Effects of gonadotropin-releasing hormone analogue on sensitivity of breast cancer cells to 5-FU and epirubicin in vitro / 中国病理生理杂志

ABSTRACT

AIM:To investigate whether gonadotropin-releasing hormone analogue(GnRHa)affect the sensitivity of breast cancer cells to 5-FU and epirubicin in vitro.METHODS:Two breast cancer cell lines(MCF-7 and MDA-MB-231)were treated with different concentrations of GnRH analogue,triptorelin acetate,or with a GnRHa+5-FU or GnRHa+epirubicin.The cellular growth profiles were determined by CCK-8.The mRNA levels of GnRH receptor,PCNA and MDR1 were measured by RT-PCR.RESULTS:Both cell lines had positive GnRH receptor mRNA expression detected by RT-PCR.GnRHa did not suppress cell growth after GnRHa exposure.IC50 of 5-FU and epirubicin was not changed in the presence of GnRHa.Suppression of cell growth by the exposure to 5-FU and epirubicin was not changed in the presence of GnRHa.GnRHa treatment up-regulated PCNA mRNA expression in MDA-MB-231 cells but not in MCF-7 cells.The expression of MDR1 mRNA was down-regulated by GnRHa in MCF-7 cell lines.No MDR1 mRNA expression in MDA-MB-231 cells was observed.CONCLUSION:The present data suggest that GnRH analogue(triptorelin acetate)does not affect the sensitivity of breast cancer cell lines MCF-7 and MDA-MB-231 to 5-FU and epirubicin.GnRHa may decrease the drug resistance by down-regulating MDR1 mRNA expression.