High expression of ceramide synthase 5 predicts a poor prognosis in gastric cancer

Background: Gastric cancer is one of the most common malignant tumors worldwide. Ceramide synthase 5 (CerS5) is a member of the CerS family. Emerging evidence has shown that overexpressed CerS5 is correlated with the poor prognosis of cancer patients. However, the role of CerS5 in gastric cancer remains unclear. The aim of this study is to delineate the relevance of CerS5 levels to gastric cancer.Methods: The expression level of CerS5 was determined by immunohistochemistry, and the survival data of gastric cancer patients were obtained by regular follow-up. The gene expression profile of CerS5 and corresponding clinical features of gastric cancer patients from public databases were obtained from The Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG). The Chi-square test and Fisher's exact test were used to determine the correlation between CerS5 expression and clinicopathological characteristics of gastric cancer patients. Univariate and multivariate Cox regression analyses were used to determine the independent prognostic factors of patients with gastric cancer.Results: Immunohistochemistry (IHC) staining indicated that CerS5 is overexpressed in gastric cancer tissues and metastatic lymph nodes. The levels of CerS5 were correlated with tumor location and carbohydrate antigen 50 (CA50). Moreover, the increased CerS5 levels were significantly correlated with poor prognosis in gastric cancer patients from the ACRG and our institute, but not TCGA, suggesting that CerS5 is probably a prognosis marker of gastric cancer for the Asian population. Finally, univariate and multivariate analyses showed that high expression of CerS5 is an independent factor of poor prognosis for gastric cancer patients.Conclusions: CerS5 is universally overexpressed in gastric cancer tissues and is an independent factor of poor prognosis for gastric cancer patients.