An Experimental Study On The Inhibitory Effect Of Docetaxel On SO-RB50 Cell

Objective:To evaluate the effects of different concentration of docetaxel for inhibiting human retinoblastoma SO-RB50 cells in vitro.To explore the combined application of doctaxel with carboplatin to these tumor cells.Methods:Cell cultivation and MTT method to evaluate the inhibition rates of proliferation of cells and IC₅₀,the 6 different concentration(0.001μg/ml to 100μg/ml 10 times increased).Analyze the change of cell cycle culured in docetaxel of different concentration(1/2IC₅₀μg/ml,IC₅₀μg/ml,2IC₅₀μg/ml)by flow cytometry.Determine apoptosis rate of these cells culured in doxetaxel by flow cytometry.To explore the combined application of docetaxel with carboplatin to SO-RB50 cells.The research were divided into 5groups:Doc(1μg/ml)+Car(5μg/ml);Doc (1μg/m)+ Car(10μg/ml);Doc(1μg/ml)+Car(20μg/ml);Doc(0.5μg/ml) +Car(10μg/ml);Doc(2μg/m)+ Car(10μg/ml).MTT method was used to observe the growth inhibition of SO-RB50 cells in each group.Results:Docetaxel can inhibit SO-RB50 cells obviously(P＜0.01).The IC₅₀of docetaxel in 24H,48H,72H is 1.102μg/ml,5.113μg/ml,1.088μg/ml.SO-RB50 cells are blocked in the phase of G₂/M(P＜0.01)by flow cytometry., the effect reach peak in 24H,after it the cell number of Go and S phase grow up gradually.The different concentration of docetaxel can induce the SO-RB50 cell to apoptosis(P＜0.01)by flow cytometry as follow.The apoptosis rates of docetacel (0.5μg/ml)at 24H,48H,72H are 3.54%±1.55%,30.03%±1.12%,51.60%±1.43%. The apoptosis rates of docetacel(1μg/ml)at 24H,48H 72H are 3.57%±1.30%. 38.22%±1.79%,59.45%±1.28%.The apoptosis rates of docetacel(1μg/ml)at24H,48H,72H are27.00%±1.75%,64.00%±0.88%,63.20%±1.35%.The typical apoptotic cells and apoptotic body were seen under the electron microscope.The condition of SO-RB50 cells cultured with chemotherapy drug become worse with the time lasted,under the fluoroscope.Docetaxel combined with carboplatin enhance sensitivity of the two use alone (P＜0.01),by MTT assay.The group[Doc(0.5μg/ml)+Car(10μg/ml)]which use low dose got the highest inhibiting rate of these test groups at 24H,48H,72H (P＜0.01).ConclusionsDocetaxel alone has inhibitory effect on SO-RB50 cells,block the cell cycle in the G₂/M phase,induce the apoptosis.The higher the concentrations of docetaxel, the longer it last,the more significant the inhibitory effects it has.Doeetaxel combined with earboplatin,enhace the cell poison activity,reduce the use of the chemotherapy drug,boost sensitivity of docetaxel.