Cells Commons^™

Loss Of Hormone Receptor Expression After Exposure To Fluid Shear Stress In Breast Cancer Cell Lines, Jonathan Cuccia, Braulio Andres Ortega Quesada, Ethan P. Littlefield, Alejandra M. Ham, Matthew E. Burow, Adam T. Melvin, Elizabeth C. Martin

School of Medicine Faculty Publications

Following metastatic spread, many hormone receptor positive (HR(+)) patients develop a more aggressive phenotype with an observed loss of the HRs estrogen receptor (ER) and progesterone receptor (PR). During metastasis, breast cancer cells are exposed to high magnitudes of fluid shear stress (FSS). Unfortunately, the role for FSS on the regulation of HR expression and function during metastasis is not fully understood. This study was designed to elucidate the impact of FSS on HR(+) breast cancer. Utilizing a microfluidic platform capable of exposing breast cancer cells to FSS that mimics in situ conditions, we demonstrate the impact of FSS exposure …

Deciphering The Contribution Of Microglia To Neurodegeneration In Friedreich's Ataxia, Sydney N. Gillette

Master's Theses

Friedreich's ataxia (FRDA) is the most prevalent inherited ataxia, affecting one in every 50,000 individuals in the United States. This hereditary condition is caused by an abnormal GAA trinucleotide repeat expansion within the first intron of the frataxin gene resulting in decreased levels of the frataxin protein (FXN). Insufficient cellular frataxin levels results in iron accumulation, increased reactive oxygen species production and mitochondrial dysfunction. Tissues most heavily impacted are those most dependent on oxidative phosphorylation as an energy source and include the nervous system and muscle tissue. This is evident in the clinical phenotype which includes muscle weakness, ataxia, neurodegeneration …

Using Rapid Protein Degradation To Determine The Effect Of Runx1 Loss-Of- Function On Dna Damage Accumulation And Repair., Jackriel Pina Morales

Theses and Dissertations

Germline mutations in RUNX1 are associated with familial platelet disorder with a predisposition to myeloid malignancy (RUNX1-FPDMM), in which patients present with low platelet counts,excessive bleeding and bruising, and an increased risk of Acute Myeloid Leukemia (AML)/Myelodysplastic Syndrome (MDS) development throughout their lifetime. To understand how these loss-of-function mutations in RUNX1 drive predispose to malignancy, it is important to develop a detailed understanding of the molecular basis of RUNX1 function. While RUNX1 is a transcription factor, preliminary data from our group and work from others suggests that RUNX1 also interacts with proteins that are critical for DNA damage …

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

The Utilization Of Mg-63 Osteosarcoma Cells As A Biocompatibility Model For Bone Regeneration In Manufactured Scaffolds, Grace Martin

University Honors College

When a bone is broken beyond traditional repairs, medical advancements have created a new pathway for bone transplants that involves manufactured scaffolds. These scaffolds can be 3Dprinted to any size, and donated bone cells can be placed onto scaffolding, and regeneration of the bone will occur. This is due to the scaffold mimicking tissue structures that are naturally found in the body acting as an anchor for the bone cells. The choice of the scaffold material is important to consider in order to help the tissue heal properly while also being able to withstand damages that come with daily life. …

A Cytoarchitectural Analysis Of The Rat Amygdala In Ultrathin Serial Sections, Katrina Schneider

Honors Scholar Theses

This study delves into the cellular composition and functional dynamics of the lateral amygdala (LA), a crucial brain region implicated in emotional and auditory processing/learning. Utilizing IHC, ultrathin serial sectioning (Ultraplex Method), and RNAscope, distinct cell types are characterized within the LA based on calcium-binding proteins (CBPs) and inhibitory markers such as GABA. Despite a modest sample size, a diverse array of cell types are identified, with calbindin-positive neurons prominently emerging in inhibitory cells. Notably, GABA intensity varies depending on cell identity and marker colocalization, hinting at complex regulatory mechanisms involving GABAergic signaling and CBPs. Analysis of vesicular glutamate transporter …

Overexpression Of Fatty Acid Synthase Upregulates Glutamine–Fructose-6-Phosphate Transaminase 1 And O-Linked N-Acetylglucosamine Transferase To Increase O-Glcnac Protein Glycosylation And Promote Colorectal Cancer Growth, James Drury, Mariah E. Geisen, Josiane Weber Tessmann, Piotr G. Rychahou, Courtney O. Kelson

