IL-17 can promote tumor growth through an IL-6–Stat3 signaling pathway

Although the Th17 subset and its signature cytokine, interleukin (IL)-17A (IL-17), are implicated in certain autoimmune diseases, their role in cancer remains to be further explored. IL-17 has been shown to be elevated in several types of cancer, but how it might contribute to tumor growth is still unclear. We show that growth of B16 melanoma and MB49 bladder carcinoma is reduced in IL-17(-/-) mice but drastically accelerated in IFN-gamma(-/-) mice, contributed to by elevated intratumoral IL-17, indicating a role of IL-17 in promoting tumor growth. Adoptive transfer studies and analysis of the tumor microenvironment suggest that CD4(+) T cells are the predominant source of IL-17. Enhancement of tumor growth by…

• NI
  National Institutes of Health

  Awards: R01CA122976, AI066008