MK polyploidization decrease after treatment with PD98059.

The effect of MAPK inhibitor PD98059 was evaluated on differentiating MKs grown in the presence of TPO (100 ng/mL) alone or in combination with SDF-1α (1 μg/mL). Percentage of polylobated MKs derived from cultures grown in the presence of either 25 μM/L (░) or 50 μM/L (▪) PD98059 was evaluated by morphological analysis. An equal volume of diluent (DMSO) added to mock culture (■) had no adverse effects on polyploidization as compared with the untreated culture. Data from day 9 culture are presented as mean values ± SEM of 3 independent experiments.