[Effects of melittin on growth and angiogenesis of human hepatocellular carcinoma BEL-7402 cell xenografts in nude mice].
OBJECTIVE
Melittin has antitumor effects on osteosarcoma, leukemia, and cervical cancer in vitro. Our previous experiments showed that melittin could inhibit proliferation and induce apoptosis of human hepatocellular carcinoma BEL-7402 cells. This study was to examine the effects of melittin on the growth and angiogenesis of BEL-7402 cell xenografts in nude mice.


METHODS
The xenografts derived from BEL-7402 cells were established in BALB/C nude mice. Inoculated mice were randomly divided into normal saline (NS, 10 ml/kg) group, positive control (thalidomide, TLD, 200 mg/kg) group, low dose melittin (40 microg/kg) group, moderate dose melittin (60 microg/kg) group and high dose melittin (80 microg/kg) group. Tumor volume was measured. Tumor tissue was observed under microscope. Microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and nuclear factor kappaB (NF-kappaB) were detected by SABC immunohistochemistry. The mRNA levels of VEGF and bFGF were analyzed by real-time fluorescent quantitative polymerase chain reaction.


RESULTS
The relative tumor volume (V/V0) and MVD were significantly lower in low, moderate and high dose melittin groups than in NS group (4.42+/-0.58, 3.47+/-0.97, and 3.06+/-1.23 vs. 9.06+/-1.45, P<0.01; 11.33+/-1.86, 9.17+/-1.17, and 6.67+/-1.21 vs. 16.50+/-2.35, P<0.01). Tumor tissue necrosis was observed in melittin-treated groups and tumor vessels were destroyed by melittin. The positive expression indexes of VEGF (2.59+/-0.27, 2.61+/-0.17, 1.55+/-0.22 vs. 3.80+/-0.60, P<0.01), bFGF (2.45+/-0.78, 2.27+/-0.36, 2.10+/-0.27 vs. 4.43+/-0.34, P<0.01) and NF-kappaB (2.79+/-0.29, 2.71+/-0.66, 2.26+/-0.56 vs. 4.98+/-0.63, P<0.01) were significantly lower in low, moderate and high dose melittin groups than in NS group. The mRNA levels of VEGF and bFGF were also significantly lower in melittin-treated groups than in NS group.


CONCLUSIONS
Melittin could inhibit the growth of BEL-7402 cell xenografts in nude mice. The down-regulation of VEGF, b-FGF and NF-kappaB expression and the inhibition of angiogenesis might play key roles in the antitumor effect of melittin.
Song
Chang-Cheng
CC
Department of Traditional Chinese Medicine, Changhai Hospital, Second Militaty Medical University, Shanghai, 200433, PR China.
Lu
Xiang
X
Cheng
Bin-Bin
BB
DU
Juan
J
Li
Bai
B
Ling
Chang-Quan
CQ
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D015536:Down-Regulation; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008555:Melitten / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D055806:Microvessels / Q000187:drug effects*; D016328:NF-kappa B / Q000378:metabolism; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D047368:Tumor Burden / Q000187:drug effects*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
D000970:Antineoplastic Agents; D016328:NF-kappa B; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D008555:Melitten