Stem Cell Dormancy Linked to Cancer Suppression

Researchers from the University of California/Los Angeles (UCLA; California, USA)  have discovered a mechanism by which certain adult stem cells suppress their ability to initiate skin cancer during their dormant phase — an understanding that could be exploited for better cancer-prevention strategies.  Using mouse models, William Lowry and colleagues applied known cancer-causing genes to hair follicle stem cells and found that during their dormant phase, the cells could not be made to initiate skin cancer. Once they were in their active period, however, they began growing cancer.  Observing that tumor suppression via adult stem cell quiescence was mediated by PTEN, a gene important in regulating the cell’s response to signaling pathways, the study authors write that: “Pten activity is necessary for quiescence-based tumour suppression, as its deletion alleviates tumour suppression without affecting proliferation. These data demonstrate that stem cell quiescence is a form of tumour suppression in [hair follicle stem cells], and that Pten plays a role in maintaining quiescence in the presence of tumorigenic stimuli.”