中文摘要：

目的：肝细胞癌（HCC）是一类常见的恶性肿瘤，主要表现为进展迅速、易复发及预后不良。侵袭转移作为肝癌的最主要的恶性表型，是造成较高致死率的主要原因。Calpain是钙激活中性蛋白酶，广泛参与了细胞多种生命过程。其中Calpainl和Calpain2是Calpain家族主要成员，对于维持肿瘤细胞恶性表型有重要作用。本研究通过RNA干涉技术下调人肝癌Huh7细胞中Calpain2基因的表达，检测下调Calpain2对人肝癌Huh7细胞黏附，侵袭和迁移能力的影响，明确Calpain2在人肝癌细胞浸润和转移过程中的作用。方法：合成Calpain2的RNAi片段，瞬时转染人肝癌细胞Huh7，降低Hull7细胞中Calpain2的表达，运用细胞黏附实验，细胞侵袭实验及划痕愈合实验检测干涉Calpain2对肝癌细胞的黏附，侵袭和迁移能力的影响。结果：合成Calpain2的RNAi片段。瞬时转染人肝癌细胞Huh73，36小时后，细胞中Calpain2的蛋白水平明显下降，干涉Calpain2后人肝癌细胞Huh7的黏附率，侵袭率及划痕修复率的显著下降。结论：以上实验结果表明Calpain2能够促进肝癌细胞黏附，侵袭及划痕修复能力，Calpain2能够促进肝癌细胞的浸润和转移的作用，是肝癌发生发展过程中的肿瘤促进因子。因此，Calpain2可以作为抑制肝癌侵袭和转移的潜在靶点，靶向Call＇ain2的药物可能成为治疗肝癌侵袭转移的新方法。

英文摘要：

Objective： Hepatocellular carcinoma （HCC） is one of the most common human cancers. It is a highly malignant tumor characterized by rapid progression, poor prognosis, and frequent tumor recurrence. Invasion and metastasis are major malignant charac- teristics of HCC, which always lead to death. Calpains are a conserved family of calcium-dependent cysteine proteinases involved in vari- ous cellular functions. Two ubiquitous isoforms, calpainl and calpain2, are key members of the calpain family that play essential roles in regulating cell migration and invasion. However, it remains unclear whether calpain2 is involved in the progression of hepatocellular car- cinoma （I-ICC）. Here, we investigated the functions ofcalpain2 in the invasive and metastatic processes of human hepatoma cells. In this study, transfection of human hepatoma cells with siRNAs targeting Calpain2, led to significant decreases in Calpain2 expression. We then used siRNAs targeting Calpain2 to investigate the effect of calpain2 to cell adhere, invade and migration potentials in human hepatoma cells. Methods： RNA interference was used to downregulate the expressions of calpain2 in human hepatoma cells Huh7. Cell adhere test was used in si-calpain2 transfected human Huh7 hepatoma cells to test ceils adhesion potential. Cell invasion test was used in si-calpain2 transfected human Huh7 hepatoma cells to test cells invasion potential. Monolayer wound healing assay was carried out in si-calpain2 transfected human Huh7 hepatoma cells to test cell migration potential. Results： Transfection of human hepatoma cells with siRNAs tar- geting Calpain2, led to significant decreases in Calpain2 compared to cells transfected with the negative control siRNA. In si-calpain2 transfected human Huh7 hepatoma ceils, the numbers of attached cells, invaded cells were significantly decreased compared to cells transfected with the negative control siRNA. Wound closure rate were markedly lowered in si-ealpain2 transfected human Hnh7 hep- atoma ceils compared to