Cancer Biology Commons^™

Selective Activation Of Thrombin Activatable Fibrinolysis Inhibitor (Tafi) Attenuates Metastatic And Angiogenic Capabilities Of Melanoma And Lung Carcinoma In Vitro, Jacklyn Krizsan

Electronic Thesis and Dissertation Repository

Metastasis and angiogenesis are hallmarks of aggressive cancers, both depending on degradation of extracellular matrix by proteases such as plasmin. Plasmin activation is inhibited by thrombin-activatable fibrinolysis inhibitor (TAFI)-mediated cleavage of terminal lysine residues on plasminogen receptors. Activation of TAFI is most effectively done in complex with thrombomodulin (TM). TM is known to have anti-cancer properties, but it is not known if this is due to TAFI activation or an alternative substrate protein C (PC). We hypothesize that specific promotion of TAFI activation with TM treatment will attenuate metastatic and angiogenic capabilities of tumour cells.

Melanoma and lung carcinoma cells …

Rhamm As A Biomarker And Therapeutic Target In Triple-Negative Breast Cancer, Britney Messam

Electronic Thesis and Dissertation Repository

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumours characterized by early metastases and poor prognosis. Discovering novel biomarkers and therapeutic targets is necessary to improve TNBC patient outcomes as resistance to chemotherapy, the main therapeutic approach for TNBC, is common. In my study, RHAMM promoted proliferation of TNBC MDA-MB-231 tumour cells. RHAMM expression increased sensitivity to doxorubicin (p=0.0002) and strongly increased sensitivity to the FDA-approved MEK1/2 inhibitor trametinib (p≤0.0001). Doxorubicin and trametinib selectively killed RHAMM^+/+ MDA-MB-231 tumour cells grown as co-cultures with RHAMM^-/- MDA-MB-231 tumour cells. RHAMM-loss or trametinib decreased phosphorylated ERK1/2 protein levels and …

The Role Of Increased Matrix Metalloproteinase (Mmp14) Expression On Apoptosis Sensitivity In Human Breast Cancer Cells, Roukayah Rifai

Undergraduate Student Research Internships Conference

A member of the matrix metalloproteinase family (MMP14) plays a crucial role in extracellular matrix (ECM) remodeling, as it possesses characteristics that aid in cell proliferation and differentiation. MMP14 domains can bind to FIH-1, which is a protein that can prevent apoptosis in cells when attached to BAX in the mitochondria. This study will investigate the varying expressions of MMP14 on FIH-1 and BAX, and their effects on apoptotic sensitivity. Three cell lines with varying levels of MMP14 expression will be used: C3 (~11 fold), ΔCD (~100 fold), and C2 (~500 fold). With the overexpression of MM14 on the cell …

The Role Of Reactive Oxygen Species In The Accumulation Of Driver Mutations In B Cell Acute Lymphoblastic Leukemia, Mia P. Sams

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is the most prevalent type of cancer in young children and is associated with recurrent mutations and high levels of reactive oxygen species (ROS). The antioxidant N-acetylcysteine was tested for its ability to prolong lifespan of a mouse model of B-ALL and reduce frequency of mutations. Mice treated with 1g/L of N-acetylcysteine in drinking water were found to have delayed onset of B-ALL at 11 weeks of age and changes in gene expression relating to B cell development, calcium-apoptosis signaling, and pathways in cancer, although no differences in lifespan were observed. Tumours from treated …

Understanding The Kinomic Contributions To Tyrosine Kinase Inhibitor Resistance In Triple Negative Breast Cancer, Cory Lefebvre

Electronic Thesis and Dissertation Repository

Resistance to tyrosine kinase inhibitors (TKIs) presents a growing challenge in the development of therapeutic targets for cancers such as triple negative breast cancer (TNBC), where conventional therapies are ineffective at combatting systemic disease. Potential targets in TNBC include the receptor tyrosine kinases EGFR (epidermal growth factor receptor) and c-Met, however, targeted anti-EGFR and anti-c-Met therapies have faced challenges in clinical trials due to acquired resistance. We hypothesize that response versus resistance of triple negative breast cancer to the tyrosine kinase inhibitors erlotinib and cabozantinib is mediated by compensatory changes in the kinome and phosphoproteome. To test this, we (1) …

