Cell Biology Commons^™

An Fgfr-P53 Developmental Signaling Axis Drives Salivary Cancer Progression, Julia M. R. Billington

USF Tampa Graduate Theses and Dissertations

Mucoepidermoid carcinoma (MEC) is the most frequently occurring salivary gland malignancy.Here, we investigated transcriptomic profiles of human fetal and adult salivary glands and MEC tumors to assess programs involved in MEC progression. Molecular and genetic analyses revealed that MEC tumors and fetal salivary glands share proliferative and developmental gene expression profiles that implicate an FGFR-p53 signaling axis in salivary MEC progression. Based on these findings, we developed a genetically engineered mouse model of advanced MEC via targeted expression of the CRTC1-MAML2 oncogene in salivary ductal cells. Specifically, CRTC1- MAML2 expression combined with p53 dysregulation in salivary ducts rewires FGF signaling …

The Only Constant Is Change: The Role Of Genetic Diversification In Cancer And Beyond, Malgorzata Tyczynska Weh

USF Tampa Graduate Theses and Dissertations

Genetic diversification, the process by which genetic variation arises in a population, is fundamental to evolution by natural selection. Mutation, a central diversification process, fuels adaptation across species, including in cancer. Yet most new mutations are neutral or deleterious on cell fitness, raising the question of how mutation-driven adaptation persists. To explore this paradox, I developed a spatial agent-based model (ABM) in which population fitness emerges from individual cells acquiring mutations at varied rates and with diverse fitness effects. I evaluated model behavior across adaptive states, mutation rates, and distributions of fitness effects. The results show that high mutation rates …

Dnajb6: A Potent Dnajb Chaperone In Regulating Tau Proteostasis, Abigail R. Esquivel

USF Tampa Graduate Theses and Dissertations

Neurodegenerative diseases often feature the pathological buildup of misfolded proteins, and tau is a principal culprit in multiple tauopathies. One chaperone of emerging interest is DnaJB6b, a member of the Hsp40/DnaJ family, which exhibits potent anti-aggregation activity against several disease-related proteins. Recent investigations highlight its unique capacity to recognize and neutralize aggregation-prone forms of tau. DnaJB6b appears potent against multiple variants of tau and may be acting against tau, in part, by directing misfolded tau toward proteasomal clearance. The first lines of evidence come from systematic chaperone screens, where DnaJB6b repeatedly emerged as a strong suppressor of tau seeding. Further …

Selective Pericyte Recruitment To Ec-Lined Tubes, Vessel Assembly Enhancement Through Pericyte Timp-3 Induction, And Pericyte Tbx2 In Capillary Formation And Maturation, Ksenia Marilyn Yrigoin Kaluguina

USF Tampa Graduate Theses and Dissertations

Capillaries, the smallest blood vascular networks, are formed by narrow and elongated endothelial cell (EC)-lined tubes with associated pericytes anchored to the abluminal tube surface. Our laboratory demonstrated that dynamic interactions between ECs and pericytes during capillary tube network assembly are required for basement membrane matrix deposition and maturation. We have also shown that key EC-derived factors promote pericyte recruitment, proliferation, and pericyte-induced basement membrane formation during capillary assembly. In the first section, we aim to identify if vascular smooth muscle cells (VSMCs) respond to the same factors and have the same invasive ability as pericytes since they are both …

Functional Studies Of Dcaf14 In Replication Fork Stability And Genome Integrity, Neysha Tirado-Class

USF Tampa Graduate Theses and Dissertations

The response to replication stress is critical for ensuring the stability of replication forks and preserving genome integrity. To aid this response, several factors are recruited to stalled replication forks to prevent irreversible collapse of the replication machinery. Replication fork proteomic analyses of stalled forks reveal enrichment of DCAF14, a component of the Cullin4-RING (CRL4) E3 ubiquitin ligase complex, that mediates replication fork protection by blocking nuclease-mediated digestion of nascent DNA. However, little is known about the molecular mechanism by which DCAF14 functions in the context of replication stress. Notably, loss of function mutations in DCAF14 are associated with a …

