Construction and validation of immunogenic cell death-related molecular clusters, signature, and immune landscape in pancreatic cancer

Pancreatic cancer (PC) is a malignancy of the gastrointestinal tract that is characterized by a poor prognosis. This study investigates the roles of immunogenic cell death (ICD) genes in the prognosis and progression of PC. Expression data for PC patients were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets, while ICD genes were sourced from published literature. We explored the expression patterns and identified two distinct clusters based on ICD genes. Kaplan-Meier analysis, differential expression analysis, tumor mutational burden analysis, and immune cell infiltration analysis were performed on these clusters. An ICD gene-based risk model was developed, categorizing samples from the TCGA and GEO datasets into low- and high-risk groups. Additionally, we investigated the expression levels of the genes included in the risk model within the TCGA cohort and our own samples. Finally, a loss-of-function assay was conducted to assess the role of MYD88 in PC. Two clusters of PC samples were identified, patients in the ICD-low cluster exhibited a higher degree of immune cell enrichment. The survival time of patients in the low-risk group was longer than that of those in the high-risk group. The genes included in the risk model (CASP1, MYD88, and PIK3CA) showed upregulated expression levels in tumor samples. Furthermore, the predictive accuracy of our risk model was validated using our own samples. Genetic inhibition of MYD88 led to significantly decreased proliferation and migration of PC cells in the loss-of-function assay. There were disparities in survival time and tumor immune microenvironment (TIME) between two ICD gene clusters. Additionally, we developed an ICD-related risk model that was validated as an independent prognostic indicator for patients with PC.