Circ-LDLRAD3 Enhances Cell Growth, Migration, and Invasion and Inhibits Apoptosis by Regulating MiR-224-5p/NRP2 Axis in Gastric Cancer

Dig Dis Sci. 2021 Nov;66(11):3862-3871. doi: 10.1007/s10620-020-06733-1. Epub 2021 Jan 2.

Abstract

Background: Emerging as a newly discovered type of noncoding RNAs, circular RNAs have been manifested as a crucial regulator in tumorigenesis of human malignancies, including gastric cancer (GC). Although circ-LDLRAD3 has been revealed as an oncogene in pancreatic cancer, the underlying role of circ-LDLRAD3 in GC remains poorly understood.

Aims: Exploring the underlying function of circ-LDLRAD3 on GC progression.

Methods: Circ-LDLRAD3 expression was detected through RT-qPCR. EdU, colony formation, TUNEL, and transwell assays were performed to analyze the function of circ-LDLRAD3 on GC progression. Luciferase reporter and RIP assays were applied to testify the interaction between circ-LDLRAD, miR-224-5p, and NRP2 in GC.

Results: We detected preliminarily the expression of circ-LDLRAD3 and observed a markedly high expression of circ-LDLRAD3 in GC cells. Besides, circ-LDLRAD3 was featured with loop structure. Biological function assays testified that silenced circ-LDLRAD3 inhibited cell proliferation, migration, and invasion capacity but facilitated apoptosis of GC cells. Molecular mechanism assays uncovered that circ-LDLRAD3 combined with miR-224-5p in GC. Moreover, rescue assays delineated that inhibited expression of miR-224-5p could restore the inhibitive influence of circ-LDLRAD3 knockdown on the progression of GC. Moreover, neuropilin 2 (NRP2) was a downstream target of miR-224-5p. Additionally, circ-LDLRAD3 regulated NRP2 expression by sponging miR-224-5p in GC. Furthermore, circ-LDLRAD3 depletion-mediated effect on GC progression could be reversed by overexpressing NRP2.

Conclusions: Circ-LDLRAD3 facilitates GC progression by regulating miR-224-5p/NRP2 axis, providing new insights for the researches of GC treatment.

Keywords: Circ-LDLRAD3; Gastric cancer; NRP2; ceRNA; miR-224-5p.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Cell Line, Tumor
  • Cell Movement / physiology*
  • Cell Proliferation / physiology*
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Humans
  • Male
  • Mice
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasms, Experimental
  • Neuropilin-2 / genetics
  • Neuropilin-2 / metabolism*
  • Receptors, LDL / genetics
  • Receptors, LDL / metabolism*
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / pathology

Substances

  • LDLRAD3 protein, human
  • MIRN224 microRNA, human
  • MicroRNAs
  • Neuropilin-2
  • Receptors, LDL
  • neuropilin-2, human