Effects of RNAi targeting survivin gene on A549 cell radiosensitivity

Objective To construct the RNAi vector targeting survivin gene, in order to observe its effect on lung adenoearcinoma A549 cell radiosensitivity, and explore the possible mechanism. Methods One pair of RNA interference sequence targeting survivin gene was designed according to the eDNA sequence, the recombinant RNAi plasmid pGenesil2-survivin was constructed. After certified by enzyme digestion and sequencing, the pGenesil2-survivin plasmid was transfected into A549 cells. Survivin mRNA and protein was measured by RT-PCR and Western blot, respectively. The apoptosis was analyzed with flow cytometry. The radiosensitivity was measured by clone formation assay. Results The pGenesil2-survivin vector was successfully established. After the pGenesil2-survivin was transfeeted into A549 cells for 48 h, surviving protein and mRNA in pGenesil2 group were not obviously changed compared with that in normal group. They were increased after 5 Gy X-ray irradiation, but obviously inhibited in pGenesil2-survivin group. The cell apoptosis in pGenesil2-survivin and 5 Gy X-ray groups was obviously increased (t1 = 10.63, P < 0.001 ; t2 = 3.75 , P < 0.05), the effect was more manifest in combined group(t = 4.83, P < 0.05). D0 and Dq in normal and pC, enesil2 group were not obviously different, but those in pGenesil2-survivin group were lower. Conclusions RNAi targeting survivin gene could inhibit survivin mRNA and protein expression, enhance the A549 cell apoptosis rate and cell radiosensitivity. Key words: RNAi;  Survivin;  Apoptosis ;  Radiosensitivity