Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

Identification And Molecular Analysis Of Dna In Exosomes, Jena Tavormina

Dissertations and Theses (Open Access)

Exosomes are heterogeneous nanoparticles 50-150nm in diameter. Exosomes contain many functional cargo components, such as protein, DNA, and RNA. While protein and RNA exosome content has been extensively studied, very little work has been done to characterize exosomal DNA. Here, we demonstrate that exosomal DNA is heterogeneous and its packaging into exosomes is dependent on the cell of origin. Furthermore, through a rigorous assessment of various isolation methods, we identify Size Exclusion Chromatography (SEC) as the best method for the isolation of exosomal DNA for downstream applications. Additionally, we evaluate the methylation status of exosomal DNA and demonstrate that exosomal …

Evaluating The Therapeutic Efficacy Of Grb2 Inhibition In Ovarian Malignancies, Olivia Lara

Dissertations and Theses (Open Access)

Purpose: Adaptor proteins such as growth factor receptor-bound protein-2 (Grb2) play important roles in cancer cell signaling. In the present study, we examined the biological effects of liposomal antisense oligodeoxynucleotide that blocks Grb2 expression (L-Grb2) in ovarian cancer models.

Experimental Design: Murine orthotopic models of ovarian cancer (OVCAR5 and SKOV3ip1) were used to study the biological effects of L-Grb2 on tumor growth. In vitro experiments (cell viability assay, Western blot analysis, siRNA transfection, and reverse phase protein array) were carried out to elucidate the mechanism and potential predictors of tumor response to L-Grb2.

Results: Treatment with L-Grb2 decreased tumor growth …

Multimodality Somatostatin Analog For Fluorescence-Guided Surgery In Cancer, Servando Hernandez Vargas

Dissertations and Theses (Open Access)

Cancer surgery remains the primary curative treatment for most solid cancers and has major therapeutic implications for patients with neuroendocrine tumors (NETs). Anatomical and functional imaging technologies are widely used during the pre- and postoperative stages, but intraoperative disease recognition relies on direct visual inspection and the hands of surgeons. The limited number of clinical tools for real-time intraoperative visual feedback restricts the ability to remove the complete cancer source and is partially responsible for the high rate of disease recurrence in patients. Intraoperative imaging with fluorescent contrast agents has the potential to improve the ability of surgeons to detect …

Development Of Automated Radiotherapy Treatment Planning For Cervical And Breast Cancer For Resource-Constrained Clinics, Kelly Kisling

Dissertations and Theses (Open Access)

Globally, cancer rates are on the rise, especially in low- and middle-income countries (LMICs). However, many of these countries lack access to radiotherapy, which is due in part to a substantial shortage of the staff necessary to deliver safe and effective radiotherapy. This staff shortage could be mitigated by the automation of the radiation treatment planning process. To this end, we developed automated planning for cervical and postmastectomy breast cancer radiotherapy, the two most common types of cancer in women in many LMICs.

For radiotherapy of cervical cancer in resource-constrained clinics, the recommended treatment technique is a four-field box. We …

Simvastatin Does Not Sensitize Ibc3 Her2+ Inflammatory Breast Cancer Brain Metastases To Whole Brain Irradiation In An Immunocompromised Mouse Model, Swaminathan Kumar

Dissertations and Theses (Open Access)

Retrospective data analysis suggests that inflammatory breast cancer (IBC) patients who take statins have better locoregional control after radiotherapy than those who do not [23]. Our lab has previously demonstrated that simvastatin radiosensitizes IBC cells in vitro [23], and brain metastases have strong expression of cholesterol-regulation genes compared to lung metastases in vivo [unpublished]. Delaying whole-brain irradiation (WBI) beyond 21 days is insufficient to reduce the incidence of brain metastases (developed by injecting IBC3 cells through the tail vein) in our mouse model because even high rates of cell killing leave substantial cell volume in established metastases [unpublished].

