Effects of kinase insert domain receptor (KDR) gene silencing on the sensitivity of A549 cells to erlotinib.

We investigated the effects of kinase insert domain receptor (KDR) gene silencing on the proliferation of A549 cells and their sensitivity to erlotinib. A KDR small interfering RNA (siRNA) sequence was designed and synthesized; then, it was transfected into A549 cells using Lipofectamine(TM) 2000. KDR mRNA and protein expression after KDR gene silencing was detected by reverse transcription polymerase chain reaction and western blotting; the A549 cell cycle was detected by flow cytometry. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and colony formation assay were performed to determine the sensitivity of A549 cells to erlotinib after KDR gene silencing. After 48h of KDR gene silencing, there was a significant decrease in KDR gene and protein expression (P < 0.05). The A549 cell cycle was arrested at the G0/G1 phase, and the number of cells in the S phase decreased; the difference was statistically significant (P < 0.05). In the KDR gene silencing group, the sensitivity of A549 cells to erlotinib was significantly enhanced (P < 0.05). KDR siRNA can significantly silence the KDR gene in A549 cells, inhibit the proliferation of A549 cells, and enhance their sensitivity to erlotinib.