Résumé
BACKGROUND:Tumor stem cels are found to be involved in the recurrence, metastasis and drug resistance of the tumor. OBJECTIVE:To explore the relationship between cel activity and multidrug resistance of CD44+CD24-/low breast cancer stem cels. METHODS:CD44+CD24-/low breast cancer stem cels sorted from multidrug resistant breast cancer cel line MCF-7/ADR were detected as percentage using flow cytometry. P-gp fluorescence intensity of the cel membrane and MDR mRNA expression in sorted cels and MCF-7/ADR were detected using flow cytometry and RT-PCR, respectively. RESULTS AND CONCLUSION: After sorting by flow cytometry, the proportion of CD44+CD24-/low breast cancer stem cels was more than 90%, indicating that the sorted cels could meet the needs of the subsequent experiment. CD44+CD24-/low cel subsets exhibited stronger ability to form microspheres than non- CD44+CD24-/low cel subsets. The P-gp fluorescence intensity and MDR mRNA expression of CD44+CD24-/low cels were significantly higher than those of MFC-7/ADR cel line (P < 0.05). These experimental findings suggest that CD44+CD24-/low breast cancer stem cels sorted from MCF-7/ADR cel lines have a strong ability to form cel microspheresin vitro, and significantly raise the level of P-gp protein and MDR mRNA expression, which may be one of the causes of multidrug resistance.