α-Hederin Increases The Apoptosis Of Cisplatin-Resistant Gastric Cancer Cells By Activating Mitochondrial Pathway In Vivo And Vitro.

introductionGastric cancer remains an important cancer worldwide, and conventional chemotherapeutic drugs have the defects of drug resistance and cell toxicity. α-Hederin has been found to have certain therapeutic effects on various types of human cancers. However, studies on the α-hederin that exert biological activities on the cisplatin-resistant gastric cancer cells are limited. In this study, we evaluated the effects of α-hederin in HGC27/DDP and the potential mechanisms both in vivo and in vitro.

methodsHGC27/DDP cells were cultured in DMEM/F12 medium. Cell proliferation and viability were assessed quantitatively using Cell Counting Kit-8. Cell invasion and migration were detected by Transwell invasion assay and wound healing assay. Cell apoptosis was examined by employing Hoechst 33258 Staining Kit and an Annexin V-PE apoptosis kit. Intracellular GSH levels were examined by using a GSH Assay Kit. DCFH-DA and JC-1 Kit were used to detect levels of intracellular reactive oxygen species (ROS) and changes in mitochondrial membrane potential (∆Ψm). The protein levels of Apaf-1, AIF, Bax, Bcl-2, Cyt C, Survivin, cleaved caspase-3, cleaved caspase-9, MMP-9 and MMP-2 were detected by Western blot analysis. The effect of α-hederin in vivo was observed by xenograft tumor models in nude mice.

resultsThe α-hederin treatment significantly inhibited the proliferation in a dose- and time-dependent manner of HGC27/DDP and induced obvious apoptosis compared with the control group (P<0.05). Meanwhile, the ability of cells to invade and migrate was suppressed (P<0.05). The α-hederin induced the depletion of GSH (P<0.05) and the accumulation of intracellular ROS (P<0.05), changed the mitochondrial membrane potential (P<0.05), increased the Bax, Apaf-1, AIF, Cyt C, cleaved caspase-3 and cleaved caspase-9 expression and decreased the protein level of Bcl-2, survivin, MMP-9 and MMP-2 (P<0.05). Pretreatment with NAC (12 mM) enhanced the tendency and pretreatment with BSO (8 mM) attenuated the tendency above (P<0.05). Meanwhile, α-hederin inhibited xenograft tumor growth in vivo (P<0.05).

conclusionOur study provides strong molecular evidence to support our hypothesis that α-hederin inhibits the proliferation and induces the apoptosis of HGC27/DDP cells by increasing the levels of intracellular ROS and triggering mitochondrial pathway activation.