Correlation between IL-17A expression in nasopharyngeal carcinoma tissues and cells and pathogenesis of NPC in endemic areas.

ABSTRACT

OBJECTIVE: We investigated the correlation between the expression of IL-17A in nasopharyngeal carcinoma tissues and cells and the occurrence and development of NPC was also investigated. METHODS: Forty-five NPC biopsy specimens from January 2014 to January 2016 were selected. Forty-five NPC tissue specimens and 45 chronic nasopharyngitis tissue samples were detected by immunohistochemistry. Statistical methods were used to analyze the correlation between IL-17A expression and the clinicopathological variables of NPC. The NPC patients were followed up. The levels of IL-17A mRNA in 40 NPC tissue specimens and 45 chronic nasopharyngitis tissue samples were detected by real-time PCR. IL-17A expression in 15 NPC tissue specimens and chronic nasopharyngitis tissue samples was further detected by Western blotting assays. RESULTS: IL-17A expression in NPC tissues was significantly higher than that of chronic nasopharyngitis tissues (P < 0.05). IL-17A was expressed in the nucleus and cytoplasm of both NPC tissues and chronic nasopharyngitis tissues. Stage III + IV NPC, tumor volume ≥ 50 mm, and hepatic envelope invasion and cervical lymph node metastasis were associated with significantly higher IL-17A levels versus stage I + II NPC, tumor size < 50 mm, no membrane invasion and lack of cervical lymph node metastasis (P < 0.05). IL-17A was statistically associated with tissue differentiation, serum EBV-lgA levels, and EBV infection. IL-17A-positive patients had significantly longer median survival versus IL-17A-negative patients (21.0 vs. 13.0 months, log-rank test P < 0.05). Furthermore, 65% (26/40) of NPC tissue samples had significantly higher IL-17A mRNA levels than chronic nasopharyngitis (P < 0.05). IL-17A expression was significantly higher in NPC ≥ 50 mm, stage III + IV NPC and NPC with cervical lymph node invasion than its corresponding chronic nasopharyngitis tissue. CONCLUSION: IL-17A may be involved in the regulation of various malignant biological behaviors of NPC, which is closely related to the occurrence and development of NPC.