Targeted silencing of CXCR2 via small interference RNA for inhibition of liver carcinoma cells proliferation

Objective To investigate the inhibitory effect of siRNA-CXCR2 on in vitro proliferation of hepatocellular carcinoma.Methods CXCR2-siRNA plasmid was transfected by using the liposome technique into hepG2,the hepatocellular carcinoma cells,for the determination of fluorescence under fluorescence microscope at hour 24.The expression of CXCR2 mRNA and protein in the Chang cells derived from normal liver tissues,untransfected hepG2 cells and the hepG2 cells transfected with siRNA-CXCR2 was detected by reverse transcriptase polymerase chain reaction and Western blotting at hours 24,48 and 72,respectively.The CCK8 technique was,by using the untransfected hepG2 cells as control,employed to examine the proliferation of hepG2 cells transfected with CXCR2-siRNA at hours 24,48 and 72.The invasive capacity of the transfected hepG2 cells at hour 24 following transfection and following incubation in a Transwell chamber was assessed respectively compared with hepG2 cells.Results Following transfection,there was a preponderance of green fluorescence (80％) in hepG2 cells at hour 24 under fluorescent microscope and the transfected rate was 80％.Compared with Chang cells,the transfected hepG2 cells yielded a higher levels of CXCR2 mRNA and protein expression (1.69±0.22 vs 0.63 ±0.31 for mRNA and 1.93±0.25 vs 0.84±0.29 for protein,both P＜0.05).Compared with untransfected hepG2 cells,the transfected cells were associated with a reduced level of CXCR2 mRNA expression at hours 24 and 48 (0.75±0.24 and 0.83±0.21 vs 1.78±0.25,both P＜0.05).This held true even at hour 72,however,the level of which was not statistically different from that of untransfected cells (1.35 ±0.18 vs 1.78 ±0.25,P＞0.05).The transfected cells were,compared with untransfected cells,linked to lower level of CXCR2 protein expression at hours 24 and 48 (0.91±0.25 and 1.16±0.23 vs 1.98±0.31,P＜0.05).Despite that there was an increase in CXCR2 protein expression at hour 72,which was not markedly different from that of untransfected cells (1.71 ±0.18 vs 1.98±0.31,P＞0.05).Furthermore,there was no statistically significant difference in the mRNA and protein expression in the transfected hepG2 cells at hours 24,48 and 72.However,transfection with CXCR2-siRNA resulted in inhibition of hepG2 cell proliferation at hours 24,48 and 72 compared with untransfected cells (all P＜0.05).In addition,compared with untransfected cells,the transfeeted cells yielded a markedly attenuated capacity of invasion to the Transwell chamber [(36±5)/HP(×200) vs (526±9)/HP(×200),P＜ 0.05].Conclusion Silencing of CXCR2 genes with siRNA effectively inhibits proliferation of hepatocellular carcinoma cells. Key words: RNA, small interfering;  Receptors, interleukin-8B;  Liver neoplasms,experimental;  Gene silencing