Androgen Drives Melanoma Invasiveness And Metastatic Spread By Inducing Tumorigenic Fucosylation, Qian Liu

USF Tampa Graduate Theses and Dissertations

Melanoma incidence and mortality rates are historically higher for men than women, with an estimated ~47% more new cases and twice the lethality in men in the US in 2023. Consistent with these discrepancies, emerging studies have highlighted the tumorigenic role of the male sex hormone androgen and its receptor (AR) in promoting melanoma aggressiveness. However, underlying cellular and molecular mechanisms and their precise pathological contributions are not well-defined. We recently discovered a sex-associated disparity in melanoma fucosylation, the post-translational modification of proteins with the dietary sugar L-fucose. Fucosylation, the conjugation of fucose moieties onto different glycan linkages on target …

Why Should Early-Career Scientists Publish In Society Journals, Stephen K. Dolan, Lori D. Banks, Wenqi Yu

Molecular Biosciences Faculty Publications

In this editorial, written by early-career scientists, we advocate for the invaluable role of society journals in our scientific community. By choosing to support these journals as authors, peer reviewers, and as editors, we can reinforce our academic growth and benefit from their re-investment back into the scientific ecosystem. Considering the numerous clear merits of this system for future generations of microbiologists and more broadly, society, we argue that early-career researchers should publish our high-quality research in society journals to shape the future of science and scientific publishing landscape.

The Inaugural Mbio Junior Editorial Board—Lessons Learned And The Path Forward Toward Improving The Peer Review Process, Cynthia Ayefoumi Adinortey, Stephen K. Dolan, Sarah Doore, Rebeccah Lijek, Diana Priscila Pires, Wenqi Yu, Elizabeth B. Draganova, Lennart Schada Von Borzyskowski

Molecular Biosciences Faculty Publications

The inaugural Junior Editorial Board (JEB) of mBio consisted of 64 early-career researchers active from 2022 to 2023. The goal of the JEB was to train early-career researchers in the art of peer review under the guidance of experienced editors. JEB members gained hands-on experience in peer review by participating in modules detailing the publishing process through the lenses of the journal, editor, and reviewer. Ultimately, JEB members applied this new knowledge by reviewing mBio manuscripts. Here, we summarize the background, the mission, and the achievements of the first mBio JEB. We also include possible trajectories for the future editions …

Novel Roles Of The Blm Syndrome Dna Helicase In Genome Maintenance And Mitochondrial Regulation, Brian B. Rodemoyer

USF Tampa Graduate Theses and Dissertations

Bloom syndrome (BS) is an extremely rare autosomal recessive genetic disorder caused by defects in the BLM gene. Patients with BS display a broad phenotypic spectrum including abnormally short stature, microcephaly, sun sensitivity, insulin resistance, perpetual oxidative stress, and a ~300-fold greater propensity for developing cancer than the general population. As such, BS patients typically do not live past their 20’s. The BLM gene encodes the BLM helicase, a member of the highly conserved RecQ family of 3’ to 5’ DNA helicases. Most of our cellular understanding of BLM is through its role in DNA damage repair through the homologous …

Exploring Strain Variation And Bacteriophage Predation In The Gut Microbiome Of Ciona Robusta, Celine Grace F. Atkinson

USF Tampa Graduate Theses and Dissertations

Current microbiome studies have shown that the maintenance of homeostasis betweenmicrobial populations (e.g. bacteria, viruses) and the host immune system (e.g. innate immune molecules) is necessary for balancing health and disease outcomes within the host. These studies most often utilize vertebrate models; however, research in this field can benefit from diverse model systems that facilitate our ability to conduct experiments to identify phylogenically conserved rules influencing homeostasis in the gut of animals. The Dishaw has developed the use of a filter-feeding marine invertebrate chordate, Ciona robusta, to model such fundamental interactions[1]–[6]. While most biological diversity and functional contribution within microbiomes …

