Cell Biology Commons^™

Global Erk/Mapk Activation Determines Oncogenic Fitness In Kras-Mutant Pancreatic Ductal Adenocarcinoma, Rachel A. Burge

MUSC Theses and Dissertations

In pancreatic ductal adenocarcinoma (PDAC), ~95% of cases harbor an activating KRAS mutation. The most common KRAS mutations in PDAC are KRAS^G12D (42%), KRAS^G12V (31%), and KRAS^G12R (15%). Patients harboring KRAS^G12R mutations have increased overall survival compared to those with KRAS^G12D/V-mutations. While KRAS^G12D/Vare common in all KRAS-mutant cancers, KRAS^G12Ris only common in PDAC.

KRAS^G12R is unable to activate the lipid kinase PIK3CA, a KRAS effector that is important for tumorigenesis in murine models. To investigate the tumorigenic potential of KRAS^G12R and the mechanisms that enable this mutation …

The Role Of Cleavage And Polyadenylation Spcific Factor 6 (Cpsf6) In Hematopoiesis, Fengxi Ye

Dissertations and Theses (Open Access)

Cleavage and polyadenylation specific factor 6 (Cpsf6) translocation is frequently reported in APLL, which is Acute Promyelocytic Leukemia (APL)-like acute myeloid leukemia (AML) and other types of blood diseases associated with abnormal hematopoiesis. CPSF6 is a subunit of the Cleavage Factor I mammalian (CFIm) complex, which regulates post-transcriptional alternative polyadenylation (APA) of pre-mRNAs. Previous research indicated that Cpsf6 plays an essential role in alternative polyadenylation, development, and tumorigenesis. However, the role of Cpsf6 in hematopoiesis is unknown. Given its roles in APA, development and cancer, we hypothesize that Cpsf6 plays a critical role in hematopoiesis and that its …

A Toi Rna Editing In Three Members Of The Microbotryum Violaceum Fungal Complext And Characterization Of Adar Genes Of Microbotryum Superbum., Shikhi Baruri

Electronic Theses and Dissertations

A-to-I RNA editing is a process that occurs post-transcriptionally. Through this process, adenosine (A) is replaced by inosine (I) in RNAs by adenosine deaminase enzymes that act on the single-stranded RNA. These enzymes, also known as ADARs, act on RNA. The translation and splicing mechanisms subsequently interpret inosine as guanosine (G), which effectively alters genetic information. This kind of RNA alteration can cause both nonsynonymous and synonymous changes in codon, which may have an impact on protein function. A group of over 89 basidiomycete fungal species known as the Microbotryum violaceum complex infects a similarly large group of plant host …

Metabolic And Physiological Regulation In C. Elegans: Insights Into Sperm Activation And Peroxisome-Mediated Longevity, Yash Flora

LSU Doctoral Dissertations

Organelle dynamics lie at the heart of cellular signaling and metabolic regulation, orchestrating physiological processes such as reproduction and aging across the lifespan. In this dissertation, I investigate how organelle-based signaling coordinates sperm activation and modulates organismal aging in the nematode Caenorhabditis elegans. I identify SPIN-4, a previously uncharacterized Spinster family transporter, as a key regulator of spermiogenesis. SPIN-4 is strongly expressed in developing sperm, localizes to the plasma membrane, and promotes sperm activation by facilitating the export of sphingosine-1-phosphate (S1P). Loss of spin-4 results in defective pseudopod formation, reduced motility, and compromised fertility, phenotypes that can be rescued …

Topodino: Self-Supervised Topological Representation Learning For Neuronal Morphologies, Yasser Binbisher

