Medical Toxicology Commons^™

Brain-Derived Extracellular Vesicles Potentially Mediate Crosstalk With Peripheral Organs In Neurodegenerative Diseases, Ramzi H. Hamdalla, Vibha B. Bhaskar, Changhai Tian

Toxicology and Cancer Biology Faculty Publications

Brain-Derived Extracellular vesicles (BDEVs) are emerging mediators of intra- and interorgan communication in neurodegenerative diseases (NDs) such as Alzheimer’s Disease (AD) and Parkinson’s Disease (PD). A growing body of evidence suggests that BDEVs play an important role in modulating intercellular communication within the central nervous system in the pathogenesis of many NDs. By transporting non-coding RNAs (e.g., miRNAs) and important pathological proteins, BDEVs also influence peripheral organs and contribute to the progression of disease in the central nervous system (CNS). This review extends the understanding of NDs beyond solely brain dysfunction and gives a novel framework for the progression of …

Artesunate Enhances The Efficacy Of Enzalutamide In Advanced Prostate Cancer, Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R. Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu

Toxicology and Cancer Biology Faculty Publications

Prostate cancer (PCa) is one of the leading causes of death among men worldwide. Treatments targeting the androgen receptor pathway remain the standard therapy for PCa patients. Enzalutamide (ENZ), a second-generation androgen receptor inhibitor, was developed to treat castration-resistant prostate cancer. However, while patients initially respond to ENZ, drug resistance typically develops within a few months. Artesunate (ART), a semisynthetic derivative of the Artemisinin plant, is approved for antimalaria treatment. In this study, we conducted an FDA-approved drug screening and identified ART as a potential candidate for overcoming ENZ resistance in PCa. Mechanistically, ART induces the degradation of c-Myc, enhancing …

Cardiac Injury Regulates Neuroinflammation Through Extracellular Vesicle–Mediated Heart-Brain Crosstalk, Qingxuan Li, Ramzi H. Hamdalla, Neha Dhyani, Lijun Sun, Lie Gao, Tara L. Rudebush, Irving H. Zucker, Changhai Tian

Toxicology and Cancer Biology Faculty Publications

Cognitive impairment is common in heart failure patients, contributing to morbidity and mortality. This impairment may be linked to neuroinflammation in heart failure. However, the primacy of the heart-brain axis remains to be completely understood. Here, we elucidate the potential effects of myocardial injury on pathways and inflammatory mediators responsible for cognitive impairment using a rodent myocardial injury model. The results demonstrate direct extracellular vesicle (EV)-mediated heart-brain crosstalk and the glial uptake of cardiac EVs. In addition, brain inflammation was also elicited following myocardial injury. Moreover, cardiac EVs promote brain microglial cell activation in vitro, potentially mediated by EV-enriched micro-RNAs …

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 …

Untargeted Lipidomics Of Non-Small Cell Lung Carcinoma Demonstrates Differentially Abundant Lipid Classes In Cancer Vs. Non-Cancer Tissue, Joshua M. Mitchell, Robert M. Flight, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

Lung cancer remains the leading cause of cancer death worldwide and non-small cell lung carcinoma (NSCLC) represents 85% of newly diagnosed lung cancers. In this study, we utilized our untargeted assignment tool Small Molecule Isotope Resolved Formula Enumerator (SMIRFE) and ultra-high-resolution Fourier transform mass spectrometry to examine lipid profile differences between paired cancerous and non-cancerous lung tissue samples from 86 patients with suspected stage I or IIA primary NSCLC. Correlation and co-occurrence analysis revealed significant lipid profile differences between cancer and non-cancer samples. Further analysis of machine-learned lipid categories for the differentially abundant molecular formulas identified a high abundance sterol, …

Co-Targeting Plk1 And Dnmt3a In Advanced Prostate Cancer, Zhuangzhuang Zhang, Lijun Cheng, Qiongsi Zhang, Yifan Kong, Daheng He, Kunyu Li, Matthew Rea, Jianlin Wang, Ruixin Wang, Jinghui Liu, Zhiguo Li, Chongli Yuan, Enze Liu, Yvonne N. Fondufe-Mittendorf, Lang Li, Tao Han, Chi Wang, Xiaoqi Liu

