Cancer Biology Commons^™

Advances In 3d Culture Systems For Therapeutic Discovery And Development In Brain Cancer, Janith Wanigasekara, Patrick J. Cullen, Paula Bourke, Brijesh Tiwari, James F. Curtin

Articles

This review focuses on recent advances in 3D culture systems that promise more accurate therapeutic models of the glioblastoma multiforme (GBM) tumor microenvironment (TME), such as the unique anatomical, cellular, and molecular features evident in human GBM. The key components of a GBM TME are outlined, including microbiomes, vasculature, extracellular matrix (ECM), infiltrating parenchymal and peripheral immune cells and molecules, and chemical gradients. 3D culture systems are evaluated against 2D culture systems and in vivo animal models. The main 3D culture techniques available are compared, with an emphasis on identifying key gaps in knowledge for the development of suitable platforms …

The Role Of Irf-1 In Spontaneous Mouse Glioma, Aakash B. Vaidya

Theses and Dissertations

Glioblastoma Multiforme has been shown to be one of the deadliest primary brain cancers. One of the reasons why GBM is so deadly, is a unique immunosuppressive tumor microenvironment that promotes GBM growth and progression. Both astrocyte and microglia have been implicated in immunosuppression. In this study, we explored the role of Interferon Regulatory Factor 1 (IRF-1) in astrocytes and glioma cells on the growth of spontaneous glioma tumors. IRF-1 is regulated by the JAK/STAT pathway and induces expression of Programmed death ligand 1 (PD-L1). PD-L1 downregulates immune responses to glioma. We found that IRF-1 had no effect on spontaneous …

Combination Of Oncolytic Adenoviruses, T-Cell Activation, And Blockade Of Ido Metabolic Circuitry For The Treatment Of Glioma, Teresa Nguyen

Dissertations & Theses (Open Access)

Glioblastoma is the most common malignant primary brain tumor in adults; the current aggressive treatment results in a 5% five-year survival rate. More effective therapies should be developed. One promising alternative is oncolytic adenovirus, Delta-24-RGD, which elicits cancer cell lysis and immunogenic cell death. In fact, Delta-24-RGD produced complete responses in 20% of recurrent glioblastoma patients through immune mechanisms that activate anti-tumor cytotoxic properties of T-cells. This cytolytic effect can further be enhanced by adding immune agonists, namely OX40L, which engages the OX40 receptor to co-stimulate activated T cells for enhanced proliferation. Hence, we produced the next generation of Delta-24-RGD, …

Glioma-Derived Exosomes Drive The Differentiation Of Neural Stem Cells To Astrocytes, Krishna D. Sharma, Danielle Schaal, Rajshekhar A. Kore, Rabab N. Hamzah, Sahitya Chetan Pandanaboina, Abdallah Hayar, Robert J. Griffin, Malathi Srivatsan, Nathan S. Reyna, Jennifer Yanhua Xie

Articles

Exosomes appear to be effective inter-cellular communicators delivering several types of molecules, such as proteins and RNAs, suggesting that they could influence neural stem cell (NSC) differentiation. Our RNA sequencing studies demonstrated that the RNAs related to cell proliferation and astrocyte differentiation were upregulated in human mesenchymal stem cells (hMSC) when co-cultured with exosomes obtained from the culture medium of human glioma cells (U87). Metallothionein 3 and elastin genes, which are related to cell proliferation, increased 10 and 7.2 fold, respectively. Expression of genes for astrocyte differentiation, such as tumor growth factor alpha, induced protein 3 of the NOTCH1 family, …

Microglia-Neuron Interactions In A Mouse Model Of Low Grade Neuroepithelial Tumors, Veolette Hanna

Honors Scholar Theses

Microglia are the macrophages of the brain and spinal cord, playing an important role in the immune response to disease states of the nervous system. This study conducts an investigation on the activity of microglia in response to low grade neuroepithelial tumors. Using mouse models and microglial markers, a qualitative and quantitative analysis of microglia activation, migration, and invasion within the brain cortex during early stages of tumor development was conducted. It was found that the presence of a low grade neuroepithelial tumor in the cortex of one hemisphere of the brain causes significant microglia activation in comparison to the …

