Expression and prognostic analysis of AEG-1, NKD-1and β-catenin in gastric cancer tissues

Objective: To investigate the expressions of AEG-1, NKD-1 and β-catenin in gastric cancer (GC), and analyze their relationship with clinicopathological features and prognosis and the correlation among the three proteins.Methods: Fifty GC tissues and 50 adjacent normal tissues of patients who underwent radical gastrectomy in the Third Affiliated Hospital of Inner Mongolia Medical University during December 2015 to June 2017 were collected. The expressions of AEG-1, NKD-1 and β-catenin were detected by immunohistochemical SP method and qRT-PCR. The relationship between positive expression and clinical features and survival time of patients was analyzed, and the correlation between the three was analyzed.Results: The positive expression rates of AEG-1 and β-catenin in gastric cancer were 74% (37/50), 60% (30/50), respectively, which was significantly higher than that of paracancer tissue (18% [9/50] and 26% [13/50]). The positive expression rate of NKD1 in gastric cancer tissues was 20% (10/50), which was significantly lower than that in adjacent tissues [88% (44/50)]; and the differences were statistically significant (p < . 05). AEG-1 mRNA expression level (1.0148±0.0019) and β-catenin mRNA expression level (1.0000±0.0005) in gastric cancer tissues were significantly higher than that of AEG-1 mRNA expression level (1.0002±0.0036) and β-catenin expression level in adjacent tissues mRMA expression level (0.9984±0.0012), and the differences were statistically significant (p < .05). The expression level of NKD1 mRNA in gastric cancer tissues (1.0008±0.0073) was significantly lower than that in adjacent tissues (1.0291±0.0041), and the differences were statistically significant (p < .05). The positive expression of AEG-1, NKD1 and β-catenin in gastric cancer tissues was not related to age, sex or tumor size (p > .05), but was related to differentiation degree, TNM stage and lymph node metastasis (p < .05). In gastric cancer, there was a positive correlation between AEG-1 and β-catenin protein expression (r = .678, p < .001), and a negative correlation between AEG-1 and NKD1 protein expression (r = -.323, p = .012). β-catenin expression was negatively correlated with NKD1 expression (r = -.347, p = .007). The survival time of patients with positive expression of AEG-1 and β-catenin was significantly shortened compared with those with negative expression (p < .05), while the survival time of patients with positive expression of NKD1 was longer than that of patients with negative expression of NKD1 (p < .05).Conclusion: The abnormal expression of AEG-1, NKD-1 and β-catenin is closely related with the occurrence, development, invasion, metastasis and prognosis of  gastric cancer, which provide a therapeutic target and may become markers for prognosis evaluation.