With the …

Discovery And Effects Of Pharmacological Inhibition Of The E3 Ligase Skp2 By Small Molecule Protein-Protein Interaction Disruptors, John K. Morrow

Dissertations and Theses (Open Access)

Skp2 (S-phase kinase-associated protein 2), one component of the SCF E3 ubiquitin ligase complex, directly interacts with Skp1 and indirectly associates with Cullin1 and Rbx1 to bridge the E2 conjugating enzyme with its protein substrate to execute its E3 ligase activity. Skp2 is an Fbox protein (due to it containing an Fbox domain) and it is the rate-limiting component of the SCF complex. Skp2 targets several cell-cycle regulatory proteins for ubiquitination and degradation; most notable and significant for cancer are the cyclin-dependent kinase inhibitor, p27. Skp2 is an oncogene and studies have shown that over-expression of Skp2 leads to increased …

Randomized Controlled Trials Evaluating Patient-Reported Outcomes After Cholecystectomy: A Systematic Review, Krislynn M Mueck, Deepa V Cherla, Amy Taylor, Tien C Ko, Mike K Liang, Lillian S Kao

Library Staff Publications

No abstract provided.

Evaluating The Therapeutic Efficacy Of Restoring Wild-Type P53 Activity In P53-Mutant Tumors, Connie A. Larsson

Dissertations and Theses (Open Access)

The p53 transcription factor is the most frequently altered in human cancers usually via missense mutations that undermine its transcriptional activity. Clinically, TP53 mutations have been shown to be remarkably predictive of refractoriness to treatment, resulting in poor outcome. Consequently, the development of p53 pathway activating agents is rapidly evolving and gaining more attention in cancer therapeutics research, with several small molecule compounds currently in preclinical and clinical trials. However, it remains largely unknown what types or proportions of p53-mutant tumors will respond to p53 restoration-based therapies.

Using a mouse model of Li Fraumeni syndrome, we genetically restored wild-type …

Memory Potential, Molecular Characterization, And Translational Applications Of The Novel Theo/Tceo T Cell Phenotype, Todd Bartkowiak, Todd Bartkowiak

Dissertations and Theses (Open Access)

T cells comprise a substantial arm of the immune system and are exquisitely adapted to combat pathogens and tumors. The inflammatory environment largely dictates the nature of T cell response. A hallmark of T cell-mediated immunity is formation of immunological memory; the ability to respond more potently to re-encounter with pathogens. The immune system is also capable of recognizing tumors as foreign, much like viral or bacterial pathogens. Tumors have evolved, though, to generate an immunosuppressive environment to avoid destruction. The field of immunotherapy seeks to overcome immune suppression, in part by targeting T cell co-receptors on the cell surface …

Quantitative Dwi As An Early Imaging Biomarker Of The Response To Chemoradiation In Esophageal Cancer, Benjamin C. Musall

Dissertations and Theses (Open Access)

For patients diagnosed with stages IIa-IIb esophageal cancer, the current standard of care treatment is tri-modality therapy (TMT), where neoadjuvant chemoradiation (nCRT) is followed by surgical resection. Histopathology of resected tumors reveals that pathological complete response (pCR) is achieved in 20-30% of patients through nCRT alone. Because of the high mortality and morbidity associated with esophagectomy, it may be advantageous for patients exhibiting pCR from nCRT alone to be placed under observation rather than completing their TMT. Therefore, a method for predicting response at an early time-point during nCRT is highly desirable. Conventional methods such as endoscopic ultrasound, re-biopsy, and …

Improvements In Four-Dimensional And Dual Energy Computed To Mography, Rachael M. Martin

Dissertations and Theses (Open Access)

Dual energy and 4D computed tomography (CT) seek to address some of the limitations in traditional CT imaging. Dual energy CT, among other purposes, allows for the quantification and improved visualization of contrast materials, and 4D CT is often used in radiation therapy applications as it allows for the visualization and quantification of object motion. While much research has been done with these technologies, areas remain for potential improvement, both in preclinical and clinical settings, which will be explored in this dissertation. Preclinical dual energy cone-beam CT (CBCT) can benefit from wider separation between the peak energy of the two …

