FIGURE 1.

Kinetics of mRNA expression ratios of mTOR/PLD2-PLD1 and S6K/PLD2-PLD1 in HL-60 cells in response to DMSO. HL-60 cells in suspension were induced to differentiate in the presence of 1.25% DMSO for the indicated days. At each time point, total RNA was extracted from differentiated HL-60 cells, reverse-transcribed to cDNA, and probed with fluorescein amidite-tagged PLD1, PLD2, mTOR, or S6K primers. Gene fold expression was calculated from ΔCt as indicated under “Materials and Methods” (error bars are S.E. with n = 4 in duplicate). A, individual gene expression of PLD1, PLD2, mTOR, and S6K expressed as % of Control for PLD1. B, endogenous expression of PLD1, PLD2, mTOR, and S6K in the presence of DMSO as a function of time expressed as ratios mTOR/PLD2, mTOR/PLD1, S6K/PLD1, and S6K/PLD2. Asterisks denote statistically significant (p < 0.05) differences to controls (zero time) by analysis of variance. C, analysis of the differentiation potential of HL-60 cells in response to DMSO. Differentiation was assessed at the molecular level by determining expression kinetics of CD16b by flow cytometry as a function of time of DMSO exposure and at a functional level by determining cell migration in 6.5-mm Transwell plates and phagocytosis (formazan). Cells that migrated to the bottom wells after 90 min were counted. Results are the mean ± S.E. from four independent experiments conducted in duplicate.