Regulation of metastasis-promoting LOXL2 gene expression by antitumor microRNAs in prostate cancer

J Hum Genet. 2017 Jan;62(1):123-132. doi: 10.1038/jhg.2016.68. Epub 2016 Jun 9.

Abstract

Our recent studies of microRNA (miRNA) expression signatures of prostate cancer (PCa) showed that six miRNAs (specifically, miR-26a, miR-26b, miR-29a, miR-29b, miR-29c and miR-218) were markedly reduced in cancer tissues. Moreover, ectopic expression of these miRNAs suppressed PCa cell aggressiveness, indicating that these miRNAs acted in concert to regulate genes that promoted metastasis. Genome-wide gene expression analysis and in silico database analysis identified a total of 35 candidate genes that promoted metastasis and were targeted by these 6 miRNAs. Using luciferase reporter assays, we showed that the lysyl oxidase-like 2 (LOXL2) gene was directly controlled by these tumor-suppressive miRNAs in PCa cells. Overexpression of LOXL2 was confirmed in PCa tissues and knockdown of the LOXL2 gene markedly inhibited the migration and invasion of PCa cells. Aberrant expression of LOXL2 enhanced migration and invasion of PCa cells. Downregulation of antitumor miRNAs might disrupt the tightly controlled RNA networks found in normal cells. New insights into the novel molecular mechanisms of PCa pathogenesis was revealed by antitumor miRNA-regulated RNA networks.

MeSH terms

  • 3' Untranslated Regions / genetics
  • Amino Acid Oxidoreductases / genetics*
  • Amino Acid Oxidoreductases / metabolism
  • Amino Acid Sequence
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Gene Expression Profiling / methods
  • Gene Expression Regulation, Neoplastic*
  • Genes, Tumor Suppressor
  • Humans
  • Immunohistochemistry
  • Male
  • MicroRNAs / genetics*
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Homology, Nucleic Acid

Substances

  • 3' Untranslated Regions
  • MIRN218 microRNA, human
  • MIRN26A microRNA, human
  • MIRN29a microRNA, human
  • MicroRNAs
  • Amino Acid Oxidoreductases
  • LOXL2 protein, human