Prognostic value of serum soluble interleukin‐23 receptor and related T‐helper 17 cell cytokines in non‐small cell lung carcinoma

The signaling of interleukin (IL)‐23 and its receptor (IL‐23R) play a crucial role in the development of cancers. However, the clinical significance of human serum soluble IL‐23R (sIL‐23R) and its relationship with IL‐23 are still not explored in non‐small cell lung cancer (NSCLC). In our study, sIL‐23R was first identified in the serum of NSCLC patients, but not in healthy controls, by proteomics. The IL‐23R mRNA and protein were upregulated in NSCLC cell lines and tissues tested by quantitative PCR, western blot analysis and immunohistochemistry. The levels of sIL‐23R, IL‐23, and IL‐17 in 195 NSCLC patients’ serum were determined by ELISA, and high levels of sIL‐23R were significantly associated with advanced N stage (P = .039), clinical stage (P = .007), and poor 5‐year survival rate. In vitro, sIL‐23R was shown binding to IL‐23 and the balance could affect patients’ N and T stage, overall survival, and downstream cytokine IL‐17 in a potential antagonistic relationship. Although sIL‐23R, IL‐23, and IL‐17 were all associated with poor prognosis, only the sIL‐23R/IL‐23 ratio (hazard ratio, 1.945; 95% confidence interval, 1.147‐3.299; P = .014) was found to be an independent factor for prognosis. Therefore, we identified fragments of soluble cytokine receptor of IL‐23R with affinity ability to its natural ligand IL‐23 in NSCLC patients’ serum. The balance between the 2 antagonists can work as a potential prognostic serum marker.