Apoptosis induced by DNA primase inhibitor 3,3'-diethyl-9-methylthia-carbocyanine iodide in human leukemia HL-60 cells.
OBJECTIVE
To investigate apoptosis induced by 3,3'-diethyl-9-methylthia-carbocyanine iodide (DMTCCI), an inhibitor of DNA primase found in our previous study, and the mechanism of DMTCCI in human myelogenous leukemia HL-60 cells.


METHODS
HL-60 cells were cultured in RPMI-1640 medium and treated with different concentrations of DMTCCI. MTT assay was used to detect growth inhibition. Flow cytometry and DNA ladders were used to detect apoptosis. Western blotting was used to observe the expression of survivin, Bcl-xL, Bad, Bax, Bcl-2, caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity was measured by ApoAlert Caspase-3 Assay Kit.


RESULTS
DMTCCI inhibited proliferation of human leukemia HL-60 cells with IC50 value of 0.24 micromol x L(-1). The results of flow cytometry and DNA ladders showed that DMTCCI could induce apoptosis of HL-60 cells. The expression levels of protein survivin and Bcl-xL were down-regulated, Bad and Bax were up-regulated, while Bcl-2 protein had no change in response to DMTCCI treatment in HL-60 cells. Treatment of HL-60 cells with DMTCCI induced the proteolytic cleavage of caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity apparently increased at 3 h and reached a peak at 12 h after exposure to 1 micromol x L(-1) of DMTCCI in HL-60 cells.


CONCLUSIONS
DMTCCI inhibited proliferation and induced apoptosis of human leukemia HL-60 cells. Bcl-2 family proteins, survivin and caspases family proteins might play a role in the apoptosis process induced by DMTCCI.
Li
Zhi-Ming
ZM
State Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.
Jiang
Wen-Qi
WQ
Guan
Zhong-Zhen
ZZ
Zhu
Xiao-Feng
XF
Zhou
Jun-Min
JM
Xie
Bing-Fen
BF
Feng
Gong-Kan
GK
Zhu
Zhen-Yu
ZY
Liu
Zong-Chao
ZC
D017209:Apoptosis / Q000187:drug effects*; D002232:Carbocyanines / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004249:DNA Damage; D053938:DNA Fragmentation / Q000187:drug effects; D019915:DNA Primase / Q000037:antagonists & inhibitors*; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D007951:Leukemia, Myeloid / Q000378:metabolism / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D000077022:Survivin; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051025:bcl-Associated Death Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
C484503:3,3'-diethyl-9-methylthiacarbocyanine iodide; C494811:BCL2L1 protein, human; C107489:BIRC5 protein, human; D002232:Carbocyanines; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D000077022:Survivin; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein; D019915:DNA Primase; D053148:Caspase 3