Abstract
Myeloproliferative Neoplasms (MPN) are stem and progenitor cell (HSPC) neoplasms which present an overproduction of differentiated cells. These neoplasms, comprised of Essential Thrombocythemia (ET), Polycythaemia Vera (PV) and Primary Myelofibrosis (PMF), often present JAK2V617F mutation and they are accompanied by chronic bone marrow (BM) inflammation, although the source of inflammation is still unclear (Mendez Luque et al, 2019). Previous research shows that mesenchymal stromal cells (MSCs) from MPN patients present an altered phenotype, and they contribute to the progression of the disease and development of fibrosis (Leimkühler et al, 2021).The pathogenesis of MPN has been investigated using murine models like retroviral bone marrow transplants and genetically engineered models. Xenograft models have been mainly tested in myelofibrotic settings, since ET and PV HSPCs presented low engraftment and required a significant number of cells to be injected, adding another level of complexity for the feasibility of the experiments (Mullally et al, 2012; Celik et al, 2021; Ivanov et al, 2023; Grockowiak et al, 2023). Furthermore, some aspects of the BM microenvironment are not recapitulated due to the absence of human stroma, highlighting the need of modelling MPN in vivo in humanised settings.
To achieve new insights on the role of ET and PV patient derived MSCs in the expansion of JAK2V617F clones, we first performed bulk RNA sequencing to obtain ET- and PV- specific transcriptomic differences compared to healthy BM MSCs. Then, we utilised our in vivo humanised 3D scaffold model (Abarrategi et al, 2017) to study ET and PV JAK2V617F HSPCs cells in scaffolds containing ET and PV stroma. Finally, we used gene editing to induce JAK2V617F mutation on umbilical cord blood (UCB) HSPCs, to study the effects of the mutation in stem cells and their crosstalk with MSCs in a non-pathogenic setting.
In conclusion, we found that ET and PV MSCs are transcriptomically altered compared to HD MSCs, and they are able to sustain engraftment of ET and PV HSPCs, respectively, in our 3D scaffold model in vivo. Further research is needed to evaluate the effects of JAK2 mutation in UCB HSPCs in vivo.
Date of Award | 1 Oct 2024 |
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Original language | English |
Awarding Institution |
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Supervisor | Dominique Bonnet (Supervisor) & Shahram Kordasti (Supervisor) |