CTCF Regulates Erythroid Differentiation Through Control of Core Erythroid Transcription Factors

Erythropoiesis is tightly regulated by lineage-specific transcription factors that govern erythroid commitment, proliferation, and differentiation. A core erythroid transcriptional network, together with non-DNA-binding cofactors, occupies regulatory regions of genes essential for erythroid development. This process is further shaped by epigenetic mechanisms, including histone post-translational modifications and long-range chromatin interactions. CCCTC-binding factor (CTCF) is a multifunctional regulator with a central role in three-dimensional chromatin organization. Although CTCF has been implicated in hematopoietic differentiation and leukemogenesis, its specific function in erythropoiesis remains poorly defined. Here, we investigated the role of CTCF during erythroid differentiation using two complementary models: pluripotent K562 leukemia cells and primary human CD34+ hematopoietic stem/progenitor cells, each induced toward the erythroid lineage by distinct stimuli. In both systems, CTCF silencing impaired erythroid differentiation by repression of key erythroid transcription factor genes, including LMO2, KLF1, MYB, and ETS1. This repression was associated with enrichment of repressive histone marks at CTCF-binding sites within their regulatory regions. Moreover, CTCF cooperated with cohesin to establish and stabilize long-range chromatin interactions at these loci. These results provide new insight into how CTCF-dependent chromatin regulation contributes to normal erythroid development and suggest that perturbation of this regulatory axis may have implications for hematopoietic disorders and malignancies.