Inhibitor of growth (ING) proteins have been classified as type II tumour suppressor proteins due to their ability to facilitate cellular events such as chromatin remodelling, apoptosis, angiogenesis, DNA replication, DNA repair, cell cycle progression, cell senescence and hormone response regulation. These processes are all associated with combating oncogenesis; conversely, recent evidence suggesting that ING proteins also function as oncogenes in certain cancers has spurred the investigation of ING proteins as potential anticancer targets. In order to better understand the complex role ING proteins play in the cell, the mechanisms that direct ING proteins to the chromatin template require extensive study. This dissertation investigates the role the chromatin environment plays in recruiting ING proteins by characterizing the interaction between ING proteins and chromatin. ING proteins have been shown to interact with the histone H3 lysine 4 trimethylated (H3K4me3) epigenetic mark through binding studies between peptides comprising the ING plant homeodomain (PHD) finger and the H3 N-terminal tail. However, these studies do not take into account the effect of organizing H3 into a nucleosome or the effect of the remaining ING protein structural domains. In order to address these elements, this dissertation describes binding studies between the PHD finger of Yng1 (Yng1PHD) and H3K4me3 in the context of a nucleosome, and between full-length Xenopus laevis ING1 (xING1) and H3K4me3 in the context of a nucleosome. A 6XHis tagged xING1 protein was purified, Yng1PHD was obtained from Dr. Leanne Howe, and an analog of H3K4me3 (H3KC4me3) was installed into recombinant H3 protein and used to reconstitute nucleosomes. Affinity-tag based anti-Yng1PHD and anti-xING1 pull-down assays were then used to display an in vitro H3K4 methylation-dependent interaction between Yng1PHD / xING1 and H3KC4me3 containing nucleosomes. In addition, analytical ultracentrifuge (AUC) analysis of the xING1 protein displayed the presence of 3 species containing sedimentation coefficients consistent with those that would be expected from monomeric, dimeric and tetrameric forms of xING1. Several studies have focused on the interaction between ING proteins and DNA binding proteins such as transcription factors and hormone receptors which recruit ING proteins to specific genes. However, little knowledge is available regarding the role chromatin plays in recruiting ING proteins with the exception of the interaction between the ING PHD fingers and H3K4me3. This dissertation addresses this gap in knowledge by investigating the nature of chromatin bound by the human ING1b (hING1b) protein. For this purpose, HEK293 cells were transfected with a Flag-hING1b construct. Upon fractionation of the HEK293 chromatin, Flag-hING1b was found to localize exclusively to the “Pellet” fraction. ChIP analysis of the HEK293 chromatin showed that Flag-hING1b bound nucleosomes were deprived of H3K9me3, H3K27me3 and H3S10P, contained no enrichment for H3K4me3 and H3K36me3, and were significantly enriched for H2A.Z. Lastly, a hING1b-GFP construct was transiently transfected into SKN-SH human neuroblastoma cells and found to be evenly distributed throughout the nucleus with moderate enrichment on chromatin and within the nucleolus. / Graduate

Interleukin-2 activates lymphocytes to become highly cytotoxic for a wide range of tumour cell types in vitro (Iymphokine activated killer or LAK cells), and in animal models. However, only limited therapeutic benefit was observed in clinical trials of LAK cell therapy. This project aimed to investigate the molecular and cellular interactions involved in the production and effector functions of LAK cells, to identify factor(s) which might be responsible for the poor clinical responses observed in LAK cell therapy. Tumour cell lines were heterogeneous in their response to killing by cytokines (TNFα, LT, IFNγ and IL-1β), and purified monocytes or lymphocytes, but were consistently highly sensitive to LAK cell cytotoxicity. Autologous monocytes and lymphocytes were not killed by LAK cells, in contrast to human umbilical vein endothelial cells and fibroblasts. Supernatants from LAK cells were considerably less cytotoxic than the effector cells, and physical separation of effector and target cells resulted in inhibition of killing. Lymphocyte and LAK cell cytotoxicity was associated predominantly with the CD8+ (cytotoxic T-cell) lymphocyte sub-population, and was significantly inhibited by anti-TNFα and anti-LT, demonstrating that these cytokines were the primary effector molecules in this system. LAK cells and A375 melanoma cells showed procoagulant activity, predominantly via the tissue factor pathway, and LAK cells also possessed surface factor V. In addition, A375 cells were highly fibrinolytic. Tumour cell killing by LAK cells was inhibited by plasma, and further experiments determined that polymerised fibrin, but not fibrin monomer was responsible. From these results it was suggested that culture of small numbers of cells from tumour biopsies, and the determination of their sensitivity to cytotoxic drugs, cytokines and effector cells may lead to more effective treatment protocols for immunotherapy of individual tumours. In order to enhance the efficacy of immunotherapy, further in vivo research is required to elucidate the interactions between immune effector cells and the coagulation/fibrinolytic systems.

