Determination of genes and microRNAs involved in the resistance to fludarabine <it<in vivo </it<in chronic lymphocytic leukemia

<p<Abstract</p< <p<Background</p< <p<Chronic lymphocytic leukemia (CLL) cells are often affected by genomic aberrations targeting key regulatory genes. Although fludarabine is the standard first line therapy to treat CLL, only few data are available about the resistance of B cells to this purine nucleoside analog <it<in vivo</it<. Here we sought to increase our understanding of fludarabine action and describe the mechanisms leading to resistance <it<in vivo</it<. We performed an analysis of genomic aberrations, gene expression profiles, and microRNAs expression in CLL blood B lymphocytes isolated during the course of patients' treatment with fludarabine.</p< <p<Results</p< <p<In sensitive patients, the differentially expressed genes we identified were mainly involved in p53 signaling, DNA damage response, cell cycle and cell death. In resistant patients, uncommon genomic abnormalities were observed and the resistance toward fludarabine could be characterized based on the expression profiles of genes implicated in lymphocyte proliferation, DNA repair, and cell growth and survival. Of particular interest in some patients was the amplification of <it<MYC </it<(8q) observed both at the gene and transcript levels, together with alterations of myc-transcriptional targets, including genes and miRNAs involved in the regulation of cell cycle and proliferation. Differential expression of the sulfatase <it<SULF2 </it<and of miR-29a, -181a, and -221 was also observed between resistant and sensitive patients before treatment. These observations were further confirmed on a validation cohort of CLL patients treated with fludarabine <it<in vitro</it<.</p< <p<Conclusion</p< <p<In the present study we identified genes and miRNAs that may predict clinical resistance of CLL to fludarabine, and describe an interesting oncogenic mechanism in CLL patients resistant to fludarabine by which the complete <it<MYC</it<-specific regulatory network was altered (DNA and RNA levels, and transcriptional targets). These results should prove useful for understanding and overcoming refractoriness to fludarabine and also for predicting the clinical outcome of CLL patients before or early during their treatment.</p<.

Medienart:

E-Artikel

Erscheinungsjahr:

2010

Erschienen:

2010

Enthalten in:

Zur Gesamtaufnahme - volume:9

Enthalten in:

Molecular Cancer - 9(2010), 1, p 115

Sprache:

Englisch

Beteiligte Personen:

Muller Arnaud [VerfasserIn]
Bernardin François [VerfasserIn]
Leners Bernadette [VerfasserIn]
Van Moer Kris [VerfasserIn]
Aouali Nasséra [VerfasserIn]
El Khoury Victoria [VerfasserIn]
Wenner Thomas [VerfasserIn]
Poirel Hélène A [VerfasserIn]
Vallar Laurent [VerfasserIn]
Palissot Valérie [VerfasserIn]
Moussay Etienne [VerfasserIn]
Cornillet-Lefebvre Pascale [VerfasserIn]
Delmer Alain [VerfasserIn]
Duhem Caroline [VerfasserIn]
Ries Fernand [VerfasserIn]
van Dyck Eric [VerfasserIn]
Berchem Guy [VerfasserIn]

Links:

doi.org [kostenfrei]
doaj.org [kostenfrei]
www.molecular-cancer.com [kostenfrei]
Journal toc [kostenfrei]

Themen:

Neoplasms. Tumors. Oncology. Including cancer and carcinogens

doi:

10.1186/1476-4598-9-115

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

DOAJ057628300