Kindlin-1 Is Involved In Spreading, Migration, And Protein Regulation In Epidermal Scc-13 Cells, Naomi Mishan

Electronic Thesis and Dissertation Repository

Kindlin-1 is a scaffold protein linking the cytoskeleton to the extracellular matrix. Loss of function mutations in the FERMT1 gene (encoding Kindlin-1) cause gastrointestinal and skin defects associated with increased susceptibility to aggressive epidermal squamous cell carcinoma (SCC). This study investigated the consequences of targeted FERMT1 inactivation in the SCC-13 cell line of epidermal SCC. My studies demonstrate Kindlin-1 is not essential for SCC-13 proliferation or clonogenic potential in culture. Kindlin-1 was required for cell spreading on collagen I, but not on laminin-332, and its absence enhanced SCC-13 directional migration. Finally, I identified several proteins involved in tumor formation and …

Insights Into O-Glcnac-Mediated Regulation Of Galectin Expression And Secretion In Promyelocytic Hl-60 Cells, Adam J. Mctague

Electronic Thesis and Dissertation Repository

Galectins are a family of -galactoside-binding proteins involved in cell stress responses and differentiation. Galectins are multifunctional proteins widely studied in many cell models including acute myeloid leukemia HL-60 cells where they mediate numerous intra- and extracellular functions in response to many stress-inducing stimuli. O-GlcNAcylation is a dynamic post-translational modification implicated in the regulation of many cellular diseases including cancers. The O-GlcNAc mediated expression and secretion of galectins during neutrophilic differentiation was examined in HL-60 cells. Galectin gene (LGALS), galectin protein expression, and galectin secretion were determined by RT-qPCR, immunoblotting, and ELISA, respectively. Inhibition of O-GlcNAcylation induced markers of differentiation …

Numerical Simulation Of Adaptive Metabolic Response To Anti-Angiogenic Treatment In Renal Cell Carcinoma, Saranya Varakunan

Undergraduate Student Research Internships Conference

Renal cell carcinoma, a malignant kidney cancer, is often treated using anti-angiogenic drugs to prevent the growth of blood vessels within the tumour. Although tumours initially respond to this treatment, they eventually develop resistance. This resistance is hypothesized to be caused by a switch to a symbiotic metabolism that allows cells to survive even with a low blood supply.

This project seeks to computationally model the transport of oxygen, lactate, and glucose within a tumour in order to examine how cancer metabolism adapts to changes in blood vessels.

Investigation Of Β5 Integrin Function In Epithelial Ovarian Cancer Cell Adhesion And Metastatic Properties Of Spheroids, Dolly Dhaliwal

Electronic Thesis and Dissertation Repository

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy in the developed world. EOC metastasis is unique since malignant cells detach directly from the primary tumor site into the abdominal fluid and form multicellular aggregates, called spheroids, that possess enhanced survival mechanisms while in suspension. As such, altered cell adhesion properties are paramount to EOC metastasis with cell detachment from the primary tumor, dissemination as spheroids, and reattachment to peritoneal surfaces for secondary tumor formation. These interactions play a crucial role in cell-cell and cell-extracellular matrix interactions, having implications in multiple steps of cancer progression. We previously showed that …

The Regulation Of Pannexin1 And Pannexin2 In The Skin In Health And Disease, Rafael E. Sanchez Pupo

Electronic Thesis and Dissertation Repository

Pannexins (PANX1, 2, 3) are a family of channel-forming glycoproteins that mediate intracellular and paracrine signaling. In contrast to PANX2, PANX1 has been extensively investigated in the skin, modulating cell differentiation, wound healing, and melanoma development. PANX1 and PANX2 can co-exist in the same cell and form mixed channels where their glycosylation seems to regulate their intermixing. N-glycosylation and caspase cleavage have been proposed as modulators of the function of PANX1, but their effects on PANX2 are unknown. We explored the PANX2 expression in mouse skin and showed that a Panx2 splice variant (PANX2-202) is continuously expressed throughout aging skin. …

