KRAS–SOS-1 Inhibition as New Pharmacological Target to Counteract Anaplastic Thyroid Carcinoma (ATC)

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid cancer. Tumor cells have been shown to activate alternative signaling pathways, making treatments less effective. One of the major proteins involved in the progression of ATC is the proto-oncogene KRAS that belongs to a group of small guanosine triphosphate (GTP)-binding proteins. Despite its recognized importance in cancer malignancy, KRAS is considered non-druggable and has never been studied in the field of ATC. In this context, a new synthetic molecule, BAY-293, has recently been developed that selectively inhibits the KRAS–SOS-1 interaction. Based on these findings, the aim of this study was to evaluate for the first time the antitumor effect of BAY-293 using in vitro and in vivo models of ATC. The in vitro model included different thyroid cancer (TC) cell lines used to study the effect of BAY-293 on the modulation of mitogen-activated protein kinase (MAPK) pathways, apoptosis, and cell migration. To confirm the in vitro findings and better mimic the complex tumor microenvironment, an in vivo orthotopic model of ATC was used. The results of the study indicate that BAY-293, both in vitro and in vivo, effectively blocked the KRAS/MAPK/ERK pathway and β-catenin, which act as downstream effectors essential for cell migration, and increased the apoptotic process by slowing the progression of ATC. In conclusion, this study demonstrated that KRAS/SOS-1 inhibition could be a promising therapeutic target for the treatment of ATC and highlighted BAY-293 as an innovative molecule that needs further research to fully evaluate its efficacy in the field of thyroid cancer.