Identification of SSBP1 as a prognostic marker in human lung adenocarcinoma using bioinformatics approaches

Single-stranded DNA-binding protein 1 (SSBP1) plays an important role in DNA repair processes and the maintenance of genomic stability. The aim of this study was to evaluate the expression of SSBP1 and its prognostic value in lung adenocarcinoma (LUAD) using bioinformatics approaches.

We applied databases including UALCAN, Kaplan-Meier plotter, LinkedOmics, Webgestalt, cBioPortal and TIMER2.0 in this study.

We found that SSBP1 expression was up-regulated in LUAD samples and was correlated with clinicopathological features including age, cancer stage, and nodal metastasis status by the UALCAN analysis. Multivariate Cox regression analysis by the Kaplan-Meier plotter showed that high SSBP1 expression was independently correlated with poor overall survival (hazard ratio = 1.63, 95% confidence interval: 1.08-2.46, logrank P = 0.02). The LinkedOmics analysis showed that 5078 genes were positively correlated with SSBP1 expression, whereas 7905 genes were negatively correlated with SSBP1 in LUAD. Functional enrichment analysis using the Webgestalt tool showed that for SSBP1 and the genes positively correlating with it, the significantly enriched biological process was ribosomal large subunit biogenesis, and the significantly enriched pathway was proteasome. According to the cBioPortal database, the frequency of SSBP1 alterations was 1.7% in LUAD patients, and patients with SSBP1 alterations had worse prognosis (logrank P = 4.26e-05) compared with those unaltered for SSBP1. Finally, SSBP1 expression was negatively correlated with B cell infiltration level (Rho = -0.193, P = 1.54e-05) and the expression of B cell biomarkers including CD79A and CD19.

Our results suggest that SSBP1 may be a prognostic marker for human LUAD.