We sought to determine whether activation of the Wnt signaling pathway altered the function of hNSCs in vitro. We took three approaches to activate Wnt signaling: Wnt3a, constitutively stabilized β-catenin (ΔN90), and the GSK3 inhibitor BIO. While Wnt3a and ΔN90 had no effect on proliferation in both stem cell (+EGF/FGF) and differentiating (-EGF/FGF) conditions, BIO reduced proliferation in both. All methods of Wnt signaling activation promoted neuronal lineage commitment during hNSC differentiation. Furthermore, BIO was able to induce mild neuronal differentiation in stem cell conditions, suggesting that GSK3-inhibition interferes with several pathways to regulate hNSC fate decisions. We also probed BTSC function using BIO-mediated GSK3 inhibition. We found that in stem cell conditions, BIO was able to induce neuronal differentiation, decrease proliferation, and induce cell cycle arrest. Together this data suggests that GSK3-inhibition, possibly through activation of Wnt signaling, may offer a novel mechanism for the differentiation treatment of glioblastomas.

We sought to determine whether activation of the Wnt signaling pathway altered the function of hNSCs in vitro. We took three approaches to activate Wnt signaling: Wnt3a, constitutively stabilized β-catenin (ΔN90), and the GSK3 inhibitor BIO. While Wnt3a and ΔN90 had no effect on proliferation in both stem cell (+EGF/FGF) and differentiating (-EGF/FGF) conditions, BIO reduced proliferation in both. All methods of Wnt signaling activation promoted neuronal lineage commitment during hNSC differentiation. Furthermore, BIO was able to induce mild neuronal differentiation in stem cell conditions, suggesting that GSK3-inhibition interferes with several pathways to regulate hNSC fate decisions. We also probed BTSC function using BIO-mediated GSK3 inhibition. We found that in stem cell conditions, BIO was able to induce neuronal differentiation, decrease proliferation, and induce cell cycle arrest. Together this data suggests that GSK3-inhibition, possibly through activation of Wnt signaling, may offer a novel mechanism for the differentiation treatment of glioblastomas.

Light delivery and sample handling systems are essential for any high performance imaging application. The custom design for two such devices with medical imaging applications are presented. The first device, a galvanometer-stage combination, is for general use optical coherence tomography and can be configured to scan over a large range of sample sizes and types. The second device, constructed in parallel, a rotation-linear stage combination, has been carefully designed for a specific imaging task: assessing tumour margins. The design of the two devices is driven by operational requirements and although requirements vary greatly from application to application, there are several common parameters that must be considered for every system. In this thesis, parameters like total scan time, scan resolution, sampling rate, and sample type flexibility are analysed and are some of the primary factors that influence the viability of a system for further development. This work's contribution to medical imaging research is the design of two light delivery systems and an analysis process that can be applied to future iterations of scan systems. The devices are shown to be flexible enough for use in test-bed systems, while providing the necessary functionality to meet the needs of medical histology and pathology. Controlling the light delivery and sample positioning of an imaging device adds important functionality to a scan system and is not a trivial task when high spatial-resolution scan spacing is required. The careful design of an imaging system to meet the unique requirements of the application enables better information and better resulting decision making. Advanced imagery provides new insights and perspectives to everyday scenes. It is these new perspectives that allow for re-evaluation and examination of problems with a fresh eye.

