Prognostic value analysis of TOP2A gene expression for bladder cancer

Abstract

Objective To investigate the relationship between DNA topoisomerase Ⅱα (TOP2A) gene expression and clinicopathological characteristics and its significance of prognostic evaluation for patients with bladder cancer. Methods Bladder cancer gene expression profile GSE13507 (n=165) and GSE31189 (n=52) were obtained. The expression profile and clinical information of patients with bladder cancer were retrospectively analyzed, and the survival analysis was made. Gene set enrichment analysis (GSEA) was conducted to explore the related pathways which were regulated by TOP2A. Results Compared with normal bladder tissues, TOP2A was upregulated in bladder cancer tissues (5.823±1.079 vs. 4.820±1.129), with a statistically significant difference (t=4.336, P<0.001). The TOP2A gene expression in patients with bladder cancer was correlated with the age of patients (χ2=5.926, P=0.015), sex (χ2=6.046, P=0.014), T staging (χ2=19.484, P<0.001), N staging (χ2=9.178, P=0.002), M staging (χ2=21.142, P<0.001), tumor grade (χ2=47.005, P<0.001), and progression (χ2=11.735, P=0.001), but it was not correlated with recurrence (χ2=0.808, P=0.369). Survival analysis showed that the specific survival rate in the 100 months of TOP2A gene high expression group and low expression group had a statistically significant difference (66.59% vs. 87.95%, χ2=15.820, P<0.001). The median overall survival time of TOP2A gene high expression group and low expression group were 51.77 months and 134.97 months respectively, with a statistically significant difference (χ2=11.280, P=0.008). The results of GSEA indicated that TOP2A could regulate gene sets related with several pathways like MYC-V1 signaling (P=0.035, FDR=0.132), MYC-V2 signaling (P=0.012, FDR=0.058), E2F signaling (P<0.001, FDR=0.006) and G2M checkpoint (P=0.006, FDR=0.044). Conclusion The TOP2A gene expression is closely related with clinicopathological characteristics of patients with bladder cancer. TOP2A may function as a potential marker of prognosis for patients with bladder cancer. Key words: DNA topoisomerases, type Ⅱ; Urinary bladder neoplasms; Gene expression; Prognosis