Interaction of Avapritinib with Congo Red in Pancreatic Cancer Cells: Molecular Modeling and Biophysical Studies

Pancreatic cancer is a malignant tumor with one of the worst prognoses among solid tumors, characterized by resistance to treatment. Therefore, there is an urgent need for new methods of targeted therapy. Previous studies have shown that the overexpression of receptor tyrosine kinases such as c-KIT or PDGFR can increase proliferation, migration, and invasion of cancer cells. The aim of our study was to analyze aggregates between a supramolecular carrier (Congo red, CR) and a tyrosine kinase inhibitor (BLU-258) as well as to investigate the effect of the free inhibitor and its aggregate with Congo red (CR-BLU-258) on selected properties of pancreatic cells, including these cells' viability and three-dimensional cell spheroid cultures. To better understand the interactions between Congo red and BLU-258, we used molecular modeling in addition to biophysical methods. These attempts allowed us to determine the optimal molar ratio, which we used for in vitro studies on pancreatic cancer cell lines. A significantly greater decrease in the viability of the tested 3D cultures was observed after 48 h of incubation with CR-BLU-258, which resulted in a lower IC₅₀ value for the tested co-aggregate compared with BLU-258 alone. Moreover, a higher resistance of PANC-1 and BxPC3 spheroid cells to the tested compounds was noted compared with the 2D culture model. A significantly lower response was observed in 3D cell cultures (BxPC3 and PANC-1) treated with BLU-258 alone compared with the 2D culture. Thus, our results showed that both BLU-258 (alone) and in its co-aggregate with Congo red exhibit anticancer activity, inhibiting the growth of pancreatic cancer cells and reducing their viability, survival, and migration. Both tested compounds also affected the phosphorylation of the selected signaling proteins. We conclude that the selected tyrosine kinase inhibitor (alone) and in its co-aggregate with Congo red exhibit anticancer activity and should be considered as a novel effective therapy against pancreatic cancer.