[mTOR/p70s6k signaling pathway is involved in megakaryocyte polyploidization].
OBJECTIVE
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.


CONCLUSIONS
mTOR/S6K1 pathway is involved in megakaryocyte polyploid cell cycle control.
Department of Experimental Medicine, Northern Hospital, Shen-yang 110840, China. hyingy@sina.com
Hui-ying
HY
Yu
Dong-chu
DC
Ma
Di
D
Lin
Ying-hui
YH
Sun
Shun-yan
SY
Tao
D002453:Cell Cycle / Q000187:drug effects; D006801:Humans; D008533:Megakaryocytes / Q000187:drug effects / Q000201:enzymology*; D015739:Nocodazole / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011123:Polyploidy; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D050257:Tubulin Modulators / Q000494:pharmacology
D050257:Tubulin Modulators; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; D015739:Nocodazole