IL-17 promoted metastasis of non-small-cell lung cancer cells.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Recent data suggested that IL-17 might be a pivotal cytokine involved in tumor progression of NSCLC. However, the direct effect of IL-17 on metastasis of NSCLC cells still remains intractable. In this study, we found that the metastasis of NSCLC was significantly impaired in IL-17⁻/⁻ mice. Further, we revealed that IL-17 could directly promote the invasion of NSCLC cells both in vitro and in vivo. Furthermore, we found that IL-6-Stat3 pathway was crucial for IL-17 to enhance the invasive potential of NSCLC cells. Finally, we found that elevated expression of IL-17 in peripheral blood was associated with the TNM stage, and elevated expression of IL-17R in NSCLC cells was associated with their invasive potential in NSCLC patients. These findings could facilitate our understanding of the potential role of IL-17 in tumor biology, and provide clues for developing promising strategies against NSCLC.