Effects of As_2O_3 on hTERT gene expression and telomerase activity in HL-60 cells

Objective To evaluate the effects of arsenic trioxide (As 2O 3) on human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in HL 60 cells.Methods Apoptosis was detected by morphological observation and flow cytometric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcription polymerase chain reaction (RT PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label respectively. Telomerase activity was determined by polymerase chain reaction enzyme linked immunoassay (PCR ELISA) in HL 60 cells untreated or treated with As 2O 3. Results Both hTERT mRNA and protein levels were decreased during induced apoptosis of HL 60 cells with As 2O 3. Telomerase activity of HL 60 cells was significantly inhibited.Conclusion It is suggested that telomerase activity might be specifically inhibited in HL 60 cells treated by As 2O 3 through the downregulation of hTERT gene expression.