Deuterium Concentration as a Dual Regulator: Depletion and Enrichment Elicit Divergent Transcriptional Responses in A549 Lung Adenocarcinoma Cells

Deuterium abundance has been proposed as a modulator of cellular metabolism; however, its influence on cancer-associated gene expression networks remains incompletely characterized. We analyzed A549 lung adenocarcinoma cells cultured across four deuterium concentrations (40, 80, 150, and 300 ppm) using NanoString nCounter profiling. Expression data were processed through multistep filtering, symbolic trajectory encoding, and density-based spatial clustering (DBSCAN) to identify extreme expression responders, and Gaussian mixture modeling (GMM-6) to resolve coordinated gene-expression modules. DBSCAN identified 11 outlier genes under deuterium depletion, including reduced expression of multidrug-resistance-associated <i>ABCB1</i> (-42% at 80 ppm), proliferative signaling component <i>FGFR4</i> (-19%), and transcriptional amplifier <i>MYCN</i> (-24%). In contrast, enrichment at 300 ppm produced a broad increase in oncogenic expression (mean +44%), with marked elevation of inflammation-related (<i>IL6</i>, <i>TGFBR2</i>) and invasion-associated (<i>MMP9</i>) genes. GMM-6 clustering of the remaining core network resolved six functional modules, indicating that depletion preferentially reduces expression of genes associated with plasticity-related programs (Cluster 5: <i>TGFB1</i>, <i>S100A4</i>), while basal survival-associated genes (Cluster 6: <i>BIRC5</i>, <i>RET</i>) remain comparatively stable. Together, these results indicate that deuterium concentration acts as a bidirectional modulator of gene expression programs in the A549 model, with enrichment broadly elevating oncogenic expression and moderate depletion associated with selective downregulation of genes linked to resistance, signaling, and invasive behavior. Significance: Deuterium depletion is associated with reduced expression of genes involved in multidrug resistance, growth-factor signaling, and transcriptional amplification, revealing deuterium-responsive transcriptional vulnerabilities within the A549 lung adenocarcinoma model.