Medical Toxicology Commons^™

The Effects Of Paclitaxel On Cellular Migration And The Cytoskeleton, Ashley Salguero-Gonzalez

Thinking Matters Symposium

In a clinical setting, some patients are exposed to an anti-cancer chemotherapy agent, paclitaxel. Cancerous cells undergo rapid, continuous cell division without control. Chemotherapy treatments try to slow and stop the uncontrollable cell division cycles and eliminate cancerous cells in the process. Paclitaxel serves as a treatment for some types of cancers, including lung, melanoma, bladder, and esophageal. Because it targets the cytoskeleton, paclitaxel can also influence cell migration. This project utilizes a cellular migration assay and an immunohistochemistry assay to analyze the effects of paclitaxel on the movement of cells and on the cytoskeleton of neuroglia rat cells with …

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 …

N-Glycosylation-Defective Splice Variants Of Neuropilin-1 Promote Metastasis By Activating Endosomal Signals, Xiuping Huang, Qing Ye, Min Chen, Aimin Li, Wenting Mi, Yuxin Fang, Yekaterina Y. Zaytseva, Kathleen L. O'Connor, Craig W. Vander Kooi, Side Liu, Qing-Bai She

Markey Cancer Center Faculty Publications

Neuropilin-1 (NRP1) is an essential transmembrane receptor with a variety of cellular functions. Here, we identify two human NRP1 splice variants resulting from the skipping of exon 4 and 5, respectively, in colorectal cancer (CRC). Both NRP1 variants exhibit increased endocytosis/recycling activity and decreased levels of degradation, leading to accumulation on endosomes. This increased endocytic trafficking of the two NRP1 variants, upon HGF stimulation, is due to loss of N-glycosylation at the Asn150 or Asn261 site, respectively. Moreover, these NRP1 variants enhance interactions with the Met and β1-integrin receptors, resulting in Met/β1-integrin co-internalization and co-accumulation on endosomes. This provides persistent …

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 …

Escherichia Coli Itat Is A Type Ii Toxin That Inhibits Translation By Acetylating Isoleucyl-Trnaile, Brendan Wilcox, Ilya Osterman, Marina Serebryakova, Dmitry Lukyanov, Ekaterina Komarova, Bridget Gollan, Natalia Morozova, Yuri I Wolf, Kira S Makarova, Sophie Helaine, Petr Sergiev, Svetlana Dubiley, Sergei Borukhov, Konstantin Severinov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Prokaryotic toxin-antitoxin (TA) modules are highly abundant and are involved in stress response and drug tolerance. The most common type II TA modules consist of two interacting proteins. The type II toxins are diverse enzymes targeting various essential intracellular targets. The antitoxin binds to cognate toxin and inhibits its function. Recently, TA modules whose toxins are GNAT-family acetyltransferases were described. For two such systems, the target of acetylation was shown to be aminoacyl-tRNA: the TacT toxin targets aminoacylated elongator tRNAs, while AtaT targets the amino acid moiety of initiating tRNAMet. We show that the itaRT gene pair from Escherichia coli …

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 …

Comparative Cytotoxicity Study Of Nicotine And Cotinine On Mrc-5 Cell Line, Ana-Maria Vlasceanu, Daniela Luiza Baconi, Bianca Galateanu, Miriana Stan, Cristian Balalau

Journal of Mind and Medical Sciences

Nicotine has several health hazards regarding carcinogenic potential. It also imparts increased risk for respiratory, cardiovascular, and gastrointestinal disorders. Several mechanisms have been proposed for the carcinogenic potential, including effects on cell proliferation, inducing oxidative stress, DNA mutation, or inhibition of apoptosis. The cotinine metabolite is generally thought to have effects similar to nicotine in some experimental systems. The purpose of this study was to assess the nicotine and cotinine cytotoxicity on MRC-5 lung fibroblasts. The pulmonary fibroblasts were treated with various concentrations of nicotine or cotinine (in the range 1 µM – 2 mM) for 24 or 48 h …

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 …

Structure-Activity Relationships Governing The Interaction Of Nanoparticles With Mammalian Cells- Predictive Models For Toxicology And Medical Appliances, Marcus A. Maher

Doctoral

Nanoscience is seen as one of the key enabling technologies of the 20th century and as its range of applications increases it is important to look at how nanomaterials interact with biological environments. Some of these interactions have given rise to toxic effects and thus, the creation of the field of nanotoxicology, it has also been noted that current methods of evaluating toxicity may not be sufficient to keep up with the rapidly emerging range of nanomaterials becoming available. It is clear that alternatives are necessary. In this thesis, a phenomenological rate equation model is constructed to simulate nanoparticle uptake …

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 …

Influence Of Exposure To Benzo[A]Pyrene On Mice Testicular Germ Cells During Spermatogenesis, Hueiwang Anna Jeng, Silvina M. Bocca

Community & Environmental Health Faculty Publications

The objective of this study was to assess the toxicological effect of exposure to benzo(a)pyrene, B[a]P, on germ cells during spermatogenesis. Mice were exposed to B[a]P at 1, 10, 50, and 100 mg/kg/day for 30 days via oral ingestion. Germ cells, including spermatogonia, spermatocytes, pachytene spermatocytes, and round spermatids, were recovered from testes of mice exposed to B[a]P, while mature spermatozoa were isolated from vas deferens. Reproductive organs were collected and weighed. Apoptotic response of germ cells and mature spermatozoa were qualified using the terminal deoxynucleotidyl transferase mediated deoxy-UTP nick end labeling (TUNEL) assay. B[a]P exposure at