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 G(1) and G(2)/M phases of the cell cycle. Upon exposure to oxidative stress, cells in G(1) arrest in G(1), while S-phase cells complete DNA synthesis and subsequently arrest in G(2)/M. Nitroxide spin labels with differing permeabilities are able to protect the cells, which suggests that both the G(1) and the G(2)/M arrest involve oxidation of targets located at the cell surface. (C) 1995 Academic Press, Inc.