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New genetic tools to study chromatin remodeling in hematopoiesis
Published on July 10, 2025
The team led by Julie Lessard, Director of IRIC’s Chromatin Structure and Stem Cell Biology Research Unit, has generated new genetic tools to study the role of two subunits of the SWI/SNF chromatin remodeling complexes in hematopoiesis. The work, led by research advisor Pierre Priam, is published in the journal Experimental Hematology.
Bcl7b and Bcl7c are not required for adult hematopoiesis
SWI/SNF remodeling complexes regulate chromatin compaction, and hence gene expression. They are major regulators of hematopoiesis, the process of blood cell production. Some fifteen subunits, including the Bcl7 family of proteins, make up these complexes.
The Lessard laboratory has developed new genetic tools to identify the roles of Bcl7 proteins in hematopoiesis. Using these tools, the team observed that the Bcl7b and Bcl7c subunits are not required for either survival or adult hematopoiesis. In their absence, stem cells retain their capacity for long-term repopulation in the various hematopoietic lineages. It is therefore possible that Bcl7b and Bcl7c function redundantly with the Bcl7a subunit or other regulators of hematopoiesis, which would fulfill their role in their absence.
Many avenues to be explored
Despite this, aberrant expression of the Bcl7b and Bcl7c subunits correlates with cancer in several tissues; a putative role in cancer initiation and progression therefore remains to be investigated. Similarly, the regulation of SWI/SNF complex activity via specific post-translational modifications identified on Bcl7b and Bcl7c in leukemia cells remains to be explored. Finally, as the absence of Bcl7b causes exencephaly, a malformation characterized by the absence of a cranial vault and protrusion of the brain outside the cranial cavity, further studies will elucidate its potential role in nervous system development. The tools developed by the Lessard team will be useful in examining these different avenues.
Cited study
Priam P, Krasteva V, Polsinelli A, Côté L, Dilauro F, Poinsignon T-M, Thibault P, Lessard J. Bcl7b and Bcl7c subunits of BAF chromatin remodeling complexes are largely dispensable for hematopoiesis. Exp Hematol. 2025 Jun;146:104769. doi: 10.1016/j.exphem.2025.104769
