Objective To investigate the H

2O

2-induced expression of human histone acetyltransferase-like protein （hALP）

a telomerase regulation-associated gene

and its effects on the stress-triggered cellular senescence.Methods The induced expression of hALP was measured by semi-quantitative RT-PCR and immunofluorescent histochemistry after treatment of HeLa cells by H

2O

2.The effects of hALP expression on cellular responses to H

2O

2 were analyzed by MTT

flowcytometry

and SA-β-gal staining

respectively.Results hALP mRNA could be dose-dependently induced by treatments of 0.2-1.6 mmol/L H

2O

2

and the induction could be observed after 6 hours and kept for 36 hours in the presence of 0.4 mmol/L H

2O

2.Meanwhile

the immunofluorescent staining showed marked stronger nuclear intensity of hALP protein in H

2O

2-treated HeLa cells.In the treatment of H

2O

2

the ectopic expression of hALP enhanced continuous growth and overcame G

2/M arrest as well as decreased senescence-associated β-gal staining.On the contrary

the transfected clones with antisense or blank vector and original HeLa cells presented growth suppression

G

2/M delay and higher percentage of SA-β-gal activities in the presence of H

2 O

2.Conclusions The expression of hALP could be up-regulated by treatment of H

2O

2

and elevated expression could enhance cellular resistance to H

2O

2-induced cellular senescence.The data might be of references to elucidation of basic biological function of hALP gene and its associated telomerase activity.