Inhibition of focal adhesion kinase impairs tumor formation and preserves hearing in a murine model of NF2-related schwannomatosis.

Abstract

NF2 (neurofibromatosis type 2)-related schwannomatosis (NF2-SWN) is a cancer predisposition syndrome characterized by the development of bilateral vestibular (VS) and spinal schwannomas. While benign, these tumors can cause substantial morbidity, and effective pharmacological treatments remain limited. Here, we demonstrate that genetic ablation of focal adhesion kinase (<i>Fak/Ptk2</i>) impairs tumor formation and preserves hearing in a murine model of NF2. Mechanistically, we show that <i>Fak</i> deletion decreases macrophage infiltration, attenuates nucleotide-binding oligomerization domain-containing protein 2-, leucine rich repeats (LRR)- and pyrin domain-containing protein 3 inflammasome activation, and suppresses the hepatocyte growth factor-MET axis. Pharmacological inhibition of FAK with single agent VS-4718 did not significantly reduce macroscopic tumor volume; however, its use in combination with the mitogen-activated protein kinase kinase (MEK) inhibitor selumetinib resulted in both a significant reduction in tumor volume and the preservation of dorsal root ganglion architecture. Our findings establish a critical role for FAK in schwannoma development and provide rationale for evaluation of combination FAK plus MEK inhibition in future clinical trials for NF2-associated SWN.