Medicine and Health Sciences Commons^™

Therapeutic Potential Of Tumor Treating Fields For Malignant Brain Tumors, Youyou Zhou, Xiaoqing Xing, Jinyun Zhou, Han Jiang, Peili Cen, Chentao Jin, Yan Zhong, Rui Zhou, Jing Wang, Mei Tian, Hong Zhang

Journal Articles

BACKGROUND: Malignant brain tumors are among the most threatening diseases of the central nervous system, and despite increasingly updated treatments, the prognosis has not been improved. Tumor treating fields (TTFields) are an emerging approach in cancer treatment using intermediate-frequency and low-intensity electric field and can lead to the development of novel therapeutic options.

RECENT FINDINGS: A series of biological processes induced by TTFields to exert anti-cancer effects have been identified. Recent studies have shown that TTFields can alter the bioelectrical state of macromolecules and organelles involved in cancer biology. Massive alterations in cancer cell proteomics and transcriptomics caused by TTFields …

Impact Of Timing To Initiate Adjuvant Therapy On Survival Of Elderly Glioblastoma Patients Using The Seer-Medicare And National Cancer Databases, Ping Zhu, Xianglin L Du, Lu-Yu Hwang, David Lairson, Ruosha Li, Yoshua Esquenazi, Jay-Jiguang Zhu

Journal Articles

The optimal time to initiate adjuvant therapy (AT) in elderly patients with glioblastoma (GBM) remains unclear. We investigated the impact of timing to start AT on overall survival (OS) using two national-scale datasets covering elderly GBM populations in the United States. A total of 3159 and 8161 eligible elderly GBM patients were derived from the Surveillance, Epidemiology and End Results (SEER)-Medicare linked dataset (2004-2013) and the National Cancer Database (NCDB) (2004-2014), respectively. The intervals in days from the diagnosis to the initiation of AT were categorized based on two scenarios: Scenario I (quartiles), ≤ 15, 16-26, 27-37, and ≥ 38 …

Modeling Of Cns Cancer With A Focus On The Immune Component, Daniel Zamler

Dissertations & Theses (Open Access)

The knowledge surrounding cancers of the central nervous system remains poorly developed, in particular with regard to the immune component. The works contained in this thesis look at craniopharyngioma, glioblastoma, and several forms of brain metastasis. While some attention is given to the tumor cells themselves, as well as the patient setting which these studies model, the immune component of disease progression and treatment plays a strong role in each and is the primary focus of the works contained.

Craniopharyngioma is a relatively rare tumor in adults. Although histologically benign, it can be locally aggressive and may require additional therapeutic …

Atrx Inactivation And Idh1-R132h Drive Preferential Sensitivity To Proton Vs. X-Ray Radiotherapy In Glioma Stem Cells, Ángel Adrián Garcés

Dissertations & Theses (Open Access)

Background: Glioma Stem Cells (GSCs) are self-renewable, treatment resistant cells in the glioma tumor mass known to promote tumor development. In contrast to traditional photon-based radiation therapy (XRT), proton radiation therapy (PRT) may induce more complex DNA damage and therefore might have the potential to eliminate GSCs. Although previous studies have individually linked IDH mutations, specifically IDH1^R132H, and ATRX inactivating mutations to improved patient outcomes and suppressed DNA damage repair compared to their respective wild-types, the mechanisms by which these two genetic alterations interact in GSCs treated with PRT compared to XRT are currently unknown. We hypothesize that …

Investigating The Metabolic Progression Of Glioblastoma With Hyperpolarized Magnetic Resonance, Travis Salzillo

Dissertations & Theses (Open Access)

Rapid diagnosis and therapeutic monitoring of aggressive diseases such as glioblastoma (GBM) can improve patient survival by providing physicians the time to optimally deliver treatment. This includes early in development, while the tumor is still manageable, or following initial therapy, when alternative treatments should be considered. The main goal of this project was to determine whether metabolic imaging with hyperpolarized magnetic resonance spectroscopy (MRS) could detect changes in tumor progression more rapidly than conventional anatomic magnetic resonance imaging (MRI) in patient-derived GBM murine models. To comprehensively capture the dynamic nature of cancer metabolism, in vivo pyruvate-to-lactate conversion with hyperpolarized MRI, …

Wisp1 Is An Overexpressed Driver Of Glioblastoma, Pushan R. Dasgupta

Dissertations & Theses (Open Access)

Despite current multimodal therapies for glioblastoma (GBM) the prognosis remains very grim. There is a tremendous need to identify new genetic drivers which can serve as potential therapeutic targets. In order to find new drivers, we leveraged genomic datasets to conduct a context specific in vivo functional genomic screen of overexpressed and/or amplified genes in GBM. We identified WISP1, a secreted extracellular matrix protein, to be an overexpressed driver in GBM. Overexpression of WISP1 was able to drive tumor growth in various in vivo models. Knockdown of WISP1 with shRNAs resulted in reduced colony formation in vitro and reduced tumor …

Rest Regulatory Circuit Controls Distinct Oncogenic Properties Of Glioblastoma Stem Cells Through Specific Micrornas, Anantha L Marisetty

Dissertations & Theses (Open Access)

Glioblastoma Multiforme (GBM) is the most common and aggressive primary malignant brain tumor in adults. With an average survival of only 12-16 months the prognosis for GBM patients remains dismal, with less than 5% of patients surviving 5 years. New mechanism-based approaches are necessary for the management of patients with GBM. Many GBM tumors are believed to be caused by self-renewing, glioblastoma-derived stem-like cells (GSCs). These GSCs are resistant to chemo- and radiation therapies, and are believed to be responsible for tumor recurrence. In a recent paper from our lab we have shown that REST, RE1-silencing transcription factor, regulates oncogenic …

