title: [Inhibitory effect of exogenous insulin-like growth factor binding protein 7 on proliferation of human breast cancer cell line MDA-MB-453 and its mechanism].
abstract: The present study was to investigate the effects of exogenous insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation of human breast cancer cell line MDA-MB-453 and its possible mechanism. By means of MTT method in vitro, the results showed exogenous IGFBP7 inhibited the growth of MDA-MB-453 cells (IC50 of IGFBP7 = 8.49 μg/mL) in time- and concentration-dependent manner. SB203580, p38(MAPK) inhibitor, blocked the anti-proliferative effect of exogenous IGFBP7. The flow cytometry assay showed that exogenous IGFBP7 remarkably induced G0/G1 arrest in MDA-MB-453 cells. The Western blot showed that exogenous IGFBP7 promoted phosphorylation of p38(MAPK), up-regulated expression of p21(CIP1/WAF1), and inhibited phosphorylation of Rb. SB203580 restrained exogenous IGFBP7-induced regulation of p21(CIP1/WAF1) and p-Rb in MDA-MB-453 cells. In conclusion, the present study suggests that exogenous IGFBP7 could activate the p38(MAPK) signaling pathway, upregulate p21(CIP1/WAF1) expression, inhibit phosphorylation of Rb, and finally induce G0/G1 arrest in MDA-MB-453 cells.
authors.affiliation: Laboratory of Molecular Biology, Luohe Medical College, Luohe 462002, China. lhyzsgh@163.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Yuan
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Fan
authors.forename: Xu-Guang
authors.initials: XG
authors.lastname: Yang
authors.forename: Shu-Mei
authors.initials: SM
authors.lastname: Rao
authors.forename: Jin-Ling
authors.initials: JL
authors.lastname: Song
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Song
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D018969:Insulin-Like Growth Factor Binding Proteins / Q000494:pharmacology*; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D013002:Somatomedins; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D007093:Imidazoles; D018969:Insulin-Like Growth Factor Binding Proteins; D011725:Pyridines; D013002:Somatomedins; C102529:insulin-like growth factor binding protein-related protein 1; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580