Alternative Lengthening of Telomeres in Human Cells

Reddel, R. R., Bryan, T. M., Colgin, L. M., Perrem, K. T. and Yeager, T. R. Alternative Lengthening of Telomeres in Human Cells.Activation of a telomere maintenance mechanism appears to be essential for immortalization. In most human tumors and tumor cell lines, the telomere maintenance mechanism involves the activity of telomerase, a reverse transcriptase holoenzyme that synthesizes telomeric repeat DNA. In some cases, telomere maintenance occurs in the absence of telomerase activity by a mechanism referred to as alternative lengthening of telomeres (ALT). The development of telomere-targeted anticancer therapies will be facilitated by an understanding of the molecular mechanisms of ALT and of the means whereby ALT is repressed in normal cells.