Pancreatic CAF-Derived Autotaxin Drives Autocrine CTGF Expression to Modulate Protumorigenic Signaling

Area of Science:

• Oncology
• Cancer Biology
• Tumor Microenvironment Research

Background:

• Autotaxin (ATX) is a target in pancreatic ductal adenocarcinoma (PDAC).
• The ATX/lysophosphatidic acid (LPA) axis role in PDAC's tumor microenvironment (TME) is not fully understood.
• Cancer-associated fibroblasts (CAFs) are key components of the PDAC TME.

Purpose of the Study:

• To investigate the source and function of ATX in the PDAC TME.
• To identify downstream mediators of ATX signaling in CAFs.
• To explore the dual role of ATX (enzymatic and chaperone) in CAF-mediated protumorigenic signaling.

Main Methods:

• Analysis of patient samples and cell line datasets to determine ENPP2 (ATX) expression.
• Utilizing the ATX inhibitor IOA-289 in a PDAC CAF-derived cell line (0082T).
• Genetic and pharmacologic inhibition of ATX in CAFs to assess CTGF secretion and LPA signaling.

Main Results:

• The majority of ENPP2 expression in PDAC originates from the TME, particularly CAFs.
• CAF-derived ATX promotes protumorigenic signaling through autocrine and paracrine mechanisms.
• Inhibition of ATX in CAFs reduced connective tissue growth factor (CTGF) secretion via LPA receptor signaling.
• Extracellular LPA levels increased upon ATX inhibition, suggesting a role for ATX's chaperone function.

Conclusions:

• ATX, primarily from CAFs, promotes a protumorigenic PDAC microenvironment.
• ATX influences CAF secretion through both its enzymatic (LPA production) and chaperone functions.
• Targeting ATX offers a potential therapeutic strategy for PDAC by disrupting CAF-mediated pro-tumorigenic signaling.