Functional Role Of Dream And Dyrk1a In High-Grade Serous Ovarian Cancer Cell Dormancy, Pirunthan Perampalam

Electronic Thesis and Dissertation Repository

High-grade serous ovarian cancer (HGSOC) is the most common form of ovarian cancer. The majority of women are disproportionately diagnosed at an advanced stage (stage III-IV) of the disease when tumours have progressed beyond the ovaries or fallopian tubes and into the peritoneal cavity. Survival rates at late-stage are as low as 25% and chemoresistant disease recurrence is common, affecting up to 90% of patients. Multicellular clusters called spheroids contribute to dormancy, chemoresistance, and metastases and are a major challenge to treatment of HGSOC. Spheroid cells undergo reversible quiescence to evade chemotherapy in a process mediated by the mammalian DREAM …

Metabolic Reprogramming By Dna Tumour Viruses, Martin Prusinkiewicz

Electronic Thesis and Dissertation Repository

Viruses are the etiological agents of approximately 12% of human cancers. However, only a subset of viral infections eventually progress to cancer. As obligate intracellular parasites, viruses create a host-cell environment that is amenable to virus replication. These changes to host-cell processes during infection are enacted by virally-encoded proteins that act as molecular hubs. When these processes intersect with pathways that encourage the development of cancer, such as the p53 tumour suppressor pathway, these virally-encoded molecular hub proteins function as viral oncoproteins. One major requirement of both virus infected cells and rapidly growing cancer cells is an altered metabolism that …

Hpv Mediated Antagonism Of The Il-18 Proinflammatory Pathway In Head And Neck Cancer, Wyatt W. Anderson

Electronic Thesis and Dissertation Repository

In this thesis, I examined the effect of human papillomavirus (HPV) on the proinflammatory IL-18 cytokine pathway in head and neck cancers. I investigated the expression and methylation of genes associated with this pathway using The Cancer Genome Atlas (TCGA) data. In HPV+ cancers, IL18, CASP1, and AIM2 were downregulated, while IL18BP was upregulated compared to HPV- cancers and adjacent non-cancerous tissues, and IL18’s promoter was significantly more methylated. I compared HPV+ and HPV- head and neck cancer cell lines for expression of RNA and protein levels of IL-18 and IL-18BP by qPCR, western blot, and ELISA. IL-18 …

Pan-Cancer Analysis Of Telomerase Reverse Transcriptase (Tert) Isoforms, Mathushan Subasri

Electronic Thesis and Dissertation Repository

Reactivation of the multi-subunit ribonucleoprotein telomerase is the primary telomere maintenance mechanism in cancer, but it is rate-limited by the enzymatic component, telomerase reverse transcriptase (TERT). While regulatory in nature, TERT alternative splice variant/isoform regulation and functions are not fully elucidated and are further complicated by their highly diverse expression. In this thesis, I characterized TERT expression across normal and neoplastic tissues using TCGA and GTEx RNA-sequencing data. In doing so, I demonstrated the global overexpression and splicing shift towards full-length TERT in neoplastic tissue. Furthermore, my studies identified tumour subtype expression differences possibly regulated by subtype-specific characteristics, detailed heterogeneity …

Exploiting The Immunomodulatory Potentials Of Inkt Cells In Sepsis And Cancer., Joshua Choi

Electronic Thesis and Dissertation Repository

Invariant natural killer T (iNKT) cells are a unique unconventional T cell subset that recognize glycolipids presented by CD1d expressing cells. The prototypical glycolipid agonist of iNKT cells, α-Galactosylceramide (α-GalCer), can induce the rapid release of an arsenal of cytotoxic effector molecules and enormous amounts of immunomodulatory cytokines as early as two hours after activation. In addition to α-GalCer, various glycolipid agonists are available that allow for specific, in vivo targeting of iNKT cells, and can exert divergent T-helper (T_H)1 and/or T_H2 immune responses. Therefore, the type of response instigated by iNKT cells can profoundly influence …

