Medical Toxicology Commons^™

Effects Of Alternative Chemotherapeutic Agents On Thyroid Cancer Cell Line Ml-1, Husref Rizvanovic

MSU Graduate Theses

Though differentiated thyroid carcinomas have decent prognosis when detected early, radioactive iodine (RAI) resistant and advanced thyroid cancers are still difficult to treat with existing therapies. Better therapeutic agents are needed. Studies have shown that aggressive thyroid cancers (ML-1) express the extracellular matrix protein, matrix metalloproteinase (MMP-2). MMP-2 has been linked to metastasis and aggressiveness of several cancers and has been shown to play a crucial role in tumor invasion. Chlorotoxin is a selective MMP-2 receptor agonist, and Saporin is a well-known ribosome-inactivating protein used for anti-cancer treatment; however, these two agents have never been studied when conjugated together. I …

The Role Of Neural Precursor Cell Expressed Developmentally Down-Regulated Protein 9 In Enhanced Aggressiveness Of Hexavalent Chromium Transformed Bronchial Epithelial Cells, Peter Van Wie

Theses and Dissertations--Toxicology and Cancer Biology

Hexavalent chromium (Cr(VI)) is classified as a confirmed human carcinogen by the International Agency for Research and Cancer (IARC) and by the U.S. Environmental Protection Agency (EPA). Chronic exposure to (Cr(VI)) causes malignant cell transformation in human bronchial epithelial BEAS-2B cells. These Cr(VI)-transformed cells exhibit a highly aggressive phenotype including increased migration, invasion, and angiogenesis. The Cas family protein neuronal precursor developmentally down regulated protein 9 (NEDD9/Cas-L/HEF1) was dramatically overexpressed in Cr(VI)-transformed cells compared to normal BEAS-2B cells. Knockdown of NEDD9 by its shRNA reduced migration and invasion in vitro measured by migration and invasion assays. shNEDD9 reduced tumor formation …

Metabolism Reprogramming In Hexavalent Chromium-Induced Human Lung Carcinogenesis, James Tate Fortin Wise

Theses and Dissertations--Pharmacology and Nutritional Sciences

Hexavalent chromium, Cr(VI), is an established human carcinogen that is a worldwide environmental health concern. It is well understood that reactive oxygen species, genomic instability, and DNA damage repair deficiency are important contributors to Cr(VI)-induced carcinogenesis. After decades of research some cancer hallmarks remain understudied for the mechanism of Cr(VI) carcinogenesis. Dysregulated cellular energetics have been established as a hallmark of cancer. Energy pathways that become dysregulated in cancer include mitochondrial respiration, lipogenesis, pentose phosphate pathway, one carbon metabolism, and increased anaerobic glycolysis in the presence of oxygen or ‘Warburg effect’.

To investigate metabolism changes in Cr(VI) carcinogenesis, we exposed …

Mechanistic Study Of Diatrizoic Acid Induced Proximal Tubule Cytotoxicity, Dakota Blake Ward

Theses, Dissertations and Capstones

Radiocontrast media (RCM) are necessary for many diagnostic procedures such as arteriography, percutaneous coronary intervention (PCI), and computed tomography. Contrast-induced acute kidney injury (CI-AKI) is the third most common cause of hospital-associated kidney damage accounting for 10-25% of cases worldwide. The mechanisms of contrast-induced renal impairment are not entirely known, but diminished renal hemodynamics, inflammatory responses, and direct cytotoxicity have been hypothesized. The purpose of this study was to investigate the mechanisms of direct cytotoxicity observed in HK-2 cells following treatment with diatrizoic acid (DA) and to determine the source of this damage. Mitochondrial function, endoplasmic reticulum (ER) stress, oxidative …

Characterization Of The Hepatotoxicity Of Rifampicin And Isoniazid, Christopher T. Brewer

Theses and Dissertations (ETD)

In a mouse model, rifampicin and isoniazid combination treatment results in cholestatic liver injury that is associated with an increase of protoporphyrin ix (PPIX), the penultimate heme precursor. Excess PPIX is believed to bind to bile acids, precipitate in bile canaliculi, and form bile plugs leading to cholestasis fol owed by liver injury. Both ferrochelatase (FECH/Fech) and aminolevulinic acid synthase 1 (ALAS1/Alas1) are crucial enzymes in regulating heme biosynthesis. Isoniazid has recently been reported to up-regulate Alas1 but down-regulate Fech protein levels in mice; however the mechanism of isoniazid mediated heme synthesis …

Role Of Oxidized Extracellular Vesicles As Early Biomarkers And Inflammatory Mediators In Chemotherapy-Induced Normal Tissue Injury, Chontida Yarana

Theses and Dissertations--Toxicology and Cancer Biology

Significant advances in the efficacy of cancer therapy have been accompanied by an escalation of side effects that result from therapy-induced injury to normal tissues. Patients with high grade cancer or metastasis are often treated with chemotherapy, 50% of which are associated with reactive oxygen species generation and cellular oxidative stress. Heart is the normal tissue most susceptible to chemotherapy-induced oxidative stress and heart disease is the most common leading cause of death in cancer survivors. However, early and sensitive biomarkers to identify heart disease are still lacking. Extracellular vesicles (EVs) are released from cells during oxidative stress and send …

An Optimized Solid-Phase Reduction And Capture Strategy For The Study Of Reversibly-Oxidized Cysteines And Its Application To Metal Toxicity, John Andrew Hitron

Theses and Dissertations--Toxicology and Cancer Biology

The reversible oxidation of cysteine by reactive oxygen species (ROS) is both a mechanism for cellular protein signaling as well as a cause of cellular injury and death through the generation of oxidative stress. The study of cysteine oxidation is complicated by the methodology currently available to isolate and enrich oxidized-cysteine containing proteins. We sought to simplify this process by reducing the time needed to process samples and reducing sample loss and contamination risk.

