Low-level oxidative stress causes cell-cycle specific arrest in cultured cells.

Oxidative stress is involved in a multitude of pathological conditions. In the present study, cell cycle arrest was demonstrated in monolayer cultures of Chinese hamster ovary cells subjected to low-level oxidative stress induced by the addition of hydrogen peroxide. Fluorescence-activated cell sorting analysis characterized this arrest as occurring in both the G1 and G2/M phases of the cell cycle. Upon exposure to oxidative stress, cells in G1 arrest in G1, while S-phase cells complete DNA synthesis and subsequently arrest in G2/M. Nitroxide spin labels with differing permeabilities are able to protect the cells, which suggests that both the G1 and the G2/M arrest involve oxidation of targets located at the cell surface.