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Biology subjects

Lauret, E.

Publications and source records attributed to Lauret, E..

2 recordsLinked to original sources

Classical Myelo-Proliferative Neoplasms emergence and development based on real life incidence and mathematical modeling

Mathematical modelling allows us to better understand the emergence and evolution of myeloproliferative neoplasms. We tested different mathematical models on a first cohort (patients) (Cote dOr Registry) to determine the onset and evolution times before JAK2V617F classical myeloproliferative disorders (polycythemia vera and essential thrombocythemia) are diagnosed. We considered the time to diagnosis as the sum of two periods: the time (from embryonic development) for the JAK2V617F mutation to appear, not disappear and enter proliferation, and a second period corresponding to the expansion of the clonal population until diagnosis. Using increasingly complex models, we show that the rate of active mutation cannot be constant, but rather increases exponentially with age, following the well-known Gompertz model. We found that it takes an average of 63.1 +/- 13 years for the first tumor cell to appear and start proliferating. On the other hand, the expansion time is constant: 8.8 years once the mutation has occurred. These results were validated in an external cohort (national FIMBANK cohort). Using this model, we analyzed JAK2V167F Essential Thrombocythemia versus Polycythemia Vera and found that the time to active mutation in PV is about 1.5 years longer than in ET, while the expansion time is similar. In conclusion, our multi-step approach and the final age-dependent model for the onset and development of MPN shows that the onset of a JAKV617F mutation should be linked to an ageing mechanism and indicates a period of 8-9 years for the development of a full MPN.

cancer biology↗

Identification of new proviral and antiviral factors through the study of the Dicer-2 interactome in vivo during viral infection in Drosophila melanogaster

RNA interference, which has a major role in the control of viral infection in insects, is initialized by the sensing of double stranded RNA (dsRNA) by the RNAse III enzyme Dicer-2. Although many in vitro studies have helped understand how Dicer-2 is able to discriminate between different dsRNA substrate termini, much less is known about how this translates to the in vivo recognition of viral dsRNA. Indeed, although Dicer-2 associates with several dsRNA-binding proteins (dsRBPs) that can modify its specificity for a substrate, it remains unknown how Dicer-2 is able to recognize the protected termini of viral dsRNAs. In order to study how the ribonucleoprotein network of Dicer-2 impacts antiviral immunity, we used an IP-MS approach to identify in vivo interactants of different versions of GFP::Dicer-2 in transgenic lines. We provide a global overview of the partners of Dicer-2 in vivo, and reveal how this interactome is modulated by different factors such as the viral infection and/or different point mutations inactivating the helicase or RNase III domains of GFP::Dicer-2. Our analysis uncovers several previously unknown Dicer-2 interactants associated with RNA granules (i.e. Me31B, Rump, eIF4E1 & Syp). Functional characterization of the candidates reveals pro- and antiviral factors in the context of the infection by the picorna-like DCV virus. In particular, the protein Rasputin has been identified as a novel antiviral candidate. The resources provided by this work can be used to gain a better understanding of the molecular complexes assembled around Dicer-2 in the context of antiviral RNAi and beyond.

immunology↗