Circular RNA PRKCI silencing represses esophageal cancer progression and elevates cell radiosensitivity through regulating the miR-186-5p/PARP9 axis

Life Sci. 2020 Oct 15:259:118168. doi: 10.1016/j.lfs.2020.118168. Epub 2020 Jul 30.

Abstract

Aims: Circular RNA PRKCI (circPRKCI) and poly ADP-ribose polymerase 9 (PARP9) are related to the development of cancers. In this study, we aimed to explore the regulatory mechanisms between circPRKCI and PARP9 in EC progression and radioresistance.

Materials and methods: The levels of circPRKCI, PARP9 mRNA, and miR-186-5p were assessed by quantitative real time polymerase chain reaction (qRT-PCR). Western blot analysis was employed to examine the levels of several proteins. The viability, colony formation, cell cycle progression, and apoptosis of EC cells were determined with CCK-8, colony formation, or flow cytometry assays. The relationship between circPRKCI or PARP9 and miR-186-5p was verified with the dual-luciferase reporter and RIP assays.

Key findings: We observed that circPRKCI and PARP9 were upregulated while miR-186-5p was downregulated in EC tissues and cells. Furthermore, circPRKCI knockdown decreased tumor growth in vivo and constrained cell viability, colony formation, cell cycle progression, elevated cell radiosensitivity in EC cells in vitro. Importantly, circPRKCI modulated PARP9 expression through sponging miR-186-5p. Besides, PARP9 overexpression overturned circPRKCI silencing-mediated effects on the viability, colony formation, cell cycle progression, and radiosensitivity of EC cells.

Significance: CircPRKCI regulated cell malignancy and radioresistance through modulating the miR-186-5p /PARP9 axis in EC, which provided a might target for EC treatment.

MeSH terms

  • Animals
  • Apoptosis
  • Cell Cycle
  • Cell Line, Tumor
  • Disease Progression
  • Esophageal Neoplasms / genetics*
  • Esophageal Neoplasms / radiotherapy
  • Esophageal Neoplasms / therapy*
  • Gene Expression Regulation, Neoplastic / genetics
  • Gene Knockdown Techniques
  • Humans
  • Isoenzymes / genetics*
  • Mice
  • MicroRNAs / genetics*
  • Neoplasm Proteins / genetics*
  • Neoplastic Stem Cells
  • Poly(ADP-ribose) Polymerases / genetics*
  • Protein Kinase C / genetics*
  • RNA Interference
  • RNA, Circular / genetics*
  • Radiation-Sensitizing Agents / therapeutic use
  • Xenograft Model Antitumor Assays

Substances

  • Isoenzymes
  • MIRN186 microRNA, human
  • MicroRNAs
  • Neoplasm Proteins
  • PARP9 protein, human
  • RNA, Circular
  • Radiation-Sensitizing Agents
  • Poly(ADP-ribose) Polymerases
  • Protein Kinase C
  • protein kinase C lambda