Myosin light-chain kinase contributes to the proliferation and migration of breast cancer cells through cross-talk with activated ERK1/2

Myosin light-chain kinase (MLCK) plays a crucial role in the cell migration and tumor metastasis. Herein, we investigated the signaling pathways involved in MLCK using ML-7, a specific inhibitor of MLCK, in breast Cancer cell proliferation and migration. Our data showed that reduction of MLCK in breast Cancer cells mediated by 20 microM ML-7 was able to depress the cell proliferation and migration using two parallel cell lines (MCF-7 and LM-MCF/MDA-MB-231) with different metastatic abilities through reciprocal cross-talk with activated ERK1/2, in which both phosphorylated Myosin light chain (p-MLC) and cascades of beta-catenin, cyclin D1, Survivin, and c-Myc serve as essential downstream effectors.