Current Laboratory Members

Principal Investigator
Daniel Choi,  B.Sc.  Graduate Student  
Darryl Glubrecht, B.Sc. Research Technologist
Saket Jain, B.Sc.  Graduate Student  
David Jay, Ph.D.  Visiting Scientist  
Lei Li, Ph.D. Research Associate
Research Associate
Elizabeth Monckton, M.Sc. Research Technologist
Kevin (The) Vo,  B.Sc.  Graduate Student  
Jack Wang,  B.Sc.  Graduate Student  
Xia Xu, Master of Medicine  Graduate Student  

Research Interests - Overview

My research group has three main areas of interest: (i) regulation of gene expression during retinal development (see Project Details Project 1), (ii) characterization of a DEAD box protein called DDX1 in the human tumour of the retina called retinoblastoma (Project 2), and (iii) induction of differentiation in brain tumours (Project 3)

Projects 1 and 2: Retinoblastoma, a childhood tumour of the eye, occurs when both copies of the retinoblastoma (RB) gene are mutated in retinal precursor cells. In spite of extensive investigations of the RB gene, no one truly understands how retinal precursor cells become tumorigenic. We are using different approaches spanning the fields of molecular biology, cellular biology and developmental biology, to study the spectrum of changes in retinal cells compared to retinoblastoma tumour cells.

Project 3: Malignant gliomas are deadly brain tumours that are extremely aggressive and hard to treat. We believe that malignant glioma tumours are derived from a glial cell that is normally highly invasive during brain development. We propose that a better understanding of the genes expressed in normal glial cells will shed light on how to control the aggressive properties of brain tumours.

Ongoing Research Highlights

Identification of a transcription factor that is specifically expressed in two types of neuronal cells in the developing retina: amacrine and horizontal

Discovery of a novel member of the DEAD box protein family called DDX1 that is over-expressed in childhood tumours

Identification and characterization of a novel alternatively spliced form of Disabled-1 (Dab-1) expressed in retinal precursor cells

Discovery of a new type of nuclear body called DDX1 foci found in a wide variety of cell types

Finding that a glial cell marker called brain fatty acid-binding protein (B-FABP) is expressed in malignant glioma tumours

Identification of genes that are asymmetrically expressed at early stages of retinal development


Selected Trainee Publications

Sachin Katyal : Ph.D. Student

In this paper, Sachin identifies a novel form of the Disabled-1 (Dab1) gene that is specifically expressed in the undifferentiated cells of the developing retina. He characterizes the function of this novel form of Dab1 and identifies regions within the Dab1 protein that are critical for relaying extracellular signals, through modulation of protein phosphorylation.

Lei Li : Ph.D. 
Mol. Cell. Biol.

In this paper, we study the role of the putative RNA helicase, DEAD box 1 (DDX1), in cells treated with ionizing radiation. We report that DDX1 protein is rapidly recruited to sites of DNA double-strand breaks where it co-localizes with g-H2AX and phosphorylated ATM. DDX1 function appears to be mediated through phosphorylation by ATM. Our data suggest that DDX1 unwinds RNA-DNA hybrid molecules at sites of DNA double-strand breaks and likely plays a role in the clearance of RNA to facilitate repair of DNA.