[Enhancement of antitumor activity of bleomycin A5 in mouse sarcoma 180 cells in vitro and in vivo by verapamil].
Verapamil (Ver), a calcium influx blocker, enhanced the cytotoxicity of bleomycin A5 (BLM) in cultured S-180 cells. IC50 of BLM to the cells was about 2.6 micrograms/ml when the cells were treated with BLM alone, but when the cells were treated with BLM plus Ver 1, 5, 10 micrograms/ml, the IC50 were 1/1.2, 1/5.2, 1/7.4 of the cells treated with BLM alone, respectively. In colony test, the survival fractions of the cells treated with BLM 20, 60, 100 micrograms/ml plus Ver 60 micrograms/ml were 1/7, 1/8, 1/11 of the cells treated with BLM alone, respectively. Ver enhanced the growth inhibitory actions of BLM in mice bearing S-180 sarcoma by 60% or over. The mean survival the growth inhibitory actions of BLM in mice bearing S-180 sarcoma by 60% or over. The mean survival time of the mice bearing S-180 ascites sarcoma treated with BLM plus Ver was prolonged 21% from that of the mice treated with BLM alone. The results suggest that Ver may be used clinically as an antitumor enhancer of BLM.
He
N G
NG
Department of Biology, Beijing Normal University, China.
Zhang
H Q
HQ
Wang
R H
RH
Yang
X L
XL
Xue
S B
SB
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001761:Bleomycin / Q000494:pharmacology / Q000627:therapeutic use* / Q000031:analogs & derivatives; D004357:Drug Synergism; D005260:Female; D008297:Male; D051379:Mice; D012510:Sarcoma 180 / Q000188:drug therapy* / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology / Q000627:therapeutic use*
D000903:Antibiotics, Antineoplastic; D001761:Bleomycin; C025703:bleomycetin; D014700:Verapamil