Myosin light chain kinase inhibitor, ML-7, suppressed cholangiocarcinoma cell survival but not cell invasion and matrix metalloproteinase-2 secretion

Abstract

Myosin regulatory light chain (MRLC) regulated myosin activity which underlies various activities of the cells including migration invasion and survival of cells. The function of MRLC is activated by phosphorylation catalyzed by myosin light chain kinase (MLCK). In this study, the role of MRLC in cholangiocarcinoma cells was investigated by inhibiting the MRLC activity using myosin light chain kinase, ML-7, a MLCK inhibitor. ML-7 reduced MRLC phosphorylation dose dependently, correlating with suppression of cell viability as determined by MYY assay. However, ML-7 was not significantly reduction of invasiveness and MMP-2 gelatinase activity at sub-toxic dosage. These data indicate that MRLC activity is vital to cell viability but not significantly reduce the metastatic properties in cholangiocarcinoma cells.