Julie Lessard, Ph.D.

Awards & Honours

  • Recipient of Canada’s Top 40 Under 40 Award, 2009
  • Career Development Award, Human Frontier Science Program, 2008-2012
  • Canada Research Chair in Molecular Genetics of Stem Cells Hematopoiesis, 2007-
  • Human Frontier Science Program Postdoctoral Fellow, HFSP Organization, 2004-2007
  • Dean’s Honor List for Doctoral Thesis, Université de Montréal, 2003
  • Berlex Canada Award for Excellence in Hematology-Oncology, 2002

Training

  • Postdoctoral training with Gerald R. Crabtree, Stanford University, Palo Alto, 2003-2007
  • Ph.D. in Molecular Biology with Guy Sauvageau, Institut de recherches cliniques de Montréal (IRCM), Université de Montréal, 1996-2003

Research Support

  • Canada Foundation for Innovation
  • Canadian Cancer Society Research Institute
  • Canadian Institutes of Health Research

When Julie Lessard began her doctoral studies at the Institut de recherches cliniques de Montréal (IRCM) in 1997, she chose to investigate the role of a family of epigenetic regulators of the chromatin structure, the Polycomb Group (PcG) genes, in normal and leukemic hemopoiesis. Her studies established that the PcG gene Bmi-1 is a key genetic determinant of the self-renewal capacity of adult hemopoietic stem cells (HSCs). Most importantly, her work also showed that this function of Bmi-1 is preserved in leukemic stem cells (L-HSCs), providing the first molecular basis for the concept that stem cell function (whether normal or neoplastic) is regulated by common regulatory genes. These exciting findings lend strong support to the idea that the initial cancer-causing (transforming) mutations occur in normal hemopoietic stem cells, causing them to start dividing in an aberrant manner. Moreover, they reinforced the notion of a structure in the leukemic hierarchy, where Bmi-1 defines “stemness”.

Julie Lessard did her postdoctoral training at Stanford University in California where she was awarded the prestigious Human Frontier Science Program Fellowship (2004-2007). Her work led to the discovery of a novel epigenetic regulatory mechanism of mammalian neural development. Using proteomics approaches, she found that subunit exchange within neural, ATP-dependent SWI/SNF-like BAF chromatin remodeling complexes is essential for the transition from proliferating neural stem/progenitors to post-mitotic differentiated neurons. Most compellingly, she showed that self-renewal and proliferative activities of neural stem/progenitor cells require a specialized npBAF complex containing the double-PHD domain BAF45a subunit and the actin-related protein (Arp) BAF53a, assembled on the Brg/Brm ATPases. The dynamic exchange of these progenitor-specific subunits for the homologous BAF45b, BAF45c and BAF53b subunits during neural development is essential for cell cycle withdrawal and the acquisition of neuronal properties.

She returned from abroad in 2007 to begin work as a principal investigator at IRIC. Using modern proteomics and molecular genetics approaches, the goal of her research is to provide a molecular understanding of the role of SWI/SNF-like BAF chromatin remodeling complexes in the generation, self-renewal, proliferation and differentiation of normal and leukemic stem cells.

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