Preliminary study of the effects of β-elemene on breast cancer stem cells in cell line MCF-7/ADM

Objective To investigate the differences between breast cancer cell line MCF-7/ADM resistant to adriamycin(ADM) and sensitive cell line MCF-7/S in proportion of breast cancer stem cells(BCSCs) and expression levels of breast cancer resistance protein(BCRP) and P-glycoprotein(P-gp),and to further observe the effects of traditional Chinese medicine β-elemene(βELE) on BCSCs and expressions of BCRP and P-gp.Methods MCF-7 / ADM and MCF-7 / S cell lines were cultured in the serum-free medium(SFM) and microspheres formation ratio was observed under phase contrast microscope.The expression levels of resistance genes BCRP and P-gp were detected by RT-PCR.The ratio of BCRP and P-gp positive cells and percentage of CD44+CD24-/ lowsubpopulation were analyzed by flow cytometry.The microsphere formation ratio and the expressions of BCRP,P-gp protein and mRNA in cell line MCF-7 / ADM were detected after being treated by 15μg / ml β-ELE for 48h.Results The results of morphology and RT-PCR indicated that microspheres formation ratio in the SFM and expression levels of BCRP and P-gp in MCF-7 / ADM were higher than those in MCF-7 / S.The flow cytometry analysis showed the positive rates of protein expressions of BCRP and P-gp in MCF-7 / ADM were(77.78 ±9.55) % and(32.33 ±5.12) %,and the percentage of CD44+CD24-/ lowsubpopulation was(64.79 ± 11.78) %,significantly higher than(3.97 ± 1.51) %,(14.26 ± 2.51) %,(18.79 ± 3.28) % in MCF-7 / S with statistically significant differences.βELE inhibited obviously microspheres formation ratio,decreased mRNA and protein levels of BCRP and P-gp.Conclusion MCF-7 / ADM cell line is a resistant cell population which enriched relatively BCSCs and high-expressed resistance proteins.β-ELE can inhibit proportion of BCSCs and microspheres formation ratio,and reduce the expression levels of resistance proteins in MCF-7 / ADM.