MPP7 is a potential prognostic marker and is associated with cancer metabolism and immune infiltration in clear cell renal cell carcinoma: a bioinformatics analysis based on the TCGA database

BACKGROUND: Metastasis is a major negative prognostic marker in clear cell renal cell carcinoma (ccRCC). Membrane palmitoylated proteins (MPPs) are a class of cell polarity-associated proteins that function in both cell-cell junction and adhesion. However, the relationship between MPP7 and the prognosis of ccRCC remains elusive. In this study, we aimed to investigate the associations between MPP7 expression with clinical prognosis of ccRCC using bioinformatics analyses. METHODS: The messenger RNA (mRNA) and protein expression patterns of MPP7 in different cancer types were examined using The Cancer Genome Atlas (TCGA) and Human Protein Atlas (HPA) databases, with key clinical characteristics (TNM and pathological stages, pathological grade, survival status) included. A nomogram model using MPP7 expressions and other clinical factors was built to predict the survival probability. The Kaplan-Meier plotter and Cox regression were employed to investigate the clinical significance and prognostic value of MPP7 in ccRCC. MPP7 expression-associated signaling pathways with were analyzed by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) tools. The Tumor Immune Estimation Resource (TIMER) database was used to investigate the correlation between MPP7 and the infiltration patterns of immune cells. RESULTS: By analyzing TCGA-kidney renal clear cell carcinoma (TCGA-KIRC) and HPA databases, we found that MPP7 was differentially expressed in tumor tissues and adjacent normal tissues (P<0.001). The MPP7 expression patterns were associated with pathological stage (P<0.001), histological grade (P<0.01), and survival status (P<0.001). Using nomogram model, Cox regression and survival analysis, it showed that MPP7 expressions combined with key clinical factors could accurately predict the clinical prognosis. The promoter methylation patterns of MPP7 were correlated with the clinical factors of ccRCC patients. Furthermore, the KEGG and GO analyses demonstrated that MPP7 is associated with mitochondrial oxidative metabolism. MPP7 expression was associated with multiple types of immune cells and correlated with the enrichment of these cells. CONCLUSIONS: MPP7 is a critical gene links with ccRCC prognosis and is associated with tumor immune status and metabolism. MPP7 could become a potential biomarker and important therapeutic target for ccRCC patients.