Long non-coding RNA SNGH7 Is activated by SP1 and exerts oncogenic properties by interacting with EZH2 in ovarian cancer

J Cell Mol Med. 2020 Jul;24(13):7479-7489. doi: 10.1111/jcmm.15373. Epub 2020 May 18.

Abstract

Long non-coding RNAs (lncRNAs) are key regulators or a range of diseases and chronic conditions such as cancers, but how they function in the context of ovarian cancer (OC) is poorly understood. The Coding-Potential Assessment Tool was used to assess the likely protein-coding potential of SNHG7. SNHG7 expression was elevated in ovarian tumour tissues measured by qRT-PCR. The online database JASPAR was used to predict the transcription factors binding to SNHG7. Twenty-four-well Transwell plates were used for invasion assays. RNA immunoprecipitation was performed to determine RNA-protein associations. EdU assay was introduced to detect cell proliferation. Chromatin immunoprecipitation was performed to confirm the directly interaction between DNA and protein. We discovered that in the context of OC there is a significant up-regulation of the lncRNA SNHG7. Knocking down this lncRNA disrupted both OC cell invasion and proliferation, while its overexpression had the opposite effect. SP1 binding sites were present in the SNHG7 promoter, and chromatin immunoprecipitation (ChIP) confirmed direct SP1 binding to this region, activating SNHG7 transcription. We found that at a mechanistic level in OC cells, KLF2 is a probable SNHG7 target, as we found that SHNCCC16 directly interacts with EZH2 and thus represses KLF2 expression. In summary, this research demonstrates that lncRNA SNHG7 is an SP1-activated molecule that contributes to OC progression by providing a scaffold whereby EZH2 can repress KLF2 expression.

Keywords: EZH2; KLF2; cell migration; lncRNA SHNG7; ovarian cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Carcinogenesis / genetics*
  • Carcinogenesis / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Enhancer of Zeste Homolog 2 Protein / metabolism*
  • Epigenesis, Genetic
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / pathology
  • Promoter Regions, Genetic / genetics
  • Protein Binding / genetics
  • RNA, Long Noncoding / genetics
  • RNA, Long Noncoding / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sp1 Transcription Factor / metabolism*
  • Transcription, Genetic
  • Up-Regulation / genetics

Substances

  • KLF2 protein, human
  • Kruppel-Like Transcription Factors
  • RNA, Long Noncoding
  • RNA, Messenger
  • Sp1 Transcription Factor
  • Enhancer of Zeste Homolog 2 Protein