Dcaf14 Regulates Cdt2 To Promote Set8-Dependent Replication Fork Protection, Neysha Tirado-Class, Caitlin Hathaway, Anthony Nelligan, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

DDB1- and CUL4-associated factors (DCAFs) CDT2 and DCAF14 are substrate receptors for Cullin4–RING E3 ubiquitin ligase (CRL4) complexes. CDT2 is responsible for PCNA-coupled proteolysis of substrates CDT1, p21, and SET8 during S-phase of cell cycle. DCAF14 functions at stalled replication forks to promote genome stability, but the mechanism is unknown. We find that DCAF14 mediates replication fork protection by regulating CRL4CDT2 activity. Absence of DCAF14 causes increased proteasomal degradation of CDT2 substrates. When forks are challenged with replication stress, increased CDT2 function causes stalled fork collapse and impairs fork recovery in DCAF14-deficient conditions. We further show that stalled fork protection …

Otud5 Limits Replication Fork Instability By Organizing Chromatin Remodelers, Angelo De Vivo, Hongseon Song, Yujin Lee, Neysha Tirado-Class, Anthony Sanchez, Sandy D. Westerheide, Huzefa Dungrawala, Younghoon Kee

Molecular Biosciences Faculty Publications

Proper regulation of replication fork progression is important for genomic maintenance. Subverting the transcription-induced conflicts is crucial in preserving the integrity of replication forks. Various chromatin remodelers, such as histone chaperone and histone deacetylases are known to modulate replication stress, but how these factors are organized or collaborate are not well understood. Here we found a new role of the OTUD5 deubiquitinase in limiting replication stress. We found that OTUD5 is recruited to replication forks, and its depletion causes replication fork stress. Through its C-terminal disordered tail, OTUD5 assembles a complex containing FACT, HDAC1 and HDAC2 at replication forks. A …

The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw

Molecular Biosciences Faculty Publications

We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival …

Regulation Of The Heat Shock Response Via Lysine Acetyltransferase Cbp-1 And In Neurodegenerative Disease In Caenorhabditis Elegans, Lindsey N. Barrett

USF Tampa Graduate Theses and Dissertations

The decline of proteostasis is a hallmark of aging that is, in part, affected by the dysregulation of the heat shock response (HSR), a highly conserved cellular response to proteotoxic stress in the cell. The heat shock transcription factor HSF-1 is well-studied as a key regulator of proteostasis, but mechanisms that could be used to modulate HSF-1 function to enhance proteostasis during aging are largely unknown. In this study, we examined lysine acetyltransferase regulation of the HSR and HSF-1 in C. elegans. We performed an RNA interference screen of lysine acetyltransferases and examined mRNA expression of the heat-shock inducible gene …

Defining And Modeling Pericyte-Induced Capillary Network Assembly, Capillary Regression Preceding Pericyte-Stimulated Fibrosis, And Lymphatic Capillary Regression, Scott Stephen Kemp

USF Tampa Graduate Theses and Dissertations

Capillary formation and maturation can only occur through a series of highly orchestrated events that requires the coordinated efforts of both endothelial cells (ECs) and pericytes. While ECs are perfectly capable of creating tube networks on their own, the maturation and stabilization of these tube networks require the presence of a second cell type, pericytes, to create stable capillary networks. Previous studies have identified factors required for pericyte recruitment to EC tube networks, however, we hypothesized that there were still unaccounted for EC-derived molecules that were contributing to pericyte recruitment. In the first part of this study, we used serum-free, …

Defining The Role Of Oxidized Mitochondrial Dna In Myelodysplastic Syndromes, Grace Anne Ward

