X-ray and ultraviolet C irradiation-induced γ-H2AX and p53 formation in normal human periosteal cells in vitro: markers for quality control in cell therapy

Intensive oxidative stress induces sustained high levels of γ-H2AX and p53, which force cells toward senescence or non-apoptotic cell death. Lower doses of oxidative stress induced more modest and transient increases in γ-H2AX and p53, and these cells eventually survive. However, because DNA is repaired without a template in the majority of these cells, G1 mutations accumulate. Therefore, we recommend that any cell population expressing elevated γ-H2AX and p53 levels be excluded from cell transplantation therapy.