Background and purpose:Exposure to estrogen is an important independent determinant of the risk of breast cancer.Moreover,chemokines and its corresponding receptors play an important role in breast cancer occurrence and development.Our study is to investigate the impact and related mechanism of estrogen on chemokines expression in breast cancer cells.Methods:Microarray was performed to analyse chemokine and corresponding receptors' mRNA expression in MCF-7 cells treated with estradiol.Real-time(RT)-PCR was applied to confirm the change of chemokine expression at different time point with different dose of estradiol in presence or absence of ICI182,780.ELISA was used to analyse the change of extracelluar secrete protein.Results:Physiological estradiol could obviously up-regulate CXCL12 mRNA expression in breast cancer cell MCF-7,which emerged from 4h after treatment and continued to 24 h.In addition,estradiol could stimulate CXCL12 protein secretion from 2h to 24h after treatment.These effects could be totally inhibited when MCF-7 was treated with ICI182,780(ER antagonist)prior to estradiol.Conclusions:Our study demonstrated that estrogen could up-regulate CXCL12 mRNA expression and its extracelluar protein secretion,which was mediated through ER signaling pathway.

This study primarily explored and discussed‘generality and individuality’mode in clinical teaching of congenital heart disease(Congenital heart disease,CHD)from the aspects of teaching methods,comparison with traditional method,requirements for teachers and problems existed under present conditions.At last the paper summarized advantages and disadvantages of this model in clinical teaching of CHD and offered a new approach for clinical teaching of cardiology.