USF Tampa Graduate Theses and Dissertations

Myelodysplastic Syndromes (MDS) are heterogeneous bone marrow (BM) failure malignancies characterized by constitutive innate immune activation, NLRP3 inflammasome (IFM) driven pyroptotic cell death, and the induction of interferon-stimulated genes (ISG). MDS often diagnostically resembles other hematologic disorders, as such, additional tools are needed for the discrimination from overlapping disorders. We observed that oxidized mitochondrial DNA (ox-mtDNA) is released upon cytolysis. We hypothesize that levels of ox-mtDNA are high in MDS, allowing us to use it as a diagnostic biomarker; and that cell free ox-mtDNA is contributing to feedforward BM failure.

ROC/AUC analysis demonstrated that ox-mtDNA is a sensitive and specific …

The Role Of Eicosanoid Metabolism In Mammalian Wound Healing And Inflammation, Kenneth D. Maus

USF Tampa Graduate Theses and Dissertations

Inflammatory wounds, both chronic and acute, lead to increased morbidity and mortality rates, especially in the elderly population. The annual healthcare cost for chronic wound care alone is over $39B in the US and the demographic of susceptible patients is steadily increasing due to an aging population and lifestyle-related diseases (e.g., hyperlipidemia, obesity, and type 2 diabetes). In fact, many chronic wounds currently have a worse 5-year outlook than certain types of cancers. This shows the need for expediting the wound healing process in such a way that compresses inflammatory signaling and encourages wound resolution without sacrificing pathogen removal and …

Impact Of Arginine Metabolism And Sensing In Mouse Models Of Alzheimer’S Disease, Chao Ma

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) remains the most common neurodegenerative disease in the central nervous system (CNS), with amyloidosis and tauopathy as their two main hallmarks. Typical AD pathologies include cerebral plaques deposited by amyloid-β, neurofibrillary tangles aggregated by tau, and neuroinflammation caused by activated brain myeloid cells. A critical theme is centered on impaired brain metabolism. Emerging evidence showed that impaired arginine metabolism was a novel biomarker pathway for AD. The manipulation of arginine metabolism by a critical enzyme arginase 1 (ARG1) in neurons indicated therapeutic benefits in alleviating tau pathology. Balanced cellular proteostasis was governed by the mechanistic target of …

Adrenergic Modulation Of Precursor Cells Of Ovarian Cancer, Sweta Dash

USF Tampa Graduate Theses and Dissertations

Ovarian cancer remains one of the most lethal gynecological cancer and ranks eighth in cancer-related mortality among women. The high mortality rate can be attributed to majority of the cases being diagnosed at advanced stages of the disease when the survival rate and overall prognosis are poor. There is lack of effective screening modalities to detect ovarian cancer at early stages. Hence, a better understanding of the molecular mechanisms leading to ovarian cancer initiation is required.

Epidemiological studies have reported that conditions which cause chronic behavioral stress are associated with a higher risk of developing ovarian cancer. The activation of …

Determining The Role Of Dendritic Cells During Response To Treatment With Paclitaxel/Anti-Tim-3, Alycia Gardner

USF Tampa Graduate Theses and Dissertations

Intratumoral CD103+ dendritic cells (cDC1) are required for anti-tumor immune responses. In tumors that are poorly responsive to immunotherapeutic approaches targeting T cells, targeting cDC1 represents an alternative approach that may be useful in improving patient response rates. As such, it is critical to understand cDC1 function within tumors, and what may be preventing optimal function of cDC1. TIM-3 is a receptor that is highly expressed by cDC1 in murine and human mammary tumors, and TIM-3 blocking antibodies are currently being evaluated in clinical trials for a number of solid and hematological malignancies. In order to best design combinatorial therapeutic …

Characterizing The Impact Of Postharvest Temperature Stress On Polyphenol Profiles Of Red And White-Fruited Strawberry Cultivars, Alyssa N. Smith

