Overexpression of STOML1 is associated with good prognosis in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a prevalent head and neck malignancy characterized by high recurrence rate, adversely affecting patient prognosis. The present study aimed to identify key genes and mechanisms affecting NPC prognosis using DNA microarray, bioinformatics analysis and clinical data integration. The gene expression profile of patients with NPC with favorable (n=12) and unfavorable (n=8) prognoses was assessed using cDNA profiling. Bioinformatics analysis was performed to identify key prognostic factors, whilst immunohistochemistry assays were performed to evaluate the association between gene-protein expression in 107 NPC samples. The prognostic significance was assessed using Cox regression analysis, Kaplan-Meier curves, log-rank tests and receiver operating characteristic (ROC) analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to assess the underlying mechanisms. cDNA profiling identified six genes, including stomatin like 1 (STOML1), as significant prognostic factors. The Kaplan-Meier Plotter and The Cancer Genome Atlas database indicated that the mRNA expression levels of STOML1 were significantly associated (P<0.05) with head and neck squamous cell carcinoma prognosis. In addition, tissue microarray analysis revealed that high protein expression levels of STOML1 were significantly associated (P<0.05) with improved overall survival (OS) and disease-free survival (DFS). Furthermore, univariate and multivariate Cox analyses demonstrated that STOML1 expression is an independent prognostic factor for OS and DFS. ROC analysis also revealed improved predictive accuracy for 5-year OS when combining STOML1 expression with tumor-node-metastasis (TNM) staging [area under the curve (AUC)=0.874; P<0.001], compared with TNM staging alone (AUC=0.715; P=0.043) and STOML1 expression alone (AUC=0.774; P=0.010). Finally, GO and KEGG analyses demonstrated that the identified genes were mainly involved in pathways associated with apoptosis and cancer progression. Overall, the results of the present study suggested that STOML1 could serve a crucial role in NPC progression and could therefore serve as a valuable biomarker for NPC diagnosis and prognosis.