Roles of RUNX in B Cell Immortalisation

Area of Science:

• * Hematology
• * Virology
• * Molecular Biology

Background:

• * RUNX1 and RUNX3 are key transcription factors (TFs) regulating B-cell development.
• * Epstein-Barr virus (EBV), a tumor-associated virus, profoundly impacts B-cell proliferation.
• * EBV manipulates RUNX gene expression to control B-cell growth and immortalization.

Purpose of the Study:

• * To elucidate the mechanisms by which EBV controls RUNX1 and RUNX3 transcription in B lymphocytes.
• * To investigate the role of EBV transcription factors (TFs) EBNA2, EBNA3B, and EBNA3C in regulating RUNX gene expression.
• * To explore the interplay between EBV TFs, RUNX proteins, and B-cell gene regulation during viral immortalization.

Main Methods:

• * Analysis of RUNX1 and RUNX3 expression levels in resting versus EBV-infected B cells.
• * Investigation of EBV TF binding sites and their overlap with RUNX3 binding sites in the B-cell genome.
• * Examination of the role of super-enhancers and RBP-J in EBV-mediated RUNX gene regulation.

Main Results:

• * EBV infection leads to decreased RUNX1 and increased RUNX3 expression in B cells.
• * RUNX3, upregulated by EBNA2 via a super-enhancer, represses RUNX1 transcription.
• * EBV TFs (EBNA2, EBNA3B, EBNA3C) interact with RBP-J to modulate RUNX gene expression through super-enhancers.
• * EBV TF binding sites significantly overlap with RUNX3 binding sites, suggesting co-factor roles.

Conclusions:

• * EBV actively remodels RUNX transcription to promote B-cell proliferation and overcome RUNX1-mediated growth suppression.
• * EBV utilizes super-enhancers and RBP-J to precisely control RUNX gene expression during B-cell immortalization.
• * EBV may leverage RUNX proteins as co-factors to dysregulate B-cell gene transcription, facilitating viral-induced transformation.