Host Epigenome Research Articles

1369 UROPATHOGENIC E. COLI INFECTION PROVOKES EPIGENETIC DOWNREGULATION OF CDKN2A (P16INK4A) IN UROEPITHELIAL CELLS

You have accessJournal of UrologyInfections/Inflammation of the Genitourinary Tract: Kidney & Bladder1 Apr 20111369 UROPATHOGENIC E. COLI INFECTION PROVOKES EPIGENETIC DOWNREGULATION OF CDKN2A (P16INK4A) IN UROEPITHELIAL CELLS Cornelia Tolg, Akshita Kapila, Rene Cortese, Karen Aitken, Arturas Petronis, and Darius Bagli Cornelia TolgCornelia Tolg Toronto, Canada More articles by this author , Akshita KapilaAkshita Kapila Toronto, Canada More articles by this author , Rene CorteseRene Cortese Toronto, Canada More articles by this author , Karen AitkenKaren Aitken Toronto, Canada More articles by this author , Arturas PetronisArturas Petronis Toronto, Canada More articles by this author , and Darius BagliDarius Bagli Toronto, Canada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1193AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Host cell and bacterial factors determine severity and duration of infections. To allow for bacteria pathogenicity and persistence, bacteria have developed mechanisms that modify expression of host genes involved in cell cycle progression, apoptosis, differentiation and the immune response. Recently, H. pylori infection of the stomach has been correlated with epigenetic changes in the host genome prompting us to investigate whether E. coli induced urinary tract infection (UTI) leads to changes in the host epigenome. Since changes in host cell DNA methylation affect gene expression and persist over several cell generations, DNA methylation may correlate with UTI recurrence and act as biomarker allowing selection of patients that will benefit from antibiotic prophylaxis. METHODS To identify epigenetic changes, we developed an in vitro model of persistent infection of human uroepithelial cells with uropathogenic E. coli (UPEC) resulting in intracellular bacteria colonies without inducing host cell apoptosis. Cells inoculated with FimH negative E. coli (N-UPEC) that are not internalized and non-inoculated cells were used as controls. IF, Q-PCR and pyrosequencing were used to analyze expression and methylation of candidate genes. RESULTS UPEC infection significantly induced DNMT activity (12.5 fold p=0.002 UPEC vs. non-inoculated and 250 fold p=0.001 UPEC vs. N-UPEC inoculated cells) and Dnmt1 RNA expression (6 fold p=0.04 UPEC vs. non-inoculated cells) compared to controls. DNMT1 protein levels were significantly increased in three uroepithelial cell lines (5637, J82, HT1197) in response to UPEC infection as demonstrated by confocal analysis. Real time PCR analysis of candidate genes previously associated with bacteria infection and/or innate immunity, revealed UPEC induced downregulation of the tumour suppressor gene CDKN2A (3.3 fold p=0.007 UPEC vs. non-inoculated and 3.3 fold p=0.001 UPEC vs. N-UPEC) and the DNA repair gene MGMT (9 fold p=0.03 UPEC vs. non-inoculated). Expression of CDH1, MLH1, DAPK1 and TLR4 was not affected. Pyrosequencing of CDKN2A and MGMT CpG islands revealed increased methylation in CDKN2A exon 1 (3.8 fold p=0.04 UPEC vs N-UPEC and UPEC vs. non-inoculated). Methylation of MGMT was not affected. CONCLUSIONS UPEC induced methylation of host cell genes such as CDKN2A exon 1 may presage UTI risk, and be useful as a biological marker for UTI susceptibility or recurrence. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e546 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Cornelia Tolg Toronto, Canada More articles by this author Akshita Kapila Toronto, Canada More articles by this author Rene Cortese Toronto, Canada More articles by this author Karen Aitken Toronto, Canada More articles by this author Arturas Petronis Toronto, Canada More articles by this author Darius Bagli Toronto, Canada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Viral manipulation of the host epigenome for oncogenic transformation

The cancerous cellular state is associated with multiple epigenetic alterations, but elucidating the precise order of such alterations during tumorigenic progression and their contributions to the transformed phenotype remains a significant challenge in cancer biology. Here we discuss recent findings on how viral oncoproteins exploit specific epigenetic processes to coerce normal cells to replicate when they should remain quiescent - a hallmark of cancer. These findings may highlight roles of epigenetic processes in normal biology and shed light on epigenetic events occurring along the path of non-viral neoplastic transformation.