This study pioneers an integrated bioinformatics dissection of DNA methylation and histone acetylation crosstalk, revealing cohesive epigenetic networks in lung adenocarcinoma beyond isolated marks. It has been aimed to systematically profile DNMT۱, DNMT۳A, MECP۲, HDAC۱, HDAC۲, and EP۳۰۰ expression, correlating epigenetic dynamics with stage, survival, and pathway networks to identify precision targets. To unravel the epigenetic landscape of lung adenocarcinoma, we employed a multi-tiered bioinformatics strategy integrating expression profiling, survival modeling, and functional enrichment. Using GEPIA, we interrogated TCGA and GTEx RNA-seq data to assess DNMT۱, DNMT۳A, MECP۲, HDAC۱, HDAC۲, and EP۳۰۰ expression across normal and tumor tissues, correlating transcript levels with clinical stages and patient outcomes. Subsequently, Metascape facilitated pathway enrichment and protein interaction clustering, enabling comprehensive biological contextualization of our findings. Expression profiling revealed that DNMT۱ and DNMT۳A were significantly upregulated in lung adenocarcinoma, whereas MECP۲, HDAC۱, HDAC۲, and EP۳۰۰ were markedly downregulated, indicating widespread epigenetic dysregulation. Survival and stage‑wise analyses, however, showed no statistically significant associations, suggesting that these expression changes represent early, constitutive events rather than progression‑driven markers. Strikingly, correlation analysis uncovered a densely interconnected network among all six genes, with the strongest pairwise links between DNMT۳A and HDAC۲ (R=۰.۵۸) and HDAC۱–HDAC۲ (R=۰.۴۹), pointing to coordinated crosstalk between methylation and acetylation machineries. Functional enrichment powerfully reinforced this view, identifying "non‑mutational epigenetic reprogramming" and "epigenetic regulation of gene expression" as top pathways, with ۱۰۰% gene involvement. Protein‑interaction clustering further highlighted the MECP۲–HDAC۱–HDAC۲ complex as a central functional hub, while disease association analyses linked these genes to hepatoblastoma, Rett syndrome, and leukemia, underscoring their pleiotropic oncogenic and neurological significance. The findings reveal a tightly coordinated epigenetic network in lung cancer, offering promising multi‑target avenues for precision‑directed therapeutic intervention.
