Journal Article

Growth Arrest-Specific Transcript 5 Associated snoRNA Levels Are Related to p53 Expression and DNA Damage in Colorectal Cancer

Mirnezami, Reza, Frampton, Adam E., Harding, Victoria, Castellano, Leandro, Stebbing, Justin, Krell, Jonathan, Roca Alonso, Laura, Cohen, Patrizia, De Giorgio, Alex, Colombo, Teresa, Ottaviani, Silvia, Buchanan, Gordon, Pellegrino, Loredana, Jacob, Jimmy

2014

Overview

The growth arrest-specific transcript 5 gene (GAS5) encodes a long noncoding RNA (lncRNA) and hosts a number of small nucleolar RNAs (snoRNAs) that have recently been implicated in multiple cellular processes and cancer. Here, we investigate the relationship between DNA damage, p53, and the GAS5 snoRNAs to gain further insight into the potential role of this locus in cell survival and oncogenesis both in vivo and in vitro. We used quantitative techniques to analyse the effect of DNA damage on GAS5 snoRNA expression and to assess the relationship between p53 and the GAS5 snoRNAs in cancer cell lines and in normal, pre-malignant, and malignant human colorectal tissue and used biological techniques to suggest potential roles for these snoRNAs in the DNA damage response. GAS5-derived snoRNA expression was induced by DNA damage in a p53-dependent manner in colorectal cancer cell lines and their levels were not affected by DICER. Furthermore, p53 levels strongly correlated with GAS5-derived snoRNA expression in colorectal tissue. In aggregate, these data suggest that the GAS5-derived snoRNAs are under control of p53 and that they have an important role in mediating the p53 response to DNA damage, which may not relate to their function in the ribosome. We suggest that these snoRNAs are not processed by DICER to form smaller snoRNA-derived RNAs with microRNA (miRNA)-like functions, but their precise role requires further evaluation. Furthermore, since GAS5 host snoRNAs are often used as endogenous controls in qPCR quantifications we show that their use as housekeeping genes in DNA damage experiments can lead to inaccurate results.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antisense RNA / Biology and Life Sciences / Biotechnology / Cancer / Cancer genetics / Cell cycle / Cell growth / Cell survival / Colorectal cancer / Colorectal carcinoma / Colorectal Neoplasms - genetics / Colorectal Neoplasms - pathology / Damage assessment / DEAD-box RNA Helicases - genetics / Deoxyribonucleic acid / DNA / DNA Damage / Doxorubicin - pharmacology / Gene expression / Gene Expression Regulation, Neoplastic - drug effects / Gene Knockdown Techniques / Genes, Essential / Growth / HCT116 Cells / Humans / In vitro methods and tests / In vivo methods and tests / Medicine and Health Sciences / MicroRNA / miRNA / Mutation / Nucleoli / p53 Protein / Prostate cancer / Proteins / Ribonuclease III - genetics / Ribonucleic acid / RNA / RNA polymerase / RNA, Long Noncoding - genetics / RNA, Small Nucleolar - genetics / snoRNA / Surgery / Transcription / Tumor cell lines / Tumor proteins / Tumor Suppressor Protein p53 - genetics / Tumorigenesis