Identification of 40S ribosomal protein S8 as a novel biomarker for alcohol‑associated hepatocellular carcinoma using weighted gene co‑expression network analysis.

Abstract

Alcohol-associated hepatocellular carcinoma (HCC) is a subtype of HCC with poor prognosis. The present study aimed to identify key biomarkers for alcohol-associated HCC. The gene data profiles and corresponding clinical traits of patients with alcohol-associated HCC were downloaded from The Cancer Genome Atlas (TCGA) database. Firstly, good genes and good samples were identified, which were subsequently used to conduct weighted gene co-expression network analysis (WGCNA). Hub genes in the significant modules were selected following Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and from constructing a protein-protein interaction (PPI) network. Real hub genes among hub genes were determined following progression, survival analysis and gene set enrichment analysis (GSEA), as well as reverse transcription-quantitative PCR and immunohistochemical staining of non-alcohol- and alcohol-associated HCC samples. In total, 64 good samples of alcohol-associated HCC with height score <160 were selected, from which 15,195 good genes were identified and used to conduct WGCNA; 8 gene co-expressed modules were identified using WGCNA, while 3 modules (including pink, magenta and turquoise) were significantly associated with Child-Pugh score, T-stage and body weight. Following GO and KEGG analysis and construction of the PPI network, a total of 30 hub genes were identified in the aforementioned 3 gene co-expressed modules, while 16 hub genes (including AURKB, BUB1, BUB1B, CCNB1, CCNB2, CDC20, CDCA8, CDK1, PLK1, RPS5, RPS7, RPS8, RPS14, RPS27, RPSA and TOP2A) were associated with the development of alcohol-associated HCC, and had a significant prognosis value. Among these genes, only RPS8 was highly expressed in alcohol-associated HCC, but not in non-alcohol-associated HCC, while RPS5 was not significantly associated in either alcohol- or non-alcohol-associated HCC. GSEA demonstrated that 10 pathways, including RNA polymerase and ribosome pathways were enriched in alcohol-associated HCC samples where RPS8 was highly expressed. Taken together, the results of the present study demonstrate that RPS8 may be a novel biomarker for the diagnosis of patients with alcohol-associated HCC.