Global miRNA/proteomic analyses identify miRNAs at 14q32 and 3p21, which contribute to features of chronic iron-exposed fallopian tube epithelial cells

Sci Rep. 2021 Mar 18;11(1):6270. doi: 10.1038/s41598-021-85342-y.

Abstract

Malignant transformation of fallopian tube secretory epithelial cells (FTSECs) is a key contributing event to the development of high-grade serous ovarian carcinoma (HGSOC). Our recent findings implicate oncogenic transformative events in chronic iron-exposed FTSECs, including increased expression of oncogenic mediators, increased telomerase transcripts, and increased growth/migratory potential. Herein, we extend these studies by implementing an integrated transcriptomic and mass spectrometry-based proteomics approach to identify global miRNA and protein alterations, for which we also investigate a subset of these targets to iron-induced functional alterations. Proteomic analysis identified > 4500 proteins, of which 243 targets were differentially expressed. Sixty-five differentially expressed miRNAs were identified, of which 35 were associated with the "top" proteomic molecules (> fourfold change) identified by Ingenuity Pathway Analysis. Twenty of these 35 miRNAs are at the 14q32 locus (encoding a cluster of 54 miRNAs) with potential to be regulated by DNA methylation and histone deacetylation. At 14q32, miR-432-5p and miR-127-3p were ~ 100-fold downregulated whereas miR-138-5p was 16-fold downregulated at 3p21 in chronic iron-exposed FTSECs. Combinatorial treatment with methyltransferase and deacetylation inhibitors reversed expression of these miRNAs, suggesting chronic iron exposure alters miRNA expression via epigenetic alterations. In addition, PAX8, an important target in HGSOC and a potential miRNA target (from IPA) was epigenetically deregulated in iron-exposed FTSECs. However, both PAX8 and ALDH1A2 (another IPA-predicted target) were experimentally identified to be independently regulated by these miRNAs although TERT RNA was partially regulated by miR-138-5p. Interestingly, overexpression of miR-432-5p diminished cell numbers induced by long-term iron exposure in FTSECs. Collectively, our global profiling approaches uncovered patterns of miRNA and proteomic alterations that may be regulated by genome-wide epigenetic alterations and contribute to functional alterations induced by chronic iron exposure in FTSECs. This study may provide a platform to identify future biomarkers for early ovarian cancer detection and new targets for therapy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Azacitidine / pharmacology
  • Biomarkers, Tumor / genetics
  • Cell Line, Transformed
  • Cell Transformation, Neoplastic / genetics
  • Down-Regulation / drug effects
  • Epithelial Cells / drug effects*
  • Epithelial Cells / metabolism*
  • Fallopian Tubes / drug effects*
  • Fallopian Tubes / metabolism*
  • Female
  • Ferric Compounds / pharmacology*
  • Gene Expression Profiling / methods
  • Genetic Loci*
  • Humans
  • MDS1 and EVI1 Complex Locus Protein / genetics
  • MDS1 and EVI1 Complex Locus Protein / metabolism
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Ovarian Neoplasms / genetics
  • Proteome / genetics*
  • Proteomics / methods
  • Quaternary Ammonium Compounds / pharmacology*
  • Transcriptome / drug effects*
  • Transfection
  • Vorinostat / pharmacology

Substances

  • Biomarkers, Tumor
  • Ferric Compounds
  • MDS1 and EVI1 Complex Locus Protein
  • MECOM protein, human
  • MIRN138 microRNA, human
  • MicroRNAs
  • Proteome
  • Quaternary Ammonium Compounds
  • Vorinostat
  • Azacitidine
  • ferric ammonium citrate