Markey Cancer Center Faculty Publications

Fatty acid synthesis has been extensively investigated as a therapeutic target in cancers, including colorectal cancer (CRC). Fatty acid synthase (FASN), a key enzyme of de novo lipid synthesis, is significantly upregulated in CRC, and therapeutic approaches of targeting this enzyme are currently being tested in multiple clinical trials. However, the mechanisms behind the pro- oncogenic action of FASN are still not completely understood. Here, for the first time, we show that overexpression of FASN increases the expression of glutamine–fructose-6-phosphate transaminase 1 (GFPT1) and O-linked N-acetylglucosamine transferase (OGT), enzymes involved in hexosamine metabolism, and the level of O-GlcNAcylation in vitro …

Nf-Κb As An Inducible Regulator Of Inflammation In The Central Nervous System, Sudha Anilkumar, Elizabeth Wright-Jin

Department of Medicine Faculty Papers

The NF-κB (nuclear factor K-light-chain-enhancer of activated B cells) transcription factor family is critical for modulating the immune proinflammatory response throughout the body. During the resting state, inactive NF-κB is sequestered by IκB in the cytoplasm. The proteasomal degradation of IκB activates NF-κB, mediating its translocation into the nucleus to act as a nuclear transcription factor in the upregulation of proinflammatory genes. Stimuli that initiate NF-κB activation are diverse but are canonically attributed to proinflammatory cytokines and chemokines. Downstream effects of NF-κB are cell type-specific and, in the majority of cases, result in the activation of pro-inflammatory cascades. Acting as …

Diagnostic Accuracy Of Intraoperative Frozen Section For Margin Evaluation Of Oral Cavity Squamous Cell Carcinoma, Javaria P. Ali, Bakhtawar Allauddin Mallick, Khushbakht Rashid, Umair Arshad Malik, Atif Ali Hashmi, Shamail Zia, Muhammad Irfan, Amir Khan, Naveen Faridi

Section of Internal Medicine

Objectives: Intraoperative frozen-section evaluation is a valuable technique for detecting positive margins intraoperatively for oral squamous cell carcinoma. We conducted this study to determine the diagnostic accuracy of frozen section in detecting margin status and the effect of tumor grade and stage on diagnostic accuracy.
Results: A total of 251 biopsy-proven cases of oral squamous cell carcinoma were included in this study. The tissue specimen resected during surgery was sent to the laboratory for frozen section evaluation. The frozen section results were then compared with the permanent section results to determine the sensitivity, specificity, positive predictive value, negative predictive value, …

Oxidative Stress And Ion Channels In Neurodegenerative Diseases, Razan Orfali, Adnan Z. Alwatban, Rawan S. Orfali, Liz Lau, Noble Chea, Abdullah M. Alotaibi, Young-Woo Nam, Miao Zhang

Pharmacy Faculty Articles and Research

Numerous neurodegenerative diseases result from altered ion channel function and mutations. The intracellular redox status can significantly alter the gating characteristics of ion channels. Abundant neurodegenerative diseases associated with oxidative stress have been documented, including Parkinson’s, Alzheimer’s, spinocerebellar ataxia, amyotrophic lateral sclerosis, and Huntington’s disease. Reactive oxygen and nitrogen species compounds trigger posttranslational alterations that target specific sites within the subunits responsible for channel assembly. These alterations include the adjustment of cysteine residues through redox reactions induced by reactive oxygen species (ROS), nitration, and S-nitrosylation assisted by nitric oxide of tyrosine residues through peroxynitrite. Several ion channels have been directly …

Nanosecond Pulsed Electric Fields Increase Antibiotic Susceptibility In Methicillin-Resistant Staphylococcus Aureus, Alexandra E. Chittams-Miles, Areej Malik, Erin B. Purcell, Claudia Muratori

Bioelectrics Publications

Staphylococcus aureus is the leading cause of skin and soft-tissue infections (SSTIs). SSTIs caused by bacteria resistant to antimicrobials, such as methicillin-resistant S. aureus (MRSA), are increasing in incidence and have led to higher rates of hospitalization. In this study, we measured MRSA inactivation by nanosecond pulsed electric fields (nsPEF), a promising new cell ablation technology. Our results show that treatment with 120 pulses of 600 ns duration (28 kV/cm, 1 Hz), caused modest inactivation, indicating cellular damage. We anticipated that the perturbation created by nsPEF could increase antibiotic efficacy if nsPEF were applied as a co-treatment. To test this …

