Abstract 1498: TGFβ signaling in cancer-associated fibroblasts drives a hepatic gp130-dependent pro-metastatic inflammatory program in CMS4 colorectal cancer

Abstract Background: Colorectal cancer (CRC) is characterized by a metastatic pattern that shows tropism towards the liver which is the major cause of CRC-related deaths. The current CRC classification, Consensus Molecular Subtypes (CMS), suggests an association between transforming growth factor (TGF) -β signaling, cancer-associated fibroblasts (CAFs), and the risk of liver metastasis. However, the key downstream effectors of TGFβ signaling in CAFs and their role in hepatic metastases remain poorly understood. Methods: The aim of this study was to investigate the TGF-β/CAF dependent cross talk with the hepatocytes in pre-metastatic niche formation. CAFs from 18 primary CRC tissues and 7 liver-metastasized CRC were stimulated with TGFβ1 and qPCR arrays/ELISAs were performed to identify differentially expressed genes. Results were cross-referenced with RNAseq expression data of CMS-classified CRC and in fresh samples from CRC patients. To investigate CAF-liver crosstalk hepatocytes were stimulated with the TGFβ primed CAF-derived cytokines and the effect on pro-inflammatory gene expression and neutrophil migration was determined. Subsequently, blockade of these pathways via chemical inhibition and CRISPR/Cas9 genetic ablation was performed to study the molecular mechanism involved in the induction of this hepatic pro-inflammatory program. Results: TGFβ signaling in primary CRC-derived CAFs leads to increased expression of different IL-6 cytokine family members, which was also reflected in human CRC samples. CAF-derived IL6 family members induce upregulation of myeloid chemoattractants, including SAA1, in hepatocytes and increased neutrophil-to-hepatocyte migration in vitro. Chemical blockade and genetic ablation of the IL-6 family cytokine signaling pathway showed the critical role of the gp130 co-receptor in the regulation of this inflammatory response in hepatocytes and the potential formation of a premetastatic niche. Conclusion: TGFβ signaling in CAFs actively contributes to the formation of a neutrophil-dependent, pre-metastatic hepatic niche, and this mechanism might play a role in CMS4 subtype CRC. Citation Format: Subinuer Abudukelimu, Tom J. Harryvan, Stef G. Janson, Imke Stouten, Els M. Verdegaal, Lukas JAC Hawinkels. TGFβ signaling in cancer-associated fibroblasts drives a hepatic gp130-dependent pro-metastatic inflammatory program in CMS4 colorectal cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1498.