Abstract 3201: Single-cell trajectory analysis reveals a melanoma-driven distinct hematopoietic response in murine spleen

Abstract

Growing evidence suggests that tumor progression can interfere with normal hematopoiesis and skew the host system to undergo myeloid biased changes. Hematopoietic stem and progenitor cells (HSPCs) are a rare population of precursor cells giving rise to progeny that replenish blood cells throughout life. HSPCs are mainly localized in the bone marrow niche in healthy adults, however pathophysiological conditions such as cancer can cause extramedullary hematopoiesis in organs like the spleen. In this study, we investigated tumor-driven phenotypic and molecular alterations in the HSPC compartment at a single-cell level during extramedullary hematopoiesis using single-cell multiomics. We used a B16-F10 melanoma mouse model to uncover the tumor-mediated changes. Mice with tumor-burden showed splenomegaly and alterations in the composition of the HSPC compartment in the spleen consistent with extramedullary hematopoiesis. We then isolated four HSPC populations, including Lin- Sca1+ cKit+ (LSK), common myeloid progenitor (CMP), granulocyte-macrophage progenitor (GMP) and megakaryocyte-erythrocyte progenitor (MEP) cells from the spleen and bone marrow of melanoma-burdened mice using the BD FACSMelody™ Cell Sorter. Next, we used an integrated workflow on the BD Rhapsody™ Single-Cell Analysis System for the downstream single-cell multiomics analysis. We utilized oligo-conjugated antibodies for NGS-based sample multiplexing and protein detection (BD® Single-Cell Multiplexing Kit, BD® AbSeq Assay), along with whole transcriptome analysis for a comprehensive analysis of mRNA expression. Data analysis using the X-shift algorithm paired with single-cell force-directed layout visualization enabled delineation of the developmental trajectories of HSPC populations and exploration of phenotypic and transcriptomic changes across different hematopoietic subpopulations and across distinct anatomic sites. The analysis also identified unique hematopoietic cell clusters present during melanoma-driven extramedullary hematopoiesis in the spleen. Overall, our findings highlight melanoma-driven perturbations in hematopoiesis by utilizing advanced single-cell multiomics technology. Disclaimers: For Research Use Only. Not for use in diagnostic or therapeutic procedures. Class 1 Laser Product. BD-23277 (v1.0) 1120 BD, the BD Logo, FACSMelody and Rhapsody are trademarks of Becton, Dickinson and Company or its affiliates. © 2020 BD. All rights reserved. Citation Format: Nihan Kara, Nikolay Samusik, Xiaoshan Shi, Chip Lomas, Stephanie Widmann, Aaron J. Tyznik. Single-cell trajectory analysis reveals a melanoma-driven distinct hematopoietic response in murine spleen [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3201.