E2F1-mediated MNX1-AS1-miR-218-5p-SEC61A1 feedback loop contributes to the progression of colon adenocarcinoma

J Cell Biochem. 2019 Apr;120(4):6145-6153. doi: 10.1002/jcb.27902. Epub 2018 Oct 25.

Abstract

The long noncoding RNA MNX1-AS1 has been reported to facilitate the progression of glioblastoma and ovarian cancer. Nevertheless, the biological roles and underlying mechanisms of MNX1-AS1 in colon adenocarcinoma have not been studied until now. In the current study, MNX1-AS1 was upregulated in colon adenocarcinoma. JASPAR prediction tool showed that E2F1 could bind to the promoter region of MNX1-AS1. The chromatin immunoprecipitation assay and luciferase reporter assay were used to verify the interactions between MNX1-AS1 and E2F1. Then functional assays revealed that downregulation of MNX1-AS1 decreased cell proliferation, migration, and invasion in colon adenocarcinoma, but upregulation of E2F1 reversed the effects. Moreover, subcellular fractionation assay manifested that MNX1-AS1 was enriched in the cytoplasm of colon adenocarcinoma cells, thus we speculated whether MNX1-AS1 could function as a competing endogenous RNA (ceRNA) to play roles in colon adenocarcinoma. Bioinformatics analysis and luciferase reporter assay indicated that MNX1-AS1 could sponge microRNA-218-5p (miR-218-5p). Furthermore, we discovered that SEC61A1 was downstream target of miR-218-5p, and MNX1-AS1 acted as a ceRNA to upregulate the expression of SEC61A1 through sponging miR-218-5p. Finally, rescue assays confirmed that MNX1-AS1 facilitated the progression of colon adenocarcinoma through regulating miR-218-5p/SEC61A1 axis. Taken together, we concluded that E2F1-mediated MNX1-AS1-miR-218-5p-SEC61A1 feedback loop contributed to the progression of colon adenocarcinoma.

Keywords: E2F1; MNX1-AS1; colon adenocarcinoma; miRNA-218-5p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / pathology
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Movement / physiology
  • Cell Proliferation / genetics
  • Cell Proliferation / physiology
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism*
  • Colonic Neoplasms / pathology
  • Disease Progression
  • E2F1 Transcription Factor / genetics
  • E2F1 Transcription Factor / metabolism*
  • Gene Expression Regulation, Neoplastic / genetics
  • Gene Expression Regulation, Neoplastic / physiology
  • HT29 Cells
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • In Vitro Techniques
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • RNA, Long Noncoding / genetics
  • RNA, Long Noncoding / metabolism*
  • SEC Translocation Channels / genetics
  • SEC Translocation Channels / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • E2F1 Transcription Factor
  • E2F1 protein, human
  • Homeodomain Proteins
  • MIRN218 microRNA, human
  • MNX1 protein, human
  • MicroRNAs
  • RNA, Long Noncoding
  • SEC Translocation Channels
  • SEC61A1 protein, human
  • Transcription Factors