MEK5/ERK5 activation regulates colon cancer stem-like cell properties

a HCT116, HT29, SW480, and SW620 cells were cultured under sphere-forming or adherent conditions. MEK5 and ERK5 phosphorylation levels were evaluated by western blot. b–d SW480 adherent cultures were transfected with CA-MEK5 expression construct or empty vector. b MEK5 overexpression and ERK5 activation status were confirmed by immunoblotting. c mRNA levels of several stemness- and differentiation-associated markers were determined by qRT-PCR. d Steady-state protein levels of NANOG, OCT4, and SOX2 were evaluated by immunoblot analysis. Blots are representative of three independent experiments with similar results. Results are expressed as mean？±？standard error of mean from at least three independent experiments. *p？<？0.05, **p？<？0.01, and ***p？<？0.001 from respective adherent cultures (a) or empty vector cells (c). Ad Adherent, Ts tumorsphere, CA constitutively activ