Glioblastoma multiforme (GBM) is one of the most common and aggressive primary brain tumours, with a median patient survival time of 6-12 months in adults. It has been recently suggested that a typically small sub-population of brain tumour cells, in possession of certain defining properties of stem cells, is responsible for initiating and maintaining the tumour. More recent experiments have studied the interactions between this subpopulation of brain cancer cells and tumour microenvironmental factors such as hypoxia and high acidity. In this thesis a computational approach (based on Gillespie’s algorithm and cellular automata) is proposed to investigate the tumour heterogeneities that develop when exposed to various microenvironmental conditions of the cancerous tissue. The results suggest that microenvironmental conditions highly affect the characterization of cancer cells, including the self-renewal, differentiation and dedifferentiation properties of cancer cells.

In der vorliegenden prospektiven Studie wurde der postoperative Krankheitsverlauf von 93 Hündinnen mit Mammatumoren untersucht. Ziel der Studie war es, eine präoperative Einschätzung der Dignität der Tumoren und der Prognose für die Hündin anhand der Relaxin-Plasmakonzentration zu gewinnen. In einer humanmedizinischen Studie konnte gezeigt werden, dass an Brustkrebs erkrankte Frauen mit einer hohen Relaxin-Plasmakonzentration häufiger an einem malignen Tumor erkrankt sind, der Tumor häufiger bereits metastasiert hatte und die Frauen früher starben. Der Kastrationsstatus (p = 0,132), eine hormonelle Läufigkeitsunterdrückung (p = 0,960), vorausgegangene Graviditäten (p = 0,780) und das Auftreten von Pseudograviditäten (p = 0,138) bei den an Mammatumoren erkrankten Hündinnen hatten keinen Einfluss auf die präoperativ bestimmte Relaxin-Plasmakonzentration. An Mammatumoren erkrankte Hündinnen und gesunde Kontrolltiere hatten keine unterschiedlichen Relaxin-Plasmakonzentrationen (p = 0,813). Die Relaxin-Plasma-konzentrationen von Hündinnen mit einer Herzerkrankung aus der Patientengruppe waren identisch mit denen der herzgesunden Hündinnen aus der Kontrollgruppe (p = 0,328). Innerhalb der Patientengruppe war es hinsichtlich der gemessenen Relaxin-Plasmakonzentration unerheblich, ob die Hündinnen einerseits an einem solitären oder an multiplen Mammatumoren erkrankt waren (p = 0,470), oder ob andererseits bei ihnen einseitig oder beidseitig Mammatumoren feststellbar waren (p = 0,371). Weder die Tumorgröße (p = 0,518) noch eine Ulzeration (p = 0,746) wirkten sich auf die Relaxin-Plasmakonzentration aus. Das Vorliegen von Nahmetastasen (p = 0,131) oder eines malignen Mammatumors (p = 0,240) führte zu keiner erhöhten Relaxin-Plasmakonzentration. Entsprechend war auch das Stadium der Erkrankung ohne Einfluss auf das gemessene Relaxin (p = 0,829). Im Rahmen der Verlaufsuntersuchung gab es keinen Unterschied zwischen den präoperativ und den sechs Monate postoperativ bestimmten Relaxin-Plasmakonzentrationen (p = 0,983). Weder eine Rezidivierung des Mammatumors (p = 0,084) noch eine Metastasierung des Tumors in die Lunge sechs Monate postoperativ (p = 0,200) waren anhand der präoperativ bestimmten Relaxin-Plasmakonzentrationen vorhersehbar. Auch lieferte Relaxin keinen Hinweis auf einen Tod infolge der Mammatumoren (p = 0,205). In dieser Arbeit konnte nach Auswertung der vorliegenden Daten kein Hinweis auf die Verwendbarkeit der Relaxin-Plasmakonzentration als prognostischer Marker für an Mammatumoren erkrankte Hündinnen gefunden werden. Es konnte, wie in vorherigen Studien, bestätigt werden, dass Hündinnen mit Tumoren kleiner 3 cm (p = 0,001) und Hündinnen im Stadium I der Erkrankung (p = 0,009, p = 0,022) eine signifikant niedrigere Wahrscheinlichkeit haben innerhalb des ersten Jahres postoperativ an den Folgen des Mammatumors zu versterben als Hündinnen mit größeren Tumoren oder in einem höheren Stadium der Erkrankung. Hündinnen, die an einem ulzerierenden Mammatumor erkrankt waren (p = 0,002) oder bei denen histopathologisch nachweisbare Metastasen in den regionären Lymphknoten vorlagen (p = 0,001), hatten eine signifikant niedrigere Wahrscheinlichkeit das erste postoperative Jahr zu überleben. Die Tiere, bei denen sechs Monate postoperativ Metastasen in der Lunge festgestellt werden konnten (p = 0,001) oder bei denen es zu einer Rezidivierung des Mammatumors kam (p = 0,001), hatten eine sehr hohe Wahrscheinlichkeit innerhalb des ersten postoperativen Jahres zu versterben.

