Biotechnology Commons^™

Harnessing The Immunomodulatory Potential Of Radiofrequency Ablation To Improve Therapeutic Outcomes In Pancreatic Ductal Adenocarcinoma, Bhumi Maniyar

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) continues to rank among the most lethal cancers with poor prognosis. PDAC is characterized by a thick desmoplastic stroma, severe immunological suppression, and resistance tostandard treatments. The need for innovative therapeutic approaches is highlighted by the tumor microenvironment's (TME) critical role in promoting disease development and reducing the effectiveness oftreatment. A promising locoregional treatment that can induce tumor necrosis and modify the TME is endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA). However, there is still minimal understanding around its wider impact on stromal remodeling and immunological activation. This study investigates the immunomodulatory effects of RFA combined with neoadjuvant …

Timigp: A Computational Framework To Determine The Tumor Immune Microenvironment Associated With Prognosis And Immunotherapy Response, Chenyang Li

Dissertations and Theses (Open Access)

Accumulating evidence has suggested that the tumor immune microenvironment (TIME) drastically impacts cancer patients’ clinical outcomes, including prognosis and immunotherapy response. However, understanding TIME remains challenging due to its complexity and heterogeneity. In this dissertation, we introduce TimiGP (Tumor Immune Microenvironment Illustration based on Gene Pairs), a computational framework designed to address this challenge. Leveraging single-cell RNA-seq (scRNA-seq) and bulk gene expression data alongside clinical information, TimiGP constructs a cell-cell interaction network that elucidates the relationship between immune cell function and relevant clinical outcomes, such as prognosis and treatment response. With immunological insights, these cell-cell interactions also facilitate the development …

Early Onset Alzheimer’S Disease Markers In Mouse Hippocampus Unveiled By Single-Cell Transcriptomic Analysis Following Cranial Radiotherapy, Tuba Aksoy

Dissertations and Theses (Open Access)

Cranial radiation therapy plays an integral role in the treatment of brain tumors but can lead to progressive cognitive deficits in survivors by mechanisms that are poorly understood. To develop preventive or mitigative strategies, it is crucial to better understand the underlying pathogenesis of radiation-induced cognitive impairments. The study investigated single-cell transcriptomics and DNA methylation changes as potential drivers of persistent cellular dysfunction after radiation exposure, specifically concentrating on the CA1-3 regions of the hippocampus and the prefrontal cortex due to their role in cognitive functions. Thirteen-week-old mice underwent whole-brain radiation at clinically relevant doses. Following whole-brain radiation, an assessment …

Biases And Blind-Spots In Genome-Wide Crispr-Cas9 Knockout Screens, Merve Dede

Dissertations and Theses (Open Access)

Adaptation of the bacterial CRISPR-Cas9 system to mammalian cells revolutionized the field of functional genomics, enabling genome-scale genetic perturbations to study essential genes, whose loss of function results in a severe fitness defect. There are two types of essential genes in a cell. Core essential genes are absolutely required for growth and proliferation in every cell type. On the other hand, context-dependent essential genes become essential in an environmental or genetic context. The concept of context-dependent gene essentiality is particularly important in cancer, since killing cancer cells selectively without harming surrounding healthy tissue remains a major challenge. The toxicity of …

Unraveling Host-Gut Microbiota Dialogue And Its Impact On Response To Immune Checkpoint Blockade, Alexandria Cogdill

Dissertations and Theses (Open Access)

Cancer is a disease with only one degree of separation, affecting one in two men and one in three women in their lifetimes; accounting for 1 of every 6 deaths. While cancer mortality rates continue to improve, incidence rates are expected to rise and shift through 2050 due to epidemiological and demographic transitions worldwide. As such, it is imperative to continue to investigate and improve our understanding of both disease etiology and hallmarks of response to treatment. Currently, conventional therapies include, but are not limited to, surgery, chemotherapy, and radiotherapy. However, within the past decade, major advances have been made …

Ionic Mechanism Of Lysosomal Function And Cell Metabolism, Jian Xiong

Dissertations and Theses (Open Access)

Two Pore Channels (TPCs) are endolysosomal ion channels that are permeable to sodium and calcium. Defects in TPCs have been implicated to impair vesicle trafficking, autophagy and cell metabolism control; however, the detailed mechanism remains largely unknown. In this study, I show that TPCs are critical for appropriate cargo delivery to the lysosomes and deletion of either TPC1 or TPC2 leads to delayed clearance of autophagosomes, resulting in enlarged lysosomes and accumulated contents inside the lysosomes. Cells with both TPC deleted also exhibit 50% reduction in lysosomal amino acids under normal culture conditions, leading to reduced homeostatic mTORC1 activation.

