LAUSR

Pediatric T-cell acute lymphoblastic leukemia (T-ALL) is a rare cancer with a diverse set of causative genomic abnormalities. The variety and limited characterization of genomic mechanisms underlying this disease presents a unique challenge for the development of improved treatments for these patients. Using the 10x Genomics Chromium system, we have generated single-cell gene expression (scRNA) and chromatin accessibility (scATAC) data for blood and/or bone marrow samples collected at diagnosis from eight pediatric T-ALL patients. We sequenced 21,669 high-confidence cells and performed normalization and downstream analysis using the Seurat v4.0.2 package in R 4.0.3. Our data show that patient cancer cells show highly individual transcriptomes and are often characterized by combinatorial expression patterns of genes including MEF2C, BCL11B, HOXA9, NKX2-1, and LMO2, which have been previously implicated for their roles in various T-ALL subtypes. Additionally, we observe that each patient has a unique ratio of cancer cells with a CD4+ T-cell, CD8+ T-cell, and hematopoietic stem cell-like identity, which may be linked to treatment response and patient outcome. This dataset represents one of the first forays into exploring the biology of pediatric T-ALL at the single-cell level. Our comparative analysis of patient cancer cells reveals novel insights into the transcriptional and chromatin-related for distinct subsets of pediatric T-ALL cases, paving the way for future treatment selection and drug development to improve outcomes for these patients. Citation Format: Irina Pushel, Byunggil Yoo, Daniel Louiselle, Margaret Gibson, Midhat S. Farooqi, Keith August. Single-cell characterization of pediatric T-cell acute lymphoblastic leukemia transcriptomes. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3551.