Statistical Methods For Assessing Structural Change In Human & Microbial Genomes, Xuan Zhu

Dissertations and Theses (Open Access)

Genetic sequencing has been recognized as an effective approach to accurately address biological problems, such as clinical detection of disease, mutation discovery, and targeting specific biomarkers associated with complex diseases. Compared with conventional Sanger sequencing, next-generation sequencing costs much less due to massively parallel high-throughput sequencing. However, due to large numbers of short read sequences, the accuracy of high-throughput sequencing data remains a challenge in that the data obtained from next-generation sequencing often has higher error rates, which may impact downstream genomic analysis. Even if the downstream genomic analysis performs well, the quality of the result will still be impacted …

Novel Simulation To Avoid Bias In Measurement Of Hyperpolarized Pyruvate: Demonstrated In Phantom And In Vivo, Christopher M. Walker

Dissertations and Theses (Open Access)

Dynamic nuclear polarization creates a transient hyperpolarized nuclear state that can dramatically increase the signal detected by magnetic resonance imaging. This signal increase allows real-time spectroscopic imaging of specific metabolites in vivo by magnetic resonance. Real-time imaging of both the spatial and chemical fate of hyperpolarized metabolites is showing great promise to meaningfully benefit clinical care of cancer patients. Imaging of hyperpolarized agents will have a larger clinical impact if it can function as a quantitative modality upon which clinical decisions can be made. However, quantitative measurement of hyperpolarized agents is currently difficult due to the restrictions imposed by the …

Circumventing Cisplatin Resistance In Ovarian Cancers Through Reactivation Of P53 By Non-Cross-Resistant Platinum Analogs, Michelle Martinez-Rivera

Dissertations and Theses (Open Access)

Abstract

CIRCUMVENTING CISPLATIN RESISTANCE IN OVARIAN CANCERS THROUGH REACTIVATION OF P53 BY NON-CROSS-RESISTANT PLATINUM ANALOGS

Michelle Martinez-Rivera, B.S.

Advisory Professor: Zahid H. Siddik, Ph.D.

Cisplatin (cis-Pt), an anticancer platinum (Pt) drug, is used widely in the treatment of several malignancies, such as ovarian cancer. This Pt compound induces DNA damage, which results in p53 activation through post-translational modifications, mainly phosphorylation, culminating in execution of programmed cell-death. However, despite initial therapeutic response to cis-Pt, clinical resistance to this drug emerges leading to disease progression. Pt-resistance phenotypes have been associated with dysfunction in the p53 signaling pathway. Therefore, an effort to understand …

An Automated Syringe Pump System For Improving The Reproducibility Of Dynamic Hyperpolarized Mri Phantoms, Harlee G. Harrison

Dissertations and Theses (Open Access)

AN AUTOMATED SYRINGE PUMP SYSTEM FOR IMPROVING THE REPRODUCIBILITY OF DYNAMIC HYPERPOLARIZED MRI PHANTOMS

Harlee Grace Harrison, B.S.

Advisory Professor: James Bankson, Ph.D.

Magnetic Resonance Imaging (MRI) is a powerful tool in the diagnosis of cancer due to its ability to provide good soft tissue contrast and image resolution without the use of ionizing radiation. The use of hyperpolarized pyruvate as a contrast agent for tumor metabolism during MR scans has the potential to provide information about tumor metabolism in vivo that is not available from traditional imaging measurements or any other method. Hyperpolarization is achieved through dynamic nuclear polarization. …

Factors Influencing Uptake Of Risk-Reducing Salpingo-Oophorectomy By Brca1 And Brca2 Mutation Carriers, Victoria E. Breen

Dissertations and Theses (Open Access)

