Evodiamine induces apoptosis of human hepatoma cell line BEL-7402 by Hippo-YAP pathway / 中草药

ABSTRACT

Objective: To investigate the effects and the underlying mechanisms of evodiamine (EVO) on apoptosis of hepatocellular carcinoma (HCC) BEL-7402 cells. Methods: Cell counting kit-8 (CCK-8) assay was used to detect the effect of EVO on proliferation activity of BEL-7402 cells. Hoechst 33258 staining was used for observing morphological changes of apoptosis. The cell apoptosis and cycle distribution were analyzed by flow cytometry. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay were used to detect the expression levels of key genes from Hippo-YAP pathway in HL-7702 and BEL-7402 cells, including mammalian STE20-like protein kinase 1/2 (MST1/2), large tumor suppressor 1 (LATS1), and Yes-associated protein (YAP), then to examine the effect of EVO on the expression levels of these genes in BEL-7402 cells. The effect of EVO on the expression of YAP in hepatocellular carcinoma BEL-7402 cells was observed by immunofluorescence assay. Results: The proliferation of BEL-7402 cells were significantly inhibited by EVO in a dose- and time-dependent manners. Hoechst 33258 staining showed that EVO induced BEL-7402 cell typical apoptotic morphology, such as nuclear chromatin concentration and edge accumulation. Besides, flow cytometry tests showed that BEL-7402 cell apotosis were increased and cell cycle arrested in G2/M phase after being treated with EVO (P < 0.01). qRT-PCR and Western blotting showed that the expression level of MST2 and LATS1 were lower in BEL-7402 cell (P < 0.05), while the transcription and protein levels of YAP were significantly higher (P < 0.05). EVO could activate Hippo signal pathway, upregulate the expression of MST2 and LATS1 and then inhibit the expression of YAP in BEL-7402 cell (P < 0.05). Immunofluorescence assay also validated that EVO would significantly inhibit the overexpression of YAP in BEL-7402 cell (P < 0.01). Conclusion: EVO can induce the apoptosis of BEL-7402 cells, which may be through activating Hippo signal pathway and then down-regulate the expression of YAP.