Overexpression of PLD1 in HL-60 cells increases random cell migration and chemotaxis. (A) Undifferentiated, exponentially growing HL-60 cells (uHL-60) or DMSO-treated cells (dHL-60) were mock-transfected or transfected with WT HA-PLD1 (1 μg plasmid DNA), and cell migration was assayed on Transwell plates. The controls were cells transferred into Transwell plates immediately after (0 day) mock transfection. (B) Confocal immunofluorescence of transfected dHL-60 cells. The brightfield view is shown for mock-transfected cells, which had low fluorescence signal despite being incubated with the same anti-HA antibodies, as were the WT-transfected cells. Confocal epifluorescence micrographs represent single optical sections of a representative cell. (C) dHL-60 cells either mock- or WT HA-PLD1-transfected were assayed for their chemotactic responses; 100% represents 1.2 × 10⁴ ± 0.1 cells/mL. The mean ± SEM from 3 independent experiments performed in duplicate are shown.