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MiR-199a-5p Decreases Esophageal Cancer Cell Proliferation Partially through Repression of Jun-B

Pornima Phatak1,2, Mohan E Tulapurkar3, Whitney M Burrows4

  • 1Birmingham Veterans Affairs Health Care System, Birmingham, AL 35233, USA.

Cancers
|October 14, 2023
PubMed

Insights

MicroRNA (miR)-199a-5p acts as a tumor suppressor in esophageal cancer by reducing Jun-B expression. This microRNA targets Jun-B mRNA, inhibiting esophageal cancer cell proliferation and AP-1 activity.

Area of Science:

  • Oncology
  • Molecular Biology
  • Gene Regulation

Background:

  • MicroRNA (miR)-199a-5p exhibits tumor suppressor roles in various cancers, but its function in esophageal cancer remains unclear.
  • Esophageal cancer is a significant global health concern, necessitating research into novel therapeutic targets and molecular mechanisms.
  • The AP1 transcription factor, particularly its component Jun-B, is implicated in cancer progression and may be regulated by microRNAs.

Purpose of the Study:

  • To investigate the role of miR-199a-5p in esophageal cancer.
  • To elucidate the interaction between miR-199a-5p and Jun-B in esophageal cancer cells.
  • To determine the functional consequences of this interaction on cancer cell proliferation and AP-1 activity.

Main Methods:

  • Quantitative real-time PCR to assess miR-199a-5p and Jun-B expression levels in esophageal cancer tissues and cell lines.
  • Western blotting to evaluate Jun-B protein expression.
  • Biotinylated RNA-pull down assays and luciferase reporter assays to confirm direct interaction between miR-199a-5p and Jun-B mRNA.
  • Cell proliferation assays and AP-1 promoter activity analysis following miR-199a-5p overexpression or Jun-B silencing.

Main Results:

  • miR-199a-5p levels were significantly reduced in esophageal cancer specimens and cell lines, while Jun-B expression was elevated.
  • Overexpression of miR-199a-5p led to decreased Jun-B mRNA stability, protein expression, and AP-1 promoter activity.
  • A direct binding interaction between miR-199a-5p and Jun-B mRNA was experimentally validated.
  • Both miR-199a-5p overexpression and Jun-B silencing significantly inhibited esophageal cancer cell proliferation.

Conclusions:

  • miR-199a-5p functions as a tumor suppressor in esophageal cancer.
  • The tumor-suppressive role of miR-199a-5p is mediated, in part, by the repression of Jun-B.
  • Targeting the miR-199a-5p/Jun-B axis may offer a potential therapeutic strategy for esophageal cancer.
Keywords:
Jun-Besophageal cancermiR-199a-5pproliferation

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