Myelodysplastic Syndromes (MDS) are a cancer of the hematopoietic stem cell (HSC) on the rise in the aging population and cancer survivors. The only curative treatment for MDS is allogeneic stem cell transplantation with marked limitations in the majority of MDS patients. As a result, standard-of-care focuses on hypomethylating agents (HMA) azacytidine (AZA) and decitabine (DAC), which invariably result in resistance and disease progression. There is a dire need for new therapeutics; however, there are no robust models of MDS to accelerate preclinical testing. We have generated a breakthrough humanized xenograft-recipient mouse model which eliminates conditioning and facilitates engraftment of primary MDS. We will validate the model by single-cell genetic and genomic characterization of diagnostic MDS patient material before therapy and of the same cells engrafted in humanized mice, clearly dellineating the transcriptional impact of xenografting. Next, we will establish pharmacodynamic endpoints for AZA within the mouse model and apply the empirically-derived dose of AZA to the model. Human MDS material will be captured for single cell analyses post-AZA therapy from both patients and xenografts. The multi-omics comparative analyses will incisively determine the utility of MISTRG-W41 for MDS preclinical testing, by illustrating the extent to which AZA-affected programs in patients are similarly changed in the xenograft. This deep molecular, genotypic, and phenotypic understanding of HMA effects on subclonal and hierarchical cellular compositions of MDS will build the basis for comparison of novel-targeted-therapeutic agents as alternatives, concurrent, or post-HMA therapeutic approaches.
Myelodysplastic Syndromes (MDS) are blood cancers with increasing incidence with aging and in cancer survivors and limited therapeutic options. The field lacks adequate MDS models to facilitate hypothesis- and preclinical-testing. The proposed work utilizes a breakthrough humanized mouse recipient to build xenograft models, and then validate both the engrafting material and its response to standard therapy.