Cell and Developmental Biology Commons^™

Integrating Bulk And Single-Cell Transcriptomics To Investigate Intratumor Heterogeneity, Shuai Guo

Dissertations and Theses (Open Access)

Cancers are heterogeneous mixtures of tumor and surrounding cells, where each component comprises multiple distinct sub-types and/or states. Understanding the cell-type-specific contributions is critical for advancing cancer biology, yet high-throughput expression profiles from tumor tissues only represent combined signals from all diverse cellular sources. Bulk deconvolution with single-cell/nucleus (sc/sn) RNA-seq data has emerged as a powerful approach to dissect both cellular composition and cell-type-specific expression patterns, yet the technological discrepancy across sequencing platforms limits accuracy.

To systematically evaluate the impact of platform discrepancies on bulk deconvolution, we first generated a benchmark dataset of 24 healthy retinas with paired bulk and …

Clonal Phenotype Mapping Reveals Genomic Alterations Underlying Tumor Immunosuppression During Immunotherapy, Er-Yen Yen

Dissertations and Theses (Open Access)

Tumors are dynamic ecosystems that evolve under selective pressures, shaping their ability to either elicit or evade immune responses. In pancreatic ductal adenocarcinoma (PDAC), where immunotherapy has yet to become an effective treatment option, we investigated the role of intratumoral heterogeneity in influencing immune interactions. Using orthotopic clonal replica tumors, we tracked clonal dynamics in response to anti-PD1 therapy and found that while treatment had limited impact on overall tumor volume, it induced profound shifts in clonal composition. Spatial lineage analysis of treatment-naïve tumors revealed that clones with distinct immunotherapy sensitivities occupy unique tumor microenvironments, a pattern that remained stable …

Role Of Cellular Proteins In The Regulation Of Herpes Simplex Virus Type 1 Gene Expression And Dna Replication, Joseph R. Heath

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen that infects the majority of the human population. To facilitate infection, this virus relies on a combination of host and viral factors. Previous studies have revealed a number of host proteins that associate with the HSV-1 genome throughout infection but their putative role(s) in this process remain undefined. This study aims to examine two such proteins to determine their contributions to HSV-1 gene expression and DNA replication. The first of these factors is Ints3, a subunit of the Integrator complex. This protein complex functions in transcription regulation, and Ints3 …

3,5-Dihydroxy-4-Isopropylstilbene (Tapinarof) Is A Partial Aryl Hydrocarbon Receptor Agonist In Fish, Conner A. Dicks

All Theses

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is essential in regulating development, immune homeostasis, and drug and xenobiotic metabolism. Activation of the AHR by specific ligands results in its translocation to the nucleus where it induces a myriad of gene products, including cytochrome P450 (CYP) drug metabolizing enzymes (e.g., CYP1A1) and other components of the chemical defensome, as well as inflammatory control. Interestingly, the AHR can bind a wide variety of endogenous and xenobiotic ligands which are able to induce unique downstream effects dependent on cell type, inflammatory context, and ligand stability. The AHR is …

Investigating The Role Of The Lysine-Specific Demethylase 4c In Pancreatic Ductal Adenocarcinoma, Mennatallah Shaheen

Dissertations and Theses (Open Access)

Deregulation of proteins involved in chromatin regulation is common in pancreatic ductal adenocarcinoma (PDAC). Lysine demethylase 4C (KDM4C) is one of the chromatin modifying proteins frequently overexpressed across multiple solid cancers and is linked to chromatin instability, increased cell proliferation, and enhanced stem cell-like behavior. We observed upregulation of KDM4C protein in a panel of human PDAC cell lines and patient samples compared to non-neoplastic controls. CRISPR/Cas9-mediated deletion of KDM4C in human and murine PDAC cells reduced proliferation, clonogenicity, and increased survival of orthotopically implanted murine PDAC allografts. Transcriptomic and proteomics analyses revealed that loss of KDM4C in both human …

Applying Transcriptomics For Technology Development And Conservation In North American Marine Organisms, Cory Von Eiff