B Cell Acute Lymphoblastic Leukemia Is Driven By Activating Janus Kinase Mutations Cooperating With Spi1 And Spib Deletions In A Murine Model, Michelle Lim

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is caused by genetic lesions in developing B cells that function as drivers for accumulation of additional mutations in an evolutionary selection process. We investigated secondary drivers of leukemogenesis and their mechanism(s) of arising in a mouse model of B-ALL driven by PU.1/Spi-B deletion (Mb1-CreDPB). Whole exome sequencing revealed recurrent mutations in Jak3 (encoding Janus Kinase 3) and Jak1. Mutations with high variant allele frequency (VAF) were dominated by C->T transition mutations that were compatible with AID, whereas the majority of mutations, with low VAF, were dominated by C->A transversions associated with …

Absence Of Activating Transcription Factor 3 Reduces Severity Of Recurrent Pancreatitis And K-Ras Mediated Pdac In Mice, Nawab Azizi

Electronic Thesis and Dissertation Repository

Pancreatic ductal adenocarcinoma (PDAC) is a terminal cancer projected to become the leading cause of cancer-related deaths in North American by the year 2030. Constitutive activation of KRAS is seen in >90% of PDAC cases. In addition to oncogenic KRAS activity, pancreatic injury is key contributor to PDAC initiation and progression. Activating transcription factor 3 (ATF3) is required for the formation of pre-neoplastic lesions in acute pancreatitis. However, unlike recurrent or chronic forms of pancreatitis, acute pancreatitis is not predictive of PDAC. Therefore, the goal of this thesis is to determine the role of ATF3 in recurrent pancreatitis and PDAC. …

Elucidating The Mechanism Of Nuak1 Function In Ovarian Cancer Metastasis, Jamie Fritz

Electronic Thesis and Dissertation Repository

Epithelial ovarian cancer (EOC) has a unique mode of metastasis, where upon shedding from the primary tumor, cells form spheroids and spread through the peritoneal cavity. There is a need to elucidate pathways driving spheroid formation to identify novel therapeutic targets. We previously showed that LKB1 is required for EOC metastasis. Using multiplex inhibitor bead-mass spectrometry, we identified NUAK1 as a top LKB1 substrate candidate. We confirmed LKB1 maintains NUAK1 phosphorylation and expression. NUAK1KO cells had lower cell adhesion and generated spheroids with reduced integrity. We identified a cell attachment pathway that was enriched in parental compared with NUAK1 …

Ampk Signalling As A Regulator Of Autophagy In A Model Of Ovarian Tumour Dormancy, Jeremi Laski

Electronic Thesis and Dissertation Repository

One of the hallmarks of epithelial ovarian cancer (EOC) metastasis lies in the process of spheroid formation, whereby tumour cells aggregate into 3D structures. Previous literature suggests that as EOC cells form spheroids they undergo bioenergetic stress, activate AMP-activated protein kinase (AMPK) signaling, and thereby force cells to enter a metabolically quiescent state. We have previously shown that EOC spheroids up- regulate autophagy, a process that provides energy during starvation conditions. Herein, I examined the role of AMPK-mediated signaling regulation of autophagy in a model of ovarian tumour dormancy. Attenuation of AMPK signaling in EOC spheroids resulted in reduction of …

19f-Mri To Monitor Therapeutic Cell Migration And Distribution, Corby Fink

Electronic Thesis and Dissertation Repository

A major hurdle hindering the advancement of cell-based cancer vaccines is the inability to non-invasively track in vivo therapeutic cell migration. Within cancer immunotherapy, antigen presenting cell-based (APC) immunotherapies can be dendritic cell-based (DC) and elicit de novo anti-tumor immune responses or formulated as mixed APC-based immunotherapy generated from peripheral blood mononuclear cells (PBMC). Mixed APC-based therapies contain monocytes and B cells as APC and can enhance a pre-existing anti-tumor immune response such that objective anti-tumor responses are observed. In either APC-based formulation, the quantity of anti-tumor APC reaching a secondary lymphoid organ post injection is predictive of the magnitude …

