Interleukin-23 receptor signaling mediates cancer dormancy and radioresistance in human esophageal squamous carcinoma cells via the Wnt/Notch pathway

ABSTRACT: In the tumor microenvironment, inflammatory cells and molecules influence almost every process; among them, interleukin-23 (IL-23) is a pro-inflammatory molecule that exhibits pro- or anti-tumor properties, but both activities remain poorly understood. In this study, we investigated the effect of extracellular IL-23 in IL-23 receptor-positive (IL-23R(+)) esophageal squamous cell carcinoma (ESCC) and explored the mechanisms underlying this effect. We analyzed ESCC tumor tissues by immunohistochemical and immunofluorescence staining and found that IL-23, which was highly expressed, co-localized with Oct-4A in IL-23R(+) ESCC cells. In addition, IL-23 treatment significantly increased the accumulation of CD133(+) cells and activated the Wnt and Notch signaling pathways in CD133(−)IL-23R(+) ESCC cell lines. Consistently, CD133(−)IL-23R(+) cells pretreated with IL-23 showed stronger anti-apoptosis activity when exposed to radiation and higher survival than untreated groups. Moreover, the inhibition of Wnt/Notch signaling by a small-molecule inhibitor or siRNA abolished the effect of IL-23-induced dormancy and consequent radioresistance. Taken together, these results suggested that IL-23 facilitates radioresistance in ESCC by activating Wnt/Notch-mediated G0/1 phase arrest, and attenuating these detrimental changes by blocking the formation of dormancy may prove to be an effective pretreatment for radiotherapy. KEY MESSAGES: IL-23/IL-23R is correlated with the acquisition of stem-like potential in ESCC. CD133(−)IL-23R(+) ESCCs acquired dormancy via IL-23. Radioresistance depends on IL-23-mediated Wnt/Notch pathway activation in vitro and vivo. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00109-018-1724-8) contains supplementary material, which is available to authorized users.