Glutamine …

Longitudinal Clonal Lineage Dynamics And Functional Characterization Of Pancreatic Cancer Chemo-Resistance And Metastasization, Chieh-Yuan Li

Dissertations and Theses (Open Access)

In recent years, technological advancements, such as next-generation sequencing and single-cell interrogation techniques, have enriched our understanding in tumor heterogeneity. By dissecting tumors and characterizing clonal lineages, we are better understanding the intricacies of tumor evolution. Tumors are represented by the presence of and dynamic interactions amongst clonal lineages. Each lineage and each cell contributes to tumor dynamics through intrinsic and extrinsic mechanisms, and the variable responses of clones to perturbations in the environment, especially therapeutics, underlie disease progression and relapse. Thus, there exists a pressing need to understand the molecular mechanisms that determine the functional heterogeneity of tumor sub-clones …

Multiplexed Crispr Libraries For Cancer Functional Genomics, Jintan Liu

Dissertations and Theses (Open Access)

High-throughput forward genetic screenings are invaluable tools to systematically explore genetic interactions and to link gene disruption with disease contexts. The adaptation of CRISPR/Cas9 has improved the sensitivity and specificity of functional screenings. Despite this advance, there remains a long-standing need to improve functional screenings with smaller and more versatile pooled libraries. Capitalizing on the inherent multiplexing capability of a class 2 CRISPR enzyme AsCpf1, we developed a multiplexed, high throughput screening strategy that has avoided the usual trade-off between library size and library penetration, allowing library minimization without sacrificing gene targeting efficiency. We optimized the AsCpf1 protein for functional …

Ipsc Based Gene Correction And Disease Model Of A New Class Of Lgmd Due To Poglut1 Mutation, Jose Ortiz-Vitali

Dissertations and Theses (Open Access)

Recently, a novel class of muscular dystrophy has been discovered in a family due to autosomal recessive missense mutation in POGLUT1. Mutation of this enzyme leads to decreased O-glucosyltransferase activity and impaired Notch signaling, the pathways important for skeletal muscle stem cell (satellite cells) quiescence and activation. We hypothesize that reduced POGLUT1 activity and impaired Notch signaling is causative of this limb girdle muscular dystrophy through dysfunction of muscle stem cells and myogenic progenitors.

To test this, we have used iPSCs for disease modeling and rescue experiments. Using a CRISPR based gene targeting method, we aimed to correct the point …

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 …

The Characterization Of T-Cell Manufacturing For Adoptive T-Cell Therapies, Amir Alpert

Dissertations and Theses (Open Access)

Adoptive T-cell therapy using genetically modified T cells has emerged as a potential therapeutic option for several malignancies. Central to the production of the cellular therapy is the manufacturing using a stimulation, genetic engineering, and expansion methodology. Within this framework, there is a delicate balance between expansion of the cells to a therapeutically relevant dosage and the need to retain the proliferative potential of the ‘living drug’. I show that as T-cells are expanded for elongated periods of time, they lose their proliferative potential and become functionally senescent despite the presence of multiple proliferative cytokines. In addition, I show that …

Novel Mechanisms Of Β-Adrenergic Signaling In Prostate Cancer Progression, Mohit Hulsurkar

Dissertations and Theses (Open Access)

Prostate cancer is the second leading cause of cancer death among American men. The American Cancer Society estimates that 180,890 men will be will be diagnosed with prostate cancer in 2016 in the USA. (http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-key-statistics). Androgen deprivation therapy (ADT) is the standard treatment for early stage prostate cancer. But most patients relapse with aggressive variants of prostate cancer, with survival time between 1-3 years. In order to develop cure for such aggressive variants of prostate cancer, our present understanding of the mechanisms underlying its progression needs to be advanced.

Recently, it has been found that activation of β-adrenergic signaling pathway …

Rerouting Pre-Existing Host Vaccine-Induced Immunity To Wards Breast Cancer, Bharat Kumar Reddy Chaganty

Dissertations and Theses (Open Access)

For decades, investigators have attempted to activate the immune system to prevent cancer metastasis or recurrence; however, owing to host immune tolerance to cancer antigens and the immunosuppressive environment at tumor sites, many such attempts have failed. The recent success of anti-CTLA4, PD-L1 and PD-1 antibodies targeting immune checkpoint pathways and HPV vaccines has renewed hope that patient survival can be increased through enhancing T-cell responses. We propose to test a novel approach that may bypass host immune tolerance to cancer cells. We hypothesize that host T-cell immunity acquired through vaccination against or natural infection with infectious diseases—e.g., influenza—can be …

Molecular Regulation Of Vascular Calcification In Murine Models Of Atherosclerosis, Shanshan Gao

Dissertations and Theses (Open Access)

Background: Calcification occurs often in the atherosclerotic lesions of patients with coronary heart disease and animals with hypercholesterolemia, such as apolipoprotein-E deficient (ApoE-/-) mice. However, the mechanism(s) underlying the development of calcification in atherosclerosis remains unclear. ApoE acts as a lipid transporter, but also has been recognized as a potential regulator of osteogenesis. Little information is available as to whether ApoE has any direct impact on osteogenesis and calcification in vascular smooth muscle cells (VSMC). Several signal transduction pathways play a role in regulation of calcification, including the Wnt/β-catenin system and potentially GTAP, an ubiquitin-conjugating enzyme responsible for protein …

Functional Analysis Of Synthetic Gene Circuits Controlling A Protein Pump In Yeast, Junchen Diao

Dissertations and Theses (Open Access)

Synthetic biology aims to build biological devices to understand living systems and explore new applications. Synthetic gene circuits such as genetic switches, oscillators and logic gates are at the core of many synthetic biology applications. These gene circuits often include a sensor/regulator protein capable to detect small molecules and then transduce them into a regulatory signal to generate measurable output. Similar signal transduction networks are also abundant in nature. However, in many natural and engineered scenarios, the output also affects the regulator/sensor protein. How such interactions between the regulator/sensor and the output affect synthetic gene circuit function has not been …

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations and Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations and Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …