Figure 3

Treatment with HMBA increased the expression and activity of GSK-3β in the nucleus. A, SGC7901 cells were treated with (+) or without (-) 10 mMHMBA for 24 h, and harvested at the end of the treatment. Cytosol and nuclear fractions were prepared and GSK-3β activity was assayed by in vitro kinase assay using Snail protein as substrate. Phosphorylated Snail protein signals were densitometrically quantitated and expressed as fold-change with respect to untreated control groups. B, SGC7901 cells were treated with 10 mM HMBA for various times. Cytosolic and nuclear protein fractions were extracted and western blotting was performed using antibodies to GSK-3β, phospho-GSK-3β (Ser9), phospho-GSK-3α/β (Tyr278/Tyr216), α-tubulin or Topo IIβ.