71 Investigating gene regulatory mechanisms associated with B-cell acute lymphoblastic leukemia incidence in Hispanic/Latino populations

Objectives/Goals: Investigating the B-cell acute lymphoblastic leukemia (B-ALL)-associated germline SNP rs7090445, located in intron 3 of ARID5B, which is more frequently observed in individuals of Hispanic/Latino descent. Investigating the mechanisms behind this inherited single nucleotide polymorphisms (SNP) that may contribute to the higher incidence of B-ALL in this population. Methods/Study Population: Specific Aim 1: We hypothesize ARID5B SNP rs7090445 disrupts intrinsic enhancer function. Identification of critical DNA looping events impacted by ARID5B variants using Capture C. Affinity purification-mass spectrometry to identify potential ARID5B transcription mediators. Specific Aim 2: We hypothesize the B-ALL-associated SNP leads to a partial human B-cell differentiation block. Utilize Cas9-mediated homology-directed repair to create ARID5B SNP in primary human hematopoietic stem cells. Gene-edited HSCs will be differentiated into B cells using an ex vivo system. Fluorescence-activated cell sorting to sort our pool of cells into stages of B-cell development spectrum. Amplicon sequencing and variant allele frequency of rs7090445 SNP to evaluate its impact on B-cell development. Results/Anticipated Results: This proposal is conceptually innovative as it seeks to understand the mechanism by which the B-ALL-associated SNP rs7090445 in intron 3 of ARID5B disrupts enhancer function and investigates its impact on human B-cell development. Future research will investigate a tumor-suppressive role of ARID5B and whether it constitutes a “first-hit” of leukemogenesis. Discussion/Significance of Impact: Successful completion of this research will elucidate the critical role of the B-ALL-associated ARID5B SNP rs7090445 in human B-cell development and leukemogenesis. As this SNP is more prevalent in Hispanic/Latino populations, it will also provide crucial insights into the genetic factors behind the elevated incidence of B-ALL.