Dihydroethidium-Derived Fluorescence In Electrically Stressed Cells Indicates Intracellular Microenvironment Modifications Independent Of Ros, Esin B. Sözer, Iurii Semenov, P. Thomas Vernier

Bioelectrics Publications

Intracellular reactive oxygen species (ROS) generation is widely suggested as a trigger for biological consequences of electric field exposures, such as those in electroporation applications. ROS are linked with membrane barrier function degradation, genetic damage, and complex events like immunological cell death. Dihydroethidium (DHE) is commonly used to monitor ROS in cells. DHE is linked to intracellular ROS by a primary oxidation product, Ethidium (Eth⁺), that shows increased fluorescence upon binding to polynucleotides. We observed changes in DHE-derived fluorescence in Chinese hamster ovary (CHO) cells post 300-ns electric pulse exposures, comparing them to tert-butyl-hydroperoxide (t-BHP) induced oxidative stress. …

Synergistic Effects Of Nanosecond Pulsed Plasma And Electric Field On Inactivation Of Pancreatic Cancer Cells In Vitro, Edwin A. Oshin, Zobia Minhas, Ruben M. L. Colunga Biancatelli, John D. Catravas, Richard Heller, Siqi Guo, Chunqi Jiang

Bioelectrics Publications

Nanosecond pulsed atmospheric pressure plasma jets (ns-APPJs) produce reactive plasma species, including charged particles and reactive oxygen and nitrogen species (RONS), which can induce oxidative stress in biological cells. Nanosecond pulsed electric field (nsPEF) has also been found to cause permeabilization of cell membranes and induce apoptosis or cell death. Combining the treatment of ns-APPJ and nsPEF may enhance the effectiveness of cancer cell inactivation with only moderate doses of both treatments. Employing ns-APPJ powered by 9 kV, 200 ns pulses at 2 kHz and 60-nsPEF of 50 kV/cm at 1 Hz, the synergistic effects on pancreatic cancer cells (Pan02) …

The Role Of Liver-Specific Transcription Factor Hnf4 In Reprogramming Of Fibroblasts, Mary Odubote

Masters Theses

The mammalian liver, a vital organ with complex functions, relies on a network of transcription factors to regulate gene expression. Fusion of hepatoma cells with fibroblasts often leads to gene extinction, silencing approximately 400 liver-enriched genes, including critical transcription factors such as HNF4. Previous studies revealed that ectopic expression of HNF4 in fibroblasts failed to prevent the extinction of SERPINA1, a liver-specific gene, upon subsequent fusion with hepatoma cells. Here, we sought to investigate the extent to which ectopic expression of HNF4 can reprogram fibroblast cells and prevent gene extinction in hybrid cells.

Using whole-genome expression analysis, we compared RAT1 …

Elucidating The Role Of Fatty Acid Synthase In Apc-Driven Colorectal Cancer, Courtney O. Kelson

Theses and Dissertations--Toxicology and Cancer Biology

Globally, colorectal cancer (CRC) is the second leading cause of cancer related deaths. Currently, there is a growing incidence rate for individuals aged 20-49 years. Genetic and environmental factors contribute to the risk of this cancer. Early detection of CRC allows for the most effective treatment option in which surgical resection of the primary tumor occurs along with adjuvant chemotherapy. This therapeutic approach contributes to 5-year survival rate of 91%. However, surgical procedures and chemotherapy struggles against metastatic and relapsed CRC resulting in 5-year survival rate of 14%. Inefficacious treatments for relapsed and metastatic diseases emphasizes the need for more …

Dynamics Of Cell Membrane Lesions And Adaptive Conductance Under The Electrical Stress, Mantas Silkunas, Olga N. Pakhomova, Giedre Silkuniene, Andrei G. Pakhomov

Bioelectrics Publications

Exceeding physiological limits of the cell membrane potential compromises structural integrity, enabling the passage of normally impermeant solutes and disrupting cell function. Electropermeabilization has been studied extensively at the cellular scale, but not at the individual membrane lesion level. We employed fast total internal reflection fluorescence (TIRF) imaging of Ca(2+) entry transients to discern individual lesions in a hyperpolarized cell membrane and characterize their focality, thresholds, electrical conductance, and the lifecycle. A diffuse and momentary membrane permeabilization without a distinct pore formation was observed already at a -100 mV threshold. Polarizing down to -200 mV created focal pores with a …

