[Change of mitochondria during apoptosis of HL-60 cells induced by camptothecine].
OBJECTIVE
To study the changes of mitochondrial mass and membrane potential (deltapsi(m)) during apoptosis of human promyelocytic leukemia cells (HL-60) induced by camptothecine(CPT).


METHODS
HL-60 cells were stimulated with 4x10(-6) mol/L CPT. Apoptosis and necrosis of HL-60 cells were detected by annexin V-FITC/PI staining. Mitochondrial mass and membrane potential (deltapsi(m)) were measured by NAO and DiOC(6)(3) stanings, respectively.


RESULTS
After 12 hour treatment with 4x10(-6) mol/L CPT, the early apoptotic rate of HL-60 cells was significantly increased compared with the control group (12.75+/-4.61)% vs (2.88+/-2.49)%,(P<0.01), and the necrotic rate was significantly elevated too, (3.48+/-1.67)% and (0.71+/-1.10)%, (P<0.01). The result of PI staining showed that the apoptotic rate of HL-60 cells at late phase (12 h) in CPT group was (3.52+/-1.07)%, whereas that in control group was (0.46+/-1.06)%. At the same time, we observed that the cells in G(2)/M phase were arrested. The percentage of cells in G(2)/M phase in CPT group and the control was (13.45+/-1.91)% and (22.46+/-2.19)% (P<0.01) respectively. The percentage of cells with low mitochondrial mass in CPT and control groups was (25.74+/-2.09)% and (4.53+/-1.26)%, respectively (P<0.01). Mitochondrial membrane potential in CPT group and control group was (17.71+/-5.23)% and (1.64+/-2.00)%, respectively.


CONCLUSIONS
During CPT-induced apoptosis of HL-60 cells, mitochondrial mass and membrane potential drop significantly, but its depolarization heightens.
He
Fang
F
Key Laboratory of Ministry of Education for Tissue Transplantation and Immunology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China. hefangjnu@126.com
Zeng
Yao-ying
YY
Wang
Tong
T
Xing
Fei-yue
FY
Lin
Yi
Y
Liang
Pei-yan
PY
Zhao
Jing-xian
JX
D017304:Annexin A5 / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002166:Camptothecin / Q000494:pharmacology*; D045744:Cell Line, Tumor; D016650:Fluorescein-5-isothiocyanate / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D008928:Mitochondria / Q000187:drug effects* / Q000473:pathology; D009336:Necrosis / Q000139:chemically induced
D017304:Annexin A5; D016650:Fluorescein-5-isothiocyanate; D002166:Camptothecin