Breast cancer stem cells

Abstract

Cancer metastasis, resistance to therapies and disease recurrence are significant hurdles to successful treatment of breast cancer. Identifying mechanisms by which cancer spreads, survives treatment regimes and regenerates more aggressive tumors are critical to improving patient survival. Substantial evidence gathered over the last 10 years suggests that breast cancer progression and recurrence is supported by cancer stem cells (CSCs). Understanding how CSCs form and how they contribute to the pathology of breast cancer will greatly aid the pursuit of novel therapies targeted at eliminating these cells. This review will summarize what is currently known about the origins of breast CSCs, their role in disease progression and ways in which they may be targeted therapeutically.

Keywords: breast cancer; cancer stems cells; cell fate; mammary gland; transcription factors.

Figure 1

Models of CSC formation. In the linear hierarchy model of CSC formation, the transformation events that drive tumorigenesis occur in a stem or progenitor cell that then gives rise to more differentiated progeny as the tumor develops. These differentiated progeny have reduced tumor-forming potential. In the second model, cancer stem cells evolve, perhaps via induction of EMT, either as part of disease progression or in response to selective pressures in the tumor microenvironment.