Variable radiosensitivity in fibroblasts from patients with tuberous sclerosis.

It has been reported that some of the cultured cell strains derived from patients with tuberous sclerosis (TS) showed hypersensitivity to gamma-rays or a radiomimetic chemical. Thirteen fibroblast cell strains from 11 patients with TS were examined for their sensitivity to x-rays as determined from their colony-forming ability. All strains derived from normal-appearing skin of patients, either sporadic or familial cases, showed sensitivity within the normal control range. Five cell strains originating from tumorous skin of 3 patients did not show hypersensitivity. It was concluded that the sensitivity to x-rays of cultured cells of TS is essentially normal. However, the mean D0 or D10 values of the strains from tumorous skin tended to be lower compared to those for normal skin of patients. In addition, we could confirm the hypersensitivity to x-rays in the cell strains of TS which had been shown to be hypersensitive to gamma-rays. These results appear to indicate that at least some of the cells of TS are liable to change to exhibit a hypersensitive trait in unknown acquired conditions.