Sp1 cooperates with Sp3 to upregulate MALAT1 expression in human hepatocellular carcinoma

Oncol Rep. 2015 Nov;34(5):2403-12. doi: 10.3892/or.2015.4259. Epub 2015 Sep 8.

Abstract

Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), also known as nuclear-enriched transcript 2 (NEAT2), is highly conserved among mammals and highly expressed in the nucleus. It was first identified in lung cancer as a prognostic marker for metastasis but is also associated with several other solid tumors. In hepatocellular carcinoma (HCC), MALAT1 is a novel biomarker for predicting tumor recurrence after liver transplantation. The mechanism of overexpression in tumor progression remains unclear. In the present study, we investigated the role of specificity protein 1/3 (Sp1/3) in regulation of MALAT1 transcription in HCC cells. The results showed a high expression of Sp1, Sp3 and MALAT1 in HCC vs. paired non-tumor liver tissues, which was associated with the AFP level (Sp1, r=7.44, P=0.0064; MALAT1, r=12.37, P=0.0004). Co-silencing of Sp1 and Sp3 synergistically repressed MALAT1 expression. Sp1 binding inhibitor, mithramycin A (MIT), also inhibited MALAT1 expression in HCC cells. In conclusion, the upstream of MALAT1 contains five Sp1/3 binding sites, which may be responsible for MALAT1 transcription. Inhibitors, such as MIT, provide a potential therapeutic strategy for HCC patients with MALAT1 overexpression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism*
  • Cell Survival
  • Female
  • Gene Expression Regulation, Neoplastic
  • HEK293 Cells
  • Hep G2 Cells
  • Humans
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism*
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Protein Binding
  • RNA, Long Noncoding / genetics*
  • RNA, Long Noncoding / metabolism
  • Sp1 Transcription Factor / physiology*
  • Sp3 Transcription Factor / physiology*
  • Transcriptional Activation
  • Up-Regulation

Substances

  • MALAT1 long non-coding RNA, human
  • RNA, Long Noncoding
  • SP3 protein, human
  • Sp1 Transcription Factor
  • SP1 protein, human
  • Sp3 Transcription Factor