Toxicology and Cancer Biology Faculty Publications

Because there is no effective treatment for late-stage prostate cancer (PCa) at this moment, identifying novel targets for therapy of advanced PCa is urgently needed. A new network-based systems biology approach, XDeath, is developed to detect crosstalk of signaling pathways associated with PCa progression. This unique integrated network merges gene causal regulation networks and protein-protein interactions to identify novel co-targets for PCa treatment. The results show that polo-like kinase 1 (Plk1) and DNA methyltransferase 3A (DNMT3a)-related signaling pathways are robustly enhanced during PCa progression and together they regulate autophagy as a common death mode. Mechanistically, it is shown that Plk1 …

Role Of Ampk And Akt In Triple Negative Breast Cancer Lung Colonization, Jeremy Johnson, Zeta Chow, Eun Young Lee, Heidi L. Weiss, B. Mark Evers, Piotr G. Rychahou

Pathology and Laboratory Medicine Faculty Publications

Triple negative breast cancer (TNBC) is an aggressive disease with a 5-y relative survival rate of 11% after distant metastasis. To survive the metastatic cascade, tumor cells remodel their signaling pathways by regulating energy production and upregulating survival pathways. AMP-activated protein kinase (AMPK) and Akt regulate energy homeostasis and survival, however, the individual or synergistic role of AMPK and Akt isoforms during lung colonization by TNBC cells is unknown. The purpose of this study was to establish whether targeting Akt, AMPKα or both Akt and AMPKα isoforms in circulating cancer cells can suppress TNBC lung colonization. Transient silencing of Akt1 …

Upregulation Of Cpt1a Is Essential For The Tumor-Promoting Effect Of Adipocytes In Colon Cancer, Xiaopeng Xiong, Yang-An Wen, Rachelle Fairchild, Yekaterina Y. Zaytseva, Heidi L. Weiss, B. Mark Evers, Tianyan Gao

Markey Cancer Center Faculty Publications

Colon tumors grow in an adipose tissue-enriched microenvironment. Locally advanced colon cancers often invade into surrounding adipose tissue with a direct contact with adipocytes. We have previously shown that adipocytes promote tumor growth by modulating cellular metabolism. Here we demonstrate that carnitine palmitoyltransferase I (CPT1A), a key enzyme controlling fatty acid oxidation (FAO), was upregulated in colon cancer cells upon exposure to adipocytes or fatty acids. In addition, CPT1A expression was increased in invasive tumor cells within the adipose tissue compared to tumors without direct contact with adipocytes. Silencing CPT1A abolished the protective effect provided by fatty acids against nutrient …

Igf-1r Inhibition Induces Mek Phosphorylation To Promote Survival In Colon Carcinomas, Qing Wang, Yan Zhang, Jiang Zhu, Honggang Zheng, Shuntai Chen, Li Chen, Hsin-Sheng Yang

Toxicology and Cancer Biology Faculty Publications

The insulin-like growth factor 1 receptor (IGF-1R) governs several signaling pathways for cell proliferation, survival, and anti-apoptosis. Thus, targeting IGF-1R appears as a reasonable rationale for tumor treatment. However, clinical studies showed that inhibition of IGF-1R has very limited efficacy due to the development of resistance to IGF-1R blockade in tumor cells. Here, we discovered that prolonged treatment of colon cancer cells with IGF-1R inhibitors (BMS-754807 and GSK1838705A) stimulates p70 KDa ribosomal protein S6 kinase 1 (p70S6K1) activation, a well-known kinase signaling for cell survival. We also found that p70S6K1 activation by IGF-1R inhibition is independent of K-Ras and PIK3CA …

Preclinical Evaluation Of Novel Fatty Acid Synthase Inhibitors In Primary Colorectal Cancer Cells And A Patient-Derived Xenograft Model Of Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Anh-Thu Le, Timothy L. Scott, Robert M. Flight, Ji Tae Kim, Jennifer Harris, Jinpeng Liu, Chi Wang, Andrew J. Morris, Theru A. Sivakumaran, Teresa Fan, Hunter Moseley, Tianyan Gao, Eun Young Lee, Heidi L. Weiss, Timothy S. Heuer, George Kemble, B. Mark Evers

Toxicology and Cancer Biology Faculty Publications

Fatty Acid Synthase (FASN), a key enzyme of de novo lipogenesis, is upregulated in many cancers including colorectal cancer (CRC); increased FASN expression is associated with poor prognosis. Potent FASN inhibitors (TVBs) developed by 3-V Biosciences demonstrate anti-tumor activity in vitro and in vivo and a favorable tolerability profile in a Phase I clinical trial.

