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[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 ] [Article in Chinese]

YUAN Lei, FAN Wen-Juan, YANG Xu-Guang, RAO Shu-Mei, SONG Jin-ling, SONG Guo-Hua ^*

Laboratory of Molecular Biology, Luohe Medical College, Luohe 462002, China

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.

Key words: insulin-like growth factor binding protein 7; MDA-MB-453; proliferation; p38MAPK; p21CIP1/WAF1

Received: 2013-03-30　　Accepted: 2013-06-19

Corresponding author: 宋国华　　E-mail: lhyzsgh@163.com

Citing This Article：

YUAN Lei, FAN Wen-Juan, YANG Xu-Guang, RAO Shu-Mei, SONG Jin-ling, SONG Guo-Hua . [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 ] [Article in Chinese]. Acta Physiol Sin 2013; 65 (5): 519-524 (in Chinese with English abstract).