TPD52 promotes the proliferation and metastasis of gastric cancer cells.

Immunotherapy has improved outcomes for tumor patients, but only a small proportion benefits due to genetic and immunological resistance. Enhancing its efficacy is crucial. Tumor protein D52 (TPD52), a novel immune checkpoint expressed in T cells, B cells, and NK cells, plays a key role in immune regulation. This research aimed to investigate the prognostic value of TPD52 in gastric cancer (GC) and explore its biological functions. We analyzed the TCGA and GEO dataset to assess the transcriptional expression, prognostic significance, immune infiltration, and related biological functions of TPD52. Biological functions of TPD52 in GC cells were studied using CCK-8, colony formation, and transwell assays, while quantitative real-time PCR was used to assess TPD52 expression in the serum of GC patients. ROC analysis evaluated its diagnostic efficiency for GC. Results showed that TPD52 was dysregulated in most tumors and adjacent normal tissues, significantly impacting prognosis. TPD52 expression was strongly correlated with immune cell infiltration, tumor molecular subtypes, and immune checkpoint-regulated genes. Elevated TPD52 expression in GC cell lines promoted cell proliferation, migration, and invasion. Additionally, TPD52 levels were higher in the serum of GC patients, and their combination with CEA and CA199 enhanced its diagnostic efficiency for GC. In conclusion, TPD52 influences immune responses, immune cell infiltration, and tumor malignancy, making it a promising therapeutic target and biomarker for GC prognosis and immune infiltration.