The Effect Of The Loss Of Lgl1 In Murine Neural Progenitor Cells On Mapk Signaling And Proliferation, Monique R. Lacourse

Cal Poly Humboldt theses and projects

Glioblastoma is an incurable, aggressive, and highly invasive type of brain tumor that harbors tumor initiating cells characterized by disrupted polarized cell divisions. A cell polarity gene lethal (2) giant larvae 1 (Lgl1) has been implicated in gliomas and is a tumor suppressor initially identified in Drosophila with roles in proliferation. The loss of Lgl1 in Drosophila activates the MAPK protein kinase JNK and the Ras pathway and therefore its downstream kinase ERK, a transcription factor modulator. Furthermore, when Lgl1 is knocked out in mice, a phenotype similar to glioma is seen. Loss of the human form of …

The Overexpression Of Basigin-3 In Glioblastoma, Samantha M. Wightman

All NMU Master's Theses

Glioblastoma (GBM) is one of the most aggressive forms of brain tumor. With the current standard of care, survival prognosis for GBM patients is 15 months with a five-year survival rate of less than 3%. An increased understanding of the molecular mechanisms leading to cell growth and survival of GBMs may result in novel treatments to target and eradicate the disease. The protein Basigin-2 (aka EMMPRIN) induces the expression of matrix metalloproteinase (MMP) enzymes, and its expression level is positively correlated with GBM tumor grade. In 2011, Liao et al. reported that a splice variant of the basigin gene, called …

Igfbp2 Potentiates Egfr-Stat3 Signaling In Glioma, Yingxuan Chua

Dissertations & Theses (Open Access)

Gliomas are clinically challenging brain tumors with dismal survival rates due to its infiltrative nature and ineffective standard therapy. Insulin-like growth factor binding protein 2 (IGFBP2) is a pleiotropic oncogenic protein that has both extracellular and intracellular functions. Despite a clear causal role in cancer development, the contributions of intracellular IGFBP2 to tumor development and progression are poorly understood. Here we present evidence that both exogenous IGFBP2 treatment and cellular IGFBP2 overexpression lead to aberrant activation of EGFR, which subsequently activates STAT3 signaling. Furthermore, we demonstrate that IGFBP2 augments the nuclear accumulation of EGFR to potentiate STAT3 transactivation activities, via …

Atrx Loss-Of-Function In Mouse Neuroprogenitor Cells As A Model Of Early Events In Gliomagenesis, Hannah E. Goldberg

Electronic Thesis and Dissertation Repository

ATRX is a chromatin remodeling protein important for neural development, and ATRX inactivation leads to genomic instability, mitotic defects and TP53-mediated apoptosis. In the last few years, ATRX mutations were identified in a large proportion of paediatric and adult gliomas that often coincide with mutations in the tumor suppressor TP53. The present work shows that combinatorial loss of ATRX and TP53 function in vitro causes genomic instability while improving cell viability, identifying potential early events in gliomagenesis. Furthermore, several gene transcripts associated with glioma development and known oncogenic pathways were significantly upregulated in the Atrx-null neonatal mouse forebrain. …

Interaction Between Atm Kinase And P53 In Determining Glioma Radiosensitivity, Syed F. Ahmad

Theses and Dissertations

Glioblastoma multiforme (GBM) is the most common primary brain tumor. Studies have shown that targeting the DNA damage response can sensitize cancer cells to DNA damaging agents. Ataxia telangiectasia mutated (ATM) is involved in signaling DNA double strand breaks. Our group has previously shown that ATM inhibitors (ATMi) sensitize GBM cells and tumors to ionizing radiation. This effect is greater when the tumor suppressor p53 is mutated.

