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Medical Toxicology Commons

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Full-Text Articles in Medical Toxicology

H3k9 Methyltransferases And Demethylases Control Lung Tumor-Propagating Cells And Lung Cancer Progression, S. P. Rowbotham, F Li, A. F. M. Dost, S. M. Louie, B. P. Marsh, P. Pessina, C. R. Anbarasu, Christine Fillmore Brainson, S. J. Tuminello, A. Lieberman, S. Ryeom, T. M. Schlaeger, B. J. Aronow, H. Watanabe, K. K. Wong, C. F. Kim Nov 2018

H3k9 Methyltransferases And Demethylases Control Lung Tumor-Propagating Cells And Lung Cancer Progression, S. P. Rowbotham, F Li, A. F. M. Dost, S. M. Louie, B. P. Marsh, P. Pessina, C. R. Anbarasu, Christine Fillmore Brainson, S. J. Tuminello, A. Lieberman, S. Ryeom, T. M. Schlaeger, B. J. Aronow, H. Watanabe, K. K. Wong, C. F. Kim

Toxicology and Cancer Biology Faculty Publications

Epigenetic regulators are attractive anticancer targets, but the promise of therapeutic strategies inhibiting some of these factors has not been proven in vivo or taken into account tumor cell heterogeneity. Here we show that the histone methyltransferase G9a, reported to be a therapeutic target in many cancers, is a suppressor of aggressive lung tumor-propagating cells (TPCs). Inhibition of G9a drives lung adenocarcinoma cells towards the TPC phenotype by de-repressing genes which regulate the extracellular matrix. Depletion of G9a during tumorigenesis enriches tumors in TPCs and accelerates disease progression metastasis. Depleting histone demethylases represses G9a-regulated genes and TPC phenotypes. Demethylase inhibition …


Tumor Suppressor Pdcd4 Attenuates Sin1 Translation To Inhibit Invasion In Colon Carcinoma, Qing Wang, Jiang Zhu, Ya-Wen Wang, Yong Dai, Yanlei Wang, Chi Wang, Jinpeng Liu, Alyson Baker, Nancy H. Colburn, Hsin-Sheng Yang Nov 2017

Tumor Suppressor Pdcd4 Attenuates Sin1 Translation To Inhibit Invasion In Colon Carcinoma, Qing Wang, Jiang Zhu, Ya-Wen Wang, Yong Dai, Yanlei Wang, Chi Wang, Jinpeng Liu, Alyson Baker, Nancy H. Colburn, Hsin-Sheng Yang

Toxicology and Cancer Biology Faculty Publications

Programmed cell death 4 (Pdcd4), a tumor invasion suppressor, is frequently downregulated in colorectal cancer and other cancers. In this study, we find that loss of Pdcd4 increases the activity of mammalian target of rapamycin complex 2 (mTORC2) and thereby upregulates Snail expression. Examining the components of mTORC2 showed that Pdcd4 knockdown increased the protein but not mRNA level of stress-activated-protein kinase interacting protein 1 (Sin1), which resulted from enhanced Sin1 translation. To understand how Pdcd4 regulates Sin1 translation, the SIN1 5′ untranslated region (5′UTR) was fused with luciferase reporter and named as 5′Sin1-Luc. Pdcd4 knockdown/knockout significantly increased the translation …


Truncating Mutation In The Autophagy Gene Uvrag Confers Oncogenic Properties And Chemosensitivity In Colorectal Cancers, Shanshan He, Zhen Zhao, Yongfei Yang, Douglas O'Connell, Xiaowei Zhang, Soohwan Oh, Binyun Ma, Joo-Hyung Lee, Tian Zhang, Bino Varghese, Janae Yip, Sara Dolatshahi Pirooz, Ming Li, Yong Zhang, Guo-Min Li, Sue Ellen Martin, Keigo Machida, Chengyu Liang Aug 2015

Truncating Mutation In The Autophagy Gene Uvrag Confers Oncogenic Properties And Chemosensitivity In Colorectal Cancers, Shanshan He, Zhen Zhao, Yongfei Yang, Douglas O'Connell, Xiaowei Zhang, Soohwan Oh, Binyun Ma, Joo-Hyung Lee, Tian Zhang, Bino Varghese, Janae Yip, Sara Dolatshahi Pirooz, Ming Li, Yong Zhang, Guo-Min Li, Sue Ellen Martin, Keigo Machida, Chengyu Liang

