Scientific Reports (May 2017)

Exendin-4 Exhibits Enhanced Anti-tumor Effects in Diabetic Mice

  • Lan He,
  • Priscilla T. Y. Law,
  • Chun Kwok Wong,
  • Juliana C. N. Chan,
  • Paul K. S. Chan

DOI
https://doi.org/10.1038/s41598-017-01952-5
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 10

Abstract

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Abstract Type 2 diabetes (T2D) is associated with increased risk of cancers. In this connection, we previously demonstrated the promoting effect of diabetes on HPV-associated carcinogenesis using a xenograft model in db/db diabetic mice. The underlying mechanism of this observation might be partly contributed by dysregulated immune response in diabetes. In this study, we hypothesized that the impaired anti-tumor immune response in diabetic status could be modulated by exendin-4, a glucagon-like protein receptor agonist which exhibits anti-diabetic effects. We inoculated 10-week old db/db mice with 2 × 107 CUP-1 cells (Human Papilloma Virus (HPV)-16 E7 transfected continuous cell line) subcutaneously underneath the scruff, and treated mice with high (30 nmol/kg) or low (10 nmol/kg) dose of exendin-4 for 13 days. Compared with control groups, exendin-4 suppressed subcutaneous tumor growth in a dose-dependent manner, accompanied by increased interferon (IFN)-γ secreting CD8+ cytotoxic T lymphocyte (CTL)/Foxp3+ regulatory T cell (Treg) ratio as well as Th1 proinflammatory cytokines IFN-γ and IL-2. Collectively, these findings suggested an anti-tumor effect of exendin-4 in diabetic conditions, which might be resulted from direct immunomodulation.