[Experimental study of simvastatin induced apoptosis of K562 cells by caspase-12 activation].
OBJECTIVE
To explore the apoptotic effect of simvastatin on K562 cells through Caspase-12 activation.


METHODS
Morphological changes of apoptotic cells were observed by Hoechst33258 fluorescent staining under fluorescent microscope; Apoptosis rate of cells was determined with annexin V-FITC/PI double staining by flow cytometry; Intracellular calcium concentration ([ca2+]i) was measured by Laser Scanning Confocal Microscope(LSCM); The expression levels of GRP78 and Calpain gene mRNA were determined by RT-PCR; The expression levels of Caspase-3,-6,-7,-9,-12 and GRP78 proteins were evaluated by Western blot.


RESULTS
Typical morphological changes of K562 apoptosis cells were observed post 72 hours treated with 10, 20, 30 micromol/L simvastatin. The apoptotic rates of K562 cells were (12.41 +/- 0.32)%, (19.08 +/- 0.26)% and (23.41 +/- 0.36)%, respectively. The fluorescent intensities were 43 +/- 2.9, 54 +/- 2.7 and 64 +/- 2.6, respectively in K562 cells treated with 10, 20, 30 micromol/L simvastatin, which represented the increase of [ca2+]i The expression levels of GRP78 and Calpain gene mRNA were up-regulated. And the cleavage and activation of Caspase-3,-6,-7,-9,-12 and upregulation of GRP78 expression were demonstrated by Western blot detection for the treated cells.


CONCLUSIONS
Caspase-12 is a important pathway of apoptosis in cells and participates simvastatin-induced apoptosis in K562 cells.
Xu
Guo-qiang
GQ
Clinical Laboratory Department, Sichuan Academy Medical Sciences and Sichuan Provincial People's Hospital, Chengdu 610072, China.
Pu
Ze-yan
ZY
Liu
Hua
H
Yang
Yong-chang
YC
Huang
Wen-fang
WF
D017209:Apoptosis / Q000187:drug effects*; D002154:Calpain / Q000235:genetics / Q000378:metabolism; D053454:Caspase 12 / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020014:K562 Cells; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019821:Simvastatin / Q000494:pharmacology*
D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D019821:Simvastatin; D002154:Calpain; D053454:Caspase 12