层黏连蛋白与其α6整合素受体对人肝癌细胞表型的调控作用

目的 利用自制的抗整合素α6亚基胞外区的单克隆抗体(IA6ED McAb)研究人肝癌细胞表面α6整合素胞外区对人肝癌细胞系BEL-7402黏附、铺展的影响以及在控制细胞增殖与分化中的作用。方法 以层黏连蛋白(LN)、纤黏连蛋白(FN)、Matrigel分别作为细胞外基质,检测IA6ED McAb对人肝癌细胞系BEL-7402细胞在不同基质上的黏附、铺展的影响;以MTT法检测McAh对BEL-7402细胞存活或增殖的影响;以明胶酶谱法检测McAb对BEL-7402细胞分泌基质金属蛋白酶(MMPs)的影响;以微粒子免疫吸附法检测对AFP分泌的影响。结果 LN可以明显促进BEL-7402细胞AFP及MMPs的分泌;IA6ED McAb的封阻不但可以特异性抑制BEL-7402细胞在LN上的黏附及铺展,而且对BEL-7402细胞以LN为基质的存活或增殖、去分化及异常分化表型有非常显著的抑制作用。结论 人肝癌BEL-7402细胞的增殖、分化表型受LN及整合素α6的调节。人肝癌组织细胞外基质成分中LN及细胞表面整合素α6的过表达,可以增强肝癌细胞的去分化及异常分化表型;而用IA6ED McAb阻断IN与肝癌细胞表面α6β1整合素受体的相互作用,可以逆转其去分化及异常分化表型,从而可能降低癌细胞的转移潜能。

Laminin and its alpha 6 integrin receptor in the regulation of human hepatocellular carcinoma cell phenotypes

Objective To study the role of integrin a6 in cell attachment, spread, survival/proliferation and differentiation of human hepatocellular carcinoma (HCC) BEL-7402 cells on various substrates by monoclonal antibody against the extracellular domain of a6 subunit (IA6ED McAb). Methods The effect of McAb on attachment and spread of BEL-7402 cells on LN or FN substrate was examined. MTT analysis was used to examine the cell survival/proliferation, gelatin zymography to the matrix metalloproteinases (MMPs) secreted by BEL-7402 cells, and micropartical immunoabsorbant kit to AFP secretion while the cells were cultured on LN-,FN- or Matrigel-coated substrates. Results The cell attachment, spread and survival/proliferation were inhibited. Moreover importantly, the malignant cell dedifferentiation and abnormal differentiation on LN-coated substrate were also strongly inhibited by IA6ED McAb. Conclusion LN and integrin a6 regulate human HCC cell phenotypes of survival/proliferation and differentiation. The phenotypes of dedifferentiation and abnormal differentiation can be reversed by blocking the interaction between integrin a6 and LN using IA6ED McAb, which may lower metastatic potency of tumor cells.