Aim: To investigate the mechanisms of megakaryocyte polyploid cell cycle control.
Methods: The expression and phosphorylation of mTOR/p70s6k pathway proteins was detected by western blot. Double-labeling techniques were used to investigate in which of the phase of the polyploid cell cycle S6K1 at Thr421/Ser424 are phosphorylated.
Results: Nocodazole induced a relatively synchronized polyploidization in Dami cells. The expression of mTOR and the phosphorylation of mTOR at Ser2448 increased when Dami cells begin to progress from G1 to S-phase in cell cycle. Analysis of flow cytometry showed that phosphorylation of S6K1 at Thr421/Ser424 increased at G2/M-phase.
Conclusion: mTOR/S6K1 pathway is involved in megakaryocyte polyploid cell cycle control.