Expression and functional role of a transcribed noncoding RNA with an ultraconserved element in hepatocellular carcinoma

Chiara Braconi, Nicola Valeri, Takayuki Kogure, Pierluigi Gasparini, Nianyuan Huang, Gerard J. Nuovo, Luigi Terracciano, Carlo M. Croce, Tushar Patel

Research output: Contribution to journalArticle

157 Citations (Scopus)

Abstract

Although expression of non-protein-coding RNA (ncRNA) can be altered in human cancers, their functional relevance is unknown. Ultraconserved regions are noncoding genomic segments that are 100% conserved across humans, mice, and rats. Conservation of gene sequences across species may indicate an essential functional role, and therefore we evaluated the expression of ultraconserved RNAs (ucRNA) in hepatocellular cancer (HCC). The global expression of ucRNAs was analyzed with a custom microarray. Expression was verified in cell lines by real-time PCR or in tissues by in situ hybridization using tissue microarrays. Cellular ucRNA expression was modulated with siRNAs, and the effects on global gene expression and growth of human and murine HCC cells were evaluated. Fifty-six ucRNAs were aberrantly expressed in HepG2 cells compared with nonmalignant hepatocytes. Among these ucRNAs, the greatest change was noted for ultraconserved element 338 (uc.338), which was dramatically increased in human HCC compared with noncancerous adjacent tissues. Although uc.338 is partially located within the poly(rC) binding protein 2 (PCBP2) gene, the transcribed ncRNA encoding uc.338 is expressed independently of PCBP2 and was cloned as a 590-bp RNA gene, termed TUC338. Functional gene annotation analysis indicated predominant effects on genes involved in cell growth. These effects were experimentally demonstrated in both human and murine cells. siRNA to TUC338 decreased both anchorage-dependent and anchorage-independent growth of HCC cells. These studies identify a critical role for TUC338 in regulation of transformed cell growth and of transcribed ultraconserved ncRNA as a unique class of genes involved in the pathobiology of HCC.

Original languageEnglish
Pages (from-to)786-791
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume108
Issue number2
DOIs
Publication statusPublished - 2011 Jan 11

Keywords

  • Exaptation
  • Hepatocarcinoma
  • Liver cancer
  • Transposon

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Expression and functional role of a transcribed noncoding RNA with an ultraconserved element in hepatocellular carcinoma'. Together they form a unique fingerprint.

  • Cite this