Dissertations

RNA biology is a rapidly expanding field, with many avenues of discovery among marine organisms. In this study, we analyze both mollusks and sawfish. First, we perform an evaluation of sRNA biogenesis pathways throughout Mollusca, with emphasis on the easter oyster, Crassostrea virginica. Understanding these molecules prescribes RNAi-based gene silencing approaches, benefiting genetic investigation and biotechnology. Similar to other animal groups, mollusks have conserved microRNAs (miRNAs), with some shared with ecdysozoans and deuterostomes; however, there is no evidence of an endogenous small interfering RNA (siRNA) pathway. These results suggest that long double-stranded RNA (dsRNA)-based RNAi is not appropriate for gene …

The Role Of Androgen Receptor And B2/Alu Sine Rna Interaction In Hippocampal Dendritic Development, Troy A. Richter

Graduate Doctoral Dissertations

Once dismissed as “junk”, transposable elements have recently gained recognition for their regulatory roles, especially in the brain. During development, circulating androgens promote proper morphological development of hippocampal neurons. We and others have shown that murine B2 SINE RNA is a regulator in the rodent hippocampus. It is unknown, however, if B2 is necessary for the proper development of hippocampal neurons. This dissertation investigates the role of murine B2 in the development of primary hippocampal neurons in combination with androgen treatment. We first examined the role of ALU SINE and androgen receptor in a prostate cancer cell model and found …

Regulation Of Icer Degradation And Its Role In Melanoma, Justin Wheelan

Theses, Dissertations and Culminating Projects

Melanoma is the deadliest form of skin cancer, with 100,640 new cases and 8,290 deaths estimated in the United States in 2024. While targeted therapies and immunotherapy have improved patient outcomes, resistance remains a major challenge, necessitating new therapeutic approaches. Approximately 50% of melanomas harbor BRAFⱽ⁶⁰⁰ᴱ mutations, leading to constitutive MAPK pathway activation. Targeted small molecule therapies such as BRAF and MEK inhibitors are available and initially reduce tumor burden, however resistance frequently occurs, likely through many pathways including compensatory activation of cAMP signaling. ICER (Inducible cAMP Early Repressor), a transcriptional repressor of CREB-mediated gene expression, is absent in melanoma …

Bifunctional Fusion Protein Pdl1sfv/Micae For Cancer Immunothearpy, Junyi Li

All Dissertations

Cancer immunotherapy has highlighted the importance of immune checkpoint blockade and innate immune cell engagement in battling tumor-mediated immune suppression in the past few decades. However, with cancer development, advanced tumors are often found to develop resistance towards single-target immunotherapy due to the complexity of the immunosuppressive mechanisms within the tumor microenvironment (TME). To address this, we developed a novel bifunctional fusion protein, PDL1sFv/MICAe, which combines the tumor-targeting capability of an anti-PDL1 single-chain variable fragment (sFv) with the NK cells immunostimulatory properties of the MICA extracellular domain.

In vitro functional assays revealed that PDL1sFv/MICAe significantly enhanced cytotoxicity towards natural killer …

Effect Of Moderate Decrease In Contractility On Epithelial Cell-Cell Contacts Under External Stretch, Saika Sharmin

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial tissues are characterized by extensive cell–cell contacts and often subject to stretch during normal function. Cell-cell contact adhesion strength maintains mechanical continuity from cell to cell. Mechanical forces exerted by cells via actomyosin contractility are known to strengthen cell-cell adhesions to a certain extent. While it is known that a large decrease in contractility causes cell-cell contact rupture due to weakened adhesions, it is unclear how a moderate reduction in contractility affects cell-cell junction stability. Here, we studied how a moderate inhibition of non-muscle myosin II (NMII) affects the integrity of epithelial cell-cell contacts, especially when subject to the …

Ctnna3 Deficiency Promotes Heart Regeneration By Enhancing Cardiomyocyte Proliferation In Neonatal Mice, Sha Zou, Wuhou Dai, Wufan Tao, Jifen Li, Zeyi Cheng, Hongyan Wang

Department of Medicine Faculty Papers

Background: Heart regeneration requires renewal of lost cardiomyocytes. However, the mammalian heart loses its proliferative capacity soon after birth, and the molecular signaling underlying the loss of cardiac proliferation postnatally is not fully understood.

Purpose: This study aimed to investigate the role of Catenin alpha 3 (Ctnna3), coding for alpha T catenin (αT-catenin) protein in regulating cardiomyocyte proliferation and heart regeneration during the neonatal period.

Methods: Here we report that ablation of Ctnna3 and highly expressed in hearts, accelerated heart regeneration following heart apex resection in neonatal mice.

