Circulating low IL-23: IL-35 cytokine ratio promotes progression associated with poor prognosisin breast cancer.

The interleukin (IL)-12 family, composed of heterodimeric cytokines including IL-12 (formed by IL-12p35 and IL-12p40 subunits), IL-23 (formed by IL-23p19 and IL-12p40 subunits), IL-27 (formed by IL-27p28 and EBI3 subunits) and IL-35 (formed by IL-12p35 and EBI3 subunits), establishes a link between innate and adaptive immunity that involves different immune effector cells and cytokines to tumors. However, the role of IL-12 family in breast cancer (BC) progression and prognosis remains unclear. In the present study, we demonstrated evidence indicating that EBI3, IL-12p35 and IL-12p40 but not IL-23p19 or IL-27p28 were highly expressed in BC tissues, suggested that tumor derived EBI3, IL-12p35 and IL-12p40 were associated with tumor progression. Circulating IL-12 and IL-23 low expressed, but IL-27 and IL-35 high expressed in BC patients, especially circulating IL-23 associated with IL-35 to mediate BC tumor resection. Ki-67, p53 and EGFR expression on BC tissues, as well as CA125, CA153 and CA199 levels on BC bloods increased when circulating IL-23: IL-35 ratio decreased. Together, for the first time, our data suggest that circulating IL-23: IL-35 ratio may be an important indicator association with BC progression and prognosis. However, further research should be carried out to assess the implications of circulating IL-23: IL-35 ratio in a larger sample size.