Mechanism of G2/M blockage triggered by activated-Chk1 in regulation of drug-resistance in K562/A02 cell line.
- Author:
Hai-Yan WANG
1
;
Min ZHANG
;
Ping ZOU
;
Yong YOU
;
Jing-Ming GUO
;
Xiao-Qiong TANG
;
Zhi-Gang ZHAO
;
Yao-Hui WU
Author Information
1. Department of Hematology, Yichang Central People Hospital, The First Clinical Medical College, Three Gorges University, Yichang 443003, China.
- Publication Type:Journal Article
- MeSH:
Apoptosis;
physiology;
Checkpoint Kinase 1;
Doxorubicin;
pharmacology;
Drug Resistance, Neoplasm;
genetics;
G2 Phase;
Humans;
K562 Cells;
Mitosis;
Phosphorylation;
Protein Kinases;
biosynthesis;
genetics;
metabolism;
RNA Interference;
RNA, Messenger;
biosynthesis;
genetics;
Signal Transduction
- From:
Journal of Experimental Hematology
2006;14(6):1105-1109
- CountryChina
- Language:Chinese
-
Abstract:
The study was purposed to investigate the effect of phosphorylated-chk1 on cell cycle and apoptosis of human erythroleukemic cell line K562 and K562/A02, and to explore the mechanism of chk1 in regulation of drug-resistance of leukemia cells. After treatment with adrimycin for six hours, the cell cycle distribution was detected by flow cytometry; the Chk1mRNA expression was detected by RT-PCR and the Chk1 phosphorylation level was detected by Western blot. Under the condition of down-regulation of Chk1mRNA expression in cells transfected with Chk1 short hairpin RNA, the cell apoptosis rates were detected by flow-cytometry following adrimycin. The results indicated that the proportion of K562/A02 cell line in G2/M phase was (54.12 +/- 0.57)% at 6 hours after drug treatment, significantly higher than that of K562 cell line (36.99 +/- 1.28)%. No evident difference of the Chk1mRNA expression was observed between K562 and K562/A02 cell lines, while elevated Chk1 phosphorylation following DNA damage induced by adriamycin was observed in the K562/A02 cell line (0.79 +/- 0.56), significantly higher than that in K562 cell line (0.27 +/- 1.47). The cell apoptosis rate of the Chk1 shRNA group in K562/A02 cell line was 3.84-fold of blank vector group, but that in K562 cell line was 1.30-fold of blank vector group. It is concluded that the increased chk1 activity that delay the progress of cell cycle are associated with cellular resistance to adrimycin in the K562/A02 cell line.
