LncRNA PCGEM1 enhances metastasis and gastric cancer invasion through targeting of miR-129-5p to regulate P4HA2 expression

Exp Mol Pathol. 2020 Oct:116:104487. doi: 10.1016/j.yexmp.2020.104487. Epub 2020 Jul 1.

Abstract

Aim: Aberrantly expressed long non-coding RNAs (lncRNAs) are critical instigators of gastric cancer (GC) progression and metastasis. The ceRNA (competing endogenous RNAs) network is well-known in modulating tumor pathological and physiological processes. This research aims to determine the more effective molecular mechanisms of lncRNA PCGEM1 (prostate cancer gene expression marker 1).

Methods: Bioinformatics database and Ago2-RIP were performed to predict and verify the potential targets of lncRNA PCGEM1. Both gain- and loss-of-function experiments were carried out to dissect the biological functions of RNAs. Fluorescence in situ hybridization, dual-luciferase reporter assays, western blot, and real-time PCR (RT-PCR) experiments were utilized to determine the pathophysiological pathways of competitive endogenous RNAs (ceRNAs).

Results: GC cells expressed high levels of cytoplasmic PCGEM1. Loss-of-function experiments displayed that the silencing of PCGEM1 suppressed metastatic and invasive cell qualities. PCGEM1 was also found to have associations with miR-129-5p. Subsequently, luciferase reporter and RIP experiments, together with RT-PCR, verified that PCGEM1 functioned as a ceRNA of P4HA2 (Prolyl 4-Hydroxylase Subunit Alpha 2) via sponging miR-129-5p to up-regulate P4HA2 expression. Finally, the rescue assays determined that P4HA2 overexpression rescued the inhibited cell invasion and metastasis caused by PCGEM1 down-regulation.

Conclusion: These findings found that an over-expression of PCGEM1 in GC acts as a miR-129-5p sponge, leading to higher levels of P4HA2. The PCGEM1/miR-129-5p/P4HA2 axis was confirmed to possess a crucial role in GC metastasis and invasion, suggesting its utility as a potential diagnostic and therapeutic biomarker.

Keywords: Gastric cancer; P4HA2; PCGEM1; ceRNA; miR-129-5p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / genetics
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • In Situ Hybridization, Fluorescence
  • MicroRNAs / genetics*
  • Neoplasm Invasiveness / genetics
  • Neoplasm Invasiveness / pathology
  • Neoplasm Metastasis
  • Prolyl Hydroxylases / genetics*
  • RNA, Long Noncoding / genetics*
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology

Substances

  • Biomarkers, Tumor
  • MicroRNAs
  • Mirn129 microRNA, human
  • PCGEM1 non-coding RNA, human
  • RNA, Long Noncoding
  • P4HA2 protein, human
  • Prolyl Hydroxylases