Development of Combination Strategies for Focal Adhesion Kinase Inhibition in Diffuse Gastric Cancer

Area of Science:

• Oncology
• Gastroenterology
• Molecular Biology

Background:

• Diffuse gastric cancer (DGC) is an aggressive cancer subtype with limited targeted therapy options.
• Focal adhesion kinase (FAK) plays a role in DGC tumorigenesis, and FAK inhibitors show potential but face drug resistance.
• Identifying resistance mechanisms is crucial for effective DGC treatment.

Purpose of the Study:

• To identify mechanisms of resistance to FAK inhibitors in diffuse gastric cancer.
• To explore compensatory pathways activated during FAK inhibition.
• To evaluate combination therapies for enhancing FAK inhibitor efficacy in DGC.

Main Methods:

• Generated a genome-scale open reading frame (ORF) library in a DGC organoid model (Cdh1-/-RHOAY42C/+).
• Treated DGC models with FAK inhibitors to identify resistance mechanisms and compensatory pathways.
• Conducted in vitro and in vivo experiments to test combination therapies.

Main Results:

• Cyclin-dependent kinase 6 (CDK6) was identified as a promoter of FAK inhibitor resistance.
• FAK inhibition led to compensatory activation of the MAPK pathway.
• Combination therapy with CDK4/6 inhibitors or MAPK inhibitors significantly enhanced FAK inhibitor efficacy.

Conclusions:

• CDK6 and MAPK pathways are key mediators of FAK inhibitor resistance in DGC.
• Combining FAK inhibitors with CDK4/6 or MAPK inhibitors is a promising strategy for DGC treatment.
• Further clinical trials are warranted to test these combination therapies in DGC patients.