DNA methylation downregulated mir-10b acts as a tumor suppressor in gastric cancer

Gastric Cancer. 2015 Jan;18(1):43-54. doi: 10.1007/s10120-014-0340-8. Epub 2014 Jan 31.


Background: MicroRNAs act as tumor suppressors or oncogenes. The pathological roles of miRNAs in gastric tumorigenesis are largely unknown. Although miR-10b was identified as an miRNA deregulator expressed in gastric cancer (GC), there also exists some debate on whether miR-10b is acting as tumor suppressor or oncogene in GC.

Methods: Quantitative RT-PCR was employed to investigate the level of miR-10b in GC tissues and matched adjacent normal tissues (n = 100). In vitro cell proliferation, apoptosis assays, cell migration, and invasion assays were performed to elucidate the biological effects of miR-10b. Because silencing of miRNA by promoter CpG island methylation may be an important mechanism in tumorigenesis, GC cells were treated with 5-aza-2'-deoxycytidine and trichostatin A, and expression changes of miR-10b were subsequently examined by quantitative RT-PCR. Furthermore, the methylation status of the CpG island upstream of miR-10b was analyzed by methylation-specific PCR in GC tissues (n = 29).

Results: We showed here that miR-10b was significantly downregulated in GC cell lines and tissues as demonstrated by quantitative real-time PCR. Overexpression of miR-10b in MGC-803 and HGC-27 dramatically suppressed cell proliferation, migration, invasion, and induced apoptosis. Moreover, we demonstrated that T-cell lymphoma invasion and metastasis (Tiam1) was a target of miR-10b. Furthermore, 5-aza-2'-deoxycytidine and trichostain A increased miR-10b expression, and the methylation level was high in the CpG islands upstream of miR-10b gene.

Conclusions: Taken together, these findings suggest that miR-10b may function as a novel tumor suppressor and is partially silenced by DNA hypermethylation in GC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Azacitidine / analogs & derivatives
  • Azacitidine / pharmacology
  • Cell Line, Tumor / drug effects
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • CpG Islands
  • DNA Methylation* / drug effects
  • Decitabine
  • Epigenesis, Genetic
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Genes, Tumor Suppressor
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • Humans
  • Hydroxamic Acids / pharmacology
  • Male
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Middle Aged
  • Real-Time Polymerase Chain Reaction
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology
  • T-Lymphoma Invasion and Metastasis-inducing Protein 1


  • Guanine Nucleotide Exchange Factors
  • Hydroxamic Acids
  • MIRN10 microRNA, human
  • MicroRNAs
  • T-Lymphoma Invasion and Metastasis-inducing Protein 1
  • TIAM1 protein, human
  • trichostatin A
  • Decitabine
  • Azacitidine