Master's Theses

Neuronal cell types are categorized by transcriptomic identity, yet their morphological heterogeneity defies this classification. In response, researchers have adopted unsupervised graph representation learning as a tool to reveal morphological variation within single-class transcriptomic types. However, the complex geometry of neuronal morphology—especially long axons and dense dendrites—challenges graph neural networks, which struggle with message propagation across extended structures. To mitigate this, current approaches enforce sub-sampling on neuronal graphs and omit axons entirely, sacrificing critical biological features for computational efficiency. To overcome this trade-off, this thesis introduces TopoDINO, a self-supervised, topology-aware representation learning model designed to preserve the full hierarchical organization …

Investigating A Link Between Dna Repair And Dna Replication In Escherichia Coli Using A Bacterial Two-Hybrid System, Lo Cooper

University Honors Theses

Cells rely on nucleotide excision repair (NER) to remove bulky DNA lesions, such as those caused by UV light. In Escherichia coli, NER involves the UvrABC complex, and includes two main pathways, global genomic repair and transcription-coupled repair (TCR). While TCR, which preferentially removes lesions that block RNA polymerase on the transcribed strand of active genes, is well studied, less is known about whether a similar coupling between repair proteins and replisomes blocked by damaged DNA exists. Such a process has been suggested by a high throughput interactome study, using the replisome subunit HolC as bait and the damage …

The Role Of Elongin B In Drosophila Melanogaster Muscle Development, Madelyne Dayan

Student Theses and Dissertations

Muscle atrophy is a result of a number of muscle diseases, as well as aging, disuse, and infections. Muscles weakened in these ways exhibit a characteristic decrease in size, strength, and mobility. The similarities between muscle in humans and Drosophila allow for direct comparisons to be made in vertebrates from studying muscle in Drosophila. Differential gene expression has been shown to play an important role in embryonic muscle development in Drosophila melanogaster. A previous study identified Elongin B (EloB) to be involved in somatic muscle morphogenesis in Drosophila, with mutant embryos displaying severe muscle defects, including thin, mis-attached, and missing …

Hypoxia Induced Ribosomal Rna Fragmentation Mediated By Rnase L, Vanessa Kristina Pizutelli, Dimitri G Pestov

Rowan-Virtua Research Day

Ischemic injury contributes to a range of global pathologies. Ischemia/Reperfusion Injury (IRI) is a paradoxical phenomenon that involves an initial restriction of blood flow followed by a sudden restoration of perfusion. This type of injury takes place in conditions such as myocardial infarction, acute kidney disease, and ischemic stroke and often leads to cellular death. Additionally, IRI exacerbates post-surgical outcomes and plays a role in graft dysfunction and transplant rejection. Despite efforts to develop therapies targeting known IRI pathways, clinical trials have largely been unsuccessful, underscoring the need for alternative mechanisms and biomarkers associated with IRI-induced apoptosis. Reactive oxygen species …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

Degradation Of Vascular Networks In A Huvec Model Of Dm1, Bonnie E. Butler

Departmental Honors & Graduate Capstone Projects

Myotonic dystrophy type 1 (DM1) is a genetic disease that causes muscle wasting and affects multiple organ systems. DM1 is caused by expanded CTG repeats in the 3’ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene (Harper, 2001). Skeletal muscle relies on capillaries for nutrient delivery and waste clearance (Olfert, 2016). Skeletal muscle and capillaries communicate via a variety of chemicals, including PDGF-BB which both skeletal muscle and endothelial cells secrete and have receptors for (Hamaguchi, 2023). Platelet derived growth factor receptor β (PDGFRβ), when bound to platelet derived growth factor BB (PDGF-BB), induces angiogenesis (Wang, 2012). In …

Robust Sex Determination In The Caenorhabditis Nigoni Germ Line, Jonathan P Harbin, Yongquan Shen, Shin-Yi Lin, Kevin Kemper, Eric S Haag, Erich M Schwarz, Ronald E Ellis