Lung-Derived Selectins Interact With Cd44 And Enhance The Migration Of Breast Cancer Cells, Sami U. Khan

Electronic Thesis and Dissertation Repository

The lung is among the deadliest sites of breast cancer metastasis. Previous work from our laboratory demonstrated that aggressive CD44-expressing breast cancer cells preferentially metastasize to the lung in vivo, and observed the presence of multiple CD44-interacting proteins in the lung including E-, L- and P-selectin. We hypothesized that lung-derived selectins promote breast cancer migration and/or growth via interactions with CD44. Using an ex vivo model of the soluble lung-microenvironment, we demonstrate that lung-derived selectins enhance in vitro migration but not proliferation of breast cancer cells. Co-immunoprecipitation experiments reveal that CD44 expressed by breast cancer cells in vitro interacts …

The Role Of Spi-B And Pu.1 Transcription Factors In B Cell Development And In Suppression Of Leukemogenesis, Carolina Reyes Batista

Electronic Thesis and Dissertation Repository

The E26 transformation-specific transcription factors PU.1 and Spi-B are required for B cell maturation within the bone marrow. PU.1 expression is first detected in hematopoietic stem and progenitor cells, whereas Spi-B levels arise as early as the pro-B cell stage. The expression levels of both factors are maintained as B cells progress in development, and the lack of PU.1 and Spi-B at early stages impairs B cell development and can lead to B-cell leukemia. We hypothesized that PU.1 and Spi-B control events associated with the transition from high to low proliferative stages in B cell development and the absence of …

Proteomic Characterization Of Ovarian And Breast Cancer Microenvironments For Improved Diagnostics And Therapeutic Targeting, Dylan Z. Dieters-Castator

Electronic Thesis and Dissertation Repository

Cancers exist within complex microenvironments formed by heterogeneous cell types. This diversity creates significant challenges for detection, diagnosis and treatment. Mass spectrometry-based proteomics is a powerful approach capable of characterizing complex biological systems which are characteristic of cancer biology. In this thesis, proteomics was utilized to answer several questions related to ovarian cancer diagnosis and detection, and the effects of NODAL, an embryonic morphogen, on the breast cancer secretome and stromal cell recruitment. First, I compared multiple sample preparation techniques and found high-pH/low-pH fractionation to yield the greatest proteome coverage over commonly used approaches. Second, I compared the proteomes from …

The Role Of Thymine-Dna Glycosylase In Transcriptional Regulation, Bart Kolendowski

Electronic Thesis and Dissertation Repository

Precise control over transcriptional regulation is required for normal cell function. Errors in transcriptional regulation underpin many diseases including cancer. Thymine DNA Glycosylase (TDG) is a base excision repair protein and a coregulator that has been implicated in a diverse set of fundamental biological processes including embryonic development, nuclear receptor signaling and Wnt signaling. Importantly, TDG has been shown to play an important role in transcriptional regulation in a wide variety of systems. Details surrounding the mechanism through which TDG acts remain unclear. In this thesis we explore the role of TDG in Estrogen Receptor (ER)-dependent signaling and in cellular …

Characterizing The Role Of Thymine Dna Glycosylase In Transcriptional Regulation And Cancer In Vivo, Mohammad Haider Hassan

Electronic Thesis and Dissertation Repository

Cytosine methylation (5mC) is essential for transcriptional control and genomic stability and is often used as a prognostic marker in cancer. Although 5mC has long been considered a relatively stable epigenetic mark, recent studies have demonstrated that it can be reversed enzymatically by TET proteins which oxidize 5mC into 5-hydroxymethylcytosine (5-hmC), and then to 5-formylcytosine (5-fC) and 5-carboxylcytosine (5caC). This mechanism is known as active DNA demethylation and the base excision repair enzyme Thymine DNA Glycosylase (TDG) plays an essential role in this process by removing 5-fC and 5-caC which are subsequently replaced by the unmethylated cytosine. Importantly, homozygous loss …

