title: Blocking autophagic flux enhances matrine-induced apoptosis in human hepatoma cells.
abstract: Autophagy, a self-defense mechanism, has been found to be associated with drug resistance in hepatocellular carcinoma (HCC). Our study was designed to investigate the role and related mechanisms of autophagy in matrine-induced apoptosis in hepatoma cells of HepG2 and Bel7402. Cell apoptosis was detected by flow cytometry analysis (Annexin V-FITC/PI double-staining assay), the activity and activating cleavages of caspase-3, -8, and -9. MTT assay and colony forming assay were used to assess the effect of matrine on growth and proliferation of HCC cells. Autophagic flux in HCC cells was analyzed using the expression of LC3BI/II and p62/SQSTM1, GFP-LC3 transfection, and transmission electron microscopy. Moreover, regarding to the associated mechanisms, the effects of matrine on the phosphoinositide 3-kinase/AKT/mTOR pathway and beclin-1 were studied. Our results showed that: (1) both autophagy and apoptosis could be induced by treatment with matrine; (2) using the autophagic inhibitor chloroquine and beclin-1 small-interfering RNA, cell apoptosis induced by matrine could be enhanced in a caspase-dependent manner; and (3) autophagy was induced via inhibition of PI3K/AKT/mTOR pathway and up-regulation of beclin-1. In conclusion, inhibition of autophagy could enhance matrine-induced apoptosis in human hepatoma cells.
authors.affiliation: China-Japan Friendship Clinical Medicine College, Peking University Health Science Center, No.2 Yinghua East Road, Beijing 100029, China. yao_sk@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Gao
authors.forename: Shukun
authors.initials: S
authors.lastname: Yao
authors.forename: Bushan
authors.initials: B
authors.lastname: Xie
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000470:Alkaloids / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects*; D000071186:Beclin-1; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002738:Chloroquine / Q000633:toxicity; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D011807:Quinolizines / Q000633:toxicity*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D000071456:Sequestosome-1 Protein; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D000093842:Matrines
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000470:Alkaloids; D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; D020169:Caspases; D002738:Chloroquine; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D011807:Quinolizines; D034741:RNA, Small Interfering; D000071456:Sequestosome-1 Protein; D058570:TOR Serine-Threonine Kinases; D000093842:Matrines; C491997:BECN1 protein, human; C477012:MAP1LC3A protein, human; C099718:SQSTM1 protein, human; C546842:MTOR protein, human