MicroRNA library-based functional screening identified miR-137 as a suppresser of gastric cancer cell proliferation

J Cancer Res Clin Oncol. 2015 May;141(5):785-95. doi: 10.1007/s00432-014-1847-4. Epub 2014 Oct 24.

Abstract

Purposes: Uncontrolled proliferation is a key characteristic of gastric carcinogenesis and the precise mechanisms underlying the altered proliferation behaviors of GC cells have not been clearly elucidated. miRNAs has been suggested to play a crucial role in the pathogenesis and development of various cancers. In the present study, we employed an impedance-based real-time cell electronic sensing (RT-CES) system to detect the effects of ectopically expressed miRNAs on GC cell proliferation.

Methods: miRNA mimics were transfected into gastric cancer cell line SGC7901 and the effect of individual miRNA on the proliferation rate of the cells was measured by the RT-CES system. The screening results were validated with qRT-PCR and miR-137 was selected for further research. The effects of ectopically expressed miR-137 on GC cell growth and cell cycle progress were measured using MTT assay and flow cytometry. The target gene of miR-137 was predicted using different bioinformatics tools and the direct interaction between miR-137 and the 3'-UTR was confirmed with a luciferase reporter assay. The in vivo effect of miR-137 on GC cell proliferation was examined with a tumor-bearing nude mouse model. The correlation between miR-137 expression and patients' prognosis was explored in a cohort of 38 patients. Prognosis was explored in a cohort of 38 patients.

Results: Ectopic expression of miR-137 was sufficient to inhibit GC cell proliferation both in vitro and in vivo. Bioinformatics prediction and luciferase reporter assay revealed CDK6 as a target gene through which miR-137 exerted an inhibitory function. Moreover, miR-137 expression positively correlated with better prognosis.

Conclusion: Our data indicated an important regulatory role of miR-137 in GC cell proliferation and that it may be explored as a prognostic marker for GC.

MeSH terms

  • Aged
  • Animals
  • Apoptosis
  • Blotting, Western
  • Cell Cycle
  • Cell Line, Tumor
  • Cell Proliferation*
  • Cyclin-Dependent Kinase 6 / genetics*
  • Cyclin-Dependent Kinase 6 / metabolism
  • Female
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic
  • Heterografts
  • Humans
  • Lymphatic Metastasis
  • Male
  • Mice
  • MicroRNAs / metabolism*
  • Middle Aged
  • Neoplasm Staging
  • Prognosis
  • Real-Time Polymerase Chain Reaction
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / pathology*
  • Up-Regulation

Substances

  • MIRN137 microRNA, human
  • MicroRNAs
  • CDK6 protein, human
  • Cyclin-Dependent Kinase 6