USF Tampa Graduate Theses and Dissertations

All living organisms have developed mechanisms that help them prevent internal stress and survive under harsh conditions. For fruits, specifically strawberries, stress is fought against primarily by increasing the synthesis of polyphenols, which are secondary plant metabolites with bioactive activity. Characterizing these bioactive compounds and the differences between strawberry cultivars can be vital for strawberry breeders. Furthermore, understanding the mechanisms that trigger the synthesis of polyphenols and their levels within different strawberry cultivars will provide breeders with tools to successfully identify cultivars with higher resistance to pre- and postharvest stressors. To gain that understanding, this study aimed to characterize the …

Phip Variants Associated With Chung–Jansen Syndrome Disrupt Replication Fork Stability And Genome Integrity, Neysha Tirado-Class, Caitlin Hathaway, Wendy K. Chung, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

Chung–Jansen syndrome (CJS) is a rare, autosomal dominant disorder characterized by developmental delay, intellectual disability/cognitive impairment, behavioral challenges, obesity, and dysmorphic features. CJS is associated with heterozygous variants in PHIP (Pleckstrin-Homology Interacting Protein), a gene that encodes one of several substrate receptors for Cullin4-RING (CRL4) E3 ubiquitin ligase complex. Full-length PHIP, also called DCAF14, was recently identified to function as a replication stress response protein. Herein, we report the identification of two PHIP missense variants identified by exome sequencing in unrelated individuals with CJS. The variants p.D488V and p.E963G occur in different functional elements of DCAF14-WD40 repeat domain and pleckstrin …

Sequence Properties Of An Intramolecular Interaction That Inhibits P53 Dna Binding, Emily Gregory, Gary W. Daughdrill

Molecular Biosciences Faculty Publications

An intramolecular interaction between the p53 transactivation and DNA binding domains inhibits DNA binding. To study this autoinhibition, we used a fragment of p53, referred to as ND WT, containing the N-terminal transactivation domains (TAD1 and TAD2), a proline rich region (PRR), and the DNA binding domain (DBD). We mutated acidic, nonpolar, and aromatic amino acids in TAD2 to disrupt the interaction with DBD and measured the effects on DNA binding affinity at different ionic strengths using fluorescence anisotropy. We observed a large increase in DNA binding affinity for the mutants consistent with reduced autoinhibition. The ΔΔG between DBD and …

The Role Of Cpeb2 Alternative Splicing In Tnbc Metastasis, Shaun C. Stevens

USF Tampa Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related deaths for women in the U.S. Although the overall 5-year survival rate for breast cancer is 90%, this rate drops substantially for triple-negative breast cancer (TNBC) due to its high metastatic potential. Furthermore, there is a lack of targeted therapeutics for TNBC, and clinical trials have been largely unsuccessful. These characteristics validate the need for identifying novel therapeutic targets for the treatment of TNBC. The study of alternative splicing (AS) has emerged as a powerful tool to elucidate the molecular underpinnings driving cancer.

Our lab has identified cytoplasmic polyadenylation element-binding protein …

Investigation Of An Alternative Protocol For The Production Of Sars-Cov-2 Antigenic Proteins, Nichole Ninaltowski

USF Tampa Graduate Theses and Dissertations

With the COVID-19 pandemic showing no signs of slowing down, large-scale antigenic protein production is still needed for surveillance using serologic assays. From screening to vaccines to biotherapeutics, being able to produce the proteins for these assays is essential; however, the current gold standard method for producing SARS-CoV-2 spike proteins is prohibitively expensive for most research groups.