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Sexual characteristics and reproductive systems are dynamic traits in many taxa, but the developmental modifications that allow change and innovation are largely unknown. A leading model for this process is the evolution of self-fertile hermaphrodites from male/female ancestors. However, these studies require direct analysis of sex-determination in male/female species, as well as in the hermaphroditic species that are related to them. In Caenorhabditis nematodes this has only become possible recently, with the discovery of new species. Here, we use gene editing to characterize major sex-determination genes in C. nigoni, a sister to the widely studied hermaphroditic species C. briggsae. These …

Focal Adhesion Genes And Proteins Are Differentially Expressed Across Cell Types In Down Syndrome, Brian Yoon

Senior Theses

Down syndrome (DS), caused by an extra copy of chromosome 21, leads to widespread gene expression changes through mechanisms such as transcriptional dysregulation and altered protein interactions. These disruptions contribute to a range of clinical features, including impaired wound healing, immune dysfunction, and neurodevelopmental abnormalities. This study focused on how DS affects fibroblast morphology and motility—processes critical for tissue repair and brain development. Using quantitative immunocytochemistry and image analysis, we found that DS fibroblasts displayed a broader, less polarized shape, with increased cell perimeter and reduced aspect ratio. However, levels of key adhesion proteins like vinculin, FAK, and β-actin were …

Cargo Hitchhiking Autophagy - A Hybrid Autophagy Pathway Utilized In Yeast, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Macroautophagy is a catabolic process that maintains cellular homeostasis by recycling intracellular material through the use of double-membrane vesicles called autophagosomes. In turn, autophagosomes fuse with vacuoles (in yeast and plants) or lysosomes (in metazoans), where resident hydrolases degrade the cargo. Given the conservation of autophagy,

The Cdk8 Kinase Module: A Novel Player In The Transcription Of Translation Initiation And Ribosomal Genes, Brittany Friedson, Stephen D Willis, Natalia Shcherbik, Alicia N Campbell, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Survival following stress is dependent upon reprogramming transcription and translation. Communication between these programs following stress is critical for adaptation but is not clearly understood. The Cdk8 kinase module (CKM) of the Mediator complex modulates the transcriptional response to various stresses. Its involvement in regulating translational machinery has yet to be elucidated, highlighting an existing gap in knowledge. Here, we report that the CKM positively regulates a subset of ribosomal protein (RP) and translation initiation factor (TIF)-encoding genes under physiological conditions in Saccharomyces cerevisiae. In mouse embryonic fibroblasts and HCT116 cells, the CKM regulates unique sets of RP and TIF …

Genetic Analysis Of Methionine Restriction-Associated Mitochondrial Unfolded Protein Response Signaling., Josh D. Dodge

Biology Dissertations - Archive

The lifespan of an organism is dictated by various genetic and environmental factors. One such determinant is the health of mitochondria which are organelles that mediate various critical cell functions including a significant role in generating the vast supply of cellular energy. Indeed, the gradual decline of mitochondrial function is believed to be a hallmark and possible cause of aging. Paradoxically, mild mitochondrial dysfunction early in life extends lifespan in various model organisms. Cells use diverse approaches to promote mitochondrial homeostasis, including the transcriptional reprogramming of cells by mitochondrial unfolded protein response (UPRmt) to mitigate mitochondrial stress. Consistently, UPRmt activation …

Temporal Dynamics Of Programmed Genome Rearrangement In Sea Lamprey Embryogenesis: A Deep Learning & Lightsheet Imaging Approach To Studying Early Developmental Transitions, Kasturi Rajandran

Theses and Dissertations--Biology

Programmed genome rearrangement (PGR) in the sea lamprey (Petromyzon marinus) leads to the elimination of ~0.5Gb (20%) of the germline genome during early embryogenesis, yet its timing relative to the maternal-to-zygotic transition (MZT) remains unclear. In this study, we imaged embryos cleared at 3-hour intervals (up to 72 hours post fertilization (hpf)) using high-resolution lightsheet fluorescence microscopy and a custom deep-learning image-analysis pipeline (~80% accuracy) to quantify nuclei and micronuclei counts. Micronuclei, which are the hallmarks of PGR first appear between 24 to 27hpf (vs ~36hpf previously reported) indicating PGR starts earlier than previously reported in the sea …

