Dr. Bret Pearson

Investigator II

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 target new genes involved in cancer development across a wide array of stem cell driven cancers.

Current affiliations

  • Investigator II, OICR;
  • Associate Professor, Department of Molecular Genetics, University of Toronto;
  • Scientist, The Hospital for Sick Children (SickKids).

Research interests

  • Cancer stem cells;
  • Regeneration;
  • Neurogenesis;
  • Stem cell lineage development;
  • Planarians;
  • Genomics.

Select publications

Currie, KW, Molinaro, AM, and Pearson BJ (2016)
Neuronal sources of hedgehog modulate neurogenesis in the adult planarian brain
In Re-Review at eLife

Alyssa M. Molinaro and Bret J. Pearson (2016)
In silico lineage tracing through single cell transcriptomes identifies a neural stem cell population in planarians
Genome Biology 17:87, doi: 10.1186/s13059-016-0937-9

Zhu, SJ, Hallows, S., Currie, KW, Xu, CJ and Pearson, BJ (2015)
A mex3 homolog is required for differentiation during planarian stem cell lineage development
eLife doi: 10.7554/eLife.07025

Burrows, JTA, Pearson, BJ, and Scott, IC (2015)
A conserved requirement for the Mediator component Med14 in the maintenance of stem cell populations
Stem Cell Reports 4:670-684.

Alex Y.T. Lin and Bret J. Pearson (2014)
The pleiotropic roles of yorkie/YAP in planarian biology
Development 141:1197-1208.


  • 2015 CIHR Early Career Salary Award;
  • 2015 Ontario Ministry of Research and Innovation Early Career Award;
  • 2014 CIHR Early Career Award in Cancer;
  • 2010 OICR New Investigator Award;
  • 2006 Damon Runyon Image Contest;
  • 2006 Larry Sandler Graduate Thesis Award Runner Up;
  • 2005 Harold M. Weintraub Graduate Research Award;
    (Given by Fred Hutchinson Cancer Research Center).

Previous experience and education

  • Postdoctoral Fellow, Laboratory of Dr. Alejandro Sánchez Alvarado, Howard Hughes Medical Institute, University of Utah;
  • PhD, Howard Hughes Medical Institute, Laboratory of Dr. Chris Q. Doe, University of Oregon;
  • Research Technician, University of Wisconsin-Madison. Laboratory of Dr. Nansi Jo Colley.

Related links


Collaboration and contact

Dr. Pearson welcomes collaboration. Contact him at bret.pearson@sickkids.ca for more information.