Aberrant activation of hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, Met, is involved in the development and progression of many human cancers. In the cell-based screening assay, (-)epigallocatechin-3-gallate (EGCG) inhibited HGF/SF-Met signaling as indicated by its inhibitory activity on HGF/SF-induced cell scattering and uPA activation (IC50 = 15.8 microg/ml). Further analysis revealed that EGCG at low doses specifically inhibited HGF/SF-induced tyrosine phosphorylation of Met but not epidermal growth factor (EGF)-induced phosphorylation of EGF receptor (EGFR). On the other hand, high-dose EGCG decreased both Met and EGFR proteins. We also found that EGCG did not act on the intracellular portion of Met receptor tyrosine kinase, i.e., it inhibited InlB-dependent activation of Met but not NGF-induced activation of Trk-Met hybrid receptor. This inhibition decreased HGF-induced migration and invasion by parental or HGF/SF-transfected B16F10 melanoma cells in vitro in either a paracrine or autocrine manner. Furthermore, EGCG inhibited the invasion/metastasis of HGF/SF-transfected B16F10 melanoma cells in mice. Our data suggest the possible use of EGCG in human cancers associated with dysregulated paracrine or autocrine HGF/SF-Met signaling.
Animals ; Autocrine Communication/*drug effects ; Catechin/*analogs & derivatives/metabolism/pharmacology ; Cell Line, Tumor ; Cell Movement/drug effects ; Female ; *Hepatocyte Growth Factor ; Humans ; Mice ; Mice, Inbred BALB C ; Neoplasms, Experimental/*metabolism/pathology ; Paracrine Communication/*drug effects ; Phosphorylation/drug effects ; Proto-Oncogene Proteins c-met/antagonists & inhibitors/metabolism ; Receptors, Growth Factor/antagonists & inhibitors/metabolism ; Signal Transduction

OBJECTIVETo explore the regulatory effect and mechanism of Ningxin Hongqi Capsule on local ovarian autocrine and paracrine factors in peri-menopausal rats.

METHODSSD female rats aged 4 months were allocated in a normal control group (A) and those aged 14 months with vagino-cytologic figure of oestrus elongation were allocated in a senile female rat model group (B). Rats in Group B were subdivided into 5 groups randomly as the B1, B2 and B3 subgroups treated respectively with high, moderate and low dose Ningxin Hongqi Capsule, the B4 subgroup treated with estradiol and the B5 subgroup untreated for control. Rats' ovaries were obtained at the end of the experiment for observing the conditions of ovarian growing follicles and corpus luteum by HE staining, determining expressions of ovarian estradiol receptor (ER), progesterone receptor (PR), follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin alpha (INHalpha), activin (ACT) alpha-beta, follistatin (FS), and insulin-like growth factor (IGF-1).

RESULTSAs compared with Group B5, the ovary index, number of growing follicle were higher and levels of FSH and LH were lower in Group B2 and B3, expression of ER was higher in Group B1 and B4, IGF-1 and INHalpha was higher in Group B2 and B3, and ACTalpha-beta and FS were lower (all P < 0.05).

CONCLUSIONNirigxin Hongqi Capsule could adjust and balance the local ovarian autocrine and paracrine factors to improve the ovarian function.

Animals ; Autocrine Communication ; drug effects ; physiology ; Capsules ; Drugs, Chinese Herbal ; pharmacology ; Female ; Humans ; Models, Animal ; Ovary ; drug effects ; metabolism ; physiology ; Paracrine Communication ; drug effects ; physiology ; Perimenopause ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Estradiol ; biosynthesis ; Receptors, FSH ; biosynthesis ; Receptors, Progesterone ; biosynthesis