Using Abandoned Model Systems And Historical Literature To Teach Modern Concepts And Techniques In Cell Biology, Leocadia V. Paliulis, Gunar Fabig, Sandra Stein, Silke Tulok, Anja Nobst, Chukwuebuka William Okafornta, Thomas Kurth, Thomas Müller-Reichert

Faculty Journal Articles

The cell biology literature of the 19th and early-to-mid 20th centuries is full of the seminal works that were critical for the development of our current understanding of biology but were done using model systems that are no longer commonly used. We argue that these historical papers are ideal for the development of course-based research experiences, both because the background work is conceptually and technically straightforward, and because the study of the abandoned systems stopped prior to the availability of modern techniques. These abandoned systems offer outstanding opportunities for teaching modern light and electron microscopy techniques, thus providing students with …

Accurate Body Weight Class Prediction From Mirna And Gene Expression In Blood And Saliva Samples, Kimberly Lettner

Master of Science in Forensic Science Directed Research Projects

miRNA interference on protein abundance related to glucose uptake and lipid production has been evaluated in biomedical research and linked to metabolic disorders like severe obesity. The direct regulation of protein abundance caused by miRNAs on a person’s metabolism can lead to an increased weight and overall size. Body size, measured by BMI, provides additional physical descriptions that can be combined with hair color, eye color, age, and skin pigment to aid investigations of unidentified remains or unknown suspects not found in a database. The purpose of this project was to evaluate the miRNA expression of target biomarkers in dried …

Regulation And Function Of Mec-2 Alternative Splicing In Single Cells, Canyon Calovich-Benne

Biological Sciences Theses and Dissertations

One mechanism for generating diversity at the single cell level is selective expression of a unique set of transcription factors (TFs) and RNA binding proteins (RBPs). These regulatory factors contribute to functions of cells by controlling cell fate, turning genes on and off, and processing of transcripts either co- or post-transcriptionally. Many genes, especially neuronal genes, have multiple different splicing events, promoters, and/or polyadenylation sites. Post-transcriptional coordination is in the infancy of being studied and the functional consequences of this coupling at the single cell level has yet to be explored. Here we show, mec-2 coordination of alternative transcription start …

Testing Vivo-Morpholino Mediated Gene Knockdown Of Stat6, Spi1b, And Hnf4Α In Adult Threespine Stickleback, Stella Dipippo

Honors Scholar Theses

The fibrotic immune response to the cestode parasite, Schistocephalus solidus, varies among threespine stickleback populations. Fibrosis suppresses parasite growth but has costly effects on the fish. Previous genomic studies in stickleback have suggested potential roles of Spi1b, STAT6, and HNF4α in modulating fibrosis severity, but there is presently no evidence for this in-vivo. We used antisense vivo-morpholino oligonucleotides (MOs) to attempt to knockdown the expression of each gene in the liver, spleen, and intestine of adult stickleback. Vivo-MOs have been proven effective in other species of teleost fish, as well as in mice and humans, but …

The Effect Of Knockdown Of Gene Kit On Sox18 Gene Expression Through The Jak2/Stat3 Signaling Pathway Within An Ewing Sarcoma Cell, Samantha Aragon, Cristina Herrera, Felicity Rodriguez, Riley Smith, Terry Jo Shackleford

Cell and Molecular Methods

Ewing sarcoma is an aggressive cancer that affects children & adolescents. Common treatments include surgery, radiation, and chemotherapy, yet individuals have a poor survival rate and often develop side effects from treatment, including fertility issues, secondary cancer, heart problems, and growth abnormalities.1SOX18 is a gene identified to aid in cell proliferation and cell differentiation, leading to the development of several cancers, such as gastric, bladder, and lung cancer.2,3 SOX18 resides in the JAK2/STAT3 pathway as a regulator, along with another gene named KIT that instigates the formation of the cell signaling pathway.4KIT is a transmembrane tyrosine kinase, which instigates cell …

