Induction of FucT-VII corresponds to rolling on E-selectin. (A-C) JSB3 cells were activated with 1 nM PMA for 2 days, and rolling on E-selectin was measured in a parallel plate flow chamber at 1.5 dynes/cm2 on CHO cells stably transfected with human E-selectin. (A) Rolling events and (B) velocity of JSB3 cells on E-selectin. Treatment of JSB3 cells with 1 nM PMA induced levels of rolling comparable to U937 cells, a uniformly HECA-452+ myeloid cell line included as a positive control. (C) PMA-induced rolling of JSB3 cells on E-selectin is inhibited by MAPK inhibitors in a pattern essentially identical to inhibition of HECA-452 staining. JSB3 cells were activated with 1 nM PMA in media alone or in the presence of the indicated MAPK inhibitors, and rolling assays were performed at 1.5 dynes/cm2, using CHO cells stably transfected to express human E-selectin. (D) Constitutively active Ras induces rolling of JSB3 cells on E-selectin. JSB3 cells were infected with empty or V-H-Ras retroviruses, and rolling on E-selectin was measured as described in “Materials and methods.” The number of rolling events is similar to that induced by PMA treatment, paralleling the expression of HECA-452 epitopes.
