Integrated analysis of scRNA-seq and bulk RNA-seq data identifies BHLHE40 as a key gene in pancreatic cancer progression and gemcitabine resistance.

OBJECTIVE: Pancreatic cancer is characterized by its high mortality rate and short survival periods, and novel therapeutic targets and tailor personalized strategies are urgently needed. In this study, we aim to investigate the molecular mechanisms underlying pancreatic ductal adenocarcinoma (PDAC) progression and chemoresistance, with a focus on identifying novel therapeutic targets.

METHODS: Multiomics approaches were integrated to identify novel actionable targets for PDAC. Public datasets such as TCGA and GEO were utilized to investigate the relationship between gene expression and clinical outcomes. Functional enrichment, cell-cell communication, and metabolic pathway analyses were performed to reveal PDAC heterogeneity and therapeutic resistance mechanisms.

RESULTS: BHLHE40 was identified as a hub gene linked to high-CNV PDAC cells, Gemcitabine resistance, and poor prognosis in PDAC. High BHLHE40 expression is significantly correlated with immunosuppressive tumor microenvironment (TME) features such as reduced CD8+ T infiltration, TCR richness, and lower tumor mutational burden (TMB). ChIP-seq data analysis confirmed BHLHE40 could directly bind to the SAT1 promoter, establishing a transcriptional axis promoting chemoresistance. Single-cell RNA-seq analysis further revealed that the BHLHE40+/SAT1+ subpopulation cells are resistant to Gemcitabine in PDAC.

CONCLUSIONS: BHLHE40 is significantly correlated with PDAC malignancy and chemoresistance via SAT1 regulation and immune evasion. Targeting BHLHE40 may sensitize PDACs to Gemcitabine and facilitate personalized treatment for BHLHE40+ PDAC patients.