Toxicology and Cancer Biology Faculty Publications

Autophagy-related factors are implicated in metabolic adaptation and cancer metastasis. However, the role of autophagy factors in cancer progression and their effect in treatment response remain largely elusive. Recent studies have shown that UVRAG, a key autophagic tumour suppressor, is mutated in common human cancers. Here we demonstrate that the cancer-related UVRAG frameshift (FS), which does not result in a null mutation, is expressed as a truncated UVRAGFS in colorectal cancer (CRC) with microsatellite instability (MSI), and promotes tumorigenesis. UVRAGFS abrogates the normal functions of UVRAG, including autophagy, in a dominant-negative manner. Furthermore, expression of UVRAGFS can …


Chemoselective Detection And Discrimination Of Carbonyl-Containing Compounds In Metabolite Mixtures By 1H-Detected 15N Nuclear Magnetic Resonance, Andrew N. Lane, Sengodagounder Arumugam, Pawel Lorkiewicz, Richard M. Higashi, Sébastien Laulhé, Michael H. Nantz, Hunter N. B. Moseley, Teresa W-M Fan May 2015

Chemoselective Detection And Discrimination Of Carbonyl-Containing Compounds In Metabolite Mixtures By 1H-Detected 15N Nuclear Magnetic Resonance, Andrew N. Lane, Sengodagounder Arumugam, Pawel Lorkiewicz, Richard M. Higashi, Sébastien Laulhé, Michael H. Nantz, Hunter N. B. Moseley, Teresa W-M Fan

Toxicology and Cancer Biology Faculty Publications

NMR spectra of mixtures of metabolites extracted from cells or tissues are extremely complex, reflecting the large number of compounds that are present over a wide range of concentrations. Although multidimensional NMR can greatly improve resolution as well as improve reliability of compound assignments, lower abundance metabolites often remain hidden. We have developed a carbonyl-selective aminooxy probe that specifically reacts with free keto and aldehyde functions, but not carboxylates. By incorporating 15N in the aminooxy functional group, 15N-edited NMR was used to select exclusively those metabolites that contain a free carbonyl function while all other metabolites are rejected. …


Latexin Sensitizes Leukemogenic Cells To Gamma-Irradiation-Induced Cell-Cycle Arrest And Cell Death Through Rps3 Pathway, Y. You, R. Wen, R. Pathak, A. Li, W. Li, D. St. Clair, M. Hauer-Jensen, D. Zhou, Ying Liang Oct 2014

Latexin Sensitizes Leukemogenic Cells To Gamma-Irradiation-Induced Cell-Cycle Arrest And Cell Death Through Rps3 Pathway, Y. You, R. Wen, R. Pathak, A. Li, W. Li, D. St. Clair, M. Hauer-Jensen, D. Zhou, Ying Liang

Toxicology and Cancer Biology Faculty Publications

Leukemia is a leading cause of cancer death. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells. Whether Lxn functions as a tumor suppressor in leukemia and what molecular and cellular mechanisms are involved are unknown. In this study, the myeloid leukemogenic FDC-P1 cell line was used as a model system and Lxn was ectopically expressed in these cells. Using the protein pull-down assay and mass spectrometry, ribosomal protein subunit 3 (Rps3) was identified as a …


Profiling Thiol Metabolites And Quantification Of Cellular Glutathione Using Ft-Icr-Ms Spectrometry, Sadakatali S. Gori, Pawel Lorkiewicz, Daniel S. Ehringer, Alex C. Belshoff, Richard M. Higashi, Teresa W-M Fan, Michael H. Nantz Jul 2014

Profiling Thiol Metabolites And Quantification Of Cellular Glutathione Using Ft-Icr-Ms Spectrometry, Sadakatali S. Gori, Pawel Lorkiewicz, Daniel S. Ehringer, Alex C. Belshoff, Richard M. Higashi, Teresa W-M Fan, Michael H. Nantz

Toxicology and Cancer Biology Faculty Publications

We describe preparation and use of the quaternary ammonium-based α-iodoacetamide QDE and its isotopologue *QDE as reagents for chemoselective derivatization of cellular thiols. Direct addition of the reagents to live cells followed by adduct extraction into n-butanol and analysis by FT-ICR-MS provided a registry of matched isotope peaks from which molecular formulae of thiol metabolites were derived. Acidification to pH 4 during cell lysis and adduct formation further improves the chemoselectivity for thiol derivatization. Examination of A549 human lung adenocarcinoma cells using this approach revealed cysteine, cysteinylglycine, glutathione, and homocysteine as principal thiol metabolites as well as the sulfinic acid …


Targeting Lactate Dehydrogenase-A Inhibits Tumorigenesis And Tumor Progression In Mouse Models Of Lung Cancer And Impacts Tumor-Initiating Cells, Han Xie, Jun-Ichi Hanai, Jian-Guo Ren, Lev Kats, Kerri Burgess, Parul Bhargava, Sabina Signoretti, Julia Billiard, Kevin J. Duffy, Aaron Grant, Xiaoen Wang, Pawel Lorkiewicz, Sabrina Schatzman, Michael Bousamra, Andrew N. Lane, Richard M. Higashi, Teresa W-M Fan, Pier Paolo Pandolfi, Vikas P. Sukhatme, Pankaj Seth May 2014

