Abstract: Objective The aim of this study was to investigate the expression of miR-320a and cephalospermoma syndrome protein(CYLD)in patients with gastric cancer and its relationship with clinicopathological characteristics and prognosis. Methods A total of 460 patients with gastric cancer underwent tumor resection in our hospital from March 2013 to November 2014 were enrolled.Tumor tissues, non-tumor gastric mucosa tissues and normal tissues were collected.The expression of miR-320a and CYLD at levels of mRNA and protein were detected by Real-Time PCR, immunohistochemistry and Western blotting.The relationship between the expression of miR-320a and CYLD, and the clinicopathological features & prognosis of gastric cancer patients was analyzed. Results The relative expression of miR-320a and CYLD at the mRNA level in tumor tissues was(0.37±0.09), (0.91±0.23), and the relative expression in non-tumor tissues was(0.86±0.15), (1.56±0.42), respectively.The relative expression of miR-320a and CYLD mRNA in tumor tissues was significantly different from non-tumor tissues(t=60.078, 29.113, P=0.000), the positive expression rate of CYLD protein in tumor tissues was 43.48% when compared to 73.91% in non-tumor tissues.The difference was statistically significant(χ²=86.624, P=0.003).The expression level of miR-320a was significantly associated with the diameter of the tumor and lymph node metastasis(χ²=25.859 and 13.742, P＜0.05).The expression of CYLD was also significantly associated with the TNM stage and degree of tumor differentiation(χ²=37.725 and 59.323, P＜0.05).The median survival of patients with low miR-320a expression(20.36 months, 95% CI:19.252~21.462 months)and those with high miR-320a expression(28.29 months, 95% CI:27.158~29.412 months)were statistically significant(χ²=87.967, P＜0.001).The median survival of patients with CYLD negative expression(17.70 months, 95% CI:16.599~18.796 months)and those with CYLD positive expression(26.74 months, 95% CI:25.474~27.997 months)were statistically significant(χ²=109.887, P＜0.001);The median survival of patients with the co-expressed miR-320a and CYLD was(29.01 months, 95% CI:26.831~28.946 months)and those with the non-co-expressed miR-320a and CYLD(17.13 months, 95% CI:17.214~19.568 months)were statistically significant(χ²=117.680, P＜0.001).There showed a positive correlation between the expression of miR-320a and CYLD at mRNA level(r=0.607, P＜0.001);miR-320a at the low expression, CYLD at the negative expression, TNM staging, lymph node metastasis and degree of tumor differentiation were independent risk factors for the prognosis of gastric cancer(HR=1.939, 2.180, 1.561, 1.719, 1.608, 95% CI:1.141~3.295, 1.252~3.796, 1.014~2.403, 1.115~2.650, 1.097~2.357, respectively)(P＜0.05). Conclusion The expressions of miR-320a and CYLD in tumor tissues of patients with gastric cancer is significantly decreased, which is related to the occurrence and development of diseases, and poor prognosis.It is a potential target for diagnosis and treatment of gastric cancer.

Key words: MiR-320a, Cylindromatosis, Gastric cancer, Prognosis