In vitro Study of the Antagonistic Effect of Low-dose Liquiritigenin on Gemcitabine-induced Capillary Leak Syndrome in Pancreatic Adenocarcinoma via Inhibiting ROSMediated Signalling Pathways

Background: To investigate in-vitro antagonistic effect of low-dose liquiritigenin on gemcitabine-inducedcapillary leak syndrome (CLS) in pancreatic adenocarcinoma via inhibiting reactive oxygen species (ROS)-mediated signalling pathways. Materials and
Methods: Human pancreatic adenocarcinoma Panc-1 cells andhuman umbilical vein endothelial cells (HUVECs) were pre-treated using low-dose liquiritigenin for 24 h, thenadded into gemcitabine and incubated for 48 h. Cell viability, apoptosis rate and ROS levels of Panc-1 cellsand HUVECs were respectively detected through methylthiazolyldiphenyl-tetrazoliumbromide (MTT) andflow cytometry. For HUVECs, transendothelial electrical resistance (TEER) and transcellular and paracellularleak were measured using transwell assays, then poly (ADP-ribose) polymerase 1 (PARP-1) and metal matrixproteinase-9 (MMP9) activity were assayed via kits, mRNA expressions of p53 and Rac-1 were determinedthrough quantitative polymerase chain reaction (qPCR); The expressions of intercellular adhesion molecule1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and PARP-1 were measured via western blotting.
Results: Low-dose liquiritigenin exerted no effect on gemcitabine-induced changes of cell viability, apoptosis rateand ROS levels in Panc-1 cells, but for HUVECs, liquiritigenin (3 μM) could remarkably elevate gemcitabineinduceddecrease of cell viability, transepithelial electrical resistance (TEER), pro-MMP9 level and expressionof ICAM-1 and VCAM-1 (p<0.01). Meanwhile, it could also significantly decrease gemcitabine-induced increaseof transcellular and paracellular leak, ROS level, PARP-1 activity, Act-MMP9 level, mRNA expressions of p53and Rac-1, expression of PARP-1 and apoptosis rate (p<0.01).
Conclusions: Low-dose liquiritigenin exertsan antagonistic effect on gemcitabine-induced leak across HUVECs via inhibiting ROS-mediated signallingpathways, but without affecting gemcitabine-induced Panc-1 cell apoptosis. Therefore, low-dose liquiritigeninmight be beneficial to prevent the occurrence of gemcitabine-induced CLS in pancreatic adenocarcinoma.