During Youmna’s PhD candidacy in the program of molecular bases of oncogenesis at the University of Paris VII and the American University of Beirut, She investigated the mechanisms through which the Human T-lymphotropic virus 1 (HTLV-1) hijacks the cellular machinery culminating in leukemic transformation. The small percentage of infected individuals transforming into Adult T-cell Leukemia/Lymphoma (ATL) and the difficulty of generating animal models that faithfully recapitulate the disease made her appreciate the fact that malignant transformation is not entirely cell intrinsic but an evolutionary process where the outcome is context dependent. For this reason, She joined the Scadden laboratory that is worldwide famous for providing the first in vivo experimental evidence for the contribution of the bone marrow microenvironment to the maintenance of the hematopoietic stem cell.
Currently as a member of the Scadden laboratory Youmna chose to study myelodysplastic syndrome (MDS) which provides an excellent model of a progressive hematopoietic disorder that evolves into Acute Myelogenous Leukemia in a third of affected individuals. Even though our understanding of the role of karyotypic abnormalities and single gene mutations in the pathogenesis of MDS has improved in the past five years, a hypothesized role of the microenvironment remains elusive. Her approach is to leverage the knowledge acquired from established MDS animal models, the availability of clinical samples through national and international collaborations and the revolutionary advances in single cell analysis and sequencing technologies to map the bone marrow microenvironment in human MDS patients and highlight the role of extrinsic deregulated signaling networks in the pathogenesis of the disease. Ultimately, this should translate into novel therapeutic strategies. Concomitantly, She is also interested in the role of microvesicles as a recently emerging powerful method of cell-cell communication in the maintenance of hematopoietic stem and progenitor cells both under physiological and stress conditions.
The Scadden laboratory has provided Youmna with a rich environment to grow as independent scientist. She had the unique chance to hone her skills in highlighting relevant clinical and scientific problems that need to be addressed; successfully attracting funding resources (Dubai Harvard Foundation for Medical Research, Aplastic Anemia and MDS International Foundation, Leukemia Lymphoma Society) and building a strong network of collaborations both within and outside of the laboratory. She has also been privileged with the opportunity to mentor a group of talented Harvard college undergraduate students (Justine Hasson, Sebastian Cruz, Jefferson Siedl) whose contribution to her work is of great value.