[Correlation of insulin-like growth factor-1 (IGF-1) to angiogenesis of breast cancer in IGF-1-deficient mice].
OBJECTIVE
Insulin-like growth factors (IGFs) play important roles in the development and progression of tumors. But the mechanism of tumorigenesis in relation to IGF-1 is unclear yet. This study was to explore the correlation of circulating IGF-1 level to the angiogenesis of breast cancer in IGF-1-deficient mice.


METHODS
The liver-specific IGF-1-deficient (LID) mice and control mice were injected with 7,12-dimethybenz(a)anthracene (DMBA) to develop breast cancer. Ginsenoside Rg3 was used to intervene tumor growth. The occurrence rates of breast cancer were compared. The expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) was detected by immunohistochemistry.


RESULTS
The occurrence rate of breast cancer was 66.67% in untreated control mice, 33.33% in untreated LID mice, 36.00% in Rg3-treated control mice, and 12.00% in Rg3-treated LID mice. The tumor size was (0.79+/-0.20) cm in untreated control mice, (0.37+/-0.08) cm in untreated LID mice, (0.32+/-0.08) cm in Rg3-treated control mice, and (0.15+/-0.05) cm in Rg3-treated LID mice. The average light density and positive rate of VEGF were the highest in untreated control mice (0.34+/-0.10 and 0.04+/-0.02, P<0.05), and the lowest in Rg3-treated LID mice (0.13+/-0.03 and 0.01+/-0.00, P<0.05). The MVD was 31.9+/-5.3 in untreated control mice, 26.8+/-4.9 in untreated LID mice, 20.1+/-4.9 in Rg3-treated control mice, and 14.4+/-4.9 in Rg3-treated LID mice.


CONCLUSIONS
Circulating IGF-1 plays a role in the onset and development of breast cancer. Degrading serum IGF-1 level could inhibit angiogenesis and growth of breast cancer. Rg3 could promote this effect.
Tang
Hong-Bo
HB
Department of General Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, PR China.
Ren
Yu-Ping
YP
Zhang
Jun
J
Ma
Shi-Hui
SH
Gao
Feng
F
Wu
Yi-Ping
YP
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D005260:Female; D036145:Ginsenosides / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000172:deficiency* / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D055806:Microvessels / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000209:etiology*; D011897:Random Allocation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D000972:Antineoplastic Agents, Phytogenic; D036145:Ginsenosides; D042461:Vascular Endothelial Growth Factor A; C519530:insulin-like growth factor-1, mouse; C097367:ginsenoside Rg3; D015127:9,10-Dimethyl-1,2-benzanthracene; D007334:Insulin-Like Growth Factor I