Calcium/calmodulin-dependent kinase inhibitor induces growth inhibition, cell cycle arrest, and apoptosis in human choriocarcinoma cells

Abstract

KN-93, a membrane-permeant calcium/calmod-ulin-dependent kinase-selective inhibitor, induces apopto-sis in some lines of human tumor cells. We investigated the effect of KN-93in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentra-tions of KN-93, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. A WST-1 assay showed that BeWo cells were sensitive to the growth inhibitory effect of KN-93. Cell cycle analysis indicated that exposure to KN-93 decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine, by the loss of mito-chondrial transmembrane potential, and by antibodies directed against histones from fragmented DNA. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phe-notype, and apoptosis. These results suggest that KN-93 may serve as a therapeutic agent for the treatment of choriocarcinoma.