Alternative lengthening of telomeres in human cells

Radiat Res. 2001 Jan;155(1 Pt 2):194-200. doi: 10.1667/0033-7587(2001)155[0194:alotih];2.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Line, Transformed
  • Cell Transformation, Neoplastic
  • Humans
  • Neoplasms / enzymology
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Telomerase / metabolism
  • Telomere / genetics
  • Telomere / metabolism*


  • Telomerase