Results: Our results show that Ctnna3 deficiency enhances cardiomyocyte proliferation …

In Silico Prediction Of Cytotoxic T-Cell Epitopes From Helicobacter Pylori Virulence Factors Using An Immunoinformatics Approach, Demy Valerie Chacon, Kiana Alika Co, Daphne Noreen Enriquez, Aubrey Love Labarda, Reanne Eden Manongsong, Edward Kevin B. Bragais

Biology Faculty Publications

Background: Helicobacter pylori infects approximately half of the global population, leading to gastric and duodenal ulcers. Despite the availability of antibiotics, challenges such as patient reluctance, high treatment costs, and antibiotic resistance limit their effectiveness, making vaccination a promising alternative. This study used immunoinformatics to identify candidate epitopes for a multiepitope vaccine construct against H. pylori.

Material and methods: The protein variability server was utilized for conservation analysis. The epitopes were screened for antigenicity, allergenicity, toxicity, cross-reactivity, and population coverage. Selected epitopes were docked with their corresponding human leukocyte antigen (HLA) alleles, and thermodynamic quantities were determined. Five virulence …

Elevated Nr2f1 Underlies The Persistence Of Invasive Disease After Treatment Of Braf-Mutant Melanoma, Manoela Tiago, Timothy J. Purwin, Casey D. Stefanski, Renaira Oliveira Da Silva, Mitchell E. Fane, Yash Chhabra, Jelan I. Haj, Jessica L. F. Teh, Rama Kadamb, Weijia Cai, Sheera Rosenbaum, Vivian Chua, Nir Hacohen, Michael A. Davies, Jessie Villanueva, Inna Chervoneva, Ashani T. Weeraratna, Dan A. Erkes, Claudia Capparelli, Julio A. Aguirre-Ghiso, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Despite the success of targeted inhibitors in cutaneous melanoma, therapeutic responses are limited by the aged tumor microenvironment and drug-tolerant residual cells. Given the similarities between drug tolerance and cellular dormancy, we studied the dormancy marker, nuclear receptor subfamily 2 group F member 1 (NR2F1), in response to BRAF-V600E inhibitors (BRAFi) plus MEK inhibitors (MEKi) in BRAF-mutant melanoma models. Transcriptomic analysis of melanoma patient samples treated with BRAFi + MEKi showed increased NR2F1. NR2F1 was highly expressed in the drug-tolerant invasive cell state of minimal residual disease in patient-derived and mouse-derived xenografts on BRAFi + MEKi. NR2F1 over-expression was sufficient …

Combination Of Irreversible Electroporation And Clostridium Novyi-Nt Bacterial Therapy For Colorectal Liver Metastasis, Zigeng Zhang, Guangbo Yu, Qiaoming Hou, Farideh Amirrad, Sha Webster, Surya M. Nauli, Jianhua Yu, Vahid Yaghmai, Aydin Eresen, Zhuoli Zhang

Pharmacy Faculty Articles and Research

Colorectal liver metastasis (CRLM) poses a significant challenge in oncology due to its high incidence and poor prognosis in unresectable cases. Current treatments, including surgical resection, systemic chemotherapy, and liver-directed therapies, often fail to effectively target hypoxic tumor regions, which are inherently more resistant to these interventions. This review examines the potential of a novel therapeutic strategy combining irreversible electroporation (IRE) ablation and Clostridium novyi-nontoxic (C. novyi-NT) bacterial therapy. IRE is a non-thermal tumor ablation technique that uses high-voltage electric pulses to create permanent nanopores in cell membranes, leading to cell death while preserving surrounding structures, and …

Utilizing The Combinatory Power Of Chemotherapeutic Compounds In Triple Negative Breast Cancer Cells, Matthew I. Hyder

Biology Summer Fellows

Breast cancer is the leading cause of cancer-related deaths among women worldwide and the second most common cause of cancer deaths in women in the United States. Genetic variants that increase the risk of breast cancer include mutations in the breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2). Apoptosis, or programmed cell death, is a natural process that helps the body remove aged cells. However, in cancer, deregulated apoptotic signaling—especially the activation of anti-apoptotic mechanisms—enables cancer cells to evade this process, leading to uncontrolled proliferation, tumor survival, therapeutic resistance, and cancer recurrence. Most anti-cancer drugs function as chemotherapeutic …