However, CRC characteristics associated with responsiveness to FASN inhibition are not fully understood. We evaluated the effect of TVB-3664 on tumor growth in nine CRC patient-derived xenografts (PDXs) and investigated molecular and metabolic changes associated with CRC responsiveness to FASN inhibition.

CRC cells and PDXs …

Extracellular Vesicles Released By Cardiomyocytes In A Doxorubicin-Induced Cardiac Injury Mouse Model Contain Protein Biomarkers Of Early Cardiac Injury, Chontida Yarana, Dustin W. Carroll, Jing Chen, Luksana Chaiswing, Yanming Zhao, Teresa Noel, Michael Alstott, Younsoo Bae, Emily V. Dressler, Jeffrey A. Moscow, D. Allan Butterfield, Haining Zhu, Daret K. St. Clair

Toxicology and Cancer Biology Faculty Publications

Purpose—Cardiac injury is a major cause of death in cancer survivors, and biomarkers for it are detectable only after tissue injury has occurred. Extracellular vesicles (EV) remove toxic biomolecules from tissues and can be detected in the blood. Here, we evaluate the potential of using circulating EVs as early diagnostic markers for long-term cardiac injury.

Experimental Design—Using a mouse model of doxorubicin (DOX)-induced cardiac injury, we quantified serum EVs, analyzed proteomes, measured oxidized protein levels in serum EVs released after DOX treatment, and investigated the alteration of EV content.

Results—Treatment with DOX caused a significant increase in …

Targeting Ribosome Assembly Factors Selectively Protects P53 Positive Cells From Chemotherapeutic Agents, Russell T. Sapio, Anastasiya Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J. Manna, N. Minkovsky, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Many chemotherapeutic agents act in a nondiscriminatory fashion, targeting both cancerous and noncancerous cells in Sphase and Mphase. One approach to reduce the toxic side effects in normal tissue is to exploit the differences in p53 functionality between cancerous and noncancerous cells. For example, activating p53 signaling by nongenotoxic means can transiently arrest noncancerous p53 positive cells in G1 phase and protect them from the cytotoxic effects of chemotherapeutic drugs. However, since most cancerous cells have faulty p53 signaling, they will proceed to cycle, and continue to be affected by the drug. In this study we asked if this G1‐phase …

Glycolytic Reprogramming Through Pck2 Regulates Tumor Initiation Of Prostate Cancer Cells, Jiangsha Zhao, Jieran Li, Teresa W.M. Fan, Steven X. Hou

Toxicology and Cancer Biology Faculty Publications

Tumor-initiating cells (TICs) play important roles in tumor progression and metastasis. Identifying the factors regulating TICs may open new avenues in cancer therapy. Here, we show that TIC-enriched prostate cancer cell clones use more glucose and secrete more lactate than TIC-low clones. We determined that elevated levels of phosphoenolpyruvate carboxykinase isoform 2 (PCK2) are critical for the metabolic switch and the maintenance of TICs in prostate cancer. Information from prostate cancer patient databases revealed that higher PCK2 levels correlated with more aggressive tumors and lower survival rates. PCK2 knockdown resulted in low TIC numbers, increased cytosolic acetyl-CoA and cellular protein …

Loss Of Fructose-1,6-Bisphosphatase Induces Glycolysis And Promotes Apoptosis Resistance Of Cancer Stem-Like Cells: An Important Role In Hexavalent Chromium-Induced Carcinogenesis, Jin Dai, Yanli Ji, Wei Wang, Donghern Kim, Leonard Yenwong Fai, Lei Wang, Jia Luo, Zhuo Zhang

