Figure 3.
NSC49L-mediated activation of PP2AC
(A) chemical structure of NSC49L.
(B) human rPP2AC activity determined with the malachite green assay.
(C) Kact(NSC49L) and Vmax values of NSC49L with PP2AC.
(D) PP2A activity using immune complexes isolated with anti-PP2AC antibody from control and NSC49L-treated FOLFOX-HT29 cells. Data are the mean ± SE of three experiments.
(E) Okadaic acid (OA), a PP2A inhibitor, blocks NSC49L and TRAIL-induced cytotoxicity to FOLFOX-HT29 cells. Cells were treated with different concentrations of NSC49L, TRAIL and OKA either alone are in combination as indicated in the figure. After 72 h treatment, cell viability was determined using the MTT-assay. ∗ = Significantly different as compared to NSC49L group, and ∗∗ = significantly different as compared to NSC49L+TRAIL group.
(F) effect of OA on the IC50 of the TRAIL. Data are the mean ± SE of four estimations. The p < 0.05 is considered significant.