Medical Cell Biology Commons^™

Developing A Protocol For Non-Cellular Transplantation Of Donor Mitochondria Into Recipient Cells, Andrew Parton

Honors Theses

Tumor innervation has emerged as a critical feature of cancer progression, with increased nerve density correlating with enhanced aggressiveness, metastatic dissemination, and poor clinical outcome. However, the functional contribution of neurons to tumor biology remains incompletely defined. We recently identified the intercellular transfer of mitochondria from neurons to cancer cells as a mechanism that promotes tumor progression. We therefore hypothesized that disruption of this transfer could attenuate tumor aggressivity. To directly investigate this process, we developed an approach to isolate mitochondria from donor cells and transplant them into recipient cancer cells independently of canonical cell-cell interactions. Transferred mitochondria were tracked …

Pseudomonas Aeruginosa Exoenzyme Y Enzymatic Activity Inhibits Exoenzyme S-Induced Caspase Activation But Not Cytotoxicity In Pulmonary Microvascular Endothelial Cells, Connor Holm

Honors Theses

Pseudomonas aeruginosa (P. aeruginosa) is the most common cause of ventilator-associated pneumonia in intensive care unit patients. P. aeruginosa utilizes a type III secretion system that injects exoenzymes U, S, T, and/or Y into the host cell cytosol. A majority of clinically isolated P. aeruginosa strains express ExoY often in combination with ExoU and ExoT, or ExoS and ExoT. Host signaling mechanisms in response to intoxication with individual exoenzymes have been extensively studied, yet little is known about host cell response to co-intoxication. In this study, pulmonary microvascular endothelial cells (PMVECs) were infected with P. aeruginosa strains expressing different combinations …

Long G4-Rich Enhancers Physically Interacts With Promoters Via A G4:G4 Dna-Based Mechanism, Jeffrey David Demeis

Graduate Theses and Dissertations (2019 - present)

Enhancers are genomic sequences that function as regulatory elements capable of increasing the transcription of a given gene often located at a considerable distance. The broadly accepted model of enhancer activation involves bringing an enhancer-bound activator protein complex into close spatial proximity to its target promoter through chromatin looping. Equally relevant to the work described herein, roles for guanine (G) rich sequences in transcriptional regulation are now widely accepted. Non-coding G-rich sequences are commonly found in gene promoters and enhancers, and various studies have described specific instances where G-rich sequences regulate gene expression via their capacity to form G-quadruplex (G4) …

Examining Ndufab1 Expression In Head And Neck Squamous Cell Carcinoma, Addison Stevens

Poster Presentations

Honors research poster.

Introduction: Head and neck squamous cell carcinoma (HNSCC) is approximately 4% of all cancers and 2% of all cancer associated mortality in the United States. In 2023, there will be an estimated 67,000 new cases of HNSCC, along with 15,400 deaths, in the United States. HNSCC locations include the oral cavity, oropharynx, nasopharynx, hypopharynx, and larynx. Major risk factors for HNSCC include tobacco use, alcohol use, and human papilloma virus (HPV). Epidermal growth factor receptor (EGFR) is currently the only approved molecular targeted therapy for HNSCC. Therefore, new therapeutics and biomarkers for HNSCC are warranted. Mitochondria are …

Role Of Pseudomonas Aeruginosa Exoenzymes S, T, And Y In The Modulation Of Intrinsic Apoptosis In Pulmonary Microvascular Endothelial Cells, Andrea M. Vavrinek

Honors Theses

P. aeruginosa is the most common cause of ventilator-associated pneumonia in ICU patients. P. aeruginosa uses a type III secretion system to inject exoenzymes S, T, U, and Y into host cells, exhibiting unique effects. Pulmonary microvascular endothelial cells (PMVECs) are used to evaluate cellular changes caused by exoenzymes. ExoY infection of PMVECs leads to cell rounding but does not lead to cell death, unlike ExoS/T. The current study evaluated the exoenzyme-induced modulation of intrinsic apoptosis in endothelial cells. Strain PAK, producing ExoS, T, and Y, was compared to isogenic strains expressing either S, SY, T, TY, Y, or none …

Examining Ndufab1 Expression In Head And Neck Squamous Cell Carcinoma, Addison L. Stevens

Honors Theses

Head and neck squamous cell carcinoma (HNSCC) accounts for around 4% of all cancers in the USA. HNSCC includes cancers of the oral cavity, oropharynx, nasopharynx, hypopharynx, and larynx. Reprogramming of mitochondrial metabolism has been known to promote oncogenesis. NDUFAB1, a nuclear encoded subunit of respiratory complex I (RCI) in the inner mitochondrial membrane, is abundantly expressed at the mRNA level in HNSCC patients. Based on this finding, we hypothesize that NDUFAB1 protein expression is high in HNSCC and that NDUFAB1 expression predicts a poor prognosis in HNSCC patients. We determined NDUFAB1 expression in HNSCC using immunohistochemistry and pathology guided …

Substrate Stiffness: A Mechanical Determinant Of Endothelial Phenotype, Sunita Subedi Paudel

Graduate Theses and Dissertations (2019 - present)

Endothelial cells (ECs) adhere to their neighboring cells via adherens and tight junctions, and to the basement membrane via focal adhesions. These structural elements are constantly remodeling i.e., even in a quiescent state, cells are in constant motion. ECs sense the stiffness of the basement membrane, and this stiffness is a physiological signal that control the cellular phenotype. Whereas the normotensive pulmonary circulation has a substrate stiffness that is ~1.25-4 kPa, vascular remodeling in pulmonary arterial hypertension (PAH) increases substrate stiffness to ~30 kPa. The impact that this increase in substrate stiffness has no cell size, shape, and speed was …

Applying Mci-062, A Novel Pan-Ras Inhibitor, To Treat Kras-Mutant Lung Cancer., Richard Fu

Poster Presentations

Honors thesis poster presentation.

RAS, one of the most prevalent oncogenes, is mutated in 27% of human cancers. Gainof- function RAS mutations activate multiple downstream pathways, including the RASRAF- MEK-ERK and PI3K/AKT/mTOR pathways, which are critical in tumorigenesis and cancer cell proliferation. The RAS proteins KRAS, HRAS, and NRAS along with their downstream effectors are attractive targets for cancer therapy since they act as frequent drivers in lung, colorectal, and pancreatic cancers. However, RAS proteins have relatively smooth surfaces that lack traditional binding pockets, making inhibitors specific to RAS difficult to create. Recently, a novel small molecule pan-RAS inhibitor named …