Brca1 breast tumors contain distinct CD44+/CD24- and CD133+ cells with cancer stem cell characteristics.

Introduction: Whether cancer stem cells occur in BRCA1-associated breast cancer and contribute to therapeutic response is not known.

Methods: We generated and characterized 16 cell lines from five distinct Brca1deficient mouse mammary tumors with respect to their cancer stem cell characteristics.

Results: All cell lines derived from one tumor included increased numbers of CD44+/CD24- cells, which were previously identified as human breast cancer stem cells.