The Effects Of Ewing Sarcoma Through The Overexpression And Knockdown Of Transcription Factors Sox18 And Stat1, Victoria Castillo, Melany Cervantes, Nicole Robles, Terry Jo Shackleford

Cell and Molecular Methods

SOX18, a transcription factor with a DNA-binding HMG domain, plays a critical role in regulatory processes linked to cancer progression. Exhibiting oncogenic properties, SOX18 has been linked to various cancers, where it promotes tumor growth by enhancing cell invasion, uncontrolled proliferation, and resistance to apoptosis through dysregulated signaling pathways. STAT1, a protein crucial for immune system regulation, is prominently expressed in immune-associated tissues like the lymph nodes, and bone marrow, suggesting it could play a role in tumor growth. Ewing Sarcoma (EWS), an aggressive cancer that targets bone and soft tissue, carries a high mortality rate of 90% without treatment …

Single-Molecule Studies Reveal The Off-Pathway Early Paused State Intermediates As A Target Of Streptolydigin Inhibition Of Rna Polymerase And Its Dramatic Enhancement By Gre Factors, Anatolii Arseniev, Mikhail Panfilov, Georgii Pobegalov, Alina Potyseva, Polina Pavlinova, Maria Yakunina, Jookyung Lee, Sergei Borukhov, Konstantin Severinov, Mikhail Khodorkovskii

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Antibiotic streptolydigin (Stl) inhibits bacterial transcription by blocking the trigger loop folding in the active center of RNA polymerase (RNAP), which is essential for catalysis. We use acoustic force spectroscopy to characterize the dynamics of transcription elongation in ternary elongation complexes (ECs) of RNAP in the presence of Stl at a single-molecule level. We found that Stl induces long-lived stochastic pauses while the instantaneous velocity of transcription between the pauses is unaffected. Stl enhances the short-lived pauses associated with an off-pathway early paused state intermediates of the RNAP nucleotide addition cycle. Unexpectedly, we found that transcript cleavage factors GreA and …

The Role Of Siamese In G2 Checkpoint Regulation In Arabidopsis Thaliana, Martha A. Schwall

LSU Doctoral Dissertations

Cyclin-cyclin dependent kinase (Cyclin-CDK) pairs regulate progression through the checkpoints of the cell cycle. They bind with some specificity and must be bound to for their regulative properties to be active. The presence of cyclin-CDKs is conserved throughout eukaryotes, while differences in specifics exist between yeast, animals, and plants. In Arabidopsis, SIAMESE (SIM) is a CDK inhibitor that restricts progression through mitosis. Overexpression of SIM is required for endoreplication in Arabidopsis trichomes, and overexpression of SIM results in increased endoreplication in leaf epidermal cells. SIM is expressed at high levels in the root elongation zone, where it plays a …

Effects Of Cadherin Mediated Contact Normalization On Oncogenic Src Kinase Mediated Gene Expression And Protein Phosphorylation, Rachel E Nicoletto, Cayla J Holdcraft, Ariel C Yin, Edward P Retzbach, Stephanie A Sheehan, Amanda A Greenspan, Christopher M Laugier, Jason Trama, Caifeng Zhao, Haiyan Zheng, Gary S Goldberg

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Nontransformed cells form heterotypic cadherin junctions with adjacent transformed cells to inhibit tumor cell growth and motility. Transformed cells must override this form of growth control, called "contact normalization", to invade and metastasize during cancer progression. Heterocellular cadherin junctions between transformed and nontransformed cells are needed for this process. However, specific mechanisms downstream of cadherin signaling have not been clearly elucidated. Here, we utilized a β-catenin reporter construct to determine if contact normalization affects Wnt signaling in transformed cells. β-catenin driven GFP expression in Src transformed mouse embryonic cells was decreased when cultured with cadherin competent nontransformed cells compared to …

