Relevant Degree Programs
Graduate Student Supervision
Doctoral Student Supervision (Jan 2008 - May 2021)
No abstract available.
The sonic hedgehog (SHH) signaling pathway has been shown to play an integral role in the maintenance and progression of bladder cancer (BCa). Smoothened inhibitors are currently used in the clinic for treatment of some skin cancers, however they have not been evaluated in BCa and SHH inhibition may be an efficacious strategy for BCa treatment. I assessed an in-house human BCa tissue microarray comprising non-invasive, invasive and lymph node metastasized transitional cell carcinoma and found that the transcription factors downstream of SHH, Gli1 and Gli2, were increased in more aggressive tumors. A panel of BCa cell lines show that two invasive lines, UM-UC-3 and 253J-BV, both express these transcription factors but differ in other parameters in the SHH pathway. UM-UC-3 produces greater quantities of SHH ligand, is less responsive in viability to pathway stimulation by recombinant human SHH or SAG, and less responsive to inhibition by a variety of molecules including the Smoothened inhibitors cyclopamine and SANT-1. 253J-BV, on the other hand, was highly responsive to these manipulations and appears more representative of canonical SHH signaling while UM-UC-3 resembles non-canonical autocrine signaling. To overcome this variability I utilized a Gli1 and Gli2 antisense oligonucleotide (ASO) to bypass pathway mechanics and target the transcription factors directly. UM-UC-3 decreased in viability due to both ASOs but 253J-BV was only affected by Gli2 ASO. IC50s were in the nanomolar range. To evaluate in vivo efficacy I developed a murine intravesical orthotopic human bladder cancer (mio-hBC) model for the establishment of non-invasive urothelial cell carcinomas. In this model I pre-treat the bladder with poly-L-lysine for 15 minutes, followed by intravesical instillation of luciferase–transfected human UM-UC-3 cells. Cancer cells are quantified by bioluminescent imaging. Tumors grew to 541.6±0.75 fold (Mean±SE) initial size after 40 days and were confirmed to reflect patient samples by a response to mitomycin C. Treatment of these tumors with Gli2 ASO resulted in decreased tumor size, growth rate and Gli2 mRNA and protein expression. These results validate this model and support the conclusion that Gli2 ASO may be a promising new targeted therapy for BCa.
Master's Student Supervision (2010 - 2020)
Cancer is currently the leading cause of death in Canada and is responsible for 30% of all deaths. With various treatments available nowadays, it is necessary to develop a three-dimensional (3D) model to mimic in vivo condition of patients’ disease in order to test drug efficacy prior to any actual treatments. My study is focusing specifically on kidney and bladder cancer. Therefore, a 3D, acellular organ-specific extracellular matrix (ECM) can be established as bioactive substrates with the long-range goal of bioengineering tumors for drug testing. Specifically, decellularization is the process by which cells are removed from the organ to produce the aforementioned matrix. It is crucial to achieve a tight balance between effective cell removal and retention of native ECM architecture. Henceforth, the decellularized matrix can be used as a template and be repopulated with normal human organ-specific cells or cancerous cells. With these approaches, a bio-matrix that ultimately serves as a cancer model for drug testing can be developed. In this master’s thesis project, I hypothesized that decellularization preserves organ microarchitecture and retains various matrix-bound growth factors necessary for cell homing. Afterward, tumor models can be established through recellularization of human cells onto the decellularized ECMs as a proof-of-principle drug-testing platform to predict treatment response.Two objectives were pursued to test this hypothesis. Under objective 1, I optimized and established decellularization protocols for both kidney and bladder. The protocols ensure complete cell removal and preservation of ECM microarchitectures. In addition, comprehensive protein-profiling of the decellularized kidney and bladder’s ECM was completed by performing proteomic analysis with liquid chromatography–mass spectrometry (LC-MS/MS). Under objective 2, recellularization protocols for both decellularized kidney and bladder ECM were established and optimized. As the decellularized kidney and bladder’s ECM was repopulated with normal human cells and cancerous cells, the proposed in vitro urogenital cancer model can be developed.In conclusion, a 3D in vitro urogenital cancer model can be developed from kidneys and bladders using protocols optimized under objective 1 & 2. This work establishes the model as proof –of principal and sets the foundation for the developments of personalized cancer treatments.