Bioinformatics Analysis and Experimental Validation of Lactylation Related Genes in Lung Adenocarcinoma.

PURPOSE: Lactylation, a novel post-translational modification, is dysregulated in various tumors and influences lung cancer progression. However, its role in lung adenocarcinoma (LUAD) remains unclear. Based on multi-omics analysis results, this study investigated lactylation levels in LUAD tissues and explored the dual research positioning of lactylation as a prognostic marker and therapeutic target. METHODS: Lactylation levels in LUAD tissue microarrays were assessed using immunohistochemistry and immunofluorescence. Western blot analysis validated these findings. Differential expression analysis of lactylation-related genes was conducted using The Cancer Genome Atlas (TCGA, n=365), based on |log2 fold-change (FC)|≥2. KEGG pathway analysis identified key biological pathways, and COX regression analysis pinpointed prognostic genes. Single-cell RNA sequencing data from the GEO database validated these genes, with mitochondrial gene threshold <20%. RESULTS: Lactylation levels were significantly elevated in LUAD tissues compared to adjacent non-cancerous tissues, as shown by immunohistochemistry and confirmed by Western blot analysis. Differential analysis identified 17 lactylation-related genes enriched in pathways such as AMPK signaling and cellular senescence. COX regression analysis identified five risk genes: KIF2C, MKI67, HMGA1, PFKP, and CCNA2. Validation with single-cell RNA sequencing data revealed high expression levels of these genes in LUAD tissues and the LUAD cell line H1299. Functional validation revealed that the 5 genes panel significantly regulates global lactylation modification in vitro. CONCLUSION: LUAD tissues exhibit elevated lactylation levels, suggesting their potential as prognostic biomarkers. The identified genes-KIF2C, MKI67, HMGA1, PFKP, and CCNA2-are highly expressed in cancerous tissues and correlate with LUAD prognosis. These findings highlight their value as tumor biomarkers and therapeutic targets, offering new opportunities for targeted LUAD treatments.