Identifying ARRB2 as a Prognostic Biomarker and Key Player in the Tumor Microenvironment of Pancreatic Cancer through scPagwas Methodology

Introduction: Pancreatic Cancer (PC) is recognized as a highly aggressive malignancy and is anticipated to become the second leading cause of cancer-associated deaths across the United States by 2030. Owing to its late-stage diagnosis and the substantial risk of metastasis, current therapeutic strategies exhibit limited efficacy, resulting in a five-year survival rate below 10%. Consequently, identifying reliable biomarkers and therapeutic approaches remains imperative for enhancing treatment effectiveness. Methods: In this study, using the data of Cancer Genome Atlas (TCGA) and Genome-Wide Association Study (GWAS), we identified macrophage subsets and key gene arrb2 closely related to the progression of Pancreatic Adenocarcinoma (PAAD) via the scpagwas method combined with single- cell and bulk transcriptome analysis. Results: The results showed that in macrophage subpopulations closely related to disease progression, the ARRB2 gene was significantly associated with the prognosis of patients, and low expression suggested poor survival outcomes. The high-expression subgroup of ARRB2 exhibited higher sensitivity to a variety of drugs, and i-bet-762 showed strong molecular binding ability with ARRB2. The experimental detection further confirmed the low expression of ARRB2 in PAAD tissue, which provided the basis for its use as a prognostic marker and potential therapeutic target. Discussion: The results of this study suggest that ARRB2 is not only a prognostic biomarker of PAAD but may also be involved in the regulation of metabolic and immune pathways, thereby affecting drug responsiveness. There was a significant difference in drug sensitivity between the high and low-expression subgroups of ARRB2, suggesting that there may be a potential mechanism between the signal pathway and the therapeutic effect, which warrants further functional research. Considering the heterogeneity of the macrophage population and its dual role in tumor promotion and inhibition, in-depth analysis of the context-dependent function of ARRB2 in the immune-rich microenvironment is expected to provide new insights for the development of combination therapy, especially the potential of combining it with BET inhibitors (such as i-bet-762). Conclusion: Macrophages, along with ARRB2, serve an essential function in the progression of PAAD and immune regulation. The identification of ARRB2 as a prognostic biomarker and its involvement in critical oncogenic pathways furnish a theoretical foundation for targeted therapeutic interventions. These discoveries contribute to the ongoing exploration of diagnostic, prognostic, and treatment strategies for PAAD.