STAUROSPORINE INHIBITS THE PROLIFERATION, ALTERS THE CELL-CYCLE DISTRIBUTION AND INDUCES APOPTOSIS IN HT-29 HUMAN COLON ADENOCARCINOMA CELLS

Staurosporine (ST), a potent inhibitor of protein kinase C (PKC), was evaluated for its effect on the proliferation of HT-29 colon adenocarc inoma cells; PKC is associated with increased colon cell proliferation . ST inhibited cell proliferation in a time- and concentration-depende nt manner by up to 90%. It also blocked the G(2)/M phase of the cell c ycle and induced classical apoptosis (sub-diploid peak on Bow cytometr y, DNA ladder, and typical morphological changes). The kinetics of the se changes suggest that low ST concentrations (2-20 nM) may act via a different mechanism from higher (100-1000 nM) ones. The role of ST, wh ich is currently evaluated as an antitumor agent, in colon cancer requ ires further evaluation.