Lysophosphatidic Acid Mediates Activating Transcription Factor 3 Expression Which Is a Target for Post-Transcriptional Silencing by miR-30c-2-3p

PLoS One. 2015 Sep 29;10(9):e0139489. doi: 10.1371/journal.pone.0139489. eCollection 2015.

Abstract

Although microRNAs (miRNAs) are small, non-protein-coding entities, they have important roles in post-transcriptional regulation of most of the human genome. These small entities generate fine-tuning adjustments in the expression of mRNA, which can mildly or massively affect the abundance of proteins. Previously, we found that the expression of miR-30c-2-3p is induced by lysophosphatidic acid and has an important role in the regulation of cell proliferation in ovarian cancer cells. The goal here is to confirm that ATF3 mRNA is a target of miR-30c-2-3p silencing, thereby further establishing the functional role of miR-30c-2-3p. Using a combination of bioinformatics, qRT-PCR, immunoblotting and luciferase assays, we uncovered a regulatory pathway between miR-30c-2-3p and the expression of the transcription factor, ATF3. Lysophosphatidic acids triggers the expression of both miR-30c-2-3p and ATF3, which peak at 1 h and are absent 8 h post stimulation in SKOV-3 and OVCAR-3 serous ovarian cancer cells. The 3´-untranslated region (3´-UTR) of ATF3 was a predicted, putative target for miR-30c-2-3p, which we confirmed as a bona-fide interaction using a luciferase reporter assay. Specific mutations introduced into the predicted site of interaction between miR-30c-2-3p and the 3´-UTR of ATF3 alleviated the suppression of the luciferase signal. Furthermore, the presence of anti-miR-30c-2-3p enhanced ATF3 mRNA and protein after lysophosphatidic acid stimulation. Thus, the data suggest that after the expression of ATF3 and miR-30c-2-3p are elicited by lysophosphatidic acid, subsequently miR-30c-2-3p negatively regulates the expression of ATF3 through post-transcriptional silencing, which prevents further ATF3-related outcomes as a consequence of lysophosphatidic acid signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Activating Transcription Factor 3 / genetics*
  • Activating Transcription Factor 3 / metabolism
  • Cell Line, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Humans
  • Immunoblotting
  • Lysophospholipids / pharmacology*
  • MicroRNAs / genetics*
  • Microscopy, Fluorescence
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic / drug effects*

Substances

  • 3' Untranslated Regions
  • Activating Transcription Factor 3
  • Lysophospholipids
  • MIRN30b microRNA, human
  • MicroRNAs
  • lysophosphatidic acid