Extracellular matrix and radiation G1 cell cycle arrest in human fibroblasts.

It is thought that sublethal doses of radiation cause cells to pause in either G1 or G2 phase, but that then cells with repaired DNA damage reenter the cell cycle. However, it has been observed that gamma-irradiation causes normal human fibroblasts to arrest indefinitely in G1 phase unless the irradiated cells are subcultured. This indicates that cell adhesion plays a role in maintaining the arrest.