Germline mutations in the BRCA1 and BRCA2 genes are associated with significantly increased risks for ovarian cancer. The National Comprehensive Cancer Network (NCCN) currently recommends that female BRCA mutation carriers undergo risk-reducing salpingo-oophorectomy (RRSO) after age 35; however, not all women elect this option. The purpose of this study was to prospectively survey women with BRCA mutations currently undergoing ovarian cancer screening about their intention to have an RRSO and the various factors influencing their decision. Of the 26 women who completed our survey, 26 (100%, CI: 86.8-100) plan to undergo an RRSO in their lifetime. The average woman reported …

Assessment Of Uncertainty In Planning And Dose Delivery Of Proton Therapy In An Iroc- Houston Qa Phantom Due To Variable Ct Technique And Proton Energy, Mattie M. Mcinnis

Dissertations and Theses (Open Access)

As proton therapy increases in popularity, so does the need for effective quality assurance. Proton therapy institutions participating in NCI funded clinical trials rely heavily on the credentialing and auditing services of IROC-H and therefore the process must be well understood. The purpose of this project is to understand the uncertainties in proton therapy treatment planning for the IROC-H proton phantom QA program due to variations in CT technique and proton energy. It was hypothesized that variations in CT technique and proton energy will alter the delivered dose distributions of typical proton treatments by reducing the percent of passing pixels …

Src Homology 2 Domain-Containing 5’-Inositol Phosphatase-2 (Ship2) Is An Effector Of Lymphatic Dysfunction, Germaine D. Agollah

Dissertations and Theses (Open Access)

The lymphatic system is essential for the transport of excess fluid, protein, and foreign materials from interstitial tissues to lymph nodes; for immune surveillance, and to maintain fluid homeostasis. Dysregulated lymphatics can be attributed to pathological conditions including tumor metastasis, inflammation, chronic wounds, obesity, blood vascular disorders, and lymphedema. Of these, lymphedema is the most extreme of lymphatic disorders and is represented by a spectrum of symptoms ranging from mild, subtle presentation to severe, disfiguring, overt presentation. Lymphedema is more manageable in the early stages of disease but severely reduces quality of life with progression. Due to lack of molecular …

Correlation Matrix Analysis Identifies Gene Signatures Of Immune Cell Subsets And Their Interactions In Follicular Lymphoma, Jason R. Westin

Dissertations and Theses (Open Access)

There are important but ill-defined interactions between benign immune cell subsets and neoplastic B cells within follicular lymphoma (FL). Using the novel technique of correlation matrix analysis (CMA) of publicly available FL whole-tumor gene expression profiling (GEP) data, we have identified signatures of immune cell subsets. Overall survival correlated most highly with a model using signatures of macrophages, T cells, and stroma, which was able to add significantly to existing clinical prognostic tools. From our own data of a cohort of 43 FL tumors sorted into B-cell and non-B cell (NB) fractions for GEP, CMA of the tumor infiltrating NB …

The Kras/Mapk Pathway And Ligand Independent Activation Of Erα: Implications For The Treatment Of Endometrial Cancer, Kari Ring

Dissertations and Theses (Open Access)

Hormonal therapy remains a first line option for the treatment of recurrent endometrial cancer (EC), however, many tumors demonstrate de novo or acquired resistance. Member kinases of the PI3K/AKT and Ras/MAPK pathways activate estrogen receptor α (ERα) independent of estrogen, however, few studies have evaluated the role of the Ras/MAPK pathway in predicting response to hormonal therapy in EC. The aims of this project were to evaluate the role of ligand independent activation of ERα in EC and to explore therapeutic implications for the treatment of recurrent EC.

