Zhang Guangxian, Zeng Xiancheng, Zhang Ren, Liu Juan, Zhang Weici, Zhao Yujun, Zhang Xiaoyuan, Wu Zhixue, Tan Yuhui, Wu Yingya, Du Biaoyan
School of Fundamental Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
Department of General Surgery, The Second People's Hospital of Guangdong Province, Guangzhou 510317, China.
Phytomedicine. 2016 Nov 15;23(12):1329-1336. doi: 10.1016/j.phymed.2016.07.003. Epub 2016 Jul 5.
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.
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.
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.
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.
肝细胞癌（HCC）是最常被诊断出的肝脏恶性肿瘤，常发生于慢性肝损伤背景下。尽管有多种治疗方法可用，但HCC患者的预后仍然很差。薯蓣皂苷是一种存在于多种植物中的天然甾体皂苷。其抗癌和抗纤维化作用已被广泛报道。然而，薯蓣皂苷对HCC的影响仍不清楚。我们旨在研究薯蓣皂苷在体外和体内的抗HCC特性。
采用MTT（3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑）法分析薯蓣皂苷对人细胞系Bel-7402、HepG2、Lovo和EAhy926的生长抑制活性。通过使用膜联蛋白-V和碘化丙啶（PI）染色的流式细胞术、用Hochest33342和PI标记的激光扫描共聚焦显微镜（LSCM）分析以及DNA片段化分析来评估通过诱导凋亡的抗肿瘤活性。通过蛋白质印迹法检测凋亡相关蛋白肿瘤蛋白p53（TP53）、BCL2相关X蛋白（BAX）、B细胞淋巴瘤/白血病-2（BCL2）和半胱天冬酶3（CASP3）的表达。对携带Bel-7402的裸鼠腹腔注射不同剂量的薯蓣皂苷，并以5-氟尿嘧啶（5-FU）治疗作为对照。然后测量每只小鼠的肿瘤体积和肿瘤重量。
我们证明薯蓣皂苷以剂量依赖性方式抑制HCC细胞系的增殖。薯蓣皂苷还显著诱导Bel-7402细胞凋亡死亡过程中的形态变化并增加其DNA损伤。此外，我们证明薯蓣皂苷通过上调Bel-7402细胞中TP53、BAX和CASP3蛋白的表达以及下调BCL2来发挥抗癌活性。值得注意的是，进一步评估了薯蓣皂苷的体内抗癌活性，在携带Bel-7402细胞的裸鼠中，当浓度增加到24mg/kg/天时，其抑制效率比10mg/kg/天剂量的5-FU更高。
薯蓣皂苷通过诱导凋亡抑制肿瘤生长，这伴随着凋亡途径蛋白如TP53、BAX、BCL2和CASP3表达的改变。我们的研究结果表明有必要进一步评估薯蓣皂苷作为HCC的一种新型治疗方法。
