ABSTRACT
<p><b>OBJECTIVE</b>This study aims to detect the expression level of interleukin-23 (IL-23) in tongue squamous cell carcinoma tissues and its relationship with clinical prognosis, as well as explore the anti-apoptotic and drug resistance of the tongue squamous cell line-SCC9 before and after treatment with IL-23.</p><p><b>METHODS</b>The expression of IL-23 in tumor tissues from 28 tongue cancer patients was analyzed by immunohistochemistry assay. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of Wingless-related integration site (Wnt)1 and c-myc in SCC9 cells treated with different IL-23 concentrations. After interferencing the β-catenin with small interfering RNA (siRNA), the expression of β-catenin, B-cell lymphoma-2 (Bcl-2), ATP-binding cassette sub-family G member 2 (ABCG2), and permeability-glycoprotein (P-gp) in SCC9 was measured by Western blot analysis. The effect of IL-23 on the apoptotic resistance of SCC9 to cisplatin was examined by methyl thiazolyl tetrazolium test.</p><p><b>RESULTS</b>The expression of IL-23 in tongue cancer tissues was correlated with lymphatic metastasis, nerve invasion, and the recurrence after therapy (P<0.05). After dealing with IL-23, SCC9 showed the upregulation effect of Bcl-2, ABCG2 and P-gp expressions. IL-23 was closely related to the activation level of the Wnt pathway and significantly strengthened the resistance to cisplatin (P<0.01).</p><p><b>CONCLUSION</b>IL-23 activates the Wnt pathway in tongue squamous cell carcinoma, thereby enhancing its resistance to apoptosis and drug.</p>