Abstract:

Objective To investigate the expression of HOXC8 in esophageal cancer and its possible signaling pathway. Methods The RNA-Seq data of mRNA expression and clinical prognosis data of esophageal cancer dataset were downloaded and preprocessed from the TCGA (The Cancer Genome Atlas) database. The differentially expressed genes were analyzed, and the volcano map and heat map were drawn to visualize the screened differentially expressed genes. The patients with esophageal cancer were divided into high expression group and low expression group based on the median of HOXC8 expression, and survival analysis was performed using Kaplan-Meier method. GSEA 4.0.1 software was used for gene set enrichment analysis, and graphic analysis of multi-GSEA enrichment analysis was performed at the same time. Results After differential expression analysis of mRNA expression data of 161 esophageal cancer tissues and 11 paracancerous tissues, 3 454 differentially expressed genes were screened, including 2 317 up-regulated genes and 1 137 down-regulated genes. The results of cluster analysis showed that differential expression can effectively distinguish esophageal cancer from adjacent tissues, indicating that the above differential expression results had good accuracy. Difference analysis and paired difference analysis showed that HOXC8 was significantly overexpressed in esophageal cancer, and the differences with tissues adjacent to cancer were statistically significant (t=5.333, P<0.001; t=3.101, P=0.007). After removing samples with a survival time of less than 30 days, a total of 107 samples were used. The results showed that patients with high expression of HOXC8 (n=54) had a worse prognosis, with a median survival time of 553 days (95%CI: 396-710), and the median survival time of patients with low expression of HOXC8 (n=53) was 784 days (95%CI: 62-1 506), with a statistically significant difference (χ ²=4.153, P=0.042), suggesting that HOXC8 was an oncogene. The results of GSEA analysis showed that the samples with high expression of HOXC8 enriched the cell cycle, spliceosome and other related gene sets, while the samples with low expression of HOXC8 enriched the phosphatidylinositol signaling pathway and other related gene sets. Conclusion HOXC8 is significantly overexpressed in esophageal cancer, and patients with high expression of HOXC8 have a worse prognosis. It may regulate the occurrence and development of esophageal cancer through the involvement of cell cycle, spliceosome, phosphatidylinositol signaling pathway and other signaling pathways.

Key words: Esophageal neoplasms, The Cancer Genome Atlas, HOXC8