CircRNA circ_0026344 as a prognostic biomarker suppresses colorectal cancer progression via microRNA-21 and microRNA-31

Biochem Biophys Res Commun. 2018 Sep 5;503(2):870-875. doi: 10.1016/j.bbrc.2018.06.089. Epub 2018 Jun 23.


Recently, circular RNA (circRNA) is identified as a novel class of noncoding RNA with important roles in human diseases, such as cancer. However, how circRNA participates in colorectal cancer (CRC) remains unclear. In this study, we aimed to illustrate the role of circ_0026344 in CRC progression. We showed that circ_0026344 expression was downregulated in CRC tissues compared to adjacent normal tissues. Moreover, the level of circ_0026344 was inversely correlated with CRC advance and lymphoid node metastasis. Additionally, circ_0026344 low expression predicted poor prognosis in CRC patients. We identified circ_0026344 as a miRNA sponge for microRNA-21 (miR-21) and microRNA-31 (miR-31) whose expression levels were elevated in CRC tissues. And the level of circ_0026344 was reversely correlated with both miR-21 and miR-31 levels in CRC tissues. Functionally, we found that ectopic expression of circ_0026344 decreased the growth and invasion of CRC cells while promoting apoptosis in vitro. The xenograft experiment indicated that circ_0026344 overexpress led to CRC growth inhibition in vivo. Rescue assays further demonstrated that circ_0026344 exerted biological functions by sponging miR-21 and miR-31 in CRC. In conclusion, this study revealed that circ_0026344/miR-21/miR-31 regulatory signaling was implicated in CRC progression.

Keywords: Circular RNA; Colorectal cancer; Progression; circ_0026344; microRNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Biomarkers, Tumor / genetics*
  • Cell Line
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology
  • Disease Progression
  • Gene Expression Regulation, Neoplastic
  • HCT116 Cells
  • HEK293 Cells
  • HT29 Cells
  • Humans
  • Mice, Nude
  • MicroRNAs / genetics*
  • Prognosis
  • RNA / genetics*
  • RNA, Circular
  • RNA, Neoplasm / genetics*
  • Sequence Homology, Nucleic Acid
  • Transplantation, Heterologous


  • Biomarkers, Tumor
  • MIRN21 microRNA, human
  • MIRN31 microRNA, human
  • MicroRNAs
  • RNA, Circular
  • RNA, Neoplasm
  • RNA