Background & objective: Protein kinase C (PKC) has been considered to be a potentially suitable target for anticancer therapy. This study was designed to investigate the effect of PKC inhibitor staurosporine (ST) on the inhibition of proliferation, the induction of apoptosis, and the change of cell cycle in human gastric cancer cell lines MGC-803 and SGC-7901.
Methods: The inhibition rates of cell proliferation were evaluated by trypan blue exclusion. The apoptotic bodies were observed under light microscope and electron microscope. The apoptotic peaks of the cells and the changes of cell cycle were analyzed using flow cytometry.
Results: ST inhibited cell growth of MGC-803, IC(50) of 24 hours was 54 ng/ml and IC(50) of 48 hours was 23 ng/ml. ST inhibited cell growth of SGC-7901, IC(50) of 24 hours was 61 ng/ml and IC(50) of 48 hours was 37 ng/ml. MGC-803 cells were treated by ST at the concentrations of 40, 60, and 100 ng/ml for 24 hours, the percentages of G(0)/G(1) phage were 23.6+/-1.8%, 11.6+/-0.7%, and 3.3+/-0.2%, respectively (54.3+/-3.1% in control group); the percentages of G(2)/M phage were 22.6+/-4.0%, 35.5+/-0.4%, and 36.8+/-5.5%, respectively (13.5+/-0.2 in control group). SGC-7901 cells were treated by ST at the concentrations of 40, 60, and 100 ng/ml for 24 hours, the percentages of G(0)/G(1) phage were 27.1+/-1.4%, 17.0+/-3.4%, 13.7+/-0.7%, respectively (52.5+/-4.4% in control group); the percentages of G(2)/M were 21.9+/-2.6%, 39.5+/-4.9%, and 38.4+/-3.1%, respectively (13.5+/-2.2% in control roup). Compared with the control group, the percentages of G(0)/G(1) phage of two cell lines decreased and that of G(2)/M cells increased significantly in the ST treated group(P< 0.01). Treated by ST at the concentration of 200 ng/ml, the apoptotic peaks and typical apoptotic bodies were observed.
Conclusion: ST significantly inhibits the proliferation and induces apoptosis of MGC-803 cells and SGC-7901 cells; ST induces G(2)/M phase arrest.