(1)对肝细胞癌的发生发展进行分子生物学分析；(2)建立一种鉴别多中心发展与肝内转移的分子生物学诊断方法。在多中心肝细胞癌的鉴别诊断中，可获得乙肝病毒DNA(HBvDNA)在肿瘤中的整合模式，即在多中心肝癌中，HBvDNA在每个肿瘤中的整合模式是不同的。但是，在日本，肝癌合并HB病毒感染的患者不到30%。因此，对其他肝癌特异性癌基因的P53抑癌基因突变模式的分析应该是可行的。然而，由于我们无法从人类病例中获得像早期或癌前病变这样的病例，所以很难对人类肝细胞癌的发生发展进行分析。因此，在此期间，我们建立了联苯胺的一种色素DirDirect Deep Black Extra(DDB-Ex)诱导的小鼠实验性肝癌模型。这种模式的肿瘤在组织学上与人肝癌非常相似，即肿瘤呈结节状，组织学上生长在不同厚度的索状结构中，与人的小梁型肝癌相同。在分子生物学研究中，未发现p53抑制基因突变，但在该模型中检测到65%的Ha-ras癌基因突变和12%的Ki-ras癌基因突变。DDB-Ex诱导的小鼠肝细胞癌具有与人肝细胞癌相似的病理和分子生物学特征，可用于研究人肝细胞癌的发生发展。

Our experimental goal are (1) molecular biological analysis of development and progression of hepatocellular carcinoma (HCC) and (2) establishment of a molecular biological diagnostic method to differentiate multicentric development from intrahepatic metastasis of HCC.As differentiated diagnosis of multiple HCC,integration pattern of hepatitis B viral DNA (HBvDNA) in the tumor was availabel, that is in case of multicentric HCC,integration pattern of HBvDNA is different in each tumor. But, HCC patients with HB viral infection were less than 30% in Japan. So, analysis of mutation pattern of p53 supressor oncogene of other HCC specific oncogene should be available from now. While as analysis of development and progression of HCC in human was difficult, because we could not get such a case as in early stage or in precancerous lesion from human cases. So, within this term, we developed an experimental HCC model in mice induced by DirDirect Deep Black Extra (DDB-Ex), a pigment of the Benzidine. Histologically the tumors in this mode were very similar to those of human HCC,that is the tumor is nodular and histologically grow in cords of variable thickness which is same as the human trabecular pattern HCC.In molecular biological study no mutations in the p53 supressor gene were found out but 65% mutations in the Ha-ras oncogene and 12% of mutations in Ki-ras oncogene were detected in this model. The HCC in mice induced by DDB-Ex share the pathological and molecular biological character with human HCC and is available for studying the development and progression of humanHCC.