[Proteomic analysis of G2/M arrest of HL-60 cells induced by MG132].
OBJECTIVE
Proteasome inhibitor, which can induce apoptosis in various tumor cells, is a kind of potential antitumor drug. This study was to identify the proteins involved in G(2)/M arrest of leukemia cell line HL-60 exposed to proteasome inhibitor MG132 by proteomic techniques.


METHODS
Flow cytometry was used to examine cell cycle of HL-60 cells exposed to 2.5 micromol/L MG132. Nuclear extracts of HL-60 cells were prepared, and the purity was detected by light microscopy and Western blot, and the differentially expressed protein spots were determined by two-dimensional gel electrophoresis and identified with MALDI-TOF-TOF/MS.


RESULTS
There was a distinct G(2)/M phase arrest before the apoptosis of HL-60 cells induced by 2.5 micromol/L MG132. Twenty-three differentially expressed protein spots were found between MG132-treated and control HL-60 cells; 8 nuclear proteins were identified by MALDI-TOF-TOF/MS analysis.


CONCLUSIONS
The detected proteins, such as eIF5A and splicing factor, may be involved in regulation of G(2)/M arrest of HL-60 cells. These findings will be helpful for revealing molecular mechanisms of proteasome inhibitor-induced G(2)/M phase arrest and apoptosis of leukemia cell line.
Qian
Jun-Jie
JJ
Laboratory of Biochemistry and Molecular Biology, Beijing Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing, 100850, P. R. China.
Ying
Wan-Tao
WT
Sun
Guo-Jing
GJ
Song
Yi
Y
Liu
Bin
B
Dong
Yan
Y
Qian
Xiao-Hong
XH
Sun
Zhi-Xian
ZX