Bret Pearson


Despite intense research involving embryonic stem cells, relatively little is known about how adult stem cells make their cellular lineages or the ways in which this process can go awry, possibly contributing to the development of diseases such as cancer.

Dr. Bret Pearson’s lab is trying to understand the connection between adult stem cells and cancer by using the freshwater planarian as an in vivo model system. Recently, researchers in Pearson's lab have cloned planarian homologs of human disease genes, removed their function in adult stem cells, and assayed changes either in the stem cell population or in lineage output. They recently showed that the p53 tumour suppressor pathway also functions in planarian stem cells to promote differentiation while suppressing cell division – similar to how p53 functions in mammals to suppress cancer. This suggests that planarians are a relevant model system to understand human stem cell biology and dysfunction.

Currently, the lab employs both standard and high-throughput approaches to discover new regulators of adult stem cells. Ultimately, Pearson will apply information from these discoveries into therapies designed to new target genes involved in cancer development.

Contact Information

Shu Jun Zhu

shujun [dot] zhuatsickkids [dot] ca

Telephone: 416-813-7654 ext. 28806


2010 - Assistant Professor, Department of Molecular Genetics, University of Toronto., University of Toronto.
2010 - Scientist, The Hospital for Sick Children (Sickkids).
2010 - OICR Investigator I, Ontario Institute for Cancer Research (OICR).
2005 - PhD, Howard Hughes Medical Institute, Laboratory of Dr. Chris Q. Doe, University of Oregon.
2005 - 2010Postdoctoral Fellow, Laboratory of Dr. Alejandro Sánchez Alvarado., Howard Hughes Medical Institute, University of Utah.
1998 - 1999Research Technician, University of Wisconsin-Madison. Laboratory of Dr. Nansi Jo Colley.

Research Output

  • Pearson BJ and Alvarado AS
    A Planarian p53 Homolog Regulates Proliferation and Self-Renewal in Adult Stem Cell Lineages
    • Development. 2010; 137:213-221
  • Pearson BJ and Alvarado AS
    Regeneration, Stem cells and the Evolution of Tumor Suppression
    • Cold Spring Harbor Annual Symposium. 2009; Vol. 73. Control and Regulation of Stem Cells
  • Oviedo NJ, Pearson BJ, Levin M and Sánchez-Alvarado
    A Planarian PTEN homologs regulate stem cells and regeneration through TOR signaling
    • Disease Models and Mechanisms. 2008; 1:131-143
  • Pearson BJ and Doe CQ
    Specification of temporal identity in the developing nervous system
    • 2004; Vol. 20:619-647
  • Pearson BJ and Doe CQ
    Regulation of neuroblast competence in Drosophila
    • Nature. 2003; 425:624-628