Irradiation of adult human dental pulp stem cells provokes activation of p53, cell cycle arrest, and senescence but not apoptosis
Abstract
Adult human dental pulp contains stem cells (DPSCs) that are capable of differentiation into osteoblasts, odontoblasts,adipocytes, and neuronal-like cells. Because these cells have potential use in tissue regeneration, herein we characterized the response of DPSC lines to ionizing radiation (IR).
These DPSC lines have been developed from the extracted molars of healthy donors. DPSCs were cultivated in a unique media supplemented with epidermal growth factor (EGF) and platelet-derived growth factor (PDGF).
Since tissue homeostasis depends on a precise balance among cell proliferation, senescence, and cell death, we explored the effects of IR (2–20 Gy) on the proliferative activity of DPSCs and the molecular pathways involved. Even the highest dose used (20 Gy) did notinduce DPSC apoptosis.
After irradiation with doses of 6 and 20 Gy, DPSCs accumulated in the G2 phase of the cell cycle.