Research on the correlation between SEZ6L2 and the prognosis of colon cancer

• 1、Department of General Surgery，the Second Affiliated Hospital of Soochow University，Suzhou，215000

Abstract：Objective: By using gene expression data and clinicopathological data of colon cancer from the Cancer Genome Atlas (TCGA), gene SEZ6L2 was analyzed to find a potential prognostic molecule for colon cancer based on which a prognostic model were constructed. Methods: The gene expression data and clinical data of colon cancer were downloaded from TCGA databases. The data were organized by Perl and R language, from which the expression of gene SEZ6L2 was extracted. Gene SEZ6L2 was analyzed by differential analysis, survival analysis and clinical correlation analysis. Censored data was deleted to form the complete-case data to construct the prognosis model: SEZ6L2 model, which was compared with traditional TNM stage. Meanwhile, Cox analysis and Gene Set Enrichment Analysis (GSEA) were performed. Results: The expression of SEZ6L2 in tumor tissues was significantly higher than that in normal tissues. Patients with high expression of SEZ6L2 had lower survival rate than that with low expression of SEZ6L2. The patients with high expression of SEZ6L2 showed worse clinical prognostic features such as clinical stage, T stage, N stage, vascular invasion and lymphatic invasion. All results were statistically significant. In SEZ6L2 model, there were SEZ6L2, age, T stage, M stage, clinical stage and vascular invasion. Univariate and multivariate Cox analysis showed that SEZ6L2 could be used as an independent prognostic factor of colon cancer. Kaplan-Meier analysis of the SEZ6L2 model showed that patients with high scores had lower survival rates than those with low scores. The calibration curves showed that the prediction of SEZ6L2 model was consistent with the actual situation. The calculation results of IDI (Integrated Discrimination Improvement) showed that the accuracy of SEZ6L2 model in predicting the prognosis of colon cancer in the first and third year was higher than that of TNM stage, but the same in the 5th and 10th year. In other words, the short-term prognosis prediction of colon cancer by SEZ6L2 model was better than that by traditional TNM stage, but the same in long term. The results of DCA (Decision Curve Analysis) were consistent with that of IDI. GSEA showed that Notch signaling pathway, VEGF signaling pathway, GNRH signaling pathway, etc. were differentially enriched in SEZ6L2 high expression phenotype. Conclusions: SEZ6L2 is a molecular marker for the prognosis of colon cancer. Its high expression indicates poor prognosis. The short-term predictive value of SEZ6L2 model is higher than that of traditional TNM stage. Therefore, SEZ6L2 model can be used as a reference model for short-term prognosis prediction of colon cancer.

Keywords： surgery SEZ6L2 colon cancer TCGA prognosis