A xenograft model for recurrent EC was used to evaluate the effect …

Utilizing Haplotypes For Sensitive Snp Array-Based Discovery Of Somatic Chromosomal Mutations, Selina M. Vattathil

Dissertations and Theses (Open Access)

Somatic copy-number (CN) gains and losses and copy-neutral loss of heterozygosity (CNLOH) frequently occur in tumors and play a major role in the progression of disease by altering gene dosage and unmasking deleterious recessive variants. Characterizing these mutations in an individual tumor sample is therefore critical for research on the relationship of specific mutations to disease outcome and for clinical decision-making based on mutations with known impact. A pervasive hindrance to sensitive detection of these mutations is genetic heterogeneity and high levels of contaminating normal cells in tumor samples, which limit the fraction of cells carrying informative mutations. The method …

Development Of A Molecular Gram-Stain Assay For The Diagnosis Of Blood Stream Infections Associated With Sepsis, Douglas Bryan Litwin

Dissertations and Theses (Open Access)

Sepsis is a serious medical condition resulting from the severe dysregulation of the immune response that is generally triggered by infection. It affects more than 1.1 million Americans, has an average mortality rate of 30%, and is estimated to cost $24.3 billion annually. Currently, blood culture followed by Gram-stain analysis is the gold standard for diagnosing bacterial infections associated with sepsis. This method generates a high rate of false negative results and, in general, requires 20 to 48 hr to provide results. Both of these problems are related to the requirement that the bacterial pathogens grow under defined laboratory conditions. …

Anti-Gd2 Etoposide-Loaded Immunoliposomes For The Treatment Of Gd2 Positive Tumors, Brandon S. Brown

Dissertations and Theses (Open Access)

Systemic chemotherapeutics remain the standard of care for most malignancies even though they frequently suffer from narrow therapeutic index, poor serum solubility, and off-target effects. Monoclonal antibodies that specifically bind antigens overexpressed on many tumors such as the ganglioside, GD2, can be conjugated to drug-loaded liposomes to create a targeted drug delivery system. In this study, we have encapsulated etoposide, a topoisomerase inhibitor effective against a wide range of cancers, in surface modified liposomes decorated with anti-GD2 antibodies. We characterized the properties of the liposomes using a variety of methods including dynamic light scattering, electron microscopy, and Fourier transformed infrared …

Phage Display Library Screening For Psa-/Lo Prostate Cancer Cell-Binding Peptides, John R. Moore

Dissertations and Theses (Open Access)

Prostate cancer (PCa) is one of the leading malignancies affecting men worldwide. Our lab focuses on understanding the molecular mechanisms underlying prostate carcinogenesis and developing therapeutics that target the cells responsible for driving PCa and mediating therapy resistance. My master thesis research employs a phage display library screening technology aiming to identify peptides that preferentially home in to undifferentiated PCa cells, which our lab has previously demonstrated to be intrinsically resistant to castration.

There is now evidence that a population of cells in PCa possesses characteristics associated with stem cells; these cells are referred to as cancer stem cells (CSCs). …

Scanned Ion Beam Therapy For Thoracic Tumors, John Gordon Eley

Dissertations and Theses (Open Access)

Although frequently cured of Hodgkin lymphoma, adolescents and young adults can develop radiation induced second cancers. These patients could potentially benefit from scanned ion radiotherapy yet likely would require motion mitigation strategies. In theory, four-dimensional (4D) optimization of ion beam fields for individual motion states of respiration can enable superior sparing of healthy tissue near moving targets, compared to other motion mitigation strategies. Furthermore, carbon-ion therapy can sometimes provide greater relative biological effectiveness (RBE) for cell sterilization in a target but nearly equivalent RBE in tissue upstream of the target, compared to proton therapy. Thus, we expected that for some …

Development Of Hif-1Α/Hif-1Β Heterodimerization Inhibitors Using A Novel Bioluminescence Reporter Assay System For In Vitro High Throughput Screening And In Vivo Imaging, Yun-Chen Chiang

Dissertations and Theses (Open Access)

