MicroRNA-34a regulates WNT/TCF7 signaling and inhibits bone metastasis in Ras-activated prostate cancer

Oncotarget. 2015 Jan 1;6(1):441-57. doi: 10.18632/oncotarget.2690.

Abstract

Aberrant activation of Ras and WNT signaling are key events that have been shown to be up-regulated in prostate cancer that has metastasized to the bone. However, the regulatory mechanism of combinatorial Ras and WNT signaling in advanced prostate cancer is still unclear. TCF7, a WNT signaling-related gene, has been implicated as a critical factor in bone metastasis, and here we show that TCF7 is a direct target of miR-34a. In samples of prostate cancer patients, miR-34a levels are inversely correlated with TCF7 expression and a WNT dependent gene signature. Ectopic miR-34a expression inhibited bone metastasis and reduced cancer cell proliferation in a Ras-dependent xenograft model. We demonstrate that miR-34a can directly interfere with the gene expression of the anti-proliferative BIRC5, by targeting BIRC5 3'UTR. Importantly, BIRC5 overexpression was sufficient to reconstitute anti-apoptotic signaling in cells expressing high levels of miR-34a. In prostate cancer patients, we found that BIRC5 levels were positively correlated with a Ras signaling signature expression. Our data show that the bone metastasis and anti-apoptotic effects found in Ras signaling-activated prostate cancer cells require miR-34a deficiency, which in turn aids in cell survival by activating the WNT and anti-apoptotic signaling pathways thereby inducing TCF7 and BIRC5 expressions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Bone Neoplasms / genetics
  • Bone Neoplasms / metabolism
  • Bone Neoplasms / secondary*
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic / genetics*
  • Heterografts
  • Humans
  • Immunohistochemistry
  • Inhibitor of Apoptosis Proteins / genetics
  • Inhibitor of Apoptosis Proteins / metabolism
  • Male
  • Mice
  • Mice, Nude
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasm Invasiveness / genetics
  • Neoplasm Invasiveness / pathology
  • Polymerase Chain Reaction
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology*
  • Signal Transduction* / physiology
  • Survivin
  • T Cell Transcription Factor 1 / genetics
  • T Cell Transcription Factor 1 / metabolism*
  • Transfection
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism
  • ras Proteins / genetics
  • ras Proteins / metabolism

Substances

  • BIRC5 protein, human
  • Inhibitor of Apoptosis Proteins
  • MIRN34 microRNA, human
  • MicroRNAs
  • Survivin
  • T Cell Transcription Factor 1
  • TCF7 protein, human
  • Wnt Proteins
  • ras Proteins