Investigation of the Impact of m6A-Related Characteristic Genes on Pancreatic Cancer Using Mendelian Randomization and Single-Cell Sequencing

Pancreatic cancer (PC) is an aggressive malignancy with rapid progression and poor prognosis. The genetic heterogeneity of PC contributes to its malignancy. N6-methyladenosine (m6A) RNA modification and its regulatory factors are associated with poor prognosis and immunotherapy efficacy in PC patients. This study aimed to investigate the impact of m6A-related signature genes (m6ARS) on PC using single-cell RNA sequencing (scRNA-seq) and the Secretion Modification Region (SMR) method with multi-omics data. Methods included AddModule scoring, single-sample gene set enrichment analysis (ssGSEA), and weighted gene co-expression network analysis (WGCNA) to analyze m6ARS at the single-cell and whole transcriptome levels. The SMR method identified pathogenic genes associated with PC among m6ARS. Patients were stratified into high and low-expression groups based on m6ARS expression, revealing survival differences. Performance was evaluated using receiver operating characteristic (ROC) curves and immunohistochemistry (IHC) staining. Functional and pathway analyses, including GSEA and protein-protein interaction (PPI) networks, were conducted. The clinical value of m6ARS was explored through correlation analysis with clinical parameters, single-cell, and spatial transcriptome analyses, as well as immune microenvironment studies. Drug sensitivity analysis assessed m6ARS's potential role in chemotherapy response. Results identified a turquoise module comprising 882 m6ARS genes at both single-cell and bulk transcriptome levels. SMR analysis found 102 proteins associated with PC, with three key m6ARS genes—GCC2, UBE2D3, and TMX1—showing causal relationships with PC. TMX1 was confirmed as a prognostic marker for PC, with upregulation linked to tumor promotion and worse prognosis. Clinical and immune analyses, as well as drug sensitivity assessments, suggest TMX1's potential as a biomarker for PC prognosis and immunotherapy response. This study integrated single cell sequencing and SMR analysis to identify the shared gene TMX1, emphasizing its potential as a robust prognostic biomarker for PC and its response to immunotherapy. Therefore, targeting TMX1-mediated oxidative stress may represent a novel therapeutic strategy for PC and offer new avenues for future drug development.