title: siRNA-mediated beta-catenin knockdown in human hepatoma cells results in decreased growth and survival.
abstract: beta-Catenin, the chief oncogenic component of the canonical Wnt pathway, is known to be involved in a variety of cancers, including hepatocellular carcinoma (HCC). Although the mechanism of beta-catenin activation in HCC is multifactorial, it is indisputably implicated at various stages of hepatocarcinogenesis, making it an attractive therapeutic target. Here we investigate the effect of small interfering RNA-mediated beta-catenin knockdown on the growth and survival of human hepatoma cell lines with (HepG2) and without (Hep3B) beta-catenin mutations. Transfection of HepG2 and Hep3B cells with human beta-catenin (CTNNB1) small interfering RNA resulted in a significant beta-catenin decrease, as confirmed by Western blot analyses and immunofluorescence, also leading to decreased expression of known target genes such as cyclin D1 and glutamine synthetase. The decrease in beta-catenin activity was confirmed by TOPflash reporter luciferase assay. The functional impact of diminished beta-catenin was exhibited as temporal decrease in tumor cell viability by the MTT assay. A concomitant decrease in tumor cell proliferation was also evident with [(3)H]thymidine incorporation and verified with soft agar assays. Thus, beta-catenin is essential for the survival and growth of hepatoma cells independent of mutations in the beta-catenin gene and provide a proof of principle for the significance of the therapeutic inhibition of beta-catenin in HCC.
authors.affiliation: Department of Pathology, University of Pittsburgh, SOM, Pittsburgh, PA 15213, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Zeng
authors.forename: Udayan
authors.initials: U
authors.lastname: Apte
authors.forename: Benjamin
authors.initials: B
authors.lastname: Cieply
authors.forename: Sucha
authors.initials: S
authors.lastname: Singh
authors.forename: Satdarshan P S
authors.initials: SP
authors.lastname: Monga
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D019938:Cyclin D1 / Q000032:analysis; D005455:Fluorescent Antibody Technique; D005974:Glutamate-Ammonia Ligase / Q000032:analysis; D038362:Glycogen Synthase Kinase 3 / Q000502:physiology; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000628:therapy*; D009154:Mutation; D034741:RNA, Small Interfering / Q000627:therapeutic use*; D051176:beta Catenin / Q000037:antagonists & inhibitors* / Q000235:genetics
chemical_list: D034741:RNA, Small Interfering; D051176:beta Catenin; D019938:Cyclin D1; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; D005974:Glutamate-Ammonia Ligase