Reprogramming of myelopoiesis by DNMT3A mutation in lung cancer - PROJECT SUMMARY/ABSTRACT The past decade has witnessed groundbreaking work associating clonal hematopoiesis (CH), where acquired mutations define clonal outgrowths of hematopoietic stem cells, with chronic inflammatory diseases including solid cancers. While we have begun to understand suppressive mechanisms that hinder antitumor immunity, it remains unclear how immune cells in the tumor microenvironment behave differently when originating from progenitors carrying CH mutations like DNMT3A. Recent studies have established myeloid-biased hematopoiesis in the context of both DNMT3A CH and cancer-induced emergency myelopoiesis. Mechanistically, our laboratory has suggested the ability of lung tumors to communicate with distal bone marrow niches, pushing immune progenitors to produce corrupted progeny. Furthermore, recent work has shown that tumors can epigenetically rewire myeloid progenitors to increase production of immunosuppressive macrophages and interfere with tumor control. Expanding on these studies, I hypothesize that hematopoietic progenitors are molecularly reprogrammed by CH-related DNMT3A, increasing myeloid-driven immunosuppression, and enhancing bone marrow dysfunction in response to tumor-associated inflammation. Aim 1 will characterize the epigenetic wound inflicted by lung adenocarcinoma through a cohort of progenitor-enriched peripheral blood samples from lung cancer patients with DNMT3A CH. Using integrated single-cell multiomics and genotyping, I will trace molecular changes driven by DNMT3A mutation along the lineage of immune hematopoietic progenitors to circulating monocytes. I will assess the contribution of uncovered pathways to driving inflammatory phenotypes in DNMT3A mutated cell line experiments. Aim 2 extends the investigation to the lung tumors of DNMT3A CH patients, through spatial transcriptomics and genotyping. Spatial methods do not require tissue dissociation, which enables localization of both tumor myeloid cells arising from DNMT3A-mutated hematopoietic progenitors and wildtype cells. Genome-wide transcriptomic readouts will capture the full effects of enhanced immunoregulatory signaling and CH-associated inflammation on tumor immune responses. I will use co-cultures of lung cancer spheroids and myeloid cells as a simplified tumor microenvironment model to interrogate spatial transcriptomic findings. Together, these aims will identify CH-associated molecular programs in hematopoietic progenitors which may serve as novel neoadjuvant targets in patients refractory to conventional therapy. Leveraging the excellent training environment at Mount Sinai, this proposal bridges computational analyses, biological discovery, and clinical potential, serving as a well-rounded foundation for my career as an academic hematologist/oncologist.