The Influence Of Myocardin Effector Genes On The Tgf-Beta Smad3 Signaling Pathway In Human Pleural Mesothelial Cells, Hema Chandra Hrushi Dusharla

Biotechnology Theses

Pleural Fibrosis (PF) involves excessive extracellular matrix (ECM) deposition, mainly by myofibroblasts, leading to pleural thickening and impaired lung function. Pleural mesothelial cells (PMCs) contribute via mesothelial and mesenchymal transition (MesoMT), triggered by cytokines like TGF-β. Our lab identified Myocardin (MyoCD), a transcriptional co-activator of cardiac and smooth muscle, is a master regulator of pleural fibrosis through interactions with serum response factor (SRF) and Smad2/3 transcription factors which initiate fibrosis signaling. RNA sequencing and qPCR analysis revealed that silencing MyoCD decreased the expression of CTNNB1, MDFI, and Tspan2. MDFI emerged as a potent candidate, as this gene affecting the expression …

A Cancer Education Needs Assessment: Informing Middle-Aged Female Patients About The Relationships Between Obesity And Women’S Health Concerns In The Reproductive System, Breast, And Endometrial Health, Batul Mirza

MUSC Theses and Dissertations

Obesity significantly impacts women’s health, particularly among middle-aged women, by increasing the risk of hormone-sensitive cancers such as breast, endometrial, and reproductive system cancers. This study examines the educational needs of this demographic group regarding obesity-related cancer risks and explores effective intervention strategies. Obesity-induced mechanisms – hormonal imbalances, chronic inflammation, and insulin resistance – drive cancer susceptibility, emphasizing the need for targeted health education. The study employs a qualitative design, which includes interviews with subject matter experts (SMEs) and surveys of middle-aged women. The goal is to assess awareness, perceived barriers, and preferred learning methods. Findings suggest that with many …

Investigating The Capacity Of Tdp-43 Low Complexity Domain To Target Protein Aggregates In Yeast, Nicholas J. Grahame

Biology Summer Fellows

Utilizing protein TDP-43 and fluorescent proteins to:

Investigate TDP-43’s LCD region in protein aggregates. Use fluorescent protein tagging to visualize co-localization and aggregation. Leverage yeast as a model system for studying LLPS and aggregation.

Can we target chaperone proteins to TDP-43 LCD region?

Role And Electrophysiological Properties Of Sexually Dimorphic Oxytocin Receptor Expressing Neurons In The Anteroventral Periventricular Nucleus Of The Female Mice, Armita Abdollahi Govar

LSU Doctoral Dissertations

Oxytocin is a neurohypophyseal hormone that plays a crucial role in regulating mother-infant bonding and maternal behavior. Oxytocin modulates sex-specific parental behaviors by binding to the oxytocin receptor (OXTR)-expressing neurons in the brain. This study investigates the sexually dimorphic OXTR neurons in the anteroventral periventricular nucleus (AVPV) to understand how oxytocin modulates behavior in females. Specifically, we explored the behavioral roles, neural projections, and intrinsic electrophysiological characteristics of these neurons in the female mice. Using immunohistochemistry revealed that the number of OXTR-expressing neurons was enhanced in postpartum females compared with virgin females, suggesting that these neurons are involved in female-specific …

Cilia In The Brain Display Region-Dependent Oscillations Of Length And Orientation, Roudabeh Vakil Monfared, Sherif Abdelkarim, Pieter Derdeyn, Kiki Chen, Hanting Wu, Kenneth Leong, Tiffany Chang, Justine Lee, Sara Versales, Surya M. Nauli, Kevin Beier, Pierre Baldi, Amal Alachkar

Pharmacy Faculty Articles and Research

In this study, we conducted high-throughput spatiotemporal analysis of primary cilia length and orientation across 22 mouse brain regions. We developed automated image analysis algorithms, which enabled us to examine over 10 million individual cilia, generating the largest spatiotemporal atlas of cilia. We found that cilia length and orientation display substantial variations across different brain regions and exhibit fluctuations over a 24-h period, with region-specific peaks during light-dark phases. Our analysis revealed unique orientation patterns of cilia, suggesting that cilia orientation within the brain is not random but follows specific patterns. Using BioCycle, we identified rhythmic fluctuations in cilia length …