Whole blood metabolomics reveals coordinated redox-one-carbon axis disruption in NSCLC: a pilot study in an Indian cohort

Metabolic reprogramming is a defining feature of cancer progression. However, systemic metabolic alterations in non-small cell lung cancer (NSCLC), particularly at the whole-blood level, remain insufficiently characterized, especially in Indian patient cohorts. Untargeted whole blood metabolomic profiling was performed using ultra-high-performance liquid chromatography coupled with high-resolution Orbitrap Exploris 120 mass spectrometry in treatment-naïve NSCLC patients (n = 14) and age-matched healthy controls (n = 13). Data were analyzed using univariate and multivariate statistical approaches, followed by pathway enrichment and network analyses. Metabolites were annotated at MSI Level 2 using accurate mass matching and MS/MS spectral library matching. A secondary exploratory comparison was conducted between metastatic and non-metastatic cases. A total of 572 metabolites were putatively annotated, of which 40 showed significant differences between NSCLC patients and controls. Differential metabolites were mainly involved in methylation and one-carbon metabolism (SAM, SAH, MTA), antioxidant defense and redox regulation (GSH, cysteinylglycine, GSNO, γ-Glu-HMC-Gly), and energy metabolism. Additional classes included dipeptides, signaling molecules, and polyamines. PCA, sPLS-DA, and oPLS-DA showed distinct patient-control clustering, supported by VIP scores and hierarchical clustering. Enrichment analysis revealed significant associations with betaine, methylhistidine, methionine, histidine, and phosphatidylcholine metabolisms. In an exploratory subgroup analysis, five metabolites including DFA-III, 3-HC, DL-arginine, Leu-Phe, and Leu-Leu showed preliminary evidence of downregulation in metastatic compared to non-metastatic NSCLC patients. This exploratory whole-blood metabolomics study, the first in an Indian NSCLC cohort, identifies coordinated disruptions in redox and one-carbon metabolic pathways as systemic hallmarks of NSCLC. SAM, MTA, and GSH emerged as candidate biomarkers warranting validation, while DFA-III and 3-HC represent preliminary metastasis-associated leads. All findings require confirmation using authenticated reference standards and validation in larger independent cohorts before clinical utility can be established.