Knocking Down p53 with siRNA Does Not Affect the Overexpression of p21~(WAF-1) after Exposure of IMR-90 hTERT Fibroblasts to a Sublethal Concentration of H_2O_2 Leading to Premature Senescence

摘要

Premature senescence of IMR-90 human diploid fibrob-lasts (HDFs) expressing telomerase was induced by exposure to sub-lethal concentration of H_2O_2, with appearance of several biomarkers of cellular senescence like enlarged cell shape, senescence-associated P-galactosidase (SA β-gal) activity, and cell cycle arrest. The induction of stress-induced premature senescence (SIPS) was associated with a transient increase in DNA-binding activity of p53 and an increased expression of p21~(WAF-1)· p53 small interferent RNA (siRNA) affected the basal level of p21~(WAF-1) mRNA but did not affect the overexpression of p21~(WAF-1) after stress. This siRNA approach confirms previous results obtained with other methods.