The goals of this work include validation of a new ATM inhibitor, AZ32, and elucidation of how ATMi and p53 status interact to promote cell death after radiation. We propose that ATMi and …

Clinical And Pathologic Significance Of Integrin Α6Β4 Expression In Human Malignancies, Rachel L. Stewart

Theses and Dissertations--Clinical and Translational Science

Integrins are cellular adhesion molecules that bind cells to the extracellular matrix. The integrin α6β4, a receptor for laminins, is predominantly expressed on epithelial cells where it is present at the basal surface adjacent to the basement membrane. This integrin plays a critical role in maintaining normal cellular functions, yet has also been implicated in promoting invasion and metastasis in human malignancies. While overexpression of the integrin α6β4 has been detected in select human cancers, the clinical significance of integrin α6β4 expression in a number of malignancies has not been determined. The purpose of this study was to examine integrin …

Car-Modified T Cells Capable Of Distinguishing Normal Cells From Malignant Cells, Hillary G. Caruso

Dissertations & Theses (Open Access)

T cells can be redirected to target tumor-associated antigen (TAA) by genetic modification to express a chimeric antigen receptor (CAR), which fuses the specificity derived from an antibody to T-cell activation domains to result in lysis of TAA-expressing cells. Due to the potential for on-target, off-tissue toxicity, CAR⁺ T-cell therapy is currently limited to unique or lineage-restricted TAAs. Glioblastoma, a grade IV brain malignancy, overexpresses epidermal growth factor receptor (EGFR) in 40-50% of patients. EGFR also has widespread normal tissue expression. To target EGFR on glioblastoma while reducing the potential for normal tissue toxicity, EGFR-specific CAR generated from cetuximab, …

Quantification Of Protoporphyrin Ix Accumulation In Glioblastoma Cells – A New Technique, Johnathan Lawrence, Ashish Patel, Richard Rovin, Robert Belton, Catherine Bammert, Robert Winn

Johnathan Lawrence

Introduction. 5-Aminolevulinic Acid (5-ALA) is a precursor of heme synthesis. A metabolite, protoporphyrin IX (PpIX), selectively accumulates in neoplastic tissue including glioblastoma. Presurgical administration of 5-ALA forms the basis of fluorescence-guided resection (FGR) of glioblastoma (GBM) tumors. However, not all gliomas accumulate sufficient quantities of PpIX to fluoresce, thus limiting the utility of FGR. We therefore developed an assay to determine cellular and pharmacological factors that impact PpIX fluorescence in GBM. This assay takes advantage of a GBM cell line engineered to express yellow fluorescent protein. Methods. The human GBM cell line U87MG was transfected with a YFP expression vector. …

Phenytoin Reduces 5-Ala Mediated Fluorescence In Glioblastoma Cells, Christopher Steele, Johnathan E. Lawrence, Richard A. Rovin, Robert J. Winn

Johnathan Lawrence

Glioblastoma multiforme (GBM) is a devastating form of cancer, and essentially all GBM tumors recur causing fatality. A new surgical technique, fluorescence-guided resection of GBM using 5-aminolevulinic acid (5-ala), improves the extent of resection and positively impacts the length and quality of patient survival. The fluorescence achieved in neoplastic tissue depends directly on the accumulation of porphyrins derived from the metabolism of the 5-ala prodrug within the cancer cell. However, 5-ala induced fluorescence has been reported to be inconsistent. In an effort to determine the cause of the inconsistent fluorescence, the authors investigated the effect of medications commonly prescribed to …

Glioblastoma Derived Exosomes Induce Apoptosis In Cytotoxic T Cells Through A Fas Ligand Mediated Mechanism, Keith Sabin, Richard Rovin, Johnathan Lawrence, Robert Belton, Robert Winn

Johnathan Lawrence

INTRODUCTION: Glioblastoma multiforme deploy s a number of weapons to thwart the immune system. Within the tumor microenvironment, cytotoxic T cells fall victim to Fas ligand (FasL) induced apoptosis. In prostate and colorectal cancer, exosomes can mediate this FasL induced T cell apoptosis. Exosomes are tiny, membrane bound vesicles that are released from a cell. They contain functional mRNA and protein and have cell surface molecules representative of their parent cell. It is not known if GBM derived exosomes can also mediate FasL triggered apoptosis. In this study, the role of tumor derived exosomes as the delivery vehicle for FasL …

