Preliminary Study Of Maintaining In Floating-culture System And Screening Side Population In Human Breast Cancer Cell Line MCF-7

Objectives: To study whether the human breast cancer line MCF-7 contains breast tumor stem cell and its growing patten in serum-free medium supplemented with mitogens.Methods: Adherent MCF-7 cells in serum-supplemented medium were dissociated to single cell suspensions and were seeded in serum-free medium supplemented with bFGF and EGF in 6-well plates. After the MCF-7 breast cancer spheres formed,they were dissociated and passaged periodically. Limiting dilution analysis and monoclonal formation assay were also performed. Antibody CD24^-/LOW CD44⁺ cells and side population were detected with flow-cytometric analysis. MCF-7 breast cancer spheres were induced to differentiate in the medium with 10% FBS supplemented.Results: About 2.12% of MCF-7 cells are clonogenic in MCF-7 cell line. They can generate breast cancer spheres for prolonged times. MCF-7 spheres can be induced to differentiate and adherent to the bottom of the culture plates. The growing patterns of MCF-7 cell can be concerted by changing the culture mediums. By using a FACScan, there are 83.13% CD24^-/LOW CD44⁺ cells and 20% sp cell in MCF-7 cell line.Conclusion: MCF-7cell line contains some breast cancer stem cells. The cell line can be maintained in serum-free mediumwith floating-culture method for prolonged times. There are 1/8 cells which are real breast cancer stem cells, according to the result of low-cytometric analysis.