Effect of pertussis toxin and cytochalasin D on SDF-1α–up-regulated VLA-4–dependent myeloma cell adhesion.

BCECF-AM–labeled NCI-H929 cells were preincubated in medium without (Nil) and with pertussis toxin (PTx) (200 ng/mL, 2 hours) (A) or with cytochalasin D (Cyt D) (0.5 μg/mL, 30 minutes) (B). SDF-1α (100 ng/mL, 1 minute) was added, and cells were allowed to adhere to FN-H89– or sVCAM-1–coated wells for 2 minutes. Adhesions were quantified in a fluorescence analyzer. Adhesion data represent the mean ± SD of triplicate samples from one representative result of at least 4 independent experiments.