Matrine-induced autophagy counteracts cell apoptosis via the ERK signaling pathway in osteosarcoma cells

Abstract

Abstract. The aim of the present study was to observe whether autophagy was induced by matrine, and to investigate the role of autophagy in the antitumor effects of matrine on human osteosarcoma MG-63 cells and its underlying mechanism. MG-63 cells were cultured in vitro in matrine at a concentration of 0.6, 0.8, 1.0 and 1.2 g/l for 0, 24, 48 and 72 h. A MTT assay was used to evaluate the proliferation inhibition of MG-63 cells by matrine, and Annexin V-fluorescein isothiocyanate/propidum iodide (PI) staining flow cytometry was used to analyze the apoptotic rate. Alterations in cell morphology was assessed by PI and Hoechst 33258 cell staining. Matrine-induced autophagy in MG-63 cells was confirmed by green fluorescent protein-microtubule-associated protein 1-light chain 3 (LC3) b transfection and fluorescence microscopy, and cell viability was investigated by MTT assay following inhibition of autophagy by chloroquine (CQ) pretreatment. The expression level of apoptosis-associated proteins B-cell lymphoma-2 (Bcl-2) and Bcl-2-like protein 4 (Bax), autophagy-associated LC3II protein, and the activation of extracellular signal-regulated kinase (ERK) was detected by western blotting. Cell proliferation was clearly inhibited by matrine in a dose-and time-dependent manner. Flow cytometry and Hoechst 33258/PI staining verified that matrine induced apoptosis in a time-dependent manner when cells were exposed to 1.1 g/l matrine; fluorescence microscopy demonstrated that green fluorescence puncta were enhanced with prolonged time of matrine incubation. Western blotting confirmed that the expression of pro-apoptosis-associated proteins Bax and LC3II, and phosphorylated-ERK were upregulated, and anti-apoptosis protein Bcl-2 was downregulated in a time-dependent manner following treatment with matrine.The cell viability of the matrine + CQ group was increased compared with the matrine group alone, which revealed that matrine treatment alone induced protective autophagy in MG-63 cells. In addiiton, expression of LC3II/LC3I decreased and the expression of BAX/Bcl-2 increased in the matrine + U0126 group compared with the matrine alone group. The present study demonstrated, to the best of our knowledge, for the first time that matrine induced protective autophagy via ERK activation in MG-63 cells, and matrine combined treatment with CQ or U0126 led to an increase in apoptosis in osteosarcoma cells.

Metformin relieves neuropathic pain after spinal nerve ligation via autophagy flux stimulation

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Matrine inhibits the metastatic properties of human cervical cancer cells via downregulating the p38 signaling pathway

“…Matrine exhibits a wide range of pharmacological effects and has long been applied to treat viral hepatitis (6), neuropathic pain (7), isoproterenol-induced cardiotoxicity inflammatory and other diseases (8,9). In addition, increasing evidence has revealed that matrine displays anticancer effects in various cancers, such as gastric (10), rhabdomyosarcoma (11), acute myeloid leukemia (12), osteosarcoma (13), prostate (14), breast (15) and lung cancer (16). Moreover, the antitumor mechanisms of matrine have been demonstrated to involve the blockade of cell cycle progression, the induction of apoptosis, the regulation of oncogene expression, the inhibition of cytokine production and the modulation of signaling pathways (17)(18)(19).…”

Matrine inhibits cell proliferation and induces apoptosis of human rhabdomyosarcoma cells via downregulation of the extracellular signal-regulated kinase pathway

“…Recent studies showed that it has antitumor activity in various cancers such as, hepatocellular carcinoma (12), breast cancer (13), osteosarcoma (14), and RMS (15). Intensive studies confirmed the anti-tumor mechanisms of matrine, including regulation of phosphorylation of proliferation-and apoptosis-related cell signaling molecules such as β-catenin, serine/threonine kinase (AKT), mammalian target of rapamycin (mTOR), and ERK (16).…”