Zebrafish Drug Screening Identifies Erlotinib As An Inhibitor Of Wnt/ Β-Catenin Signaling And Self-Renewal In T-Cell Acute Lymphoblastic Leukemia, Majd A. Al-Hamaly, Anna H. Cox, Meghan G. Haney, Wen Zhang, Emma C. Arvin, Shilpa Sampathi, Mary Wimsett, Chunming Liu, Jessica S. Blackburn

Markey Cancer Center Faculty Publications

The Wnt/β-catenin pathway’s significance in cancer initiation, progression, and stem cell biology underscores its therapeutic potential. However, the clinical application of Wnt inhibitors remains limited due to challenges posed by off-target effects and complex cross-talk of Wnt signaling with other pathways. In this study, we leveraged a zebrafish model to perform a robust and rapid drug screening of 773 FDA-approved compounds to identify Wnt/β-catenin inhibitors with minimal toxicity. Utilizing zebrafish expressing a Wnt reporter, we identified several drugs that suppressed Wnt signaling without compromising zebrafish development. The effi- cacy of the top hit, Erlotinib, extended to human cells, where it …

The Delineation Of Platelet Pathology In Cardiometabolic Disease, Chi Peng

Theses and Dissertations--Pharmacology and Nutritional Sciences

Obesity is a multifactorial disease with many comorbidities leading to multiorgan dysfunction. Current studies point towards dysregulation of platelet signaling as a driver for increased risk of cardiovascular disease and stroke. The exact mechanisms remain elusive due to the complex interplay of factors involved, warranting the need to further understand how platelets are affected. Our preliminary data evaluating changes in platelet and coagulation parameters from bariatric patients showed that obesity did not affect platelet count or clotting time as demonstrated in INR values. However, female patients had increased bleeding events before surgery that were decreased after surgery. Due to limitations …

Synthesis And Structure-Activity Relationship Of Boronic Acid Bioisosteres Of Combretastatin A-4 As Anticancer Agents, Yali Kong, Michael C. Edler, Ernest Hamel, Asa R. Britton-Jenkins, Omar Gillan, Susan L. Mooberry, David Mu, Milton L. Brown

Department of Biomedical and Translational Sciences Faculty Publications

The boronic acid group plays an important role in drug discovery. Following our discovery of a boronic acid analog of combretastatin A-4 (CA-4), a series of analogs featuring a boronic acid group on the C phenyl ring of CA-4 was synthesized and evaluated for cytotoxicity, as well as for their ability to inhibit tubulin polymerization, inhibit the binding of [³H]colchicine to tubulin and cause depolymerization of cellular microtubules. Modifications on the C ring of CA-4, either eliminating the methoxy group or replacing the C phenyl ring with a pyridine ring, resulted in a reduced potency for inhibiting tubulin polymerization, colchicine …

Gene Expression Of Tight Junctions In Foreskin Is Not Affected By Hiv Pre-Exposure Prophylaxis, Emily L. Webb, Stefan Petkov, Heejin Yun, Laura Else, Limakatso Lebina, Jennifer Serwanga, Azure-Dee A.P. Pillay, Thabiso B. Seiphetlo, Susan Mugaba, Patricia Namubiru, Geoffrey Odoch, Daniel Opoka, Andrew S. Ssemata, Pontiano Kaleebu, Saye Khoo, Neil Martinson, Julie Fox, Clive M. Gray, Carolina Herrera, Francesca Chiodi

Department of Obstetrics & Gynecology Faculty Publications

Introduction: Tight junctions (TJs) serve as permeability filters between the internal and external cellular environment. A large number of proteins have been identified to be localized at the TJs. Due to limitations in tissue collection, TJs in the male genital tract have been understudied.

Methods: We analysed the transcriptomics of 132 TJ genes in foreskin tissue of men requesting voluntary medical male circumcision (VMMC) and enrolled in the Combined HIV Adolescent Prevention Study (CHAPS) trial conducted in South Africa and Uganda (NCT03986970). The trial evaluated the dose requirements for event-driven HIV pre-exposure prophylaxis (PrEP) with emtricitabine-tenofovir (FTC-TDF) or emtricitabine-tenofovir alafenamide …