Interleukin-33 Predicts Poor Prognosis and Promotes Renal Cell Carcinoma Cell Growth Through its Receptor ST2 and the...

Renal cell carcinoma (RCC) is currently the ninth most common cancer in men. Interleukin (IL)-33 expression has previously been associated with a number of cancers; however, its biological role in RCC is poorly understood. In this study, we sought to elucidate the role of IL-33 in RCC.

Serum IL-33 levels were measured by ELISA. IL-33 expression in clinical RCC samples was examined by immunocytochemistry. The proliferation and apoptosis rate of RCC were determined by CCK8 and flow cytometry. Mcl1 and Bcl-2 expression were measured by quantitative real-time PCR and western blotting. JNK expression were measured by western blotting and flow cytometry. The in vivo role of IL-33 in RCC tumorigenesis was examined by animal models.

We found that increased expression of IL-33 in RCC was associated with tumor-lymph node-metastasis (TNM) stage and inversely correlated with prognosis. IL-33 enhances RCC cell growth in vivo and stimulates RCC cell proliferation and prevents chemotherapy-induced tumor apoptosis in vitro. Furthermore, we demonstrated that IL-33 promotes RCC cell proliferation and chemotherapy resistance via its receptor ST2 and the JNK signaling activation in tumor cells.

Our findings suggest that targeting IL-33/ST2 and JNK signaling may have potential value in the treatment of RCC.