Life Sciences 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 …

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 …

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 …

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 …

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 …

Ccn Proteins In Metastatic Melanoma, James Hutchenreuther

Electronic Thesis and Dissertation Repository

Melanoma cells recruit host tissue to become a part of the activated tumour stroma. This stromal microenvironment is similar to that seen in fibrotic tissue. CCN1 and CCN2 are tightly spatiotemporally regulated matricellular proteins involved in development and wound healing, and are abberantly expressed in fibrosis. Additionally they have been seen to be abnormally highly expressed in several cancers, including melanoma. Recent evidence has shown that deletion of CCN2 in the fibroblasts renders mice resistant to several models of fibrosis. Given this, I tested the hypothesis that deletion of CCN1 and CCN2 from fibroblasts could similarly impede the formation of …

Nuak1 Has Tumor Suppressive Activity In Epithelial Ovarian Cancer, Parima Saxena

Electronic Thesis and Dissertation Repository

NUAK1, a downstream substrate of the stress metabolism regulator Liver kinase B1 (LKB1), has been implicated as an oncogene and tumor suppressor, with distinct roles in cell cycle, senescence and cell adhesion. Epithelial ovarian cancer (EOC) spheroids remain dormant during intraperitoneal metastasis with reduced proliferation and metabolism to survive metabolically harsh conditions, possibly implicating a role of NUAK1 in EOC spheroid biology. I hypothesize that NUAK1 is regulated by LKB1 to promote dormancy in EOC. I demonstrate that NUAK1 expression and phosphorylation is regulated by LKB1 in EOC cell lines. NUAK1 is largely under-expressed in many established and new ascites-derived …

Epithelial-To-Mesenchymal Transition Leads To Disease-Stage Differences In Circulating Tumor Cell Detection And Metastasis In Pre-Clinical Models Of Prostate Cancer, Lori E. Lowes, David Goodale, Ying Xia, Carl Postenka, Matthew M. Piaseczny, Freeman Paczkowski, Alison L. Allan

Anatomy and Cell Biology Publications

Metastasis is the cause of most prostate cancer (PCa) deaths and has been associated with circulating tumor cells (CTCs). The presence of >= 5 CTCs/7.5mL of blood is a poor prognosis indicator in metastatic PCa when assessed by the CellSearch (R) system, the "gold standard" clinical platform. However, similar to 35% of metastatic PCa patients assessed by CellSearch (R) have undetectable CTCs. We hypothesize that this is due to epithelial-to-mesenchymal transition (EMT) and subsequent loss of necessary CTC detection markers, with important implications for PCa metastasis. Two pre-clinical assays were developed to assess human CTCs in xenograft models; one comparable …

Generation Of Organ-Conditioned Media And Applications For Studying Organ-Specific Influences On Breast Cancer Metastatic Behavior, Matthew M. Piaseczny, Graciella M. Pio, Jenny E. Chu, Ying Xia, Kim Nguyen, David Goodale, Alison Allan

Anatomy and Cell Biology Publications

Breast cancer preferentially metastasizes to the lymph node, bone, lung, brain and liver in breast cancer patients. Previous research efforts have focused on identifying factors inherent to breast cancer cells that are responsible for this observed metastatic pattern (termed organ tropism), however much less is known about factors present within specific organs that contribute to this process. This is in part because of a lack of in vitro model systems that accurately recapitulate the organ microenvironment. To address this, an ex vivo model system has been established that allows for the study of soluble factors present within different organ microenvironments. …

Oncolytic Virus Therapy For The Treatment Of Metastatic Ovarian Cancer, Jessica Tong

Electronic Thesis and Dissertation Repository

The management of patients with epithelial ovarian cancer (EOC) faces two major challenges which standard treatments fail to effectively address: 1) Diffuse metastasis as a consequence of late stage diagnosis and 2) intra-tumoral heterogeneity, which fuels tumor evolution and drives the acquisition of chemotherapeutic resistance. In this thesis, we tested new therapeutic strategies using a 3-dimensional in vitro spheroid culture model that mimics key steps of epithelial ovarian cancer metastasis; and another model that mimics both temporal and cellular heterogeneity by establishing multiple cell lines from a single patient over the course of disease progression. Using these models, we investigated …

