Expression of Snail in Colorectal Cancer, Related Signal Pathway and its Relationship with Prognosis
LIU Yan,LI Shuang-biao,XU Hua
Abstract:
Objective To investigate the expression of snail in colorectal cancer, its signal pathway and its relationship with prognosis. Methods The expression level of snail gene mRNA in the TCGA database was compared with that in the colorectal cancer tissues and the adjacent tissues by using bioinformatics analysis tools. The interaction network of snail protein and protein was constructed in the string database and the function of related protein and KEGG signal pathway were enriched. According to the expression level of snail, the patients were divided into high and low expression groups.The differences of total survival (OS) and disease free progression survival (DFS) were compared. The relationship between the expression of snail protein and the clinicopathologicfeatures of 69 patients with colorectal cancer were analyzed by immunohistochemistry.Results The expression level of snail gene in colorectal cancer was significantly higher than that in the adjacent tissues. PDGFB gene (r = 0.624, P < 0.05) and slc44a4 gene (r =–0.48, P < 0.05) were positively and negatively correlated with snail respectively. The biological process, cell composition and molecular function of snail are mainly enriched in histone H4 deacetylation, ESC/E (Z) complex and NAD dependent histone deacetylase activity(H3-K14 specificity) respectively. KEGG signal pathway was enriched in tumor related signaling pathway,Notch signaling pathway, Wnt signaling pathway and colorectal cancer related signaling pathway. The total survival rate of patients with high expression of snail gene mRNA was lower than that of patients with low expression (HR = 1.6, P< 0.05), while the survival rate of patients without disease progression in high and low expression group was statistically different (P > 0.05). The high expression rate of snail protein in colorectal cancer was 59.2% (41/69). The high expression of snail protein in colorectal cancer had lower differentiation (P< 0.05), higher lymph node metastasis (P < 0.05), higher lymphatic invasion (P< 0.05) and later Dukes stage (P<0.05). Conclusion The expression of snail gene is up-regulated in colorectal cancer and it can be used as a molecular marker of poor prognosis in colorectal cancer.