Malignant glioma is a highly lethal and destructive disease with no proper cure. We have investigated some of the hallmarks of cancer in connection to glioma and found ways to disrupt these and prevent tumor growth. The work is done within the context of a glioma subtype distinguished by activation of PDGF signaling termed the proneural subtype. In two of the studies we have investigated mechanisms regulating the glioma cells themselves, and in the other two we have focused on the tumor stroma. In the first study, glioma-initiating cells were isolated in defined serum free culture medium from PDGF-B driven murine glioma and shown to be independent of EGF and FGF2 for self-renewal and proliferation. When cultured in serum the GICs displayed an aberrant differentiation pattern that was reversible. Specific depletion of the transduced PDGF-B caused a loss of self-renewal and tumorigenicity and induced oligodendrocyte differentiation. The transcription factor S-SOX5 has previously been shown to have a tumor suppressive effect on PDGF-B induced murine glioma, and to induce cellular senescence in PDGF-B stimulated cells in vitro. We found that S-SOX5 had a negative effect on proliferation of newly established human glioma cells cultured under stem cell conditions. We also revealed a connection between alterations causing up-regulation of SOX5 with the proneural subgroup and a tendency towards co-occurrence with PDGFRA alterations. Angiogenesis, the formation of new blood vessels from existing ones, is an important hallmark for glioma malignancy. We found that the anti-angiogenic protein HRG had a negative effect on glioma progression in PDGF-B induced experimental tumors and that HRG was able to completely prevent formation of glioblastomas. Subsequently it was shown that HRG could skew pro-tumorigenic tumor associated macrophages into an anti-tumorigenic phenotype. Stromal cells had not previously been fully investigated in gliomas. We observed a correlation between tumor malignancy and increased numbers of tumor-associated macrophages as well as pericytes in PDGF-B induced gliomas. There was also a correlation between tumor grade and vessel functionality that had not previously been shown. Our results offer further understanding of gliomagenesis and present possible future therapies.

The methods presented in this study are aimed at the identification of subpopulations (clones) of genetically similar cells within tissue samples through measurement of loci-specific Fluorescence in-situ hybridization (FISH) spot signals for each nucleus and analyzing cell spatial distributions by way of Voronoi tessellation and Delaunay triangulation to robustly define cell neighbourhoods. The motivation for the system is to examine lung cancer patient for subpopulations of Non-Small Cell Lung Cancer (NSCLC) cells with biologically meaningful gene copy-number profiles: patterns of genetic alterations statistically associated with resistance to cis-platinum/vinorelbine doublet chemotherapy treatment. Current technologies for gene-copy number profiling rely on large amount of cellular material, which is not always available and suffers from limited sensitivity to only the most dominant clone in often heterogeneous samples. Thus, through the use of FISH, the detection of gene copy-numbers is possible in unprocessed tissues, allowing identification of specific tumour clones with biologically relevant patterns of genetic aberrations. The tissue-wide characterization of multiplexed loci-specific FISH signals, described herein, is achieved through a fully automated, multicolour fluorescence imaging microscope and object segmentation algorithms to identify cell nuclei and FISH spots within. Related tumour clones are identified through analysis of robustly defined cell neighbourhoods and cell-to-cell connections for regions of cells with homogenous and highly interconnected FISH spot signal characteristics. This study presents experiments which demonstrate the system’s ability to accurately quantify FISH spot signals in various tumour tissues and in up to 5 colours simultaneously or more through multiple rounds of FISH staining. Furthermore, the system’s FISH-based cell classification performance is evaluated at a sensitivity of 84% and specificity 81% and clonal identification algorithm results are determined to be comparable to clone delineation by a human-observer. Additionally, guidelines and procedures to perform anticipated, routine analysis experiments are established.

