Agrimoniin combines with erlotinib to inhibit the proliferation of pancreatic cancer cells by suppressing signal interactions in the tumor microenvironment and disrupting two positive feedback loops involving lactic acid production

Erlotinib, an epidermal growth factor receptor (EGFR) small molecule inhibitor approved by the Food and Drug Administration (FDA) for the treatment of pancreatic cancer, faces significant drug resistance challenges. To address this, we investigated the potential of agrimoniin, a key active compound in the traditional Chinese medicine Agrimonia pilosa , which is known for its potent anticancer activity. This study aims to explore the combined effect of these two compounds in pancreatic cancer. We sought to verify the combined inhibitory effect of pancreatic cancer by agrimoniin and erlotinib in vitro and in vivo using various assays, including subcutaneous xenograft experiments and western blot. Single-cell RNA sequencing, bioinformatics, western blot, and lactic acid assays were performed to study how agrimoniin and erlotinib affect the tumor microenvironment and aerobic glycolysis. Finally, using signal pathway inhibitors/agonists, lactic acid assays, and Western blot, we aimed to reveal two positive feedback loops between signal pathways and lactic acid production. Agrimoniin combines with erlotinib to inhibit proliferation of pancreatic cancer cells. Together, they effectively suppress signal interactions between tumor cells, stromal cells, and macrophages within subcutaneous tumors. Simultaneously, they jointly inhibit aerobic glycolysis and lactic acid production in pancreatic cancer. Notably, this study proposes two potentially novel positive feedback loops between the PI3K/AKT/HIF-1α/HK2, MEK/ERK/HIF-1α/HK2 signaling pathways and lactic acid production. The combination of agrimoniin and erlotinib suppresses signal interactions between tumor cells, macrophages, and stromal cells in the tumor microenvironment, reprograms aerobic glycolysis, disrupts two positive feedback loops, thereby cooperatively inhibiting the proliferation of pancreatic cancer cells. This study provides a theoretical basis for agrimoniin as a sensitizer or resistance-reversing agent for erlotinib, and offers new insights and potential targets for pancreatic cancer drug development.