[The opposite roles of telomerase during initiation and progression of cancers].
Telomeres are nucleoprotein complexes that cap the end of eukaryotic chromosomes. They are essential for the functions and the stability of the genomes. In the absence of telomerase, the enzyme that adds telomeric DNA repeats to chromosome ends, telomeres shorten with cell division, a process thought to contribute to cell senescence. Reciprocally, telomere stabilization in immortalized cells, that usually appears concomitant with detection of telomerase activity, suggests that telomerase is essential for unlimited cell proliferation. Sequential modifications in the function of telomeres play antagonistic functions as far as tumorigenesis is concerned. Telomere dysfunction is thought to promote genome instability at initial stages, favoring the emergence of cancer-associated chromosomal abnormalities; reestablishment of telomere maintenance is expected afterwards if efficient cell cycling is to occur.
Brunori
Michele
M
Laboratoire de Biologie Moléculaire de la Cellule, UMR5161, Centre National de la Recherche Scientifique, Ecole Normale Supérieure de Lyon, INRA U1237, 46, allée d'Italie, 69364 Lyon cedex 07, France.
Gilson
Eric
E
D000818:Animals; D002455:Cell Division; D002471:Cell Transformation, Neoplastic; D004195:Disease Models, Animal; D018450:Disease Progression; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000201:enzymology* / Q000473:pathology; D019098:Telomerase / Q000378:metabolism*
D019098:Telomerase
Les rôles opposés de la télomérase pendant l'initiation et la progression des cancers.