Reduction of NANOG Mediates the Inhibitory Effect of Aspirin on Tumor Growth and Stemness in Colorectal Cancer

Cell Physiol Biochem. 2017;44(3):1051-1063. doi: 10.1159/000485405. Epub 2017 Nov 27.


Background/aims: Cancer stem cells (CSCs) are considered to be responsible for tumor relapse and metastasis, which serve as a potential therapeutic target for cancer. Aspirin has been shown to reduce cancer risk and mortality, particularly in colorectal cancer. However, the CSCs-suppressing effect of aspirin and its relevant mechanisms in colorectal cancer remain unclear.

Methods: CCK8 assay was employed to detect the cell viability. Sphere formation assay, colony formation assay, and ALDH1 assay were performed to identify the effects of aspirin on CSC properties. Western blotting was performed to detect the expression of the stemness factors. Xenograft model was employed to identify the anti-cancer effects of aspirin in vivo. Unpaired Student t test, ANOVA test and Kruskal-Wallis test were used for the statistical comparisons.

Results: Aspirin attenuated colonosphere formation and decreased the ALDH1 positive cell population of colorectal cancer cells. Aspirin inhibited xenograft tumor growth and reduced tumor cells stemness in nude mice. Consistently, aspirin decreased the protein expression of stemness-related transcription factors, including c-Myc, OCT4 and NANOG. Suppression of NANOG blocked the effect of aspirin on sphere formation. Conversely, ectopic expression of NANOG rescued the aspirin-repressed sphere formation, suggesting that NANOG is a key downstream target. Moreover, we found that aspirin repressed NANOG expression in protein level by decreasing its stability.

Conclusion: We have provided new evidence that aspirin attenuates CSC properties through down-regulation of NANOG, suggesting aspirin as a promising therapeutic agent for colorectal cancer treatment.

Keywords: Aspirin; Cancer Stem Cells; Colorectal Cancer; NANOG; Protein Stabilization.

MeSH terms

  • Animals
  • Aspirin / therapeutic use
  • Aspirin / toxicity*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Cell Survival / drug effects
  • Colorectal Neoplasms / drug therapy
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology
  • HCT116 Cells
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Nanog Homeobox Protein / antagonists & inhibitors
  • Nanog Homeobox Protein / genetics
  • Nanog Homeobox Protein / metabolism*
  • Neoplastic Stem Cells / cytology
  • Neoplastic Stem Cells / drug effects
  • Neoplastic Stem Cells / metabolism
  • Octamer Transcription Factor-3 / metabolism
  • Protein Stability / drug effects
  • Proto-Oncogene Proteins c-myc / metabolism
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • SOXB1 Transcription Factors / metabolism
  • Transplantation, Heterologous


  • Nanog Homeobox Protein
  • Octamer Transcription Factor-3
  • Proto-Oncogene Proteins c-myc
  • RNA, Small Interfering
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • Aspirin