Toxicology and Cancer Biology Faculty Publications

Hexavalent chromium (Cr(VI)) compounds are confirmed human carcinogens for lung cancer. Our previous studies has demonstrated that chronic exposure of human bronchial epithelial BEAS-2B cells to low dose of Cr(VI) causes malignant cell transformation. The acquisition of cancer stem cell-like properties is involved in the initiation of cancers. The present study has observed that a small population of cancer stem-like cells (BEAS-2B-Cr-CSC) exists in the Cr(VI)-transformed cells (BEAS-2B-Cr). Those BEAS-2B-Cr-CSC exhibit extremely reduced capability of generating reactive oxygen species (ROS) and apoptosis resistance. BEAS-2B-Cr-CSC are metabolic inactive as evidenced by reductions in oxygen consumption, glucose uptake, ATP production, and lactate …

Clinical And Experimental Studies Of A Novel P525r Fus Mutation In Amyotrophic Lateral Sclerosis, Lisha Kuang, Marisa Kamelgarn, Alexandra Arenas, Jozsef Gal, Deborah Taylor, Weiming Gong, Martin Brown, Daret St. Clair, Edward J. Kasarskis, Haining Zhu

Molecular and Cellular Biochemistry Faculty Publications

Objective: To describe the clinical features of a novel fused in sarcoma (FUS) mutation in a young adult female amyotrophic lateral sclerosis (ALS) patient with rapid progression of weakness and to experimentally validate the consequences of the P525R mutation in cellular neuronal models.

Methods: We conducted sequencing of genomic DNA from the index patient and her family members. Immunocytochemistry was performed in various cellular models to determine whether the newly identified P525R mutant FUS protein accumulated in cytoplasmic inclusions. Clinical features of the index patient were compared with 19 other patients with ALS carrying the P525L mutation in the same …

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced …

Analysis Of Rna Expression Of Normal And Cancer Tissues Reveals High Correlation Of Cop9 Gene Expression With Respiratory Chain Complex Components, Christina A. Wicker, Tadahide Izumi

Toxicology and Cancer Biology Faculty Publications

BACKGROUND: The COP9 signalosome, composed of eight subunits, is implicated in cancer genetics with its deneddylase activity to modulate cellular concentration of oncogenic proteins such as IkB and TGFβ. However, its function in the normal cell physiology remains elusive. Primarily focusing on gene expression data of the normal tissues of the head and neck, the cancer genome atlas (TCGA) database was used to identify groups of genes that were expressed synergistically with the COP9 genes, particularly with the COPS5 (CSN5), which possesses the catalytic activity of COP9.

RESULTS: Expressions of seven of the COP9 genes (COPS2, COPS3, COPS4, COPS5, COPS6, …

Synthetic Triterpenoids Can Protect Against Toxicity Without Reducing The Efficacy Of Treatment With Carboplatin And Paclitaxel In Experimental Lung Cancer, Karen T. Liby

Dartmouth Scholarship

Synthetic oleanane triterpenoids are multifunctional drugs being developed for the prevention and treatment of a variety of chronic diseases driven by inflammation and oxidative stress. Low nanomolar concentrations of triterpenoids inhibit the induction of inflammatory cytokines, and these drugs are potent activators of the Nrf2 cytoprotective pathway. In contrast, low micromolar concentrations of triterpenoids increased the production of ROS and induced apoptosis in a dose-dependent manner in malignant MCF10 CA1a breast cancer cells. Because cancer cells respond differently to ROS than normal cells, it should be possible to exploit these differences therapeutically. In an experimental model of lung cancer, the …

Policy For Identifying And Assessing The Health Risks Of Toxic Substances, Maine Bureau Of Health

Maine Collection

Policy for Identifying and Assessing the Health Risks of Toxic Substances

by Norman T. Anderson, Environmental Toxicology Program, Division of Disease Control, Bureau of Health (February, 1988).

Contents: Section I: Introduction / Section II: Methods / Section III: Exposure Assessment / Section IV: Hazard Identification / Section V: Hazard Assessment / Section VI: Risk Characterization / List of Figures / List of Tables