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 …

Role Of The Ang-Tie2 Pathway In The Invasive Recurrence Of Gbm Following Anti-Vegf Therapy, Nahir Cortes Santiago

Dissertations & Theses (Open Access)

Strong pre-clinical and clinical data supporting the effectiveness of bevacizumab, a humanized monoclonal anti-VEGF antibody, for the treatment of gliomas led to its accelerated approval for the treatment of patients with recurrent glioma. However, despite strong anti-tumor effects, upon treatment with bevacizumab, patients will invariably recur with a tumor characterized by enhanced invasiveness and resistance to therapy. This study aims to elucidate the mechanisms leading to this enhanced malignancy with the hope of uncovering new potential therapeutic targets for combined treatment. Using tissue sections from U87-derived glioma bearing mice treated with or without aflibercept (another anti-VEGF antibody) we have gathered …

Discovery And Elucidation Of The Fgfr3-Tacc3 Recurrent Fusion In Glioblastoma, Brittany C. Parker Kerrigan

Dissertations & Theses (Open Access)

Fusion genes occur due to chromosomal instability where two previously separate genes rearrange and fuse together, forming a hybrid gene. The first fusions were reported in leukemias; however, with the advent of more powerful sequencing technologies, fusions have recently been reported in several solid tumors. Using next-generation deep sequencing approaches, we discovered a fusion gene connecting the fibroblast growth factor receptor 3 (FGFR3) gene to the transforming coiled-coil containing protein 3 (TACC3) gene in glioblastoma multiforme. The fusion occurred in 8.3% of patient samples, but not in low grade or normal samples. FGFR3-TACC3 produced an in-frame …

Methodological Development Of A Multi-Parametric Quantitative Imaging Biomarker Framework For Assessing Treatment Response With Mri, Ryan J. Bosca

Dissertations & Theses (Open Access)

Quantitative imaging biomarkers (QIBs) are increasingly being incorporated into early phase clinical trials as a means of non-invasively assessing the spatially heterogeneous treatment response to anticancer therapies, particularly as indicators for early response. MR QIBs are derived from the analysis of in vivo imaging data, such as that acquired via dynamic contrast enhanced (DCE), dynamic susceptibility enhanced (DSC), and diffusion tensor imaging (DTI). To date, preclinical and clinical applications of such QIBs have provided strong evidence for potential efficacy, but efforts to create meaningful estimates of localized treatment response using multiple QIBs have been stifled by the need for rigorous …

Αvβ8 Integrin Interacts With Rhogdi1 To Regulate Rac1 And Cdc42 Activation And Drive Glioblastoma Cell Invasion, Steve Reyes

Dissertations & Theses (Open Access)

As an interface between the circulatory and central nervous systems, the neurovascular unit is vital to the development and survival of tumors. The malignant brain cancer glioblastoma multiforme (GBM) displays invasive growth behaviors that are major impediments to surgical resection and targeted therapies. Adhesion and signaling pathways that drive GBM cell invasion remain largely uncharacterized. Here we have utilized human GBM cell lines, primary patient samples, and pre-clinical mouse models to demonstrate that integrin αvβ8 is a major driver of GBM cell invasion. β8 integrin is overexpressed in many human GBM cells, with higher integrin expression correlating with increased invasion …

Elucidating The Igfbp2 Signaling Pathway In Glioma Development And Progression, Kristen M. Holmes

Dissertations & Theses (Open Access)

Diffuse gliomas are highly lethal central nervous system malignancies which, unfortunately, are the most common primary brain tumor and also the least responsive to the very few therapeutic modalities currently available to treat them. IGFBP2 is a newly recognized oncogene that is operative in multiple cancer types, including glioma, and shows promise for a targeted therapeutic approach. Elevated IGFBP2 expression is present in high-grade glioma and correlates with poor survival. We have previously demonstrated that IGFBP2 induces glioma development and progression in a spontaneous glioma mouse model, which highlighted its significance and potential for future therapy. However, we did not …

Taz As A Regulator Of Mesenchymal Transformation And Clinical Aggressiveness In Gliomas, Katrina Salazar

Dissertations & Theses (Open Access)

Glioblastoma multiforme (GBM) is an aggressive, high grade brain tumor. Microarray studies have shown a subset of GBMs with a mesenchymal gene signature. This subset is associated with poor clinical outcome and resistance to treatment. To establish the molecular drivers of this mesenchymal transition, we correlated transcription factor expression to the mesenchymal signature and identified transcriptional co-activator with PDZ-binding motif (TAZ) to be highly associated with the mesenchymal shift. High TAZ expression correlated with worse clinical outcome and higher grade. These data led to the hypothesis that TAZ is critical to the mesenchymal transition and aggressive clinical behavior seen in …

Applications Of Ephb4 Receptor Specific Peptides In Targeted Cancer Imaging And Therapy, Miao Huang

Dissertations & Theses (Open Access)

EphB4 receptors, a member of the largest family of receptor tyrosine kinases, are found over-expressed in a variety of tumors cells including glioma cells as well as angiogenic blood vessels. Noninvasive imaging of EphB4 could potentially increase early detection rates, monitor response to therapy directed against EphB4, and improve patient outcomes. Targeted delivery of EphB4 receptor specific peptide conjugated hollow gold nanoshells (HAuNS) into tumors has great potential in cancer imaging and photothermal therapy. In this study, we developed an EphB4 specific peptide named TNYL-RAW and labeled with radioisotope ⁶⁴Cu and Cy5.5 dye. We also conjugate this specific peptide …