Leptin Promotes Glioblastoma, Johnathan Lawrence, Nicholas Cook, Richard Rovin, Robert Winn

Johnathan Lawrence

The hormone leptin has a variety of functions. Originally known for its role in satiety and weight loss, leptin more recently has been shown to augment tumor growth in a variety of cancers. Within gliomas, there is a correlation between tumor grade and tumor expression of leptin and its receptor. This suggests that autocrine signaling within the tumor microenvironment may promote the growth of high-grade gliomas. Leptin does this through stimulation of cellular pathways that are also advantageous for tumor growth and recurrence: antiapoptosis, proliferation, angiogenesis, and migration. Conversely, a loss of leptin expression attenuates tumor growth. In animal models …

Effects Of Ss3-Adrenergic Receptor Agonist On Gene Expression Of Leptin In Glioblastoma, Johnathan E. Lawrence, Nicholas J. Cook, Richard A. Rovin, Robert J. Belton, Robert J. Winn

Johnathan Lawrence

In the 25 years since temozolomide entered phase I clinical trials, few new primary or adjuvant therapies have been developed for the treatment of glioblastoma multiforme (GBM) tumors. Our laboratory has been exploring novel methods for the treatment of GBMs. Recent studies indicate that the expression of the hormone leptin and its receptor (OBR) increases in gliomas and positively correlates with the malignancy of the tumor. Interestingly, ß3-adrenergic receptor agonists are known to decrease leptin expression in adipocytes but have not been examined in GBM cells. We hypothesized that b3-adrenergic agonists downregulate the expression of leptin and its receptor. In …

Mechanisms Of Adenovirus-Mediated Autophagy, Erin White

Dissertations & Theses (Open Access)

A patient diagnosed with a glioma, generally, has an average of 14 months year to live after implementation of conventional therapies such as surgery, chemotherapy, and radiation. Glioblastomas are highly lethal because of their aggressive nature and resistance to conventional therapies and apoptosis. Thus other avenues of cell death urgently need to be explored. Autophagy, which is also known as programmed cell death type II, has recently been identified as an alternative mechanism to kill apoptosis- resistant cancer cells. Traditionally, researchers have studied how cells undergo autophagy during viral infection as an immune response mechanism, but recently researchers have discovered …

Β3-Adrenergic Agonists Mimic Eustress Response And Reduce Leptin-Mediated Proliferation In A Gbm Cell Line, Johnathan E. Lawrence, Nicholas J. Cook, Richard A. Rovin, Robert J. Winn

Johnathan Lawrence

A great deal of mental stress, depression, and anxiety often overwhelm cancer patients; those diagnosed with glioblastoma multiforme (GBM) are no exception. Different types of stress invariably impact what has been termed “the brain-adipocyte BDNF/leptin axis” (Dr. Cao and colleagues of the Comprehensive Cancer Center at The Ohio State University). For example, eustress (good stress) and distress (bad stress) both lead to increased sympathetic activity and adrenal gland stimulation, yet eustress reduces leptin levels and attenuates tumor growth while distress increases leptin levels and augments tumor growth. Complicating matters in GBM is that leptin and its receptor are expressed at …

Glioblastoma Derived Exosomes Contribute To Tumor Immune Evasion, Keith Z. Sabin, Danny Lebert, Vanessa Thibado, Richard A. Rovin, Johnathan E. Lawrence, Robert J. Winn

Johnathan Lawrence

Glioblastoma multiforme (GBM) is the most frequent and lethal primary brain tumor in adults. Despite intense biomedical research, the median survival after diagnosis is 15 months. One factor contributing to this poor prognosis is the immune protection afforded by the tumor microenvironment. Tumors have a diverse repertoire of immune-evasive techniques. One method of evasion not well explored is the release of tumor-derived exosomes. Exosomes are tiny membrane-bound vesicles of endocytic origin that contain viable mRNA and functional proteins that can affect the physiology of recipient cells. Exosome release has been reported for numerous cancer types, including GBM. Exosomes from colon …

