Chemoresistance of hepatoma side population and its mechanism

Objective To explore the effect and the mechanism of side population of hepatoma cell line Li-7 in chemoresistance. Methods Side population and main population cells were sorted by flow cytometer. MTS based Doxombicin resistant assay and ABCG2/BCRP expression assay were performed to show the chemoresistance of side population cells. The modulation of side population phenotype and its chemoresistance by Akt signaling were analyzed through the effects of PI3K inhibitor LY294002. Results (2.07±0.22) % cells in Li-7 cell line were side population. They survived better than main population cells with the treatment of Doxorubicin. The absorbance was (0.33±0.06 vs 0.05 +0.02 ,P<0.05) at day 9 and (0.58±0.09 vs 0.04±0.02, P<0.01 ) at day 12. The ABCG2/BCRP expression was higher in side population, and the fluorescence intensity was (212.72±21.01 vs 96.36±18.36, P<0.05). With the treatment of LY294002, the side population percentage was decreased to (0.96±0.21)%, and their chemoresistance of Doxorubicin partly disappeared. The cells viability was decreased from (64.93±6.96)% to (38.73±5.25)% ,P<0.01. Conclusion Side population cells contained higher ability of chemoresis-tance, which might be closely related to Akt signaling. Key words: Carcinoma,hepatocellular; Multidrug resistance; Mechanism