Mixed lineage leukemia (MLL) fusion proteins directly activate the expression of key downstream genes such as MEIS1, HOXA9 to drive an aggressive form of human leukemia. However, it is still poorly understood what additional transcriptional regulators, independent of the MLL fusion pathway, contribute to the development of MLL leukemia. Here we show that the transcription factor PU.1 is essential for MLL leukemia and is required for the growth of MLL leukemic cells via the promotion of cell-cycle progression and inhibition of apoptosis. Importantly, PU.1 expression is not under the control of MLL fusion proteins. We further identified a PU.1-governed 15-gene signature, which contains key regulators in the MEIS-HOX program (MEIS1, PBX3, FLT3, and c-KIT). PU.1 directly binds to the genomic loci of its target genes in vivo, and is required to maintain active expression of those genes in both normal hematopoietic stem and progenitor cells and in MLL leukemia. Finally, the clinical significance of the identified PU.1 signature was indicated by its ability to predict survival in acute myelogenous leukemia patients. Together, our findings demonstrate that PU.1 contributes to the development of MLL leukemia, partially via crosstalk with the MEIS/HOX pathway.
Previously, we identified SETD2 loss-of-function mutations in 22% of MLL-rearranged (MLLr) acute leukemia patients, implicating a mechanism for cooperativity between SETD2 mutations and MLL fusions. However, the detailed mechanism of how SETD2-H3K36me3 downregulation accelerates MLLr leukemia remains unclear. Here, we show that in MLLr leukemia, both H3K79me2 and H3K36me3 are aberrantly elevated and co-enriched in a group of genes. SETD2 inactivation leads to a global reduction of H3K36me3 and a further elevation of H3K79me2, but does not change the expression of known MLL fusiontarget genes. Instead, this pattern of histone changes is associated with transcriptional deregulation of a novel set of genes; downregulating tumor suppressors (for example, ASXL1) and upregulating oncogenes (for example, ERG). Taken together, our findings reveal a global crosstalk between the oncogenic DOT1L-H3K79me2 axis and the tumor suppressive SETD2-H3K36me3 axis in gene regulation, provide molecular insights into how SETD2 mutations accelerate MLLr leukemogenesis through differential regulation of additional tumor suppressors and oncogenes.
Background: Spondyloarthritis (SpA) is a group of multifactorial bone diseases influenced by genetic factors, the environment and lifestyle. However, current studies have found a limited number of SpA-related genes, and the genetic and pathogenic mechanism of SpA is still unclear. Methods: A tissue-specific transcriptome-wide association study (TWAS) of SpA was performed by using genome-wide association study (GWAS, including 3966 SpA patients and 452264 controls) summary data and gene expression weights of whole blood and skeletal muscle. The SpA-associated genes identified by TWAS were further compared with the differentially expressed genes (DEGs) identified in the SpA gene expression profile acquired from the Gene Expression Omnibus database (GEO, GSE58667). Finally, FUMA and Metascape were used to perform functional enrichment and annotation analysis.Results: The TWAS detected 28 significant genes associated with SpA in whole blood and skeletal muscle, such as CTNNAL1 (PSM=0.0304, PWB=0.0096). The gene expression profile of SpA identified 20 candidate genes that overlapped in the TWAS data, such as MCM4 (PTWAS=0.0132, PDEG=0.0275) and KIAA1109 (PTWAS=0.0371, PDEG =0.0467). Enrichment analysis of the genes identified by TWAS identified 93 significant GO terms 33 and KEGG pathways, such as mitochondrion organization (GO:0007005) and axon guidance (hsa04360).Conclusion: We identified multiple candidate genes that were genetically related to SpA. Our study may provide novel clues of the genetic mechanism, diagnosis, and treatment of SpA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.