Isolation and characterization of breast cancer stem cells from malignant tumours in Vietnamese women

Abstract

Cancer stem cells are the origin of tumors and have been isolated successfully from different kinds of tumors. Breast cancer stem cells have been recently identified in breast carcinoma with markers CD44+/CD24-/dim. This population can cause tumor and display stem cell-like properties. However, direct evidences that breast cancer stem cells can be propagated in vitro is still lacking. This research was carried out to isolate and propagate in vitro breast cancer stem cells from tumor biopsy. Breast tumor biopsy was used to isolate breast cancer cells by primary tissue culture. As such, breast cancer stem cells were isolated from breast cancer cells by catcher-tube based cell sorter on flow cytometter machine. These cells were propagated by an in vitro culture in a free serum specific medium. The results showed that the CD44+CD24-/dim cell population that were maintained, were capable of self-renewal and extensive proliferation as clonal non-adherent spherical clusters. Interestingly, cultured cells were CD44+CD24-/dim expressed by the putative stem cell marker Oct-4, resistant with verapamil at 50 µg/ml, and gave rise to new tumors when as few as 1000 cells were injected into the mammary fat pad of immune-deficient mice. This population was a suitable in vitro model to study breast cancer stem cells and develop therapeutic strategies to treat breast cancer. Key words: Breast cancer, breast tumor, cancer stem cell, CD44+CD24-/dim.