Glenn L. Mersky

Figure S2. CPT1A ‘activity-signature’ score (GSVA) K-Means clustering and association with SCNA clusters in TCGA-UVM data.

Table S1. PScore and CPT1A ‘activity’ signature gene sets.

Figure S3. Etomoxir-induced, pyroptotic DAMP release does not require GSDMD.

Figure S1. GSDMD cleavage fragments induced by Etomoxir.

Table S2. UM patient ICb treatment groups in figure 7.

Few treatment options are available for patients with metastatic uveal melanoma. Although the bispecific tebentafusp is FDA approved, immunotherapy has largely failed, likely given the poorly immunogenic nature of uveal melanoma. Treatment options that improve the recognition of uveal melanoma by the immune system may be key to reducing disease burden. We investigated whether uveal melanoma has the ability to undergo pyroptosis, a form of immunogenic cell death. Publicly available patient data and cell line analysis showed that uveal melanoma expressed the machinery needed for pyroptosis, including gasdermins D and E (GSDMD and E), caspases 1, 3, 4, and 8, and ninjurin-1. We induced cleavage of GSDMs in uveal melanoma cell lines treated with metabolic inhibitors. In particular, the carnitine palmitoyltransferase 1 (CPT1) inhibitor, etomoxir, induced propidium iodide uptake, caspase 3 cleavage, and the release of HMGB1 and IL-1β, indicating that the observed cleavage of GSDMs led to pyroptosis. Importantly, a gene signature reflecting CPT1A activity correlated with poor prognosis in patients with uveal melanoma and knockdown of CPT1A also induced pyroptosis. Etomoxir-induced pyroptosis was dependent on GSDME but not on GSDMD, and a pyroptosis gene signature correlated with immune infiltration and improved response to immune checkpoint blockade in a set of patients with uveal melanoma. Together, these data show that metabolic inhibitors can induce pyroptosis in uveal melanoma cell lines, potentially offering an approach to enhance inflammation-mediated immune targeting in patients with metastatic uveal melanoma.Implications:Induction of pyroptosis by metabolic inhibition may alter the tumor immune microenvironment and improve the efficacy of immunotherapy in uveal melanoma.

Targeted therapies in cancer are limited by cells exhibiting drug tolerance. We aimed to target drug tolerance in order to delay the development of acquired resistance. In melanoma, tolerance to MAPK pathway inhibitors is associated with loss of SOX10 and an enhanced TEAD transcriptional program. We show that loss of SOX10 is sufficient to up-regulate TEAD targets with dependence on the co-activator, TAZ. Active TAZ is sufficient to mediate tolerance to BRAF inhibitors and MEK inhibitors. We develop two covalent inhibitors, OPN-9643 and OPN-9652, designed to target the central palmitate binding pocket of TEADs. In SOX10-deficient cells, OPN-9643 and OPN-9652 reduce TEAD-dependent reporter activity and expression of TEAD targets, CTGF and CYR61. OPN-9643 and OPN-9652 treatment enhances the inhibitory effects of MAPK-targeted therapies in 2D and 3D growth assays in SOX10 knockout cells and reverses tolerance mediated by active TAZ. In vivo, OPN-9652 delays the onset of acquired resistance to BRAF inhibitors and MEK inhibitors from minimal residual disease. Thus, TAZ-TEAD activity plays an important role in melanoma drug tolerance and the development of acquired resistance.

TGM2 overexpression modulates tumor onset in immunocompetent mice, but does not affect 3D spheroid growth

BRD4 binds to the TGM2 promoter

TGM2 is upregulated following SOX10 knockout