Expression Characteristics, Prognostic Value, and Immune-Related Analysis of PPP2R1A in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is a major subtype of lung cancer with poor prognosis. This study investigates the expression, prognostic significance, and functional role of the PPP2R1A gene in LUAD. Using the Xiantao Academic Online tool, we observed a significant upregulation of PPP2R1A in 26 cancers, including LUAD, confirmed by both unpaired and paired analysis ( P  < 0.05). The diagnostic potential of PPP2R1A in LUAD was modest, with an AUC of 0.593. Kaplan-Meier survival analysis revealed that overexpression of PPP2R1A was associated with poor progression-free survival (FP) and overall survival (OS) in LUAD patients, particularly in early-stage disease ( P  < 0.05). Subgroup analysis indicated a significant correlation between PPP2R1A expression and clinical features such as N stage and tumor stage, with higher expression in advanced-stage LUAD. A protein-protein interaction (PPI) network identified key interaction partners of PPP2R1A, including PRPF31 and SCAF1, and functional enrichment analysis highlighted roles in protein dephosphorylation, cell cycle regulation, and metabolic pathways. Moreover, the genetic mutation frequency of PPP2R1A was low (2.3%), with missense mutations in the phosphatase domain. Immunoinfiltration analysis revealed significant correlations between PPP2R1A expression and macrophage infiltration, as well as the presence of regulatory T cells, suggesting a potential immunomodulatory role in LUAD. Functional assays showed that PPP2R1A knockdown significantly inhibited the proliferation, invasion, and metastasis of LUAD cells, further supporting its role in tumor progression. These findings suggest that PPP2R1A plays a critical role in LUAD pathogenesis and may serve as a potential diagnostic and therapeutic target.