miR-638 promotes melanoma metastasis and protects melanoma cells from apoptosis and autophagy

Oncotarget. 2015 Feb 20;6(5):2966-80. doi: 10.18632/oncotarget.3070.

Abstract

The present study identified miR-638 as one of the most significantly overexpressed miRNAs in metastatic lesions of melanomas compared with primary melanomas. miR-638 enhanced the tumorigenic properties of melanoma cells in vitro and lung colonization in vivo. mRNA expression profiling identified new candidate genes including TP53INP2 as miR-638 targets, the majority of which are involved in p53 signalling. Overexpression of TP53INP2 severely attenuated proliferative and invasive capacity of melanoma cells which was reversed by miR-638. Depletion of miR-638 stimulated expression of p53 and p53 downstream target genes and induced apoptosis and autophagy. miR-638 promoter analysis identified the miR-638 target transcription factor associated protein 2α (TFAP2A/AP-2α) as a direct negative regulator of miR-638, suggestive for a double-negative regulatory feedback loop. Taken together, miR-638 supports melanoma progression and suppresses p53-mediated apoptosis pathways, autophagy and expression of the transcriptional repressor TFAP2A/AP-2α.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Autophagy*
  • Cell Line, Tumor
  • Cell Movement
  • Disease Progression
  • Feedback, Physiological
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Melanoma / genetics
  • Melanoma / metabolism*
  • Melanoma / secondary
  • Mice, Inbred NOD
  • Mice, SCID
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasm Invasiveness
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • RNA Interference
  • Signal Transduction
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology
  • Time Factors
  • Transcription Factor AP-2 / genetics
  • Transcription Factor AP-2 / metabolism
  • Transfection
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • MIRN638 microRNA, human
  • MicroRNAs
  • Nuclear Proteins
  • TFAP2A protein, human
  • TP53 protein, human
  • TP53INP2 protein, human
  • Transcription Factor AP-2
  • Tumor Suppressor Protein p53