Abstract:

Objective To investigate the expression levels of serum microRNA-24（miR-24） and X-linked inhibitor of apoptosis protein（XIAP） mRNA in patients with oral adenoid cystic carcinoma（ACC） and the relationship with prognosis. Methods Totally，60 patients with oral ACC treated in Zhangjiakou First Hospital from June 2010 to February 2016 were enrolled as oral ACC group，and 60 healthy subjects during the same period were enrolled as healthy control group. Serum samples from all the subjects were collected. Cancer and para-cancer（≥5 cm from tumor tissue margin） tissue samples and clinical data were collected. The expression levels of miR-24 and XIAP mRNA in serum of the 2 groups were determined. The relationship between the expression levels of serum miR-24 and XIAP with the clinicopathologic characteristics of oral ACC patients were analyzed by pearson method. All the ACC patients were followed up. Kaplan-Meier survival curve and Log-rank χ² test were used to analyze the relationship between the relative expression levels of serum miR-24 and XIAP mRNA and the prognosis of patients with oral ACC. Cox regression analysis was used to evaluate the prognostic risk factors of patients with oral ACC. Results Compared with healthy control group，the relative expression level of serum miR-24 in oral ACC group was decreased（P<0.05），and the relative expression level of XIAP mRNA was increased（P<0.05）. Compared with para-cancer tissues，the relative expression of miR-24 in cancer tissues was decreased（P<0.05），and the relative expression of XIAP mRNA was increased（P<0.05）. There was a negative correlation between serum miR-24 and XIAP mRNA in oral ACC patients（r=-0.486，P<0.05）. Oral ACC patients were classified into high expression group and low expression group using the mean values of serum miR-24 and XIAP mRNA relative expression levels as cut-off values. The numbers of nerve invasion and lymphatic metastasis in miR-24 low expression group and XIAP mRNA high expression group were higher than those in miR-24 high expression group and XIAP mRNA low expression group，respectively（P<0.05）. Kaplan-Meier survival curve analysis showed that the cumulative survival rate of miR-24 low expression group and XIAP mRNA high expression group was lower than that of miR-24 high expression group and XIAP mRNA low expression group（Log-rank χ² values were 7.212 and 8.568，P=0.007 and 0.003，respectively）. Cox regression analysis showed that nerve invasion and high-expressed XIAP mRNA were independent risk factors for poor prognosis in oral ACC patients（P<0.05），and high-expressed miR-24 was independent protective factor for oral ACC patients（P<0.05）. Conclusions Serum miR-24 and XIAP mRNA in patients with oral ACC are correlated with prognosis，and may be used as new biomarkers to evaluate the prognosis of oral ACC.

Key words: MiRNA-24, X-linked inhibitor of apoptosis protein, Oral cavity, Adenoid cystic carcinoma, Prognosis