SSBP1: A Potential Prognostic Marker of Lung Adenocarcinoma

Abstract

Background: Single-stranded DNA-binding protein 1 (SSBP1) is pivotal to mitochondrial DNA (deoxyribonucleic acid) replication, reintegration, and reconstruction. However, precisely how SSBP1 contributes to lung adenocarcinoma (LUAD) remains unclear. Methods: In this bioinformatics study, raw datasets were obtained from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and the Genotype-Tissue Expression (GTEx) project. SSBP1 expression was investigated using TCGA, GEO, GTEx, cBioPortal, TIMER2.0, and Gene Expression Profiling Interactive Analysis databases. SSBP1 expression in clinical specimens was determined using fluorescence-based reverse-transcription quantitative polymerase chain reaction and immuno-histochemical experiment. Results: As LUAD progressed, SSBP1 was drastically upregulated and closely associated with disease progression. To assess the prognostic and diagnostic value of SSBP1, the Kaplan-Meier plot, Cox proportional hazard model, and receiver operating characteristic curve methods were employed. SSBP1 reliably and accurately predicted and diagnosed LUAD. SSBP1 overexpression correlated with poor overall survivability, as well as T, N, and pathological stages. Simultaneously, based on gene set enrichment analyses, SSBP1-related genes were closely related to the mitochondrial translation pathway. Furthermore, SSBP1 expression positively correlated with the infiltration degrees of aDC (activated dendritic cells), Th2 (T helper2 cells), and Tgd (gammadelta T cells);By contrast, negative correlations were observed with the infiltration degrees of CD56 bright cells, mastocytes, macrophages, iDC (interstitial dendritic cells), eosinophils, DC (dendritic cells), CD8 T cells, B cells, Tcm (central memory T cells), Tem (effective memory cells), TFH (T follicular helper cells), Th17 cells (T helper 17 cells), pDC (plasmacytoid dendritic cells), and NK cells (natural killer cells). Conclusions: In summary, SSBP1 may play a central role in mitochondrial translation and can be regarded as a molecular target for predicting LUAD prognosis.