SIMILAR GENE-EXPRESSION PATTERN IN SENESCENT AND HYPEROXIC-TREATED FIBROBLASTS

Different DNA-damaging treatments produce a senescence-like phenotype. Young human fibroblasts are transferred to a senescence-like state af ter 4 to 6 weeks of culture under 40% ambient oxygen partial pressure. In order to understand the causes of senescence it would be advantage ous to know how well this state equals accelerated senescence. Therefo re, we measured;the expression of genes with known senescence-specific expression pattern in human fibroblasts, which were irreversibly prol iferation-inhibited by chronic hyperoxic treatment A senescence specif ic gene expression pattern was confirmed by semiquantitative RT-PCR fo r eight out of nine examined genes in BJ foreskin fibroblasts and for four out of four genes in MRC-5 lung fibro blasts. For all these eases , gene expression under hyperoxia was similar to that in senescent cel ls, suggesting that chronic mild hyperoxia is a valid model for accele rated senescence.