Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive Schwann cell (SC)-lineage derived sarcomas with poor prognosis. The molecular events underlying SC lineage cells-to-MPNST transformation remain elusive. Here, we show that human MPNSTs exhibit elevated HIPPO-TAZ/YAP expression, and that TAZ/YAP hyperactivity in SCs caused by Lats1/2 loss potently induces high-grade nerve-associated tumors with full penetrance. Lats1/2 deficiency reprograms SCs to a cancerous, progenitor-like phenotype and promotes hyper-proliferation. Conversely, disruption of TAZ/YAP activity alleviates tumor burden in Lats1/2-deficient mice and inhibits human MPNST cell proliferation. Moreover, genome-wide target profiling reveals that TAZ/YAP-TEAD1 directly activates a set of oncogenic programs in SCs including PDGFR/RAF signaling. Co-targeting TAZ/YAP and PDGFR/RAF signaling efficaciously reduces tumorigenicity in Lats1/2-deficient tumors. Thus, our findings establish a previously unrecognized convergence between LATS1/2-TAZ/YAP pathway and MPNST pathogenesis, suggesting that combined inhibition of TAZ/YAP-PDGFR/RAF signaling may be beneficial in MPNSTs.