FoxD3-regulated microRNA-137 suppresses tumour growth and metastasis in human hepatocellular carcinoma by targeting AKT2

Oncotarget. 2014 Jul 15;5(13):5113-24. doi: 10.18632/oncotarget.2089.

Abstract

microRNAs, frequently deregulated in human cancer, have been implicated in the progression of hepatocarcinogenesis. Here, we show that microRNA (miR)-137 is significantly down-regulated in hepatocellular carcinoma (HCC). Its decreased expression is associated with vein invasion, incomplete Involucrum, and distant metastasis. Multivariate analysis suggests that miR-137 is an independent indicator for poor survival. We next show that over-expression of miR-137 suppresses cell proliferation, migration and invasion in vitro. Conversely, miR-137 inhibition promotes HCC cell growth. We also identify AKT2 as a key target of miR-137 in this context. Statistical data reveal a reverse correlation of AKT2 and miR-137 expression in HCC patients. Silencing of AKT2 phenotypically copied miR-137-induced phenotypes, whereas re-expression of AKT2 reversed the suppressive effects of miR-137. Further investigations showed that miR-137 exerted its anti-tumour activity via inhibiting the AKT2/mTOR pathway. Moreover, we demonstrate that FoxD3 directly binds to the promoter of miR-137 and activates its transcription. In vivo studies confirm that FoxD3-regulated miR-137 inhibited HCC growth and metastasis via targeting AKT2. Together, our findings indicate that miR-137 is a valuable biomarker for HCC prognosis and the FoxD3/miR-137/AKT2 regulatory network plays an important role in HCC progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Animals
  • Base Sequence
  • Blotting, Western
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Movement / genetics
  • Cell Proliferation
  • Female
  • Forkhead Transcription Factors / genetics*
  • Forkhead Transcription Factors / metabolism
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Male
  • Mice, Inbred BALB C
  • Mice, Nude
  • MicroRNAs / genetics*
  • Middle Aged
  • Neoplasm Metastasis
  • Prognosis
  • Proto-Oncogene Proteins c-akt*
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Burden / genetics
  • Xenograft Model Antitumor Assays / methods

Substances

  • 3' Untranslated Regions
  • FOXD3 protein, human
  • Forkhead Transcription Factors
  • MIRN137 microRNA, human
  • MicroRNAs
  • AKT2 protein, human
  • Proto-Oncogene Proteins c-akt