Effect of nanoparticles containing Bcl-xl small interference RNA on apoptosis of human lung adenocarcinoma cells

Objective To study the effect of nanoparticle-mediated Bcl-xl small interference RNA (siRNA) on apoptosis of human lung adenocarcinoma A549 cell. Methods Nanoparticles containing Bcl-xl siRNA was prepared. A549 cells were cultured in vitro. The Bcl-xl siRNA was transfected into cultured cells by nanopaticles. The cells were divided into 4 groups: saline group, nanoparticles group, siRNA-c-nanoparticles group and siRNA-nanoparticles group. The latter two groups were also divided into 0.1,0.2, 0.4,0.8μmol/L groups. Apoptosis changes after transfection was observed by TUNEL. Bcl-xl mRNA expression was assessed by RT-PCR, and Bcl-xl protein expression was measured by immunochemistry. Results After transfection with Bcl-xl siRNA, the apeptotic index of lung cancer cells were increased with concentrations [the apoptotic index in 0.1,0.2,0.4,0.8 μmol/L group were (19.7±2.6)%, (32.4±5.5)%, (46.0±5.3)% and (55.4±5.9)% respectively]. Compared with saline group, nanoparticles group, siRNA-c-nanoparticles group, was significantly different (P<0.05). At the concentration of 0.8 μmol/L, the expression level of Bcl-xl mRNA and protein reduced obviously. The positive unit of Bcl-xl protein expression decreased to 0.0787±0.0233, and the Bcl-xl mRNA to 0. 856±0.242, which were significantly different compared to other groups (P<0.05). Conelutions Bcl-xl siRNA is effectively transfected into cultured cells mediated by the nanopaticles. The Bcl-xl siRNA can specially down-regulate Bcl-xl mRNA and protein expression,inhibit the proliferation of tumor cells and induce cells apoptosis. Key words: RNA interference; Nanoparticles; Bcl-xl; Apoptosis; Lung neoplasms; Adenocarcinoma