Exploring The Regulation And Function Of Epithelial-Mesenchymal Plasticity In Ovarian Cancer Spheroids, Samah Rafehi

Electronic Thesis and Dissertation Repository

Epithelial-mesenchymal transition (EMT) serves as a key mechanism driving tumour cell migration, invasion, and metastasis in many carcinomas. Transforming growth factor-beta (TGFβ) signalling is implicated in several steps during cancer pathogenesis and acts as a classical inducer of EMT. Since epithelial ovarian cancer (EOC) cells have the potential to switch between epithelial and mesenchymal states during metastasis, we predicted that modulation of TGFβ signalling would significantly impact EMT and the malignant potential of EOC spheroid cells. Ovarian cancer patient ascites-derived cells naturally underwent an EMT response when aggregating into spheroids, and this was reversed upon spheroid re-attachment to a …

Clinical And Experimental Importance Of Circulating Tumor Cells In Prostate Cancer, Lori Lowes

Electronic Thesis and Dissertation Repository

Prostate cancer (PCa) remains a leading cause of death in men, primarily due to ineffective treatment in the metastatic setting. During this phase of PCa, circulating tumor cells (CTCs) are shed into the bloodstream and their presence and number are important in patient prognosis. The CellSearch® system (CSS) is the only U.S. Food and Drug Administration (FDA) and Health Canada approved instrument for detection of CTCs, making it the current clinical gold standard in CTC technology. Although the CSS provides a minimally invasive means of patient monitoring in the metastatic setting, little is known about the role of CTCs in …

Fibulin-3 Promotes Triple Negative Breast Cancer Cell Invasion, Michelle M. Noonan

Electronic Thesis and Dissertation Repository

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer, and metastasis is a leading cause of mortality in these patients. Fibulin-3, a secreted extracellular matrix protein, has a pro-invasive role in other cancers. However, a role for fibulin-3 in TNBC invasion is unknown. We have previously shown that KISS1R signaling promotes TNBC cell invasion through EGFR and MMP-9 activity, via β-arrestin2. Thus, we hypothesized that KISS1R signaling promotes TNBC cell invasion via fibulin-3. Our clinical data suggests that plasma fibulin-3 levels are elevated in metastatic TNBC patients. Additionally, we found that invasive breast cancer cells have increased …

The Lung Microenvironment Influences The Metastatic Behaviour Of Breast Cancer Cells In An Innovative 3d Ex Vivo Pulmonary Metastasis Model, Matt M. Piaseczny

Electronic Thesis and Dissertation Repository

Lung metastasis remains a leading cause of death in breast cancer patients. This study established an innovative 3D ex vivo pulmonary metastasis assay (PuMA) to test the hypothesis that the lung microenvironment promotes metastatic behaviour of whole population and stem-like ALDH^hiCD44⁺ breast cancer cells. Following in vivo delivery of breast cancer cells to mice, lungs were excised, maintained in culture and imaged to observe breast cancer growth over time. We observed metastatic progression of breast cancer cells in the PuMA, most notably of ALDH^hiCD44⁺ cells which progressed rapidly from single cells to multicellular colonies …

Kiss1r Signaling Promotes Breast Cancer Metastasis, Cameron G-F Goertzen

Electronic Thesis and Dissertation Repository

Kisspeptins, peptide products of KISS1, are endogenous ligands for KISS1R, a G protein-coupled receptor. In numerous cancers, KISS1 acts as a metastasis suppressor. However, studies have revealed that patients with elevated KISS1 and KISS1R breast tumor expression have increased tumor grade, increased lymph node metastases and poor survival. We hypothesize that depletion of KISS1R inhibits breast cancer cell metastasis. In order to assess the role of KISS1R in breast cancer metastasis, we used a pre-clinical orthotopic xenograft mouse model using MDA-MB-231 breast cancer cells for breast tumor establishment. We discovered that depletion of KISS1R decreased primary tumor growth and …

Recent Advances In The Molecular Characterization Of Circulating Tumor Cells, Lori E. Lowes, Alison L. Allan

