miR-186-5p Functions as a Tumor Suppressor in Human Osteosarcoma by Targeting FOXK1

Cell Physiol Biochem. 2019;52(3):553-564. doi: 10.33594/000000039.

Abstract

Background/aims: Aberrantly expressed miRNAs play a vital role in the development of some cancers, such as human osteosarcoma (OS). However, the detailed molecular mechanisms underlying miR-186-5p-involved osteosarcoma are unclear.

Methods: qRT-PCR and western blot analysis were employed to measure the expressions of miR-186-5p and forkhead box k1 (FOXK1). CCK-8 assay evaluated the effect of miR-186-5p and FOXK1 on cell proliferation. Transwell assay confirmed cell migration and invasion. Eventually, the dual-luciferase reporter assay validated 3'-untranslated region (3'-UTR) of FOXK1 as a direct target of miR-186-5p.

Results: Down-regulation of miR-186-5p was identified in OS tissues and cell lines, and negatively correlated with distant metastasis, Enneking stage and poor 5-year prognosis as well as the expression of forkhead box k1 (FOXK1) protein. Further assays demonstrated that miR-186-5p overexpression had inhibitory effects on in-vitro cell proliferation, cell cycle, and in-vivo tumor growth. miR-186-5p overexpression also inhibited the epithelial-tomesenchymal transition (EMT), migration and invasion of OS cells. Importantly, miR-186-5p directly targeted FOXK1 3'-UTR and negatively regulated its expression. Silencing of FOXK1 expression enhanced the inhibitory effects of miR-186-5p on OS cell proliferation, migration and invasion.

Conclusion: These findings highlighted miR-186-5p as a tumor suppressor in the regulation of progression and metastatic potential of OS, and may benefit the development of therapies targeting miR-186-5p in patients with OS.

Keywords: FOXK1; Osteosarcoma; Suppressor; miR-186-5p.

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Antagomirs / metabolism
  • Apoptosis
  • Bone Neoplasms / metabolism
  • Bone Neoplasms / mortality
  • Bone Neoplasms / pathology*
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Female
  • Forkhead Transcription Factors / antagonists & inhibitors
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / metabolism*
  • Humans
  • Kaplan-Meier Estimate
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Osteosarcoma / metabolism
  • Osteosarcoma / mortality
  • Osteosarcoma / pathology*
  • Prognosis
  • RNA Interference
  • RNA, Small Interfering / metabolism

Substances

  • 3' Untranslated Regions
  • Antagomirs
  • FOXK1 protein, human
  • Forkhead Transcription Factors
  • MIRN186 microRNA, human
  • MicroRNAs
  • RNA, Small Interfering