Members of the insulin-like growth factor (IGF) family are mitogenic growth factors which have been shown to play critical roles in both normal growth and development, and tumour biology. The IGF system is complex and the biological effects of the IGFs are determined by diverse interactions between many molecules, including interactions with the extracellular matrix (ECM). Recent observations have demonstrated that IGFs can associate with the ECM protein vitronectin (VN) and this interaction can modulate IGF-stimulated biological functions. It has been demonstrated previously that IGF-II can bind directly to VN, while IGF-I associates with VN indirectly via the involvement of IGF-binding proteins (IGFBPs) -2, -3, -4 and -5. As the IGF system plays important roles in both normal breast development and in the transformation and progression of breast cancer, this study aimed to describe the effects of substrate-bound IGF-I:IGFBP:VN complexes on breast cell functions and to dissect the mechanisms underlying these responses. The studies reported in this thesis demonstrate that substrate-bound IGF-I:IGFBP:VN complexes, containing IGFBP-3 and IGFBP-5, are potent stimulators of proliferation and migration in the "normal", non-tumourigenic MCF-10A breast epithelial and MCF-7 breast carcinoma cell lines. Interestingly, substrate-bound IGF-I:IGFBP:VN complexes were less effective in increasing the migration of the metastatic MDA-MB-231 breast cancer cell line. This, however, is due to these cells expressing the αvβ3 integrin which can support a highly migratory phenotype independent of IGF-I-stimulation. Taken together this suggests a particularly important role for these complexes in stimulating a highly migratory phenotype in pre-invasive or poorly metastatic breast cells. Studies using IGF-I analogues were also undertaken to establish if there was a requirement for ternary complex formation and the type-1-IGF receptor (IGF-1R) in the enhanced migration responses observed. These studies determined IGF-I:IGFBP:VN-stimulated migration to be dependent upon both heterotrimeric IGF-I:IGFBP:VN complex formation and activation of the IGF-1R. Furthermore, the enhanced cellular migration was abolished upon incubation of MCF-7 and MCF-10A cells with function blocking antibodies directed at VN-binding integrins and the IGF-IR. In addition, analysis of the signal transduction pathways underlying the enhanced cell migration revealed that the complexes stimulate a transient activation of the ERK/MAPK signaling pathway, while simultaneously producing a sustained activation of the PI3-K/AKT pathway. Optimal intracellular signaling required activation of both the IGF-1R and VN-binding integrins, as antibody mediated inhibition of either receptor led to substantial decreases in both ERK/MAPK and PI3-K/AKT pathway activation. Furthermore, experiments using pharmacological inhibitors of these pathways determined a pivotal role for PI3-K/AKT activation in substrate-bound IGF-I:IGFBP:VN-stimulated cell migration. In order to confirm an important role for the PI3-K/AKT pathway in these responses, wild-type and activated-AKT was transiently overexpressed in MCF-10A cells. Overexpression of both wild-type and activated-AKT further enhanced cellular migration in response to substrate-bound IGF-I:IGFBP:VN complexes. However, these responses still required co-activation of the IGF-1R and VN-binding integrins. In an attempt to obtain a global view of the possible molecular mechanisms underpinning IGF-I:IGFBP:VN-stimulated cell migration, oligonucleotide microarrays were used to screen for candidate genes important for the observed migratory responses. The microarray studies identified 165 genes which were differentially expressed in cells migrating in response to substrate-bound IGF-I:IGFBP:VN complexes. Gene ontology and functional analysis revealed many of these genes to be significantly associated with biological functions relevant to cancer transformation and progression, including cell growth and proliferation, cell death and cellular movement. In regard to cell migration, a number of the genes identified have previously reported roles in cellular movement, migration and metastasis, which may provide future targets to augment IGF-I:IGFBP:VN-stimulated cell migration. Taken together, the studies reported throughout this thesis have provided the first mechanistic insights into the action of IGF-I:IGFBP:VN complexes and add further evidence to support the involvement of VN-binding integrins and their co-operativity with the IGF-IR in the promotion of tumour cell migration. Importantly, identifying the molecular mechanisms by which IGF:VN complexes enhance breast cell function will lead to not only a better understanding of this critical interaction, but also aid in developing diagnostic tests and therapeutics directed at treating breast cancer.