Decreased expression of transcription elongation factor A-like 7 is associated with gastric adenocarcinoma prognosis.

Abstract

BACKGROUND: We sought to investigate the expression levels and prognosis value of TCEAL7 in primary gastric cancer. METHODS AND RESULTS: We investigated TCEAL7 and other homologous five members of the TCEAL family expression in normal gastricepithelial cell line and gastric cancer cell lines using real-time quantitative PCR. Furthermore, we examined the expression of TCEAL7 in 39 paired cancerous and matched adjacent noncancerous gastric mucosa tissues by real-time quantitative PCR and western blotting. Moreover, we analyzed TCEAL7 expression in 406 gastric cancer patients using immunohistochemistry. The relationships between the TCEAL7 expression levels, the clinicopathological factors, and patient survival were investigated. RT- qPCR data showed that mRNA expression level of TCEAL7 was significantly lower in the gastric cancer cell lines comparing with the levels of other five members of the TCEAL family. Results also revealed decreased TCEAL7 mRNA (P = 0.025) and protein (P = 0.012) expression in tumor tissue samples compared with matched adjacent non-tumor tissue samples. Immunohistochemical staining data showed that TCEAL7 expression was significantly decreased in 43.3% of gastric adenocarcinoma cases. The result also showed that the low TCEAL7 expression was significantly correlated with female, larger tumor size, higher histological grade and worse nodal status. Kaplan-Meier survival curves revealed that the reduced expression of TCEAL7 was associated with a poor prognosis in gastric adenocarcinoma patients (P<0.001). Based on a univariate analysis that included all 406 patients, TCEAL7 expression was found to have statistically significant associations with overall survival (P<0.001). Multivariate analysis also demonstrated that TCEAL7 expression (P = 0.009), age, tumor size, histological grade, lymphovascular invasion, T stage, N stage and M stage were independent risk factors in the prognosis of gastric cancer patients. CONCLUSIONS: Our study suggests that TCEAL7 might serve as a candidate tumor suppressor and a potential prognostic biomarker in gastric carcinogenesis.