Inhibitive effects of trichostatin A on telomerase activity of HL-60 cells and expression of subunit hTERT during apoptosis

Aim To investigate the inhibitive effects of trichostatin A(TSA) on telomerase activity of HL-60 cells and expression of subunit hTERT during apoptosis in vitro and its mechanism.Methods The proliferative activity of HL-60 cells was assessed using morphology and MTT assay.Cell apoptosis was confirmed using Flow Cytometer.Telomerase activity was examined using TRAP-ELISA.The expression status of telomerase subunits was analyzed using RT-PCR.Results A time-and dose-dependent inhibition was detected in HL-60 cells treated with TSA.After 48 h TSA(300 nmol·L~(-1)) treatment,the apoptotic rate detected using cytometric assay(Annexin V/PI double staining)of HL-60 cells was 42.6%.Telomerase activity and expression level of hTERT and the key subunit of telomerase decreased at 24-hour after TSA treatment.No significant changes were observed in the expression of hTR,hTP and the other two subunits of telomerase.Conclusion TSA inhibits telomerase activity and induces apoptosis in HL-60 cells.The underlying mechanism might be related to the down regulation of hTERT transcription.