Discovery of potential AXL inhibitors using virtual screening, molecular docking, molecular dynamics, molecular mechanics, and in vitro validation.

AXL is overexpressed in many cancers, including breast, lung, colon, osteosarcoma, kidney, stomach, and gliomas, and associated with poor patient survival and plays an important role in cancer cell proliferation, survival, tumor growth, progression and metastasis. In vivo studies involving genetic targeting of AXL validated it as a promising therapeutic target. In this study, we performed integrated in silico analyses, including virtual screening, molecular docking, molecular dynamics (MD) simulations, and MM/GBSA calculations to search the compound libraries from various small molecule databases to identify potential inhibitors targeting AXL. We identified key amino acid residues such as Met623, Pro621, Asp627, and Asp690 located in the binding pocket of AXL interacting with the potential inhibitors and positive control compounds through with hydrogen and pi-pi bonds. In vitro studies with the three lead compounds (STOCK1N-80636, STOCK1N-66436 and Nebivolol) demonstrated significant antiproliferative effects in four different breast cancer cell lines STOCK1N-80636 was being the most potent. In conclusion, these findings have enabled the identification of potential AXL inhibitors through integrated in silico and in vitro results.