Defective Recovery from Potentially Lethal Damage in Some Human Fibroblast Cell Strains

Abstract

The repair of potentially lethal damage [PLD] following treatment by .gamma.-radiation was investigated in human fibroblasts held in a non-cycling state by maintenance in a medium containing 0.5% fetal calf serum. Variation in their capacity to repair PLD was noted between 3 normal cell strains. A failure to repair PLD in ataxia-telangiectasia [A-T] cells (AT5BI) was confirmed. In 3 cell strains which were intermediate between normals and A-T cells in their sensitivity, XP3BR [xeroderma pigmentosum], 46BR and GM1142, a limited capacity for the repair of PLD was observed. Two other cell strains, 47BR and 67BR, which showed little if any hypersensitivity could be clearly distinguished from normals after a 24 h period for the repair of PLD. The technique might permit better discrimination between cell strains. One other cell strain, H15617, could be distinguished from normals by proving hypersensitive under all conditions. Here the repair of PLD appeared to be normal.