ENDOV upregulation and outcomes in females with colorectal adenocarcinoma.

Abstract

175 Background: Colorectal adenocarcinoma (COAD) is a common cancer in gastrointestinal tract. Endonuclease V (ENDOV), an enzyme with specificity for deaminated adenosine (inosine) in nucleic acids, was found to be involved in the development of certain cancers. Thus, this study was performed to explore the effects of ENDOV on the prognosis of COAD. Methods: RNA-sequencing FPKM data and corresponding clinical information of 41 normal tissues and 480 tumor tissues of COAD were acquired from The Cancer Genome Atlas (TCGA). Then ENDOV expression differences between the normal and cancer tissues were compared with Wilcoxon rank-sum test via ‘limma’ package. Overall survival (OS) and disease specific survival (DSS) analyses were conducted by Kaplan–Meier (K–M) method via ‘survminer’ package. Subgroup analyses of different genders were also performed. Results: The expression of ENDOV was downregulated in tumors compared with normal tissues (p < 0.001). However, higher expression of ENDOV is associated with worse OS (HR: 1.83, 95%CI: 1.23-2.73, P = 0.003) and DSS (HR: 1.75, 95%CI 1.06-2.91, P = 0.03). Subgroup analysis found that higher expression of ENDOV was associated with worse OS (HR: 2.17, 95%CI 1.18-3.98, P = 0.012) in females, but not in males (HR: 1.48, 95%CI 0.86-2.53, P = 0.158). As for DSS, higher expression of ENDOV was also correlated with worse outcome (HR: 2.36, 95%CI 1.07-5.19, P = 0.033) in females, but not in males (HR: 1.45, 95%CI 0.73-2.86, P = 0.287). Conclusions: ENDOV is overall downregulated in COAD tumor samples. However, higher expression of ENDOV in certain COAD patients is associated worse OS and DSS in females but not in males. This indicates the potential role of ENDOV in predicating the prognosis of COAD in female patients.