Coordinated single-cell tumor microenvironment dynamics reinforce pancreatic cancer subtype

Area of Science:

• Oncology
• Immunology
• Bioinformatics

Background:

• Pancreatic ductal adenocarcinoma (PDAC) bulk analyses are confounded by the complex tumor microenvironment (TME).
• Distinct tumor and stroma subtypes with prognostic value have been identified, but the signaling pathways driving these landscapes remain unclear.
• Understanding tumor-TME interdependence is crucial for developing effective PDAC therapies.

Purpose of the Study:

• To integrate single-cell RNA sequencing data to create a comprehensive PDAC atlas.
• To elucidate the signaling interactions governing distinct immune and stromal landscapes in PDAC.
• To provide tools for future research, including a cell type classifier and a signaling factor atlas.

Main Methods:

• Integration of 92 single-cell RNA-seq samples from seven independent PDAC studies.
• Comparative analysis of immune cell populations and stromal characteristics between different PDAC subtypes.
• Validation of identified signaling factors in mouse models.

Main Results:

• Patients with activated stroma exhibit increased myofibroblastic and immunogenic fibroblasts, M2-like macrophages, and regulatory T-cells.
• Patients with 'normal' stroma show M1-like macrophage recruitment and elevated effector and exhausted T-cells.
• A reproducible PDAC atlas and a pretrained cell type classifier were developed.

Conclusions:

• The study highlights distinct immune profiles associated with activated versus normal stroma in PDAC.
• These findings provide insights into the signaling networks that shape the PDAC TME.
• The developed resources facilitate further investigation into PDAC heterogeneity and therapeutic strategies.