Modification of topoisomerase genes copy number in newly diagnosed childhood acute lymphoblastic leukemia.
Fiche publication
Date publication
mars 2003
Auteurs
Membres identifiés du Cancéropôle Est :
Dr GUERIN Eric, Pr OUDET Pierre
Tous les auteurs :
Guerin E, Entz-Werle N, Eyer D, Pencreac'h E, Schneider A, Falkenrodt A, Uettwiller F, Babin A, Voegeli AC, Lessard M, Gaub MP, Lutz P, Oudet P
Lien Pubmed
Résumé
Topoisomerase genes were analyzed at both DNA and RNA levels in 25 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL). The results of molecular analysis were compared to risk group classification of children in order to identify molecular characteristics associated with response to therapy. At diagnosis, allelic imbalance at topo-isomerase IIalpha (TOP2A) gene locus was found in 75% of informative cases whereas topoisomerase I and IIbeta gene loci are altered in none or only one case, respectively. By semi-quantitative Polymerase chain reaction, we found a 2.5 to 8-fold TOP2A gene amplification in 72% of the children, which was correlated to gene overexpression in every case. These results show that TOP2A gene amplification is a frequent event in ALL at diagnosis. Interestingly, we also identified a small population of children that do not present TOP2A gene amplification or gene overexpression and who are significantly associated with very high risk classified patients showing glucocorticoid resistance. In conclusion, characterization of TOP2A gene status in childhood ALL at diagnosis provides useful complementary information for risk assessment.
Référence
Leukemia. 2003 Mar;17(3):532-40.