Enhanced Bmp Signaling Via Alk2 In Osteoclasts Decreases Bone Density In Mice, Yolanda V. Gutierrez, Hiroyuki Yamaguchi, Yuji Mishina, Yoshihiro Komatsu

Research Colloquium

Bone remodeling is a complex biological process that has been extensively studied. Bone Morphogenetic Proteins (BMPs) are recognized as one of the critical growth factors that coordinate bone remodeling. Previous studies have demonstrated that BMP signaling in osteoclasts has a positive effect on osteoclast function. However, little is known about how each BMP type I receptors control osteoclastogenesis. To investigate this question, we utilized the Cre-LoxP system to specifically activate BMP signaling through ALK2 in mice. We utilized Cathepsin K (Ctsk)-Cre driver to activate BMP signaling in osteoclasts in mice. Compared with aged- and gender-matched controls, gain-of-function of BMP mutant …

Autophagy And Meiotic Fidelity In C. Elegans, Kaitlin E. Kosinski

Dissertations, Theses, and Capstone Projects

Autophagy is an evolutionarily conserved multi-step recycling process in which cellular material is enclosed in the double membrane-bound autophagosome, which fuses with the lysosome to degrade its contents. Autophagy is essential for development and cellular adaptation to environmental or intracellular stress and is an important regulator of germline stem cell homeostasis in the model nematode C. elegans. We sought to determine if autophagy is important for genome stability during meiosis and found that the core adult C. elegans autophagy genes bec-1, atg-7, unc-51, and atg-18 were all required for proper meiotic development of oocytes. Loss of these …

Elucidating The Roles Of Septin Proteins In Thermotolerance And Cell Wall Integrity In Cryptococcus Neoformans, Stephani S. Martinez Barrera

All Dissertations

Cryptococcus neoformans is a globally distributed fungal pathogen responsible for causing cryptococcal meningitis in immunocompromised individuals. This pathogenic yeast must adapt to changes in temperature upon entering the human host. Septin proteins are conserved filament-forming GTPases that assemble as higher-order complexes at the cell cortex to support cytokinesis and morphogenesis in fungal and animal cells. In C. neoformans, four septin homologs (Cdc3, Cdc10, Cdc11, and Cdc12) assemble at the mother-bud neck, contributing to cytokinesis through poorly understood mechanisms. C. neoformans strains lacking the septins Cdc3 or Cdc12 are viable at 25°C, but fail to proliferate at 37°C, and are …

Genetics Of Mdh In Humans, Adam Haberman, Celeste N. Peterson

Biology: Faculty Scholarship

Malate dehydrogenase (MDH) performs key roles in metabolism, but little is known about its function specifically in human health and disease. In this minireview, we describe the incomplete state of our knowledge of human MDH genetics. Humans have three MDH genes with a total of four validated isoforms. MDH1 and MDH2 are widely expressed, while MDH1B is only expressed in a small subset of tissues. Many mutations in MDH1 and MDH2 have been identified in patients, but only a few have been studied to determine what symptoms they cause. MDH1 has been associated with cancer and a neurodevelopmental disorder. MDH2 …

Functional And Structural Analysis Of The Neimann-Pick Disease Type C Pathway To Include Caveolin-1, Anthony Michael Seat

Chemistry and Chemical Biology ETDs

Human disease is often thought of as an all or nothing prospect, either one has the disease or one does not. This does not bear out in clinical or personal experiences, instead demonstrating that disease occurs within a spectrum ranging from presumed unaffected to demonstrably and detrimentally affected.Neimann-Pick disease is one example of this spectrum look into diseased states, with multiple named versions of a phenotypically similar disease. We focus on Neimann-Picktype C (NPC), which is the result of a disruption in the efflux of cholesterol and sphingolipids from the endocytic pathway. NPC demonstrates this concept of a spectrum of …