Rapamycin restores differentiation in granulocytes with enforced expression of c-MYC. (A) Representative morphology of MGG-stained MPRO c-MYC-ER cells induced to differentiate prior to induction (day 0) and after induction of differentiation (day 2 and day 4) by 10−6 M AGN194204 in the presence of vehicle control (RXR + EtOH), 200 nM 4-hydroxytamoxifen (RXR + 4OHT), or 200 nM 4OHT and 80 nM rapamycin (RXR + 4OHT + rapa). (B) c-MYC-ER MPROs were treated as described in panel A. Quantitative real-time PCR (qRT-PCR) was performed using primers directed against myeloperoxidase (Mpo) and neutrophil galactosidase-associated lipocalcin (Ngal), corrected for the expression of β-2-microglobulin and normalized to expression in day-0 undifferentiated controls. (C) Surface expression of CD11b was determined by FACS analysis for MPRO c-MYC-ER cells treated as indicated in panel A. Results in panels B and C are expressed as mean plus or minus SEM for 3 independent experiments.
