[Isolation of CD44+/CD24 -/low and side population cells from MDA-MB-453 cells and the analysis of their activation of Wnt and Notch pathway].

OBJECTIVE

To explore stem cells phenotype of human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer cells, MDA-MB-453 by isolation of CD44+CD24(-/low) and side population(SP). Analyze the relationship between SP cells and the gene amplification levels of the key proteins, beta-catenin and Notch-1 in Wnt and Notch signal pathways. And study the correlation of SP cells and the gene amplification of HER2 and human epidermal growth factor receptor 3 (HER3).

METHODS

CD44+CD24(-/low) and SP phenotype were studied in MDA-MB-453 (HER2-overexpressing cell line) and MCF7 (HER2 negative cell line) respectively by flow cytometry. The gene amplification of Beta-catenin and Notch-1 in Wnt and Notch pathways were also studied by reverse transcriptase polymerase chain reaction (RT-PCR). The gene amplification levels of the proteins mentioned, HER2 and HER3 were roughly compared in MDA-MB-453 cells and their SP by RT-PCR.

RESULTS

There was no CD44+CD24(-/low) subpopulation in MDA-MB-453 cells, However, SP could be observed in MDA-MB-453. The gene amplification levels of beta-catenin and Notch-1 in Wnt and Notch pathways were both observed in MDA-MB-453 and MCF7. Their gene amplification levels were more evident in SP of MDA-MB-453 than in MDA-MB-453 cells. However, the similar gene amplification levels of HER2 and HER3 were observed.

CONCLUSION

SP can be enriched in breast cancer stem cells of MDA-MB-453. Wnt and Notch pathways are activated in MDA-MB-453, which may be related to maintenance and activity of breast cancer stem cells of MDA-MB-453.