Pan-cancer analysis of NADPH oxidase 4 identifying its prognostic and immunotherapy predictive value and in vitro experimental verification in glioblastoma.

BACKGROUND

NADPH oxidase 4 (NOX4) plays an important role in metabolic reprogramming, epithelial-mesenchymal transition (EMT), and other cellular processes by strictly regulating intracellular ROS generation. However, there is a lack of analysis on the role of NOX4 in the tumor immune microenvironment and predictive value for prognosis and immunotherapy response in various tumor types.

METHODS

This study used data from the Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), Tumor Immune Single-cell Hub (TISCH), Genotype-Tissue Expression (GTEx), cBioPortal, Tumor Immune Estimation Resource (TIMER 2.0), and ROC Plotter databases to analyze the expression, prognosis, biological function, immune cell infiltration, and genetic and epigenetic changes of NOX4 in various tumor types. Meanwhile, in vitro experiments were conducted to verify the role of NOX4 in the migration, invasion, proliferation, and apoptosis of glioblastoma (GBM).

RESULTS

The findings indicated that NOX4 is upregulated in various types of cancer, accompanied by gene amplification, mutation, and deletion. The high expression of NOX4 is associated with poor prognosis in various cancers. Functional enrichment analysis showed that NOX4 is mainly enriched in immune and cancer progression pathways, such as angiogenesis, EMT, interferon response, inflammatory response. Immune cell infiltration analysis showed that high expression of NOX4 is associated with increased infiltration of cancer-associated fibroblasts (CAF) and macrophages. In vitro experiments showed that silencing NOX4 inhibits the proliferation, migration, and invasion of GBM and increases cell apoptosis.

CONCLUSION

NOX4 can serve as a prognostic and immunotherapy response biomarker for various cancers and targeting NOX4 may be a feasible anti-tumor therapy and may have synergistic anti-tumor effects combined with immunotherapy.