miR-196a-mediated downregulation of p27kip1 protein promotes prostate cancer proliferation and relates to biochemical recurrence after radical prostatectomy

Prostate. 2020 Sep;80(12):1024-1037. doi: 10.1002/pros.24036. Epub 2020 Jul 6.

Abstract

Background: Dysregulation of microRNAs has performed vital gene regulatory functions in the genesis, progression, and prognosis of multiple malignant tumors. This study aimed to elucidate the regulatory mechanism of miR-196a in prostate cancer (PCa) and explore its clinical significance.

Methods: Quantitative real-time polymerase chain reaction was implemented to examine miR-196a and p27kip1 messenger RNA expression in PCa. Cell proliferation was evaluated via Cell Counting Kit-8, colony formation, and nude mouse tumorigenicity assays. Luciferase reporter assay was applied to identify target genes. p27kip1 protein expression in PCa was investigated using Western blot analysis and immunohistochemistry.

Results: There was a dramatic upregulation of miR-196a in PCa. Upregulated miR-196a was related to worse Gleason score (GS), later pathological stage, and poor biochemical recurrence (BCR)-free survival. In vivo and in vitro experiments exhibited that miR-196a promoted PCa proliferation and expedited G1/S-phase progression through the downregulation of p27kip1 protein. Additionally, p27kip1 protein was distinctly downregulated in PCa. Low p27kip1 protein expression had a strong correlation with increased GS and was an independent predictor of BCR after radical prostatectomy (RP).

Conclusions: Excessive expression of miR-196a and subsequent downregulation of p27kip1 protein play essential roles in promoting PCa proliferation and leading to BCR after RP. miR-196a and its target p27kip1 may become novel molecular biomarkers and therapeutic targets for PCa.

Keywords: biochemical recurrence; cell proliferation; miR-196a; p27kip1; prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation / physiology
  • Cyclin-Dependent Kinase Inhibitor p27 / biosynthesis
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism*
  • Down-Regulation
  • HEK293 Cells
  • Humans
  • Immunohistochemistry
  • Male
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Recurrence, Local / pathology
  • PC-3 Cells
  • Prostatectomy / methods
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / surgery

Substances

  • CDKN1B protein, human
  • MIRN196 microRNA, human
  • MicroRNAs
  • Cyclin-Dependent Kinase Inhibitor p27