LASS2基因抑制HCCLM3肝癌细胞的转移

目的：探讨LASS2基因对HCCLM3肝癌细胞转移的影响。方法：Northern blot分析高转移潜能肝癌细胞系HCCLM3和低转移潜能肝癌细胞系MHCC97-L中LASS2基因的mRNA水平。构建包含LASS2基因编码框的真核表达载体pCMV—HA2-LASS2，通过脂质体转染HCCLM3细胞，经G418筛选，建立稳定表达LASS2基因的HCCLM3细胞株。通过分析LASS2在HCCLM3中过表达后，HCCLM3细胞在迁移、侵袭等转移能力上的改变，Western blot、明胶酶谱及原位酶谱分析MMP-2合成、分泌、激活的变化。结果：Northern blot显示，HCCLM3细胞中LASS2基因的表达水平低于MHCC97-L细胞。当LASS2基因过表达后，HCCLM3细胞的迁移及侵袭能力受到显著抑制（P〈0．001），虽然细胞内MMP-2的合成未改变，但细胞MMP-2的分泌及MMP-2的激活均受抑制。结论：LASS2基因可下调MMP-2的分泌及激活，可使肝癌细胞HCCLM3的转移能力受到明显抑制，提示LASS2基因对肝癌细胞HCCLM3的转移具有抑制作用。

LASS2 gene inhibits the metastasis of human hepatocellular carcinoma HCCLM3 cells

Objective:To investigate the effects LASS2 gene on the metastasis of human hepatocellular carcinoma cell line,HCCLM3.Methods: The expression level of LASS2 mRNA in HCCLM3 cells was analyzed by northern blotting in high metastatic HCCLM3 cells and in low metastatic MHCC97-L cells.The eukaryotic expression vector pCMV-HA2-LASS2 was constructed and transfected into HCCLM3 cells.The stable clone with LASS2 overexpression was selected by G418 screening.The metastatic ability of HCCLM3 cells such as migration and invasion was observed in vitro after LASS2 overexpression.The synthesis,secretion,and activation of matrix metaloproteinase-2(MMP-2) were examined by western blotting,zymography,and in situ zymography.Results: Northern blot analysis showed that the level of LASS2 mRNA decreased in HCCLM3 cells compared with MHCC97-L cells.LASS2 overexpression inhibited the ability of migration and invasion of HCCLM3 cells(P<0.001).The synthesis of MMP-2 was not different but the secretion and activation of MMP-2 were down-regulated in HCCLM3 cells after LASS2 overexpression.Conclusion: Overexpression of LASS2 down-regulated the secretion and activation of MMP-2 in HCCLM3 cells and inhibited the cell ability of migration and invasion indicating that LASS2 gene had inhibitory effects on the metastasis of HCCLM3 cells.