Patient-derived zebrafish xenograft models reveal ferroptosis as a fatal and druggable weakness in metastatic uveal melanoma

Abstract

Uveal melanoma (UM) is the most common intraocular melanoma, derived from transformed melanocytes of the uvea. Although treatment of primary UM is usually successful, there is a high risk (up to 50%) of liver metastasis with negligible long-term survival. There are currently no reproducible patient-derived animal models that faithfully recapitulate the latter stages of metastatic dissemination of UM, hindering the discovery of curative treatments. To overcome this problem and to accelerate the development of new metastatic UM treatments, we developed a patient-derived zebrafish xenograft (zf-PDX) model, using spheroid cultures generated from metastatic and primary UM tissues. Engrafted UM cells derived from these spheroid cultures give rise to metastatic lesions and recapitulate the molecular features of UMs and their potential drug sensitivity. Importantly, harnessing this versatile model, we reveal a high sensitivity of circulating UM cells to ferroptosis induction in vivo by Erastin and RSL3. Our findings are further corroborated by supportive analysis of patient data implicating ferroptosis as a new, and druggable, target for the treatment of metastatic UM patients, specifically in those with BAP1 loss in the tumor.

Zebrafish Patient-Derived Xenograft Model as a Preclinical Platform for Uveal Melanoma Drug Discovery

“…The drug efficacy obtained in this proof-of-concept experiment in the zf-PDX model recapitulated published results using UM cells and the murine PDX model [38]. Our recent study harnessing this model identified ferroptosis as a new and druggable pathway for the treatment of UM patients [34]. In another group, Glinkina et al also tested target agent combinations with the zf-PDX UM model but did not detect tumor regression [44].…”

“…Next, we validated the biological properties of the patient-derived UM spheroids (Figure 2a,b). Our previous study indicated that the culturing of UM tissue as spheroids helped to preserve the expression of melanocyte-specific antigen (melan-A) and their intrinsic tumorigenic capacity [34]. Here, we determined the melanocytic origin of the cultured spheroids using the melanocyte marker SOX10 (Sry-related HMG-Box gene 10) (Figure 2b).…”

Novel Treatments of Uveal Melanoma Identified with a Synthetic Lethal CRISPR/Cas9 Screen

“…Metastatic uveal melanoma cells were derived from spXmm66-tomato red spheroid cultures, as described by Groenewoud and colleagues [45]. Cells were processed into a single-cell suspension through trituration and were subsequently filtered through a 30 µm cell strainer (Miltenyi Biotec).…”

“…Next, we examined whether the synergistic effects of the combinations of everolimus with KU57788 or OSI-906 observed in vitro could be reproduced in vivo. For this purpose, we exploited a metastatic UM-patient-derived zebrafish xenograft model (UM zf-PDX) [45]. This model is based on 3D spheroids grown from Xmm66 metastatic UM PDX cells derived from the same original donor as the MM66cell line.…”

The application of zebrafish patient‐derived xenograft tumor models in the development of antitumor agents

“…Antitumor activity is usually evaluated by confocal imaging of tumor fluorescence or by lysing zebrafish and counting tumor cells. [182][183][184] Common cancer types are currently studied in drug development using zebrafish models including breast cancer, 47 leukemia, 185 lung cancer, 186 and melanoma, 187 demonstrating the excellent generalizability of the zebrafish transplantation tumor model.…”