BJ fibroblasts display high antioxidant capacity and slow telomere shortening independent of hTERT transfection

Human foreskin BJ fibroblasts are well protected against oxidative stress a s shown by their low intracellular peroxide content, low levels of protein carbonyls, and low steady-state lipofuscin content as compared to other pri mary human fibroblasts. This correlates with a long replicative life span o f the parental cells of about 90 population doublings and a telomere-shorte ning rate of only 15-20 bp/PD. This value might define the upper limit of a telomere-shortening rate that can still be explained by the end replicatio n problem alone. In BJ clones immortalized by transfection with hTERT, the catalytic subunit of telomerase, the same telomere-shortening rate as in pa rental cells is observed over a long time despite strong telomerase activit y. Hyperoxia, which induces oxidative stress and accelerates telomere short ening in a variety of human fibroblast strains, does not do so in BJ cells. It is possible that the high antioxidative capacity of BJ cells, by minimi zing the accumulation of genomic damage, is instrumental in the successful immortalization of these cells by telomerase. (C) 2001 Elsevier Science Inc .