alexa Inhibition of U6 snRNA Transcription by PTEN.


Journal of Carcinogenesis & Mutagenesis

Author(s): Cabarcas S, Watabe K, Schramm L

Abstract Share this page

Abstract PROBLEM STATEMENT: RNA polymerase III (RNA pol III) is responsible for transcribing many of the small structural RNA molecules involved in RNA processing and protein translation, thereby regulating the growth rate of a cell. RNA pol III transcribes both gene internal (tRNA) and gene external (U6 snRNA) promoters and proper initiation by RNA polymerase III requires the transcription initiation factor TFIIIB. TFIIIB has been shown to be a target of repression by tumor suppressors such as ARF, p53, RB and the RB-related pocket proteins. Also, TFIIIB activity is stimulated by the oncogenes c-Myc and the ERK mitogen-activated protein kinase. Recently, two TFIIIB subunits, BRF1 and BRF2, have been demonstrated to behave as oncogenes, making deregulation of TFIIIB activity and thus RNA pol III transcription an important step in tumor development. PTEN is a commonly mutated tumor suppressor regulating cell growth, proliferation and survival. Thus, we sought to examine the potential role of PTEN in regulating U6 snRNA transcription. APPROACH: We examined the potential for PTEN to regulate U6 snRNA transcription using in vitro RNA pol III luciferase assays, western blotting and deletion analysis in cancer cell lines differing in their PTEN status. RESULTS: Using breast, cervical, prostate and glioblastoma cancer cells we demonstrate: (1) PTEN inhibition of gene external RNA pol III transcription is cell type specific, (2) PTEN-mediated inhibition of U6 transcription occurs via the C2 lipid-binding domain and (3) PTEN repression of U6 transcription occurs, at least in part, through the TFIIIB subunit BRF2. CONCLUSION/RECOMMENDATIONS: Our data demonstrates that regulation of the U6 snRNA gene by PTEN is mediated, in part by the TFIIIB oncogene BRF2, potentially identifying novel targets for chemotherapeutic drug design.
This article was published in Online J Biol Sci and referenced in Journal of Carcinogenesis & Mutagenesis

Relevant Expert PPTs

Relevant Speaker PPTs

  • Mingsong Wu
    Identification of differentially expressed genes in human lung adenocarcinoma: ERGIC3 as a novel lung cancer-related gene
    PPT Version | PDF Version
  • Flavia Secco Tavares de Souza
    A Comparative Study Among Elective Conventional Surgery, Urgency/Emergency Conventional Approaching and Elective Videolaparoscopic Surgery on the Treatment of Hospitalized Patients at First Surgeric Clinic of Federal Hospital of Bonsucesso with a Diagnostic of Colorectal adenocarcinoma, between January 2010 and December 2012
    PPT Version | PDF Version

Recommended Conferences

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version