Biological sciences

Administrative Assistant: Josephine Ha
Phone: 416-480-6100 ext. 63350
Email: josephine.ha@sunnybook.ca

Education:

• B.Sc., 1999, biological sciences, University of Alberta, Canada
• M.Sc., 2003, pathology and laboratory medicine, University of British Columbia, Canada
• Honorary fellow, 2007, National Heart and Lung Institute, U.K.
• PhD, 2008, pathology and laboratory medicine, University of British Columbia, Canada
• Post-doctoral fellowship, 2014, London Health Sciences Centre, Canada

Appointments and Affiliations:

• Scientist, Biological Sciences, Odette Cancer Research Program, Sunnybrook Research Institute
• Associate professor, department of medical biophysics, University of Toronto

Research Foci:

• Intravital imaging of cancer metastasis
• Urology medicine
• Extracellular vesicles/liquid biopsies in cancer
• Patient-derived xenografts for precision cancer medicine

Research Summary:

Dr. Leong’s mandate is to bring lab-grown ideas to the clinic, with a particular focus on the genitourinary system (kidney, bladder, prostate, testes, urethra, penis). The constant goal is to take concepts developed in the lab and translate them into clinical practice. The group emphasizes multidisciplinary training and collaboration to help trainees become confident and highly skilled scientists.

Dr. Leong is focused on developing “liquid biopsies” that rely on the enumeration of circulating cancer cell fragments, also known as extracellular vesicles, in the blood. Whether they are used to improve early detection for early-stage migration in pancreatic cancer, to avoid overtreatment in breast and prostate cancers, or to improve follow-up and monitoring post-treatment for kidney and colorectal cancers, the goal is to provide a noninvasive companion blood test used in combination with imaging to transform clinical outcomes.

His group also does research on “patient avatars” (patient-derived xenografts) for precision medicine purposes. Their patient-derived xenograft platform aims to improve clinical outcomes for advanced cancer patients. This platform can be used to test chemotherapies, targeted therapies and immunotherapies. 

If you are a patient with metastatic renal cell carcinoma, you may be eligible to be involved in the following clinical study: "Hyper-Personalized Medicine Using Patient Derived Xenografts (PDXovo) for Renal Cell Carcinoma Patients" (ClinicalTrials.gov Identifier: NCT04602702). This study is being conducted in collaboration with Dr. Georg Bjarnason, a medical oncologist at Sunnybrook focused on kidney cancer and other GU malignancies.

If you are a patient with metastatic breast cancer, you may be eligible to be involved in this clinical study: "Integrated Patient Avatars for Guiding Systemic Therapy Treatments in Metastatic Breast Cancer Patients" (ClinicalTrials.gov Identifier: NCT04608357). This study is being conducted in collaboration with Dr. Katerzyna Jerzak, a medical oncologist at Sunnybrook focused on breast and gynecologic cancers.

Drug discovery is also a very important research arm, as the group implements various preclinical model systems to discover new drugs for various diseases (for example, kidney stones, cancer metastasis, musculoskeletal/cartilage repair).

Selected Publications:

See current publications list at PubMed.

1. Williams KC, Searle K, Parkins K, Makela A, Hamilton A, Kim Y, Tuck A, Ronald JA, Foster PJ, Chambers AF, Leong HS. Invadopodia are chemosensing protrusions that guide cancer cell extravasation to promote brain tropism in metastasis. Oncogene. 2019 May;38(19):3598–3615.
2. Ali SN, Dayarathna TK, Ali AN, Osumah T, Ahmed M, Cooper TT, Power NE, Zhang D, Kim D, Kim R, St Amant A, Hou J, Tailly T, Yang J, Luyt L, Spagnuolo PA, Burton JP, Razvi H, Leong HS. Drosophila melanogaster as a function-based high-throughput screening model for antinephrolithiasis agents in kidney stone patients. Dis Model Mech. 2018 Nov 16;11(11).
3. Berish R, Telmer P, Ronald J, Leong HS. Pre-clinical models of prostate cancer bone metastasis. Nat Rev Urol. 2018 Jul;15(7):403–421.
4. Biggs CN, Siddiqui KM, Pardhan S, Brett SI, Guo QQ, Yang J, Power NE, Durfee P, Townson JL, MacMillan CD, Guo C, Yang J, Flesher N, Izawa JI, Chambers AF, Chin JL, Leong HS. Prostate microparticles as a liquid biopsy biomarker platform for prostate cancer using nanoscale flow cytometry. Oncotarget. 2016 Feb 23;7(8):8839–49.
5. Tran TA, Leong HS, Pavia-Jimenez A, Fedyshyn Y, Yang J, Kucejova B, Sivanand S, Spence P, Xie XJ, Pena-Llopis S, Power NE, Brugarolas J. FGFR-dependent and independent paracrine signaling by sunitinib-resistant renal cell carcinoma. Mol Biol Cell. 2016 Jun 15;36(13):1836–55.
6. Kim Y, Williams KC, Gavin CT, Jardine E, Chambers AF, Leong HS. Quantification of cancer cell extravasation in vivo. Nat Protoc. 2016 May;11(5):937–48.
7. Leong HS, Robertson AE, Stoletov K, Leith SJ, Chin CA, Chien AE, Hague MN, Ablack AL, Carmine-Simmen K, MacPherson VA, Postenka CO, Turley EA, Courtneidge SA, Chambers AF, Lewis JD. Invadopodia are required for cancer cell extravasation and are a therapeutic target for metastasis. Cell Rep. 2014 Sep 11;8(5):1558–70.

Related News and Stories:

• Behind the research: Looking to transform prostate cancer detection (YourHealthMatters, Sept. 18, 2019)

Related Links:

• U of T profile, medical biophysics