We accomplished this by eliminating precipitation steps needed for the protocol by (a) introducing an in-solution NEM-quenching step prior to reduction and (b) replacing soluble dithiothreitol …

Doxorubicin Cytotoxicity In A Human Proximal Tubular Epithelial Cell Line Was Attenuated By The Natural Product Resveratrol, Morghan Schuyler Getty

Theses, Dissertations and Capstones

The cancer chemotherapeutic agent doxorubicin (DOX), Adriamycin, is part of the treatment regimen for breast, ovarian, small cell lung cancer and acute/chronic lymphoid leukemia. Adverse effects associated with DOX are cardiotoxicity and nephrotoxicity. Interventions are needed to reduce DOX nephrotoxicity. Resveratrol (RES) is a phytochemical contained in grapes, berries and nuts, which possesses antioxidant and anticancer properties. This study tested the hypothesis that RES will attenuate DOX renal cytotoxicity in human noncancerous renal proximal tubular epithelial (HK-2) cells and that RES will reduce DOX mediated changes in mitochondrial function. HK-2 cells were plated and grown for 48 hours (h). Cells …

Acrolein Is A Critical Mediator Of Alcohol-Induced Liver And Intestinal Injury In Alcoholic Liver Disease., Wei-Yang (Jeremy) Chen

Electronic Theses and Dissertations

Alcohol consumption can cause alcoholic liver disease (ALD), which remains a major cause of morbidity and mortality in the United States. Chronic alcohol consumption causes a pro-oxidant environment in the liver and increases hepatic lipid peroxidation. Acrolein is the most reactive and toxic aldehyde generated through lipid peroxidation. Acrolein forms protein adducts and triggers endoplasmic reticulum (ER) stress and hepatocyte apoptosis, which are recognized etiologic factors in ALD. Several studies have established the critical role of the gut-liver axis in ALD pathogenesis, wherein alcohol-induced gut barrier dysfunction contributes to liver injury. This study investigates, in vitro and in vivo, the …

Role Of Sulfiredoxin Interacting Proteins In Lung Cancer Development, Hedy Chawsheen

Theses and Dissertations--Toxicology and Cancer Biology

Sulfiredoxin (Srx) is an antioxidant enzyme that can be induced by oxidative stress. It promotes oncogenic phenotypes of cell proliferation, colony formation, migration, and metastasis in lung, skin and colon cancers. Srx reduces the overoxidation of 2-cysteine peroxiredoxins in cells, in addition to its role of removing glutathione modification from several proteins. In this study, I explored additional physiological functions of Srx in lung cancer through studying its interacting proteins. Protein disulfide isomerase (PDI) family members, thioredoxin domain containing protein 5 (TXNDC5) and protein disulfide isomerase family A member 6 (PDIA6), were detected to interact with Srx. Therefore, I proposed …

Characterization Of The Nicotine-Induced Endoplasmic Reticulum Stress Response In The Rat Placenta In Vivo And In Vitro, Michael Ka Chun Wong

Electronic Thesis and Dissertation Repository

Nicotine exposure during pregnancy leads to adverse health outcomes, including compromised placental development. Although the molecular mechanisms remain elusive, recent studies identified that endoplasmic reticulum (ER) stress may underlie poor placentation. Therefore, we were interested in investigating the effects of nicotine exposure on the ER stress response in the placenta. A well-established maternal nicotine exposure rat model and Rcho-1 trophoblast giant cell model were utilized to address the research questions. Maternal nicotine exposure in vivo led to elevated ER stress in association with impaired disulfide bond formation and hypoxia. Nicotine exposure in vitro further differentiated that ER stress may be …

Multifactorial Modulation Of The Blood-Brain Barrier: Relationship To Stroke, Bei Zhang

Theses and Dissertations--Nutritional Sciences

The blood-brain barrier (BBB) is a dynamic interface, mainly consisting of highly specialized brain microvascular endothelial cells (BMECs) that segregate the central nervous system (CNS) from the peripheral circulation. Impairment of the BBB, due to disruption of tight junction (TJ) proteins and inflammatory responses, may initiate and/or contribute to the progress of CNS disorders, including stroke. Stroke is the second leading cause of death worldwide. It has been shown that aging and environmental pollutants can induce brain endothelium dysfunction, and are considered as risk factors for stroke.

Deficiency of telomerase is highly linked with aging-associated vascular diseases. Evidence indicates that …