Survival Prediction For Brain Tumor Patients Using Gene Expression Data, Vinicius Bonato

Dissertations & Theses (Open Access)

Brain tumor is one of the most aggressive types of cancer in humans, with an estimated median survival time of 12 months and only 4% of the patients surviving more than 5 years after disease diagnosis. Until recently, brain tumor prognosis has been based only on clinical information such as tumor grade and patient age, but there are reports indicating that molecular profiling of gliomas can reveal subgroups of patients with distinct survival rates. We hypothesize that coupling molecular profiling of brain tumors with clinical information might improve predictions of patient survival time and, consequently, better guide future treatment decisions. …

Expression Of Hcmv Ie1 In The U87mg Cell Line Augments Resistance To Temozolomide, Richard Rovin, Johnathan Lawrence, Justin Segula, Robert Winn

Johnathan Lawrence

INTRODUCTION: Human cytomegalovirus (HCMV) DNA and protein are found in gliomas but not in normal brain or other primary brain tumors. The role of HCMV infection in glioma biology is unclear. While it is unlikely that HCMV infection causes glioma, viral proteins might impart a proliferative and antiapoptotic phenotype that confers a survival advantage. Does this oncomodulation translate into a clinically relevant effect in glioma cells? To answer this question, we compared the response of the U87IE1 and U87MG malignant glioma cell lines to temozolomide. U87IE1 cells are U87MG cells that have been genetically engineered to produce HCMV IE1 protein. …

Hormonal And Reproductive Factors And Risk Of Glioma: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

The etiology of glioma, the most commonly diagnosed malignant brain tumor among adults in the United States, is poorly understood. Given the lower incidence rate of glioma in women than in men, it has been hypothesized that reproductive and hormonal factors may be involved in the etiology of glioma. We conducted a secondary analysis of data from the National Breast Screening Study, which included 89,835 Canadian women, aged 40–59 years at recruitment between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths from all causes, respectively, with follow‐up ending between 1998 and …

Cigarette Smoking And Risk Of Glioma: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

The etiology of glioma, the most commonly diagnosed malignant brain tumor among adults in the United States, is poorly understood. N‐nitroso compounds are known carcinogens, which are found in cigarette smoke and can induce gliomas in rats. On this basis, it has been hypothesized that cigarette smoking may be associated with an increased risk of glioma. We investigated the association between cigarette smoking and glioma risk in the National Breast Screening Study, which included 89,835 Canadian women aged 40–59 years at recruitment between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths …

Combining Cytotoxic And Immune-Mediated Gene Therapy To Treat Brain Tumors, James Curtin, Gwendalyn King, Marianela Candolfi, Remy Greeno, Kurt Kroeger, Pedro Lowenstein, Maria Castro

Articles

Glioblastoma (GBM) is a type of intracranial brain tumor, for which there is no cure. In spite of advances in surgery, chemotherapy and radiotherapy, patients die within a year of diagnosis. Therefore, there is a critical need to develop novel therapeutic approaches for this disease. Gene therapy, which is the use of genes or other nucleic acids as drugs, is a powerful new treatment strategy which can be developed to treat GBM. Several treatment modalities are amenable for gene therapy implementation, e.g. conditional cytotoxic approaches, targeted delivery of toxins into the tumor mass, immune stimulatory strategies, and these will all …

Gene Therapy And Targeted Toxins For Glioma, James Curtin, Gwendalyn King, Marianela Candolfi, Kurt Kroeger, Pedro Lowenstein, Maria Castro

Articles

The most common primary brain tumor in adults is glioblastoma. These tumors are highly invasive and aggressive with a mean survival time of nine to twelve months from diagnosis to death. Current treatment modalities are unable to significantly prolong survival in patients diagnosed with glioblastoma. As such, glioma is an attractive target for developing novel therapeutic approaches utilizing gene therapy. This review will examine the available preclinical models for glioma including xenographs, syngeneic and genetic models. Several promising therapeutic targets are currently being pursued in pre-clinical investigations. These targets will be reviewed by mechanism of action, i.e., conditional cytotoxic, targeted …