Senescence Elicits Stemness: A Surprising Mechanism for Cancer Relapse

Abstract

Cellular senescence is traditionally viewed as a permanent form of cell cycle arrest that restrains tumorigenesis. In a recent study in Nature, however, Milanovic et al. (2018) challenge this conventional view, showing that senescence can counterintuitively promote cancer stemness and tumor aggressiveness. This finding suggests that attacking senescence can be exploited in cancer therapy.

Figure 1.. Therapy-Induced Senescence Can Promote Cancer Sternness and Cancer Aggressiveness

In response to cancer therapy, such as chemotherapy or radiation therapy, tumors regress by cell death (apoptosis or necrosis) and senescence. Senescence is traditionally viewed as an endpoint of cancer therapy, as senescent cells are non-dividing. However, Milanovic et al. (2018) report that senescent cells can acquire features of sternness, partly through activation of Wnt. This can give rise to tumor-initiating cells (e.g., cancer stem cells), which can eventually lead to cancer relapse and metastasis.