ABSTRACT
Objective To investigate the inducing effect of acitrotin on the growth and apoptosis of human cutaneous squamous cell carcinoma cell line SCC13 and on caspases expression.Methods Human cutaneous squa-mous cell carcinoma cell line SCC13 was treated with five different concentrations of acitrefin [5×10-7,1×10-6,5×10-6,1×10-5,5×10-5mol/L].Cell proliferation was evaluated by MTT assay.Apoptosis was assessed by en-zyme-linked immunosorbent assay.The cell cycle was assessed by flow cytometry.The protein expressions of caspase-8 and caspase-9 were examined with Western blot.Results Acitretin inhibited the growth ( F = 83.64,96.34 and 123.17, respectively on the first, third and fifth day)and induced the apoptosis of SCC13 cells(F=74.45,107.37,and 64.28, respectively on the first, third and fifth day) in a dose- and time-dependent manner(P<0.05).Acitretin altered cell cycle distribution of SCC13 cells as compared with controls, the G1-phase population increased by 77.66% 72 hours after acitretin treatment, while the control increased only by 63.55%.An active fragment of caspase-8 occurred following 12 hours treatment of acitretin on SCC13 cells, whereas the caspase-9 active fragment occurred 24 hours after acitretin treatment, which increased time-dependently (P<0.01).Conclusion Acitretin plays an important role on the growth inhibition and apoptosis of cutaneous squamous cell carcinoma cells, which may be affected through both Fas receptor way and mitochondria way.