title: The effect of tetrandrine combined with cisplatin on proliferation and apoptosis of A549/DDP cells and A549 cells.
abstract: BACKGROUND
  Non-small cell lung cancer comprises the majority of lung cancer cases and is insensitive to chemotherapy. Most patients develop drug resistance. Recently, tetrandrine (TET), a bis-benzylisoquinoline alkaloid, was identified as a novel anti-cancer agent. However, the effect of tetrandrine combined with cisplatin on lung cancer has not yet been studied. We aimed to identify a possible synergistic effect between tetrandrine and cisplatin, besides, to investigate the effects of TET in combination with DDP on proliferation and apoptosis in cisplatin-resistant and cisplatin-sensitive A549 cell lines, and to study the underlying mechanism.
  
  
  METHODS
  Cell viability was confirmed with CCK8 assays, and the IC50values for each treatment group were calculated. The synergistic interaction of these drugs was evaluated using an isobolographic analysis. Proliferation was assessed by EDU staining. Hoechst staining and flow cytometry were used to assess apoptosis. Apoptosis- and autophagy-associated proteins were analyzed by western blot. Transmission electron microscopy was used to detect autophagy, RFP-GFP-LC3 lentivirus was used to perform autophagic flux assay.
  
  
  RESULTS
  Tetrandrine and cisplatin exerted synergistic cytotoxic effects on both cisplatin-resistant and cisplatin-sensitive A549 cell lines. The combination of tetrandrine and cisplatin induced apoptosis and inhibited proliferation in a synergistic manner. The formation of autophagosomes was evident by transmission electron microscopy. The autophagic flux of combination treatment was increased.
  
  
  CONCLUSIONS
  Tetrandrine synergized with cisplatin to reduce the viability of cisplatin-resistant and cisplatin-sensitive A549 cells, tetrandrine could reverse the resistance of A549 cells to cisplatin. Tetrandrine combined with cisplatin could induce autophagy. Therefore, tetrandrine is a potent autophagy agonist and may be a promising drug for the treatment of non-small cell lung cancer.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Ye
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Song
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.|Department of Pharmacy, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Hua-E
authors.initials: HE
authors.lastname: Xu
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Xu
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Kong
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Zeng
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Xie
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
keywords: Apoptosis; Autophagy; Non-small cell lung cancer; Proliferation; Tetrandrine