Unveiling Lipid Metabolism-Related Gene PTGDS: A Tumor Suppressor in Lung Adenocarcinoma with Therapeutic Potential.

Lung adenocarcinoma (LUAD) remains a leading cause of cancer-related mortality worldwide. Although the lipid metabolism-associated gene PTGDS has been implicated in tumorigenesis, its functional significance and regulatory mechanisms in LUAD are poorly understood. We integrated multi-omics data from TCGA and GEO cohorts to evaluate PTGDS expression and its clinicopathological relevance. Functional characterization was performed using gain-of-function models in LUAD cell lines and a xenograft mouse model, assessing proliferation, migration, invasion, and immune microenvironment alterations. PTGDS expression is markedly reduced in LUAD tissues and correlates strongly with advanced disease stage and unfavorable prognosis. Clinically, low PTGDS expression is associated with specific driver mutations and reduced tumor mutation burden. Notably, PTGDS levels correlate with enhanced cytotoxic T-cell infiltration and suppressed M2 macrophage polarization, suggesting immunomodulatory functions. Ectopic expression of PTGDS significantly suppressed malignant behaviors in vitro and tumor growth in vivo. Mechanistically, PTGDS overexpression was associated with reduced expression of CDK1 and PLK1 and increased expression of p21 and p27. Our findings establish PTGDS as a novel tumor suppressor in LUAD that restrains tumor progression through cell cycle modulation and immune microenvironment remodeling, highlighting its potential as both a prognostic biomarker and a therapeutic target.