Aikebaier Maimaiti, Amier Aili, Hureshitanmu Kuerban and Xuejun Li* Pages 255 - 262 ( 8 )
Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated.
Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods.
Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.
Gallic acid, apoptosis, voltage-dependent anion-selective channel protein 1(VDAC1), two dimensional gel electrophoresis, mass spectrography, RNAi.
Uyghur Medicine Hospital of Akesu Prefecture 843000, Uyghur Medicine Hospital of Akesu Prefecture 843000, Uyghur Medicine Hospital of Akesu Prefecture 843000, State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center and Beijing Key Laboratory of Tumor Systems Biology, Peking University, Beijing 100191