Regulation of MYB by distal enhancer elements in human myeloid leukemia

Mengjia Li,Xiaoxia Li,Zehui Zhang,Kai Cheng,Penglei Jiang,Tao Ji,Jing Chen,Xiang Wang,Yucheng Wang,Junfang Zhang,Lirong Zhao,Bingshe Han,Shuyu Lan

doi:10.1038/s41419-021-03515-z

Abstract

MYB plays vital roles in regulating proliferation and differentiation of hematopoietic progenitor cells, dysregulation of MYB has been implicated in the pathogenesis of leukemia. Although the transcription of MYB has been well studied, its detailed underlying regulatory mechanisms still remain elusive. Here, we detected the long-range interaction between the upstream regions, −34k and −88k, and the MYB promoter in K562, U937, and HL-60 cells using circularized chromosome conformation capture (4C) assay, which declined when MYB was downregulated during chemical-induced differentiation. The enrichment of enhancer markers, H3K4me1 and H3K27ac, and enhancer activity at the −34k and −88k regions were confirmed by ChIP-qPCR and luciferase assay respectively. ChIP-qPCR showed the dynamic binding of GATA1, TAL1, and CCAAT/enhancer-binding protein (C/EBPβ) at −34k and −88k during differentiation of K562 cells. Epigenome editing by a CRISPR-Cas9-based method showed that H3K27ac at −34k enhanced TF binding and MYB expression, while DNA methylation inhibited MYB expression. Taken together, our data revealed that enhancer elements at −34k are required for MYB expression, TF binding, and epigenetic modification are closely involved in this process in human myeloid leukemia cells.

Highlights

Introduction The transcription factorMYB is a key regulator for hematopoiesis[1,2]
To investigate the distal regulatory elements interacting with the MYB promoter, 4C assay was performed in human myeloid leukemia cells
K562, U937, and HL-60 cells all expressed high levels of MYB, while MYB was not detected in HeLa cells (Fig. 1A), the result is consistent with previous studies[28,29]

Summary

Introduction

MYB is a key regulator for hematopoiesis[1,2]. Dysregulation of MYB often associates with various hematological disorders including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and acute lymphoblastic leukemia (ALL)[3,4,5]. Aberrant expression of MYB has been reported in malignant solid tumors including colon cancer, breast cancer, adenoid cystic carcinoma, and brain cancer[6,7,8,9]. Genomic duplication, C-terminal truncation, and N-terminal truncation contribute to MYB have been reported in human leukemia[10,11,12,13]. The expression of MYB is precisely regulated under physiological conditions.

Methods

Results

Conclusion