OBJECTIVE: To investigate the influential factors on the formation of mammospheres from MCF-7, MDA-MB-231 and primary breast cancer epithelial cells, and to detect the proportion of CD44+/CD24(-/low) among them. METHODS: MCF- 7, MDA-MB-231 and primary breast cancer epithelial cells were cultured in suspension to generate primary mammospheres. After 7 days of cultivation, the proportion of cancer stem cells was measured in cells derived from mammosphere cells or monolayer culture cells by flow cytometry. RESULTS: MCF-7 had the highest efficiency of mammosphere formation (2.1%+/-0.3%), while MDA-MB-231 cells hardly had any mammosphere formation, and no mammosphere formation was observed in breast cancer epithelial cells. MCF-7 tended to adhere under stem cell culture conditions without B27. Flow cytometry analysis indicated that, compared with 2.0%+/-0.1% for the MCF-7 monolayer culture cells, 11.8%+/-0.3% and 8.2%+/-0.8% of the MCF-7 mammosphere cells from MCF-7 under different conditions were CD44+/CD24(-/low) (P < 0.01). The proportion of CD44+/CD24(-/low) expression in MDA-MB-231 cells and primary breast cancer epithelial cells was 92.2%+/-3.1% and 93.8%+/-2.4%, respectively. CONCLUSION: Compared with monolayer culture cells, MCF-7 mammosphere cells contained higher proportion of breast cancer stem cells, while MDA-MB-231 and primary breast cancer epithelial cells did not. The expression of CD44+/CD24(-/low) in MDA-MB-231 and primary breast cancer epithelial cells did not correlate with mammosphere formation positively.
OBJECTIVE: To investigate the influential factors on the formation of mammospheres from MCF-7, MDA-MB-231 and primary breast cancer epithelial cells, and to detect the proportion of CD44+/CD24(-/low) among them. METHODS: MCF- 7, MDA-MB-231 and primary breast cancer epithelial cells were cultured in suspension to generate primary mammospheres. After 7 days of cultivation, the proportion of cancer stem cells was measured in cells derived from mammosphere cells or monolayer culture cells by flow cytometry. RESULTS: MCF-7 had the highest efficiency of mammosphere formation (2.1%+/-0.3%), while MDA-MB-231 cells hardly had any mammosphere formation, and no mammosphere formation was observed in breast cancer epithelial cells. MCF-7 tended to adhere under stem cell culture conditions without B27. Flow cytometry analysis indicated that, compared with 2.0%+/-0.1% for the MCF-7 monolayer culture cells, 11.8%+/-0.3% and 8.2%+/-0.8% of the MCF-7 mammosphere cells from MCF-7 under different conditions were CD44+/CD24(-/low) (P < 0.01). The proportion of CD44+/CD24(-/low) expression in MDA-MB-231 cells and primary breast cancer epithelial cells was 92.2%+/-3.1% and 93.8%+/-2.4%, respectively. CONCLUSION: Compared with monolayer culture cells, MCF-7 mammosphere cells contained higher proportion of breast cancer stem cells, while MDA-MB-231 and primary breast cancer epithelial cells did not. The expression of CD44+/CD24(-/low) in MDA-MB-231 and primary breast cancer epithelial cells did not correlate with mammosphere formation positively.
Authors: Madhuri Kakarala; Dean E Brenner; Hasan Korkaya; Connie Cheng; Karim Tazi; Christophe Ginestier; Suling Liu; Gabriela Dontu; Max S Wicha Journal: Breast Cancer Res Treat Date: 2009-11-07 Impact factor: 4.872