Guangxian Zhang1, Xiancheng Zeng2, Ren Zhang1, Juan Liu1, Weici Zhang3, Yujun Zhao2, Xiaoyuan Zhang1, Zhixue Wu1, Yuhui Tan1, Yingya Wu1, Biaoyan Du4. 1. School of Fundamental Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. 2. Department of General Surgery, The Second People's Hospital of Guangdong Province, Guangzhou 510317, China. 3. Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California Davis, School of Medicine, Davis, CA 95616, USA. 4. School of Fundamental Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China. Electronic address: dubiaoyan@gzucm.edu.cn.
Abstract
BACKGROUND: Hepatocellular carcinoma (HCC) is the most commonly diagnosed malignancy of the liver, occurs frequently in the setting of chronic liver injury. Although multiple therapeutic approaches are available, the prognosis of patients with HCC remains poor. Dioscin is a natural steroid saponin that presents in various plants. The anti-cancer and anti-fibrotic effects have been extensively reported. However, the effect of dioscin on HCC remains unclear. We aimed to investigate the anti-HCC properties of dioscin in vitro and in vivo. METHODS: MTT (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide) assay was used to analyze the growth inhibition activity of Dioscin in human cell lines, Bel-7402, HepG2, Lovo, and EAhy926. Antitumor activity through induction of apoptosis was evaluated by flow cytometry using Annexin-V and propidium iodide (PI) staining, laser scanning confocal microscopy (LSCM) analysis with Hochest33342 and PI labeling, and DNA fragmentation analysis. The expression of apoptosis-related proteins tumor protein p53 (TP53), BCL2-associated X protein (BAX), B-Cell CLL/Lymphoma 2 (BCL2) and Caspase 3 (CASP3) was measured by Western blot. Nude mice bearing Bel-7402 were administered intraperitoneally at different doses of dioscin and 5-FU (5-Fluorouracil) treatment was used as a control. Tumor volume and tumor weight of each mouse were then measured. RESULTS: We demonstrated that Dioscin inhibited proliferation of HCC cell lines in a dose-dependent manner. Dioscin also significantly induced morphological changes during death by apoptosis and increased DNA damage of Bel-7402 cells. Moreover, we demonstrated that Dioscin displayed anticancer activity via up-regulating expression of TP53, BAX and CASP3 protein, as well as down-regulating BCL2 in Bel-7402 cells. Notably, the in vivo anticancer activity of Dioscin was further assessed and achieved greater inhibition efficiency at the concentration increased to 24mg/kg/day than 5-FU at dose of 10mg/kg/day in nude mice bearing Bel-7402 cells. CONCLUSIONS: Dioscin inhibited tumor growth via inducing apoptosis, which was accompanied by altered expression of apoptotic pathway proteins, such as TP53, BAX, BCL2 and CASP3. Our findings indicate that further evaluation of dioscin as a novel therapeutic approach for HCC is warranted.
BACKGROUND:Hepatocellular carcinoma (HCC) is the most commonly diagnosed malignancy of the liver, occurs frequently in the setting of chronic liver injury. Although multiple therapeutic approaches are available, the prognosis of patients with HCC remains poor. Dioscin is a natural steroidsaponin that presents in various plants. The anti-cancer and anti-fibrotic effects have been extensively reported. However, the effect of dioscin on HCC remains unclear. We aimed to investigate the anti-HCC properties of dioscin in vitro and in vivo. METHODS:MTT (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide) assay was used to analyze the growth inhibition activity of Dioscin in human cell lines, Bel-7402, HepG2, Lovo, and EAhy926. Antitumor activity through induction of apoptosis was evaluated by flow cytometry using Annexin-V and propidium iodide (PI) staining, laser scanning confocal microscopy (LSCM) analysis with Hochest33342 and PI labeling, and DNA fragmentation analysis. The expression of apoptosis-related proteins tumor protein p53 (TP53), BCL2-associated X protein (BAX), B-Cell CLL/Lymphoma 2 (BCL2) and Caspase 3 (CASP3) was measured by Western blot. Nude mice bearing Bel-7402 were administered intraperitoneally at different doses of dioscin and 5-FU (5-Fluorouracil) treatment was used as a control. Tumor volume and tumor weight of each mouse were then measured. RESULTS: We demonstrated that Dioscin inhibited proliferation of HCC cell lines in a dose-dependent manner. Dioscin also significantly induced morphological changes during death by apoptosis and increased DNA damage of Bel-7402 cells. Moreover, we demonstrated that Dioscin displayed anticancer activity via up-regulating expression of TP53, BAX and CASP3 protein, as well as down-regulating BCL2 in Bel-7402 cells. Notably, the in vivo anticancer activity of Dioscin was further assessed and achieved greater inhibition efficiency at the concentration increased to 24mg/kg/day than 5-FU at dose of 10mg/kg/day in nude mice bearing Bel-7402 cells. CONCLUSIONS:Dioscin inhibited tumor growth via inducing apoptosis, which was accompanied by altered expression of apoptotic pathway proteins, such as TP53, BAX, BCL2 and CASP3. Our findings indicate that further evaluation of dioscin as a novel therapeutic approach for HCC is warranted.