A novel method to limit breast cancer stem cells in states of quiescence, proliferation or differentiation: Use of gel stress in combination with stem cell growth factors

The majority of cancer stem cells exist in the G0, or quiescent phase of the cell cycle. However, the cells can escape quiescence following routine radiotherapy and chemotherapy, resulting in tumor recurrence. Presently, achieving the accurate regulation of cancer stem cell growth in order to study a specific state, including the quiescent (mostly G0 or G1 phase), proliferative (mostly S phase) or differential (mostly G2/M phase) states, can be challenging. This makes the determination of cell cycle state-specific characteristics and analysis of potential intervention treatments difficult, particularly for quiescent cells. Breast cancer stem cells were cultured on a soft or hard agar matrix surface in the presence or absence of stem cell growth factors. Cells could be successfully limited in either the quiescent, proliferative or differentiated states. These findings provide a foundation for further study of the cell cycle in breast cancer stem cells.