In vivo and in vitro analyses of Myc for differential promoter activities of the human telomerase (hTERT) gene in normal and tumor cells

Induction of the catalytic subunit of human telomerase, hTERT, plays a crit ical role in the activation of telomerase during tumorigenesis. Here, we is olate the hTERT gene promoter and define the functional promoter region, wh ich is inactive in normal cells but active in tumor cells. Myc directly int eracts with the hTERT promoter and activates its transcription both in vivo and in vitro. Activation or repression of Myc can alter hTERT promoter act ivities in normal or tumor cells. Furthermore, we detect high levels of Myc protein in tumor cells compared with normal cells. The ability of Myc to m odulate the activity of the hTERT promoter and, hence, the telomerase enzym e may contribute to its ability to promote tumor formation. (C) 1999 Academ ic Press.