Breast cancer is a complex and heterogeneous disease with a high degree of intratumor heterogeneity and diversity. In the present study, we isolated morphologically distinct cell types with tumorigenic potential from breast cancer tumor. The cells show epithelial, endothelial, mesenchymal and mixed cell types which were characterized by using specific molecular markers. Our data showed that these CD44+ cells distinctly expressed mesenchymal phenotype with self-renewal potential and proliferative capacity. These cells also expressed oncogenic, cytokine and chemokine markers indicating their cancer initiating stem cell nature. Interestingly, these cancerinitiating cells exhibit an A3624G BRCA2 mutation. This study reports for the first time the heterogeneous population of malignant cells in the breast cancer tumor which are responsible for cancer development. It represents a suitable in vitro model to allow us to study the mechanism of breast cancer development, and to identify and design a specific molecular target for breast cancer therapies even at advanced stage of disease.
breast cancer stem cells, molecular markers, BRCA2, mesenchymal stem cells, molecular targeted therapy.