The Effect Of Integrin Expression And MLCK Bioactivity On Hepatoma Cells' Adhesion And Migration

Constant cell morphological deformation, unstable adhesion, increased migration rate and frequently changed migration direction are the characteristics of the invasion and metastasis of tumor cells in culture. Integrin and MLCK are two key proteins involved in the process of tumor cell invasion and metastasis. The former regulates cell adhesion and the latter drives the cells to migrate. Therefore in order to better understand the mechanism of tumor cell invasion and metastasis; it is very important to clarify the roles of integrin and MLCK in the adhesion and migration of tumor cells.Object By studying the effect of the imbalance of integrin receptor-ligand on tumor cell adhesion and the influence of ML-7, an inhibitor of MLCK, on the proliferation and migration of hepatoma cells, the mechanism of the invasion and metastasis of hepatoma cells were explored.Methods Using microscopic morphological observation, image analysis, a micropipette aspiration technique and flow cytometer experimentation, the integrin expression, adhesion force and the migration of normal hepatic cells and hepatoma cells cultured on glass or Fn coated surfaces were measured and analyzed.Utilizing the techniques of cell synchronization, immunofluescence and immunohistochemistry to study the effects of ML-7 on the proliferation, cytoskeleton structure and locomotory translocation of hepatoma cells.Results hepatoma cells' integrin expression is higher than hepatic cells; Fn could down-regulate the over-expression of integrin; Upon addition of Fn in a concentration of 2.3μg/ml, the integrin expression decreased to approximately the level for hepatic cells, while the adhesion forces increased and the migration rate decreased for the hepatoma cells; With the increase of ML-7 concentration, restrained cell proliferation; hepatoma cells changed from erose to round; MLCK expression weakened with distribution from the peripheral of membrane to cytoplasm; cytoskeleton disassembled, stress fiber slacked migration rate reduced.Conclusion Fn could down-regulate the over-expression of integrin and the integrin receptor/ligand ratio is one of the key factor for the adhesion and migration of hepatoma cells. Cell morphological deformation and cytoskeleton disassembly interrelated to the degree of inhibite MLCK bioactivity; the lower concentration of ML-7 ( 6μM) could reduced hepatoma cell proliferation and migration when cytoskeleton is kept intact.