To investigate the expression and clinical significance of nucleolar protein 16 (NOP16) in lung adenocarcinoma (LUAD).

The NOP16 mRNA expression level differential was gathered and confirmed between 445 LUAD samples and 54 normal lung samples from the Cancer Genome Atlas (TCGA), and 226 LUAD samples and 20 normal lung samples from the Gene Expression Omnibus (GEO). The mRNA expression of NOP16 was compared in LUAD patients with various clinicopathological characteristics using the Wilcoxon rank-sum test and the Kruskal-Wallis H test. The Kaplan-Meier method was used to assess NOP16′s prognostic value in LUAD. The putative biological pathway of NOP16 in LUAD was investigated using Gene Set Enrichment Analysis (GSEA). Using the Tumor Immune Assessment Resource (TIMER) database, researchers examined the relationship between NOP16 mRNA expression and tumor-infiltrating immune cells (TIICs).

NOP16 mRNA expression in LUAD was significantly higher than that in normal lung tissue (P<0.01), and the NOP16 mRNA expression levels differed statistically among different clinical stages, T stages and N stages (all P<0.05). According to a Kaplan-Meier survival analysis, increased NOP16 mRNA expression was associated with a poor prognosis in LUAD patients (P<0.05). The ribosome, DNA replication, mismatch repair, and p53 signaling pathways were highly enriched in the NOP16 mRNA high expression group (P<0.05, FDR<0.25). NOP16 expression was inversely related to the abundance of B cells (r=-0.221), CD4⁺ T cells (r=-0.254), CD8⁺ T cells (r=-0.12), neutrophils (r=-0.184), macrophages (r=-0.274), and dendritic cells (r=-0.246) (all P<0.01).

NOP16 is likely to become a biomarker for LUAD diagnosis and prognosis, as well as a new therapeutic target.