Bret Pearson, Ph.D.

  • Professor of Pediatrics, School of Medicine

Biography

I trained for my PhD with Dr. Chris Doe at the University of Oregon where I worked on how neural stem cells in the developing fly embryo can give rise to different progeny on consecutive divisions (multipotency). In my thesis I described a mechanism of “temporal patterning” with cascades of transcription factors that define temporal windows. This training gave me a deep interest in stem cell biology, developmental biology, and neural differentiation.

As a postdoctoral fellow with Dr. Alejandro Sánchez-Alvarado at the University of Utah, I switched from Drosophila to a non-traditional model system: the freshwater planarian. I was interested in following up my neurobiology and stem cell work from flies in a system that can be used to study gene function and stem cells in adult animals in vivo. I was interested in defining how planarians deal with proliferation control as adults, as well as conserved mechanisms of stem cell biology and neural regeneration. In the Sánchez lab, I showed that planarians use canonical tumor suppressor pathways to control proliferation, suggesting they would be a useful model for the study of stemness in cancers – which is indeed the case.

Over the past 12 years, I have run a successful lab at the Hospital for Sick Children/University of Toronto. However, I was recently recruited back to the US in the fall of 2021 to Oregon Health & Science University in the Department of Pediatric Neurooncology, with joint appointments at the Vollum Institute and the Knight Cancer Institute. This opportunity is a perfect fit because I was specifically recruited to continue our work on the biology of stemness and identification of normal stemness pathways that have gone awry in human brain tumors as well as our work on fundamental neuro- and glio-genesis using planarians. On the cancer side, my lab uses comparative genomics and functional screens to find new regulators of stemness that are also conserved in evolution and drive cancer stem cells. On the neurogenesis side, we are trying to identify the neural stem cells and pathways of neurogenesis in planarians during both homeostasis and regeneration. Together, we take unique approaches to long-standing unknowns in neural cancers and neurobiology.

Education and training

  • Degrees

    • B.S., 1994, University of Wisconsin-Madison
    • Ph.D., 2005, University of Oregon

Publications

Selected publications

  • Wiggans M, Pearson BJ. One stem cell program to rule them all?. FEBS J. 2021 Jun;288(11):3394-3406. doi: 10.1111/febs.15598. Epub 2020 Oct 28. PubMed PMID: 33063917.
  • Chan A, Ma S, Pearson BJ, Chan D. Collagen IV differentially regulates planarian stem cell potency and lineage progression. Proc Natl Acad Sci U S A. 2021 Apr 20;118(16). doi: 10.1073/pnas.2021251118. PubMed PMID: 33859045; PubMed Central PMCID: PMC8072372.
  • ctPryszlak M, Wiggans M, Chen X, Jaramillo JE, Burns SE, Richards LM, Pugh TJ, Kaplan DR, Huang X, Dirks PB, Pearson BJ. The DEAD-box helicase DDX56 is a conserved stemness regulator in normal and cancer stem cells. Cell Rep. 2021 Mar 30;34(13):108903. doi: 10.1016/j.celrep.2021.108903. PubMed PMID: 33789112.
  • Molinaro AM, Lindsay-Mosher N, Pearson BJ. Identification of TOR-responsive slow-cycling neoblasts in planarians. EMBO Rep. 2021 Mar 3;22(3):e50292. doi: 10.15252/embr.202050292. Epub 2021 Jan 28. PubMed PMID: 33511776; PubMed Central PMCID: PMC7926258.
  • Burrows JTA, Depierreux D, Nibert ML, Pearson BJ. A Novel Taxon of Monosegmented Double-Stranded RNA Viruses Endemic to Triclad Flatworms. J Virol. 2020 Oct 27;94(22). doi: 10.1128/JVI.00623-20. Print 2020 Oct 27. PubMed PMID: 32907972; PubMed Central PMCID: PMC7592200.
  • Burgess J, Burrows JT, Sadhak R, Chiang S, Weiss A, D'Amata C, Molinaro AM, Zhu S, Long M, Hu C, Krause HM, Pearson BJ. An optimized QF-binary expression system for use in zebrafish. Dev Biol. 2020 Sep 15;465(2):144-156. doi: 10.1016/j.ydbio.2020.07.007. Epub 2020 Jul 19. PubMed PMID: 32697972.
  • Brooun M, Klimovich A, Bashkurov M, Pearson BJ, Steele RE, McNeill H. Ancestral roles of atypical cadherins in planar cell polarity. Proc Natl Acad Sci U S A. 2020 Aug 11;117(32):19310-19320. doi: 10.1073/pnas.1917570117. Epub 2020 Jul 29. PubMed PMID: 32727892; PubMed Central PMCID: PMC7430989.
  • Lindsay-Mosher N, Chan A, Pearson BJ. Planarian EGF repeat-containing genes megf6 and hemicentin are required to restrict the stem cell compartment. PLoS Genet. 2020 Feb;16(2):e1008613. doi: 10.1371/journal.pgen.1008613. eCollection 2020 Feb. PubMed PMID: 32078629; PubMed Central PMCID: PMC7059952.
  • Lindsay-Mosher N, Pearson BJ. The true colours of the flatworm: Mechanisms of pigment biosynthesis and pigment cell lineage development in planarians. Semin Cell Dev Biol. 2019 Mar;87:37-44. doi: 10.1016/j.semcdb.2018.05.010. Epub 2018 May 21. Review. PubMed PMID: 29758350.
  • Ross KG, Molinaro AM, Romero C, Dockter B, Cable KL, Gonzalez K, Zhang S, Collins ES, Pearson BJ, Zayas RM. SoxB1 Activity Regulates Sensory Neuron Regeneration, Maintenance, and Function in Planarians. Dev Cell. 2018 Nov 5;47(3):331-347.e5. doi: 10.1016/j.devcel.2018.10.014. PubMed PMID: 30399335.

