[Inhibitive effects of mifepristone on growth of breast cancer: experiment with animal model].
OBJECTIVE
To investigate the effects of mifepristone (MIF) on the growth of breast cancer.


METHODS
Forty female athymic BALB/c-nude mice underwent subcutaneous injection of breast cancer cells of the line MCF-7, ER +/PR +. Ten days later when tumor nodules were formed, the mice were randomly divided into 4 equal groups to be administered with MIF of the concentrations of 25 mg, 50 mg, 100 mg, and 200 mg/kg x d respectively by gastric perfusion. The tumor size was observed every 3 day till 3 weeks later. Ten mice were used as normal control group, undergoing gastric perfusion of vegetable oil. Parts of the animals were killed 2 weeks later, and the remaining mice were all killed 3 weeks later. The tumors were taken out and underwent immunochemistry to measure the protein expression of CD34, estrogen receptor (ER), progesterone receptor (PR), vascular endothelial growth factor (VEGF), bcl-2, Ki67, p53, and CerbB-2. Microscopy was used to measure the microvessel density (MVD).


RESULTS
The growth velocity of tumor of the mice of MIF groups were all slower than that of the control group (all P <0.01). The MVD levels of the MIF groups all decreased time- and dose-dependently. Microscopy showed that in the tumor tissues heteromorphism was significant, pathological caryomitosis was more remarkable, karyoplasmic ratio was greater, endochylema was deep blue, mesenchyma was sparse, and zone of neoplasm necrosis became lager in comparison with the control group. The expression levels of VEGF, bcl-2, Ki67, p53, and CerbB-2 of the MIF groups were all significantly lower, time and dose-dependently, than those of the control group (all P <0.05).


CONCLUSIONS
MIF inhibits the growth of breast cancer by the mechanisms related to apoptosis promotion and inhibition of angiogenesis, so it can be used in breast cancer endocrine therapy.
Tian
Xing-Song
XS
Department of Breast Surgery, Shandong Provincial Hospital, Jinan, China.
Zhou
Wen-Hong
WH
Wu
Guo-Jun
GJ
Sun
Jing-Zhong
JZ
Cong
Ming-Hua
MH
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D045744:Cell Line, Tumor; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply / Q000378:metabolism / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D015735:Mifepristone / Q000494:pharmacology* / Q000627:therapeutic use; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D011897:Random Allocation; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis; D023041:Xenograft Model Antitumor Assays
D006727:Hormone Antagonists; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D042461:Vascular Endothelial Growth Factor A; D015735:Mifepristone