Human serum albumin binding and synergistic effects of gefitinib in combination with regorafenib on colorectal cancer cell lines

This study aimed to evaluate the combination effect of gefitinib (GEF) and regorafenib (REG) against HCT116, CT26 and SW948 colorectal cancer cell lines. Results showed synergistic effects on HCT116 and CT26 cells, while the additive effect was observed on SW948 cells. Combination of GEF and REG induced sub-G1 peak as the apoptotic population on HCT116 cells, through flow cytometry histogram. Downregulation of AKT1 and TGFB2 and upregulation of CASP3 were observed in the combination of GEF and REG in HCT116 cells, using quantitative real-time PCR analysis. HSA binding properties exhibit that the first drug increased binding affinity between the second drug and HSA; as a result, HSA could transport both drugs. Thus, we hope this study creates a promising strategy to treat colorectal cancer.