Abstract / Summary
Abstract Background Lung squamous cell carcinoma remains a clinically important subtype of non-small cell lung cancer with limited biologically grounded biomarkers for risk stratification. Because lipid metabolic reprogramming contributes to tumor progression and microenvironmental remodeling, we performed a retrospective multi-cohort transcriptomic analysis to develop and evaluate a lipid metabolism-associated prognostic signature in lung squamous cell carcinoma, explore its biological and immune-related features, and provide experimental validation for selected genes within the model. Results A total of 1,064 lipid metabolism-associated genes were screened, of which 112 were differentially expressed in the TCGA lung squamous cell carcinoma cohort. These genes were mainly enriched in arachidonic acid metabolism, ether lipid metabolism, glycerophospholipid metabolism, and related metabolic pathways. A six-gene prognostic signature comprising ALOX15B , CYP24A1 , PPP2R2C , PTGIS , SPTSSB , and UGT2B17 was constructed in the TCGA training cohort and further evaluated in a TCGA internal test set and six external Gene Expression Omnibus cohorts. The signature stratified patients into high- and low-risk groups with significantly different overall survival and remained independently associated with prognosis in multivariable analyses. In GSE74777, the signature was also associated with recurrence-free survival, with high-risk patients showing poorer recurrence-free survival than low-risk patients. Risk-group comparisons indicated distinct pathway activity and immune-cell composition, and exploratory in silico analyses suggested differences in selected immunotherapy-response-related features. Connectivity Map analysis identified putative compounds for future investigation. To strengthen biological plausibility, selected genes within the signature were further examined in lung squamous cell carcinoma cell lines. Baseline quantitative real-time PCR and western blotting supported differential expression of selected genes, siRNA-mediated suppression of ALOX15B and PPP2R2C was confirmed, and functional assays provided additional support for a potential role of ALOX15B in clonogenic growth and RSL3-related viability responses. Conclusions This study defines a lipid metabolism-associated six-gene prognostic framework for lung squamous cell carcinoma that is supported by multi-cohort retrospective evaluation and selected experimental validation. The findings link survival stratification to biologically relevant metabolic and immune-related features and provide a basis for further mechanistic and prospective translational investigation.