[Z-ajoene causes cell cycle arrest at G2/M and decrease of telomerase activity in HL-60 cells].
OBJECTIVE
To investigate the molecular mechanisms of Z-ajoene mitosis blocking and telomerase inhibitory effects on HL-60 cells.


METHODS
Proliferation inhibition of HL-60 cell line was evaluated by MTT assay. Z-ajoene-induced mitotic blocking effect was investigated by flow cytometry. Immunoblotting analysis was used to determine cell cycle regulatory proteins. The telomerase activity of HL-60 cells was detected by TRAP-silver stain assay. Telomerase hTRT and TP1 mRNA level were determined by RT-PCR.


RESULTS
Z-ajoene displayed great proliferation inhibiting effect on HL-60 cells. Progressive increase in the percentage of mitotic block at G(2)/M phase was observed from 4 h to 12 h after treatment with 10 micromol/L Z-ajoene, with a peak at 10 h, which was 1.95 times higher than that in control. Z-ajoene also caused an increase in cyclin B1 accumulation and a decrease of p34(cdc2) expression. But Z-ajoene did not change the level of cyclin A. After treating with 10 micromol/L Z-ajoene for 24 h, the telomerase activity of HL-60 cells was also decreased in a dose-independent manner. Furthermore, telomerase hTRT and TP1 mRNA levels decreased after 10 micromol/L Z-ajoene treatment for 24 h.


CONCLUSIONS
The results suggest that Z-ajoene has potent anti-cancer activity, and that its inhibitory effect on telomerase activity and on cell growth might be the result of G(2)/M phase blocking.
Ye
Ying
Y
Key Laboratory of Natural and Bionic Medicines, School of Medicine, Peking University, Beijing 100083, China.
Yang
Hua-yu
HY
Wu
Jun
J
Li
Min
M
Min
Ji-mei
JM
Cui
Jing-rong
JR
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects*; D004220:Disulfides / Q000494:pharmacology*; D005737:Garlic / Q000737:chemistry; D018922:HL-60 Cells; D006801:Humans; D008938:Mitosis / Q000187:drug effects; D013454:Sulfoxides; D019098:Telomerase / Q000378:metabolism*
D000972:Antineoplastic Agents, Phytogenic; D004220:Disulfides; D013454:Sulfoxides; C048980:ajoene; D019098:Telomerase