Publications

  • A syngeneic spontaneous zebrafish model of tp53-deficient, EGFRvIII, and PI3KCAH1047R-driven glioblastoma reveals inhibitory roles for inflammation during tumor initiation and relapse in vivo

    eLife
    1. Alex Weiss
    2. Cassandra D'Amata
    3. Bret J. Pearson
    4. Madeline N. Hayes

  • Planarians require ced-12/elmo-1 to clear dead cells by excretion through the gut

    Cell Reports
    1. Nicole Lindsay-Mosher
    2. Sarah Lusk
    3. Bret J. Pearson

  • aristaless-like homeobox-3 is wound induced and promotes a low-Wnt environment required for planarian head regeneration

    Development (Cambridge)
    1. Zaleena Akheralie
    2. Tanner J. Scidmore
    3. Bret J. Pearson

  • The BAF chromatin remodeling complex licenses planarian stem cells access to ectodermal and mesodermal cell fates

    BMC Biology
    1. Mallory Wiggans
    2. Shu Jun Zhu
    3. Alyssa M. Molinaro
    4. Bret J. Pearson

  • Collagen IV differentially regulates planarian stem cell potency and lineage progression

    Proceedings of the National Academy of Sciences of the United States of America
    1. Andy Chan
    2. Sophia Ma
    3. Bret J. Pearson
    4. Danny Chan

  • Identification of TOR-responsive slow-cycling neoblasts in planarians

    EMBO Reports
    1. Alyssa M. Molinaro
    2. Nicole Lindsay-Mosher
    3. Bret J. Pearson

  • One stem cell program to rule them all?

    FEBS Journal
    1. Mallory Wiggans
    2. Bret J. Pearson

  • The DEAD-box helicase DDX56 is a conserved stemness regulator in normal and cancer stem cells

    Cell Reports
    1. Michael Pryszlak
    2. Mallory Wiggans
    3. Xin Chen
    4. Julia E. Jaramillo
    5. Sarah E. Burns
    6. Laura M. Richards
    7. Trevor J. Pugh
    8. David R. Kaplan
    9. Xi Huang
    10. Peter B. Dirks
    11. Bret J. Pearson

  • Ancestral roles of atypical cadherins in planar cell polarity

    Proceedings of the National Academy of Sciences of the United States of America
    1. Maria Brooun
    2. Alexander Klimovich
    3. Mikhail Bashkurov
    4. Bret J. Pearson
    5. Robert E. Steele
    6. Helen McNeill

