Molecular mechanisms of intrahepatic metastasis of hepatocellular carcinoma and application for diagnosis and treatment

肝内转移是影响肝细胞癌预后的重要因素之一。由rho和p160 rho相关的卷曲卷曲形成蛋白激酶（p160ROCK）信号通路介导的细胞运动最近被证明在人类HCC的肝内转移中起关键作用。其中一种高度转移的细胞系，具有高水平c-Src激酶活性的KYN-2细胞在贴壁状态下变得分散，延伸板足，并表现出高运动性。显性阴性突变型c-Src的表达导致应力纤维的形成和局灶粘连，并显著降低运动性。这表明c-Src激活在癌细胞迁移和转移中起关键作用。为了研究特异性p160ROCK抑制剂Y-27632是否也能抑制肝内转移，我们研究了Y-27632对Li7细胞运动和肝内转移的影响。Y-27632明显阻断肌动蛋白重组，提高溶血磷脂酸介导的Li7细胞的组织和运动能力。Y-27632通过微渗透泵连续注入腹腔，同时将Li7细胞原位植入SCID小鼠肝脏。y -27632治疗组小鼠转移性结节发生率降低。这些发现证实了Rho/p160ROCK信号通路在人肝癌肝内转移中的重要性，提示Y-27632可能对预防人肝癌肝内转移有一定作用。采用差异显示分析方法筛选肝癌转移相关关键基因。一个新的基因，DRH1，在HCC中经常被下调。CO-029在HCC和肝内扩散的肿瘤中频繁且显著过表达。相比之下，其他四跨蛋白CD9和CD82的mRNA表达在HCC中下调，特别是在肝内扩散的肿瘤中。提示CO-029在促进肝癌转移中有一定作用。少

Intrahepatic metastasis is one of the most important prognostic factors for patients with hepatocellular carcinoma (HCC). Cell motility mediated by Rho-and p160 Rho-associated coiled-coil forming protein kinase (p160ROCK) signaling pathways has recently been shown to play a critical role in intrahepatic metastasis in human HCC. One of such highly metastatic cell line, KYN-2 cells having a high level of c-Src kinase activity become scattered, extend lamellipodia, and exhibit high motility in adherent condition. Expression of a dominant-negative mutant form of c-Src caused formation of stress fibers and focal adhesions, and markedly reduced motility. it was suggested that c-Src activation is critically involved in carcinoma cell migration and metastasis. To investigate whether the specific p160ROCK inhibitor Y-27632 could also inhibit intrahepatic metastasis, the effect of Y-27632 on the cell motility and intrahepatic metastasis of Li7 was investigated. Y-27632 markedly blocked actin reo … More rganization and motility of Li7 cells mediated by lysophosphatidic acid. Y-27632 was administered continuously into the peritoneal cavity using a micro-osmotic pump, together with orthotopic implantation of Li7 cells into the liver of SCID mice. The incidence of mice with metastatic nodules decreased in the Y-27632-treated group. These findings confirm the importance of the Rho/p160ROCK signaling pathway in intrahepatic metastasis of human HCC, and indicate that Y-27632 may be useful for the prevention of intrahepatic metastasis of human HCC.Crucial genes involved in liver cancer metastasis were screened using differential display analysis. A novel gene, DRH1, which is frequently down-regulated in HCC was identified. CO-029 was found to be frequently and significantly overexpressed in HCC and in tumors with intrahepatic spreading. In contrast, mRNA expression of the other tetraspanins CD9 and CD82 was down-regulated in HCC, especially in tumors with intrahepatic spreading. It was suggested that CO-029 has some roles in the promotion of metastasis of HCC. Less