Influence Of The Metastatic Microenvironment On Stem-Like Human Breast Cancer Cells, Ashkan Sadri

Electronic Thesis and Dissertation Repository

Ninety percent of breast cancer-related mortalities result from metastasis. We have previously demonstrated that stem-like ALDHhiCD44+ breast cancer cells are critical for metastasis, and preferentially target the lung and bone marrow (BM). We hypothesize organ tropism occurs through promotion of the ALDHhiCD44+ phenotype. Using a 2D ex vivo model, lung and BM conditioned media (CM) were utilized to assess their influence on stem-like phenotype and behavior. Exposure of human breast cancer cells to lung-CM significantly decreased the proportion of cells with a stem-like ALDHhiCD44+ phenotype, decreased expression of cancer stem cell (CSC)-related genes, and increased gene expression related to migration …

Role Of High Molecular Weight Hyaluronan In Ultraviolet B Light-Induced Transformation, Katelyn Cousteils

Electronic Thesis and Dissertation Repository

Keratinocyte carcinomas (KCs) are the most common cancers globally. Ultraviolet light is the key risk factor for these cancers but sunscreen has proven ineffective in their prevention, indicating a need for new prophylactic agents. Chronic elevation of high molecular weight (HMW) tissue hyaluronan (HA) in skin is linked to tumor resistance in the naked mole rat. To directly assess the role of this polysaccharide in resistance to keratinocyte tumors, a HMW HA phosphatidylethanolamine (HA-PE) formulation that penetrates skin and accumulates as coats around keratinocytes was prepared. The tumor resistance properties of the HA-PE formulation were tested in a mouse model …

Regulation Of C-Raf Stability By The Ranbpm/Ctlh Complex, Christina J. Mctavish

Electronic Thesis and Dissertation Repository

RanBPM is an evolutionarily conserved multi-domain protein that has been implicated in the regulation of several cellular process, including protein stability, cell migration, gene transcription, and apoptosis. RanBPM is identified as a key member of the CTLH complex, an orthologous complex to a yeast E3 ubiquitin ligase complex, the exact function of which remains unknown. Previously, our laboratory identified RanBPM as an inhibitor of the ERK1/2 pathway through the modulation of C-RAF protein levels. This study shows that RanBPM-mediated degradation of C-RAF occurs through the proteasome and the entire CRA domain of RanBPM is necessary for direct interaction with C-RAF …

Contribution Of Activating Transcription Factor 3 To Development Of Acinar-To-Ductal Cell Metaplasia, Jelena Toma

Electronic Thesis and Dissertation Repository

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in North America. The highest risk factor for PDAC is recurrent pancreatitis. While the link between PDAC and pancreatitis is unknown, de-differentiation of acinar cells is common to both diseases. Our lab has shown that Activating Transcription Factor 3 (ATF3), a factor upregulated during pancreatic injury, contributes to the development of acinar-to-ductal cell metaplasia (ADM), a precursor phenotype of PDAC. The goal of this study was to identify how ATF3 contributes to ADM. I hypothesize that ATF3 regulates acinar gene expression promoting ADM. We observed decreased ADM development …

Inhibition Of Pannexin 1 Reduces Tumorigenic Properties Of Human Melanoma, Taylor J. Freeman

Electronic Thesis and Dissertation Repository

Pannexin 1 (PANX1) is a channel-forming glycoprotein that allows the passage of important signaling molecules, including ATP. We examined PANX1 levels in a panel of human melanomas and evaluated its potential as an effective target for melanoma therapy. We are the first to report endogenous PANX1 levels in multiple human melanoma cell lines, patient-derived melanoma biopsies, and primary melanoma cells. Treatment with two PANX1 channel blockers, Carbenoxolone (CBX) and Probenecid (PBN), on A375 and A375-MA2 melanoma cells significantly reduced cell growth and migration, and increased the production of melanin, a marker for a melanocytic-like phenotype. Daily treatment with CBX or …