  • An optimized QF-binary expression system for use in zebrafish

    Developmental Biology
    1. Jason Burgess
    2. Jeffrey T. Burrows
    3. Roshan Sadhak
    4. Sharon Chiang
    5. Alex Weiss
    6. Cassandra D'Amata
    7. Alyssa M. Molinaro
    8. Shujun Zhu
    9. Michael Long
    10. Chun Hu
    11. Henry M. Krause
    12. Bret J. Pearson

  • A novel taxon of monosegmented double-stranded RNA viruses endemic to triclad flatworms

    Journal of virology
    1. Jeffrey T.A. Burrows
    2. Delphine Depierreux
    3. Max L. Nibert
    4. Bret J. Pearson

  • Planarian EGF repeat-containing genes megf6 and hemicentin are required to restrict the stem cell compartment

    PLoS genetics
    1. Nicole Lindsay-Mosher
    2. Andy Chan
    3. Bret J. Pearson

  • Comparative transcriptomic analyses and single-cell RNA sequencing of the freshwater planarian Schmidtea mediterranea identify major cell types and pathway conservation

    Genome biology
    1. Lakshmipuram Seshadri Swapna
    2. Alyssa M. Molinaro
    3. Nicole Lindsay-Mosher
    4. Bret J. Pearson
    5. John Parkinson

  • Myths vs. FACS

    International Journal of Developmental Biology
    1. Alyssa M. Molinaro
    2. Bret J. Pearson

  • Smed-myb-1 Specifies Early Temporal Identity during Planarian Epidermal Differentiation

    Cell Reports
    1. Shu Jun Zhu
    2. Bret J. Pearson

  • SoxB1 Activity Regulates Sensory Neuron Regeneration, Maintenance, and Function in Planarians

    Developmental Cell
    1. Kelly G. Ross
    2. Alyssa M. Molinaro
    3. Celeste Romero
    4. Brian Dockter
    5. Katrina L. Cable
    6. Karla Gonzalez
    7. Siqi Zhang
    8. Eva Maria S. Collins
    9. Bret J. Pearson
    10. Ricardo M. Zayas

  • The planarian TCF/LEF factor Smed-tcf1 is required for the regeneration of dorsal-lateral neuronal subtypes

    Developmental Biology
    1. David D.R. Brown
    2. Alyssa M. Molinaro
    3. Bret J. Pearson

  • A brain unfixed

    Frontiers in Neuroscience
    1. David D.R. Brown
    2. Bret J. Pearson

  • FOX and ETS family transcription factors regulate the pigment cell lineage in planarians

    Development (Cambridge)
    1. Xinwen He
    2. Nicole Lindsay-Mosher
    3. Yan Li
    4. Alyssa M. Molinaro
    5. Jason Pellettieri
    6. Bret J. Pearson

  • Yorkie is required to restrict the injury responses in planarians

    PLoS genetics
    1. Alexander Y.T. Lin
    2. Bret J. Pearson

  • HOX gene complement and expression in the planarian Schmidtea mediterranea

    EvoDevo
    1. Ko W. Currie
    2. David D.R. Brown
    3. Shujun Zhu
    4. Chang Jiang Xu
    5. Veronique Voisin
    6. Gary D. Bader
    7. Bret J. Pearson

  • In silico lineage tracing through single cell transcriptomics identifies a neural stem cell population in planarians

    Genome biology
    1. Alyssa M. Molinaro
    2. Bret J. Pearson

  • Light-induced depigmentation in planarians models the pathophysiology of acute porphyrias

    eLife
    1. Bradford M. Stubenhaus
    2. John P. Dustin
    3. Emily R. Neverett
    4. Megan S. Beaudry
    5. Leanna E. Nadeau
    6. Ethan Burk-McCoy
    7. Xinwen He
    8. Bret J. Pearson
    9. Jason Pellettieri

  • Neuronal sources of hedgehog modulate neurogenesis in the adult planarian brain

    eLife
    1. Ko W. Currie
    2. Alyssa M. Molinaro
    3. Bret J. Pearson

  • A mex3 homolog is required for differentiation during planarian stem cell lineage development

    eLife
    1. Shu Jun Zhu
    2. Stephanie E. Hallows
    3. Ko W. Currie
    4. Changjiang Xu
    5. Bret J. Pearson