Beclin1 enhances cisplatin-induced apoptosis via Bcl-2 modulated autophagy in laryngeal carcinoma cells Hep-2

Mi Yang, Xin-Ming Yang, Dan-Hui Yin, Qing-Lai Tang, Lin Wang, Chao Huang, Ping Li,  Shi-Sheng Li

Abstract:

To investigate the role of Beclin1 in cisplatin-induced apoptosis in laryngeal carcinoma cells Hep-2 and to explore the potential mechanism. We up-regulated Beclin1 expression in Hep-2 cells. The survival rate and apoptotic rate were evaluated by MTT and flow cytometry (FCM). The Beclin1 overexpression group and the control group were treated with cisplatin for 24 hours. The proliferation and cell apoptosis of laryngeal cancer cell lines were evaluated. The mitochondrial membrane potentials were detected by DiOC6(3). Activities of Caspase-8/9/3 and convention of microtubule-associated protein one light chain 3 (LC3) were detected by western blot. The effect of Bcl-2 overexpression on increased cisplatin-sensitivity and autophagy induced by Beclin1 was investigated using Bcl-2 cDNA transfection. Expression of Beclin1 in Hep-2 cells was meaningfully enhanced by transfection, and the proliferation and the apoptosis were not considerably affected. By cisplatin treatment, the Beclin1 overexpression group showed lower survival rate and higher apoptotic rate than the control group (p<0.05). Decrease of mitochondrial membrane potential and increase of activities of Caspase-8, Caspase-9 and Caspase-3 were detected. Beclin1 overexpression increases the convention of LC3, especially after the cisplatin treatment. Overexpres¬sion of Bcl-2 decreased the cisplatin-induced apoptosis and inhibited Beclin1-induced autophagy. In conclusion, Beclin1 enhances cisplatin-induced apoptosis in laryngeal carcinoma cells Hep-2 via Bcl-2 modulated autophagy.