Matrix stiffness triggers lipid metabolic crosstalk between tumor and stromal cells to mediate bevacizumab resistance in colorectal cancer liver metastases.

Abstract

Bevacizumab is an anti-vascular endothelial growth factor (VEGF) monoclonal antibody that plays an important role in the combination treatment of advanced colorectal cancer (CRC). However, resistance remains a major hurdle limiting bevacizumab efficacy, highlighting the importance of identifying mechanism of anti-angiogenic therapy resistance. Here, we investigated biophysical properties of the extracellular matrix (ECM) related to metabolic processes and acquired resistance to bevacizumab. Evaluation of paired pre- and post-treatment samples of liver metastases from 20 CRC patients treated with combination bevacizumab therapy, including 10 responders and 10 non-responders, indicated that ECM deposition in liver metastases and a highly activated fatty acid oxidation (FAO) pathway were elevated in non-responders after anti-angiogenic therapy compared to responders. In mouse models of liver metastatic CRC, anti-VEGF increased ECM deposition and FAO in CRC cells, and treatment with the FAO inhibitor etomoxir enhanced the efficacy of antiangiogenic therapy. Hepatic stellate cells (HSCs) were essential for matrix stiffness-mediated FAO in colon cancer cells. Matrix stiffness activated lipolysis in HSCs via the focal adhesion kinase (FAK)/yes-associated protein (YAP) pathway, and free fatty acids secreted by HSCs were absorbed as metabolic substrates and activated FAO in colon cancer cells. Suppressing HSC lipolysis using FAK and YAP inhibition enhanced the efficacy of anti-VEGF therapy. Together, these results indicate that bevacizumab-induced ECM remodeling triggers lipid metabolic crosstalk between colon cancer cells and HSCs. This metabolic mechanism of bevacizumab resistance mediated by the physical tumor microenvironment represents a potential therapeutic target for reversing drug resistance.