Knockdown of prohibitin 2 promotes apoptosis in non-small cell lung cancer cell line A549

Abstract

Objective To explore mechanism of prohibitin 2(PHB2) inhibition on the apoptosis of non-small cell lung cancer cell line A549. Methods For stable knockdown of PHB2, A549 strain was infected with lentiviruses. A549 cells with PHB2 depletion were incubated with Mdivi-1(DRP1 inhibitor). Apoptotic index of A549 cells was evaluated by TUNEL and annexin V-FITC/PI. Mitochondrial morphology was visualized by MitoTracker. ATP content, citrate synthase activity and the level of cytochrome c in cytosolic and mitochondrial fractions were analyzed by commercially available kits. Western blot was used to measure the levels of PHB2, DRP1 and p-DRP1 protein expression. Results Compared with the shCtrl group, the apoptosis of A549 cells increased significantly (P＜0.05) with up-regulated DRP1-dependent mitochondrial fission (P＜0.05), down-regulated ATP content (P＜0.05) and citrate synthase activity (P＜0.05). The level of cytochrome C was decreased in mitochondrial fractions (P＜0.05). Compared with the shPHB2 group, the apoptosis of A549 cells decreased significantly (P＜0.05) with alleviated DRP1-dependent mitochondrial fission (P＜0.05), increase of ATP content (P＜0.05) and citrate synthase activity(P＜0.05). The level of cytochrome C was increased in mitochondrial fractions (P＜0.05) in the shPHB2+Mdivi-1 group. Conclusions PHB2 inhibition can significantly enhance the apoptosis rate of A549 cells, potentially through promoting DRP1-dependent mitochondrial fission.

Keywords

• prohibitin 2(phb2)|mitochondrial fission|non-small cell lung cancer|dynamin-related protein 1(drp1)|apoptosis