Tumor growth often outpaces its vascularization, leading to development of a hypoxic tumor microenvironment. In response, an intracellular hypoxia survival pathway is initiated by heterodimerization of hypoxia-inducible factor (HIF)-1α and HIF-1β, which subsequently upregulates the expression of several hypoxia-inducible genes, promotes cell survival and stimulates angiogenesis in the oxygen-deprived environment. Hypoxic tumor regions are often associated with resistance to various classes of radio- or chemotherapeutic agents. Therefore, development of HIF-1α/β heterodimerization inhibitors may provide a novel approach to anti-cancer therapy. To this end, a novel approach for imaging HIF-1α/β heterodimerization in vitro and in vivo was developed in this study …

Oxidative Stress Based Strategies For Enhancing The Efficacy Of Histone Deacetylase Inhibitors (Hdaci), Nilsa Rivera-Del Valle

Dissertations and Theses (Open Access)

Histone deacetylase inhibitors (HDACi) are anti-cancer drugs that primarily act upon acetylation of histones, however they also increase levels of intracellular reactive oxygen species (ROS). We hypothesized that agents that cause oxidative stress might enhance the efficacy of HDACi. To test this hypothesis, we treated acute lymphocytic leukemia cells (ALL) with HDACi and adaphostin (ROS generating agent). The combination of two different HDACi (vorinostat or entinostat) with adaphostin synergistically induced apoptosis in ALL. This synergistic effect was blocked when cells were pre-treated with the caspase-9 inhibitor, LEHD. In addition, we showed that loss of the mitochondrial membrane potential is the …

Design, Synthesis And Development Of Transporter Targeting Agents For Image-Guided Therapy And Drug Delivery, Ning Tsao

Dissertations and Theses (Open Access)

The purpose of this study was to design, synthesize and develop novel transporter targeting agents for image-guided therapy and drug delivery. Two novel agents, N4-guanine (N4amG) and glycopeptide (GP) were synthesized for tumor cell proliferation assessment and cancer theranostic platform, respectively. N4amG and GP were synthesized and radiolabeled with ^99mTc and ⁶⁸Ga. The chemical and radiochemical purities as well as radiochemical stabilities of radiolabeled N4amG and GP were tested. In vitro stability assessment showed both ^99mTc-N4amG and ^99mTc-GP were stable up to 6 hours, whereas ⁶⁸Ga-GP was stable up to 2 hours. Cell culture studies …

Novel Imaging-Based Techniques Reveal A Role For Pd-1/Pd-L1 In Tumor Immune Surveillance In The Lung, Todd Bartkowiak

Dissertations and Theses (Open Access)

The binding of immune inhibitory receptor Programmed Death 1 (PD-1) on T cells to its ligand PD-L1 has been implicated as a major contributor to tumor induced immune suppression. Clinical trials of PD-L1 blockade have proven effective in unleashing therapeutic anti-tumor immune responses in a subset of patients with advanced melanoma, yet current response rates are low for reasons that remain unclear. Hypothesizing that the PD-1/PD-L1 pathway regulates T cell surveillance within the tumor microenvironment, we employed intravital microscopy to investigate the in vivo impact of PD-L1 blocking antibody upon tumor-associated immune cell migration. However, current analytical methods of intravital …

Characterization Of Differentiation And Prognostic Biomarkers On Cd8+ Tumor-Infiltrating Lymphocytes In Metastatic Melanoma, Richard C. Wu

Dissertations and Theses (Open Access)

CD8⁺ cytotoxic T lymphocytes (CTL) frequently infiltrate tumors, yet most melanoma patients fail to undergo tumor regression. We studied the differentiation of the CD8⁺ tumor-infiltrating lymphocytes (TIL) from 44 metastatic melanoma patients using known T-cell differentiation markers. We also compared CD8⁺ TIL against the T cells from matched melanoma patients’ peripheral blood. We discovered a novel subset of CD8⁺ TIL co-expressing early-differentiation markers, CD27, CD28, and a late/senescent CTL differentiation marker, CD57. This CD8⁺CD57⁺ TIL expressed a cytolytic enzyme, granzyme B (GB), yet did not express another cytolytic pore-forming molecule, perforin (Perf). In …