The CaMKKα inhibitor STO-609 enhances PMA-dependent up-regulation of CD86 but blocks CD11b expression and CaMKKα nuclear localization.

<p>(A and B) U937 cells were pretreated with or without 5 µg/ml STO-609 for 6 h prior to activation with 100 nM PMA for 48 h, as indicated. Surface expression of CD11b and CD86 was quantified by flow cytometry using FITC-conjugated CD11b and PE-conjugated CD86 antibodies. Results significantly different from PMA at α = 0.05 are indicated by (*). Results represent an average of three independent experiments±SEM. (C) Cells were treated as in panel A and CaMKKα was quantified by Western analysis of nuclear lysates. Results are representative of three independent experiments. (D) U937 cells were treated as in panel A and ERK1/2 phosphorylation (ERK-p) and mass (ERK) were measured by Western analysis in whole cell lysates. Results are representative of three independent experiments.