Targeting Lactate Dehydrogenase-A Inhibits Tumorigenesis And Tumor Progression In Mouse Models Of Lung Cancer And Impacts Tumor-Initiating Cells, Han Xie, Jun-Ichi Hanai, Jian-Guo Ren, Lev Kats, Kerri Burgess, Parul Bhargava, Sabina Signoretti, Julia Billiard, Kevin J. Duffy, Aaron Grant, Xiaoen Wang, Pawel Lorkiewicz, Sabrina Schatzman, Michael Bousamra, Andrew N. Lane, Richard M. Higashi, Teresa W-M Fan, Pier Paolo Pandolfi, Vikas P. Sukhatme, Pankaj Seth

Toxicology and Cancer Biology Faculty Publications

The lactate dehydrogenase-A (LDH-A) enzyme catalyzes the interconversion of pyruvate and lactate, is upregulated in human cancers, and is associated with aggressive tumor outcomes. Here we use an inducible murine model and demonstrate that inactivation of LDH-A in mouse models of NSCLC driven by oncogenic K-RAS or EGFR leads to decreased tumorigenesis and disease regression in established tumors. We also show that abrogation of LDH-A results in reprogramming of pyruvate metabolism, with decreased lactic fermentation in vitro, in vivo, and ex vivo. This was accompanied by reactivation of mitochondrial function in vitro, but not in vivo …


Loss Of Fbp1 By Snail-Mediated Repression Provides Metabolic Advantages In Basal-Like Breast Cancer, Chenfang Dong, Tingting Yuan, Yadi Wu, Yifan Wang, Teresa W-M Fan, Sumitra Miriyala, Yiwei Lin, Jun Yao, Jian Shi, Tiebang Kang, Pawel Lorkiewicz, Daret St. Clair, Mien-Chie Hung, B. Mark Evers, Binhua P. Zhou Mar 2013

Loss Of Fbp1 By Snail-Mediated Repression Provides Metabolic Advantages In Basal-Like Breast Cancer, Chenfang Dong, Tingting Yuan, Yadi Wu, Yifan Wang, Teresa W-M Fan, Sumitra Miriyala, Yiwei Lin, Jun Yao, Jian Shi, Tiebang Kang, Pawel Lorkiewicz, Daret St. Clair, Mien-Chie Hung, B. Mark Evers, Binhua P. Zhou

Toxicology and Cancer Biology Faculty Publications

The epithelial-mesenchymal transition (EMT) enhances cancer invasiveness and confers tumor cells with cancer stem cell (CSC)-like characteristics. We show that the Snail-G9a-Dnmt1 complex, which is critical for E-cadherin promoter silencing, is also required for the promoter methylation of fructose-1,6-biphosphatase (FBP1) in basal-like breast cancer (BLBC). Loss of FBP1 induces glycolysis and results in increased glucose uptake, macromolecule biosynthesis, formation of tetrameric PKM2, and maintenance of ATP production under hypoxia. Loss of FBP1 also inhibits oxygen consumption and reactive oxygen species production by suppressing mitochondrial complex I activity; this metabolic reprogramming results in an increased CSC-like property and tumorigenicity by enhancing …


Mir-17* Suppresses Tumorigenicity Of Prostate Cancer By Inhibiting Mitochondrial Antioxidant Enzymes, Yong Xu, Fang Fang, Jiayou Zhang, Sajni Josson, William H. St. Clair, Daret K. St. Clair Dec 2010

Mir-17* Suppresses Tumorigenicity Of Prostate Cancer By Inhibiting Mitochondrial Antioxidant Enzymes, Yong Xu, Fang Fang, Jiayou Zhang, Sajni Josson, William H. St. Clair, Daret K. St. Clair

Toxicology and Cancer Biology Faculty Publications

Aberrant micro RNA (miRNA) expression has been implicated in the pathogenesis of cancer. Recent studies have shown that the miR-17-92 cluster is overexpressed in many types of cancer. The oncogenic function of mature miRNAs encoded by the miR-17-92 cluster has been identified from the 5' arm of six precursors. However, the function of the miRNAs produced from the 3' arm of these precursors remains unknown. The present study demonstrates that miR-17* is able to suppress critical primary mitochondrial antioxidant enzymes, such as manganese superoxide dismutase (MnSOD), glutathione peroxidase-2 (GPX2) and thioredoxin reductase-2 (TrxR2). Transfection of miR-17* into prostate cancer PC-3 …


The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga Aug 2008

The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga

Kimmel Cancer Center Faculty Papers

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of …