Anatomy and Cell Biology Publications

Although circulating tumor cells (CTCs) were first observed over a century ago, lack of sensitive methodology precluded detailed study of these cells until recently. However, technological advances have now facilitated the identification, enumeration, and characterization of CTCs using a variety of methods. The majority of evidence supporting the use of CTCs in clinical decision-making has been related to enumeration using the CellSearch((R)) system and correlation with prognosis. Growing evidence also suggests that CTC monitoring can provide an early indication of patient treatment response based on comparison of CTC levels before and after therapy. However, perhaps the greatest potential that CTCs …

Adaptation Of Semiautomated Circulating Tumor Cell (Ctc) Assays For Clinical And Preclinical Research Applications, Lori E. Lowes, Benjamin D. Hedley, Michael Keeney, Alison L. Allan

Anatomy and Cell Biology Publications

The majority of cancer-related deaths occur subsequent to the development of metastatic disease. This highly lethal disease stage is associated with the presence of circulating tumor cells (CTCs). These rare cells have been demonstrated to be of clinical significance in metastatic breast, prostate, and colorectal cancers. The current gold standard in clinical CTC detection and enumeration is the FDA-cleared CellSearch system (CSS). This manuscript outlines the standard protocol utilized by this platform as well as two additional adapted protocols that describe the detailed process of user-defined marker optimization for protein characterization of patient CTCs and a comparable protocol for CTC …

Imaging Breast Cancer Progression And Lymph Node Metastases In Murine Models Using Mri And Magnetic Nanoparticles, Vasiliki Economopoulos

Electronic Thesis and Dissertation Repository

Most breast cancer related deaths are caused by the spread or metastasis of the primary tumor to distant sites in the body. The lymph nodes are one of the first places where metastases can be detected and are frequently examined for macroscopic metastases to help determine course of treatment for patients. However, little is known about the significance of microscopic metastases and disseminated individual cancer cells within the nodes. The goal of this work was to use MRI to monitor the development of primary tumors and lymphatic metastases in models of breast cancer.

In this thesis, we examined the MRI …

Features Of Dormancy In Metastatic Ovarian Cancer Cells, Rohann Jm Correa

Electronic Thesis and Dissertation Repository

The most prevalent subtype of ovarian cancer – high-grade serous (HGS) carcinoma – is also the most lethal, since the majority of cases are characterized by advanced-stage (metastatic) presentation. Metastasis of this cancer proceeds by an intra-peritoneal route, involving detachment of cells from the primary tumour and dissemination throughout the peritoneal cavity as multicellular aggregates, or spheroids. Herein, we demonstrate that HGS patient-derived tumour cells cultured to form in vitro spheroids exhibit features of cancer dormancy, a cellular state known to promote therapeutic resistance and disease recurrence. We discovered that upon spheroid formation, cells became non-proliferative, exhibiting a cell cycle …

Metastatic Disease: Interactions Between Tumor Cells And Host Environment During Cancer Cell Spread, Jennifer M. Maclean

Electronic Thesis and Dissertation Repository

Tumor and metastasis formation are not cell autonomous phenomena, but rather an evolution of disease within and responding to the host environment. Metastatic spread from a primary tumor occurs as a result of a complex interplay between tumor cells and the host, wherein tumor cells must escape the primary tumor, enter the host vasculature, travel to and arrest in a distant tissue and survive and grow in that new organ. It is known that cells that progress through these stages must both escape and exploit host systems, yet the mechanisms used are not fully understood. Therefore, the goal of this …

High Aldehyde Dehydrogenase And Expression Of Cancer Stem Cell Markers Selects For Breast Cancer Cells With Enhanced Malignant And Metastatic Ability, Alysha K. Croker, David Goodale, Jenny Chu, Carl Postenka, Benjamin D. Hedley, David A. Hess, Alison L. Allan

Anatomy and Cell Biology Publications

Cancer stem cells (CSCs) have recently been identified in leukaemia and solid tumours; however, the role of CSCs in metastasis remains poorly understood. This dearth of knowledge about CSCs and metastasis is due largely to technical challenges associated with the use of primary human cancer cells in pre-clinical models of metastasis. Therefore, the objective of this study was to develop suitable pre-clinical model systems for studying stem-like cells in breast cancer metastasis, and to test the hypothesis that stem-like cells play a key role in metastatic behaviour. We assessed four different human breast cancer cell lines (MDA-MB-435, MDA-MB-231, MDA-MB-468, MCF-7) …