Agrimoniin synergistically works with erlotinib to inhibit the proliferation of pancreatic cancer by remodeling the tumor microenvironment and suppressing lactic acid expression

Erlotinib, as an EGFR small molecule inhibitor for pancreatic cancer, its efficacy as monotherapy is limited. Combination of erlotinib and gemcitabine has shown improvement in multiple survival indicators. However, drug resistance remains a challenge. Agrimoniin, the main active ingredient in Agrimonia pilosa, has anticancer potential. Whether it can serve as a synergistic or resistance-reversing drug for erlotinib require further research. In this study, we performed subcutaneous xenograft tumor experiments, CCK8, EdU assays, flow cytometry, HE staining, immunohistochemical and western blot to explore the synergistic effects of agrimoniin and erlotinib in inhibiting pancreatic cancer. Single-cell RNA sequencing was used to explore the relationship between their synergistic effects and tumor microenvironment. Through western blot and colorimetric assays for lactic acid, we studied the connection between their synergistic effects and aerobic glycolysis as well as lactic acid expression. By employing signal pathway inhibitors and agonists, we studied the positive feedback regulatory mechanism between relevant signal pathways and lactic acid expression. We found that agrimoniin and erlotinib synergistically inhibits the proliferation and promotes the apoptosis of pancreatic cancer cells. Together, they effectively suppress signal interaction among tumor cells, stromal cells and macrophages within subcutaneous tumors. They synergistically inhibit aerobic glycolysis and lactic acid expression in pancreatic cancer. Notably, we uncover the vicious cycle between the PI3K/AKT//HIF-1α/HK2, MEK/ERK/HIF-1α/HK2 signaling pathways and lactic acid expression. Combination of agrimoniin and erlotinib remodels tumor microenvironment, reprograms aerobic glycolysis, disrupts the positive feedback loop between lactic acid and two signaling pathways, thus synergistically inhibits the proliferation of pancreatic cancer cells. We transplanted PANC1 cells into the subcutaneous skin of nude mice and treated them with the carrier, cyranin, agrimoniin, agrimoniin + erlotinib, respectively, and detect the effects of different drugs on tumor