Alternative methods of transfecting mammalian cells to produce recombinant proteins that are relatively inexpensive have been used for years. Unlike the expensive, commercially available lipid-based methods, other established methods such as polyethyleneimine (PEI), are considerably easier, and cheaper to meet the needs of …

The Multifaceted Role Of Ccar-1 In The Alternative Splicing And Germline Regulation In Caenorhabditis Elegans, Doreen Ikhuva Lugano

USF Tampa Graduate Theses and Dissertations

The Cell Division Cycle and Apoptosis Regulator (CCAR) family members are an enigmatic family of proteins regulating metabolism, cancer, apoptosis, DNA damage, and stress. Mammals have CCAR family members, CCAR1 and CCAR2/DBC1, which evolved from the founding family member CCAR-1/LST-3 expressed in Caenorhabditis elegans. Several studies have shown the importance of understanding these proteins' function in standard and altered physiological processes. Our studies aim to understand the genome-wide alternative splicing and germline regulation of Caenorhabditis elegans CCAR-1 in normal and heat shock conditions. Recently, mammalian CCAR family member CCAR2/DBC1 regulates the alternative splicing by forming a complex with ZNF326. This …

Cytoplasmic Polyadenylation Element Binding Protein 2 Alternative Splicing Regulates Hif1Α During Chronic Hypoxia, Emily M. Mayo

USF Tampa Graduate Theses and Dissertations

Chronic pulmonary hypoxia commonly results in the sustained expression of HIF1 (hypoxia inducible factor 1), a heterodimeric transcription factor, that, if unrestrained, can result in dramatic vasculature remodeling, pulmonary arterial hypertension, and right-sided heart failure. Together, these pulmonary disorders cost approximately $100 billion annually to treat due to the limited therapeutic targets designed to inhibit HIF1 expression. In this study, we introduce a translational regulator of HIF1 expression, known as Cytosolic polyadenylation element binding proteins 2 (CPEB2). Our lab has previously demonstrated in cancer cells that alternatively spliced isoforms of CPEB2 regulate the translation of the HIF1 oxygen-dependent subunit, HIF1α, …

Circrev1 Expression In Triple-Negative Breast Cancer, Meagan P. Horton

USF Tampa Graduate Theses and Dissertations

Triple-negative breast cancer (TNBC) comprises only 24% of breast cancer cases, yet is the second leading cause of cancer mortality in women due to its aggressive nature (1). This increase in mortality is due to the lack of receptors for three targetable growth factors (HER2, progesterone, and estrogen receptors). Our previous studies have indicated that these cancers are highly dysregulated in respect to alternative splicing. Hence, we undertook a study aimed at identifying circular RNAs (circRNAs) generated from back-splicing events which were dysregulated in TNBC. We have identified a novel circRNA transcript, circular REV1 (circREV1), which is upregulated in our …

Bone Microenvironmental Control Of Skeletal Malignancy, Chen Hao Lo

USF Tampa Graduate Theses and Dissertations

Bone is a common site of metastasis for many solid malignancies. Bone-metastatic cancers pose a significant clinical problem worldwide and is among the main causes for cancer patient morbidity and mortality. Patients with advanced bone-metastatic diseases often present with either osteolytic or osteogenic bone diseases as their cancers progress. These bone pathologies are products of the cancer co-opting the local bone remodeling stroma to yield important growth nutrients and factors. Unfortunately, skeletal metastases remain incurable and are fatal. Identifying and understanding the causal multicellular and molecular interactions underlying skeletal malignancies can yield crucial ideas for targeting and inhibiting disease progression. …

Tracking The Subcellular Localization Of Surface Proteins In Staphylococcus Aureus By Immunofluorescence Microscopy, Salvatore J. Scaffidi, Mac A. Shebes, Wenqi Yu

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus and other Gram-positive bacteria play essential roles in bacterial colonization and host-microbe interactions. Surface protein precursors containing a YSIRK/GXXS signal peptide are translocated across the septal membrane at mid-cell, anchored to the cell wall peptidoglycan at the cross-wall compartment, and presented on the new hemispheres of the daughter cells following cell division. After several generations of cell division, these surface proteins will eventually cover the entire cell surface. To understand how these proteins travel from the bacterial cytoplasm to the cell surface, we describe a series of immunofluorescence microscopy protocols designed to detect the stepwise …