Study of mechanisms involved in the resistance to apoptosis of cells infected with the Epstein-Barr virus and development of new therapeutic strategies for treatment of B lymphomas

  • Résumé en anglais : Our team is working on the mechanisms of apoptosis induced by nutlin-3, a small molecule which binds to MDM2 and activates p53, in different lymphomas associated with Epstein-Barr virus such as Burkitt lymphoma (BL) or Post-transplant lymphoproliferative disorder (PTLD). Our results show that nutlin-3 strongly induce apoptosis in EBV (-) cells whereas EBV (+) latency III cells are much more resistant. The aim of my PhD project was to study the mechanisms involved in the resistance of EBV (+) latency III cells to apoptosis and to develop new therapeutic strategies to bypass these mechanisms. A transcriptomic analysis was realized after treatment with nutlin-3 of two cell lines which only differs by their EBV status. Based on the results obtained, a study was performed which allow us to show that: 1) autophagy is induced after nutlin-3 treatment in EBV (+) latency III cells; 2) these cells strongly expressed beclin-1 and present a constitutively high level of autophagy; 3) autophagy is involved in the resistance of apoptosis observed in these cells. Furthermore, our results demonstrate that Bcl-2 also contributes to the resistance of EBV (+) latency III cells and that treatment with ABT-737, a Bcl-2 inhibitor, restores their susceptibility to nutlin-3 treatment. We thus assessed the efficiency of this compound in vivo, in monotherapy or associated with conventional treatments (Cyclophosphamide for BL and Rituximab for PTLD). Results obtained during these pre-clinical studies show that: 1) ABT-737 reduces tumor growth and increase the overall survival of mice xenografted with a lymphoblastoïd cell line (LCL, used as a model for PTLD studies) but has no effects on mice xenografed with BL cell lines; 2) the association ABT-737/Cyclophosphamide reduces tumor growth during treatment but doesn’t improve the overall survival of mice xenografed with BL cell lines; 3) the association ABT-737/Rituximab is very efficient and induces 70% of complete remission in mice xenografted with LCL.

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Source https://theses.hal.science/tel-00767146
Author Pujals, Anaïs
Maintainer CCSD
Last Updated May 30, 2026, 04:50 (UTC)
Created May 30, 2026, 04:50 (UTC)
Identifier NNT: 2012PA11T054
Language fr
Rights https://about.hal.science/hal-authorisation-v1/
contributor Interactions moléculaires et cancer (IMC (UMR 8126)) ; Signalisation, noyaux et innovations en cancérologie (UMR8126) ; Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Centre National de la Recherche Scientifique (CNRS)
creator Pujals, Anaïs
date 2012-10-04T00:00:00
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metadata_modified 2026-03-30T00:00:00
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