Telomere length maintenance in aging and carcinogenesis.

  • Authors:
    • M Aragona
    • R Maisano
    • S Panetta
    • A Giudice
    • M Morelli
    • I La Torre
    • F La Torre
  • View Affiliations

  • Published online on: November 1, 2000     https://doi.org/10.3892/ijo.17.5.981
  • Pages: 981-990
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Abstract

Normal somatic cells have a finite number of divisions, a limited capacity to proliferate. Human telomeres, the long DNA TTAGGG repeats at the ends of chromosomes, are considered a molecular clock marker. The gradual and progressive telomere shortening at each replicative cycle is associated, through the activation of pRB and p53 pathways and genomic instability, to the replicative senescence, a non-dividing state and widespread cell death. Activation of telomere maintenance [telomerase; or alternative lengthening of telomeres mechanisms (ALT), or other adaptive responses] can revert this program. Although not completely known, several mechanisms and modulating agents may be able to up and down-regulate telomere length and its maintenance. Chemopreventive therapies for the up-regulation of telomerase activity, able to prolong the life of cell cultures in a phenotypically youthful state, could have important applications in research and medicine. On the contrary the therapeutic down-regulation of telomerase activity may be used in cancer therapy. Telomerase expression per se is not oncogenic, but telomere shortening and maintenance seem to be crucial events in tumor formation. Thus a particular focus has been pointed out relatively to the immortalization of normal or potential pre-cancerous cells. With the extension of life span the probability to get in contact with carcinogens increases, genetic instability, oncogene activation and/or onco-suppressor gene inactivation (i.e. p53, pRB, ras): the cancer transformation can be then induced in predisposed cells, depending on their genetic context, by the activation of telomere maintenance. Pharmacological intervention may be able to modulate the rate of living, by increasing life span of few specific target cells, or decreasing it in proliferating . Because of the unknown state of the enormous cell number of the human organism, is it safe to extend the human life span by therapeutic agents?

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Nov 2000
Volume 17 Issue 5

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Aragona M, Maisano R, Panetta S, Giudice A, Morelli M, La Torre I and La Torre F: Telomere length maintenance in aging and carcinogenesis.. Int J Oncol 17: 981-990, 2000
APA
Aragona, M., Maisano, R., Panetta, S., Giudice, A., Morelli, M., La Torre, I., & La Torre, F. (2000). Telomere length maintenance in aging and carcinogenesis.. International Journal of Oncology, 17, 981-990. https://doi.org/10.3892/ijo.17.5.981
MLA
Aragona, M., Maisano, R., Panetta, S., Giudice, A., Morelli, M., La Torre, I., La Torre, F."Telomere length maintenance in aging and carcinogenesis.". International Journal of Oncology 17.5 (2000): 981-990.
Chicago
Aragona, M., Maisano, R., Panetta, S., Giudice, A., Morelli, M., La Torre, I., La Torre, F."Telomere length maintenance in aging and carcinogenesis.". International Journal of Oncology 17, no. 5 (2000): 981-990. https://doi.org/10.3892/ijo.17.5.981