Effect of O-4-ethoxyl-butyl-berbamine in combination with pegylated liposomal doxorubicin on advanced hepatoma in mice.
OBJECTIVE
To study the synergistic effects of calmodulin (CaM) antagonist O-4-ethoxyl-butyl-berbamine (EBB) and pegylated liposomal doxorubicin (PLD) on hepatoma-22 (H(22)) in vivo.


METHODS
Hepatoma model was established in 50 Balb/c mice by inoculating H(22) cells (2.5 x 10(6)) subcutaneously into the right backs of the mice. These mice were divided into 5 groups, and treated with saline only, PLD only, doxorubicin (Dox) only, PLD plus EBB and Dox plus EBB, respectively. In the treatment groups, mice were given 5 intravenous of PLD or Dox on days 0, 3, 6, 9 and 12. The first dosage of PLD or Dox was 4.5 mg/kg, the other 4 injections was 1 mg/kg. EBB (5 mg/kg) was coadministered with PLD or Dox in the corresponding groups. The effect of drugs on the life spans of hepatoma-bearing mice and tumor response to the drugs were recorded. Dox levels in the hepatoma cells were measured by a fluorescence assay. Light microscopy was performed to determine the histopathological changes in the major organs of these tumor-bearing mice. The MTT method was used to analyze the effect of Dox or PLD alone, Dox in combination with EBB, or PLD in combination with EBB on the growth of H(22) cells in an in vitro experiment.


RESULTS
EBB (5 mg/kg) significantly augmented the antitumor activity of Dox or PLD, remarkably prolonged the median survival time. The median survival time was 18.2 d for control group, but 89.2 d for PLD+EBB group and 70.1 d for Dox+EBB group, respectively. However, Dox alone did not show any remarkable antitumor activity, and the median survival time was just 29.7 d. Addition of EBB to Dox or PLD significantly increased the level of Dox in H(22) cells in vivo. Moreover, EBB diminished liver toxicity of Dox and PLD. In vitro, EBB reduced the IC50 value of Dox or PLD on H(22) cells from 0.050+/-0.006 mg/L and 0.054+/-0.004 mg/L to 0.012+/-0.002 mg/L and 0.013+/-0.002 mg/L, respectively (P<0.01).


CONCLUSIONS
EBB and liposomization could improve the therapeutic efficacy of Dox in liver cancer, while decreasing its liver toxicity.
Fang
Bai-Jun
BJ
State Key Laboratory of Experimental Haematology, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.
Yu
Mei-Li
ML
Yang
Shao-Guang
SG
Liao
Lian-Ming
LM
Liu
Jie-Wen
JW
Zhao
Robert C-H
RC
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D044182:Benzylisoquinolines / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004357:Drug Synergism; D008113:Liver Neoplasms / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C
D000970:Antineoplastic Agents; D044182:Benzylisoquinolines; D002147:Calmodulin; C050387:O-(4-ethoxybutyl)berbamine; D004317:Doxorubicin