Journal: Journal of Cellular and Molecular Medicine
Article Title: The natural agent rhein induces β‐catenin degradation and tumour growth arrest
doi: 10.1111/jcmm.13346
Figure Lengend Snippet: GSK‐3β is involved in rhein‐induced degradation of β‐catenin and inhibition of cell growth. ( A ) HepG2 and Hela cells were treated with or without LiCl (10 mM) and rhein (60 μM) for 48 hrs, followed by Western blot analysis of β‐catenin. ( B ) HepG2 and Hela cells were transfected with GSK‐3β siRNA. Twenty‐four hours after transfection, the cells were treated with or without rhein (60 μM) for 48 hrs, followed by Western blot analysis of β‐catenin and GSK‐3β. ( C ) HepG2 cells were treated with or without rhein (100 μM) for indicated periods, followed by Western blot analysis. ( D ) In vitro kinase assays of immunoprecipitated GSK3β. HepG2 cells were treated with or without 100 μM rhein for 24 hrs, followed by immunoprecipitation with anti‐GSK3β antibody or normal IgG. The immunoprecipitates were subjected to in vitro kinase assays in the presence of a peptide substrate. The relative kinase activity of GSK3β was plotted. ** P < 0.01; *** P < 0.001, compared to the kinase activity of GSK3β immunoprecipitates from rhein‐untreated cells, which was set as 1. ( E ) HepG2 cells were transduced with FLAG‐tagged phosphorylation‐deficient mutant of β‐catenin (S33A, S37A, T41A, S45A), followed by treatment with or without rhein (100 μM) for 24 hrs. The endogenous β‐catenin and FLAG‐tagged phosphorylation‐deficient mutant of β‐catenin were detected by Western blotting. ( F ) HepG2 cells were transduced with wild‐type Akt1 (WT‐Akt1) or constitutively active Akt1 (CA‐Akt1), followed by treatment with or without rhein (100 μM) for 24 hrs. The effects of Akt and rhein on β‐catenin expression, Akt and GSK3β phosphorylation were detected by Western blotting. ( G ) HepG2 cells were transduced with negative control siRNA (siCtrl) or GSK3β siRNA (siGSK3β). Twenty‐four hours later, the cells were treated with or without rhein (60 μM) for another 24 hrs, followed by CCK8 assays. The relative cell growth rate was plotted. In parallel, the efficiency of GSK3β knockdown was detected by Western blotting. *** P < 0.001; ** P < 0.01, compared with siControl. (H) Hela cells were transduced with siCtrl or siGSK3β. Twenty‐four hours later, the cells were treated with or without rhein (60 μM) for another 48 hrs, followed by CCK8 assays. The relative cell growth rate was plotted. In parallel, the efficiency of GSK3β knockdown was detected by Western blotting. ** P < 0.01.
Article Snippet: Plasmids for wild‐type Akt1 (WT‐AKT1) and constitutively active Akt1 (CA‐AKT1) were purchased from Addgene.
Techniques: Inhibition, Western Blot, Transfection, In Vitro, Immunoprecipitation, Activity Assay, Transduction, Phospho-proteomics, Mutagenesis, Expressing, Negative Control, Knockdown