[Reversal of anti-apoptotic action by tetrandrine in human breast carcinoma multidrug-resistant MCF-7 cells].
OBJECTIVE
To study whether the anti-apoptotic action is reversed by tetrandrine in a combination with vincristine in human breast carcinoma MCF-7 multidrug-resistant cells.


METHODS
Chromatin condensation was observed by co-staining of fluorescent dyes Hoechst 33342 and propidium iodide; and G1 sub-peak was detected by flow cytometry. Apoptotic cells were detected with TUNEL method. Cellular free ca2+ was determined with Fluo-3 staining method.


RESULTS
Two types of chromatin condensation were observed after the sensitive and drug-resistant MCF-7 cells were treated with an antitumor drug vincristine 5 mumol.L-1 for 24 h. The number of cell with chromatin condensation was obviously reduced in the drug-resistant cells treated with the same concentration of vincristine, as compared with the sensitive MCF-7 cells. The number of the apoptotic cells was increased by a combination of non-cytotoxic tetrandrine 20 mumol.L-1 and vincristine in both the sensitive and drug-resistant cells, which was confirmed with fluorescent indication and TUNEL method. The increment of introcellular free Ca2+ level in the cells treated with tetrandrine in a combination of vincristine was detected with Fluo-3 staining method.


CONCLUSIONS
The anti-apoptotic action of human breast carcinoma MCF-7 cells can be effectively reversed by tetrandrine.
Wang
Jin-hua
JH
Institute of Chinese Materia Medica, Chinese Academy of Traditional Chinese Medicine, Beijing 100700, China.
Ye
Zu-guang
ZG
Sun
Ai-xu
AX
Xue
Bao-yun
BY
Liang
Ai-hua
AH
Li
Chun-ying
CY
Wang
Lan
L
D000470:Alkaloids / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D044182:Benzylisoquinolines; D001943:Breast Neoplasms / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D005260:Female; D006801:Humans; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology
D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D044182:Benzylisoquinolines; C009438:tetrandrine; D014750:Vincristine; D002118:Calcium