Chromosome aberration induction in human diploid fibroblast and epithelial cells

The relative sensitivity of cultured human fibroblasts and epithelial cells to radiation-induced chromosomal aberrations was investigated. Lung fibroblast and kidney epithelial cells from the same fetus were compared, as were skin fibroblasts and epithelial keratinocytes from the same foreskin sample. After exposure of proliferating fetal cells to 1.5 Gy X-rays there was a very similar aberration yield in the fibroblasts and epithelial cells; the mean frequency between 1 and 72 h post-irradiation was 25 and 29% aberrant cells, respectively. After 1.5 Gy the corresponding values in skin fibroblasts and epithelial cells were 16.5 and 11.2%, respectively, and after 2.5 Gy, 31.3 and 30%. These observations of either little or no difference in chromosomal sensitivity between human fibroblasts and epithelial cells give added confidence that quantitative cytogenetic data obtained from cultured fibroblasts are relevant to the question of sensitivity of epithelial cells which are the predominant cell type in human cancers.