The study shows how stem cell expansion in breast cancer (called Notch activity) takes place.
Breast cancer stem cells are known to be involved in therapy resistance and the recurrence of cancerous tumours.

Headed by Dr. Richard Pestell and colleagues at Thomas Jefferson University, the study was the first to show that cyclin d1 is required for breast cancer growth in mice.

It is known that cyclin d1 is over-expressed in human breast cancer, thus, the results of the study may explain how cyclin d1 contributes to breast tumour growth, and provide the rationale for targeted therapies at cancerous stem cells in humans. "Breast and other cancers are maintained through a population of cancer stem cells. By specifically targeting cancer stem cells we hope to reduce recurrence and improve therapy responses," said Pestell.

Cancer is formed due to the accumulation of multiple genetic lesions that ultimately result in unregulated cell cycle, and Notch activity is a key determinant of the cellular development and differentiation related to this process.

The molecular mechanisms regulating Notch activity are of fundamental importance for future therapy because Notch signalling is activated in human breast cancer, (and a negative regulator of Notch signalling reduces the disease).

The study is appearing in Clinical and Translational Science.