Inactivation of p53 and amplification of MYCN gene in a terminal lymphoblastic relapse in a chronic lymphocytic leukemia patient

Autor: Jitka Malčíková, Iveta Valášková, Ludmila Bourková, Katerina Stano-Kozubik, Jana Šmardová, Marek Borsky, Hana Skuhrová Francová, Šárka Pospíšilová, Martin Trbušek, Jana Kotašková, Michael Doubek, Viera Hrabčáková, Yvona Brychtová, Jiri Mayer, Boris Tichy
Rok vydání: 2009
Předmět:
Zdroj: Cancer Genetics and Cytogenetics. 189:53-58
ISSN: 0165-4608
Popis: B-cell chronic lymphocytic leukemia (CLL) is an incurable disease with a highly variable clinical course. A proportion of patients eventually progress to a higher stage of malignancy. A recent association has been observed between the presence of aberrant somatic hypermutations in leukemic cells (hypermutations occurring outside of the immunoglobulin locus) and the transformation to a diffuse large B-cell lymphoma or prolymphocytic leukemia. In this study, we report on the rarely observed blastic transformation in a CLL patient who had previously been shown to harbor aberrant somatic hypermutations in the TP53 tumor-suppressor gene (Mol Immunol 2008;45:1525-29). The enzyme responsible, the activation-induced cytidine deaminase, was still active within the transformation, as evidenced by the ongoing class-switch recombination of cytoplasmic immunoglobulins. The transformation was accompanied by a complete p53 inactivation, as well as complex karyotype changes including prominent amplification of MYCN oncogene. Our case-study supports the view that the aberrant somatic hypermutation is associated with transformation of CLL to a more aggressive malignancy.
Databáze: OpenAIRE