title: [Metformin induces apoptosis in hepatocellular carcinoma Huh-7 cells in vitro and its mechanism].
abstract: OBJECTIVE
  to investigate the effects of antidiabetic drug metformin on proliferation and apoptosis in human hepatocellular carcinoma cell line Huh-7 cells.
  
  
  METHODS
  Huh-7 cells were treated with metformin at different concentrations. Cell viability was determined by MTT assay. Cell apoptosis and CD133(+) expression rate were detected by flow cytometery (FCM). Expressions of PTEN, Akt, p-Akt, Bcl-2, Bax proteins in the cells were measured by Western blot. The effect of metformin on the hepatosphere formation was observed in the serum-free suspension culture. Reverse transcription-polymerase chain reaction (RT-PCR) was used to validate the expression levels of stemness marker genes CD133, β-catenin, and ABCG2 mRNA in the hepatospheres.
  
  
  RESULTS
  The proliferation of Huh-7 cells was inhibited by metformin in a dose- and time-dependent manner. The early and late cell apoptosis rates induced by metformin at dose of 10 mmol/L for 48 hrs were (22.29 ± 0.8)% and (13.87 ± 1.2)%, respectively, and 25 mmol/L for 48 hrs (15.28 ± 2.1)% and (25.89 ± 2.3)%, respectively. Western blotting results revealed that the expression of CD133, phosphorylated Akt and the Bcl-2/Bax ratio were downregulated, and PTEN was upregulated in the Huh-7 cells after treated with 25 mmol/L metformin for 48 hrs. Metformin inhibited the formation of hepatospheres. Metformin also downregulated the expression of several cancer stem cells (CSCs)-related genes which are involved in the signaling pathways governing the self-renewal, proliferation and differentiation of CSCs in the hepatospheres.
  
  
  CONCLUSIONS
  Metformin inhibits the proliferation of human hepatocellular carcinoma Huh-7 cells and enhances their apoptosis in vitro. It may be related to the downregulation of PI3K/Akt signal pathway and selectively targeting CD133(+) cells.
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Xiamen University, Xiamen 361004, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Xiamen University, Xiamen 361004, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Xiamen University, Xiamen 361004, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wen
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Xiamen University, Xiamen 361004, China. Email: wuguoyang_mail@aliyun.com.
authors.forename: Guo-yang
authors.initials: GY
authors.lastname: Wu
mesh_terms: D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008687:Metformin / Q000008:administration & dosage / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: C116614:ABCG2 protein, human; D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D015703:Antigens, CD; D000970:Antineoplastic Agents; C495270:CTNNB1 protein, human; D006023:Glycoproteins; D009363:Neoplasm Proteins; C000606023:PROM1 protein, human; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D051176:beta Catenin; D008687:Metformin; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human