GNAQ/11 mutations in uveal melanoma: is YAP the key to targeted therapy?

Context-dependent transcriptional regulations of YAP/TAZ in stem cell and differentiation

Hippo pathway is initially identified as a master regulator for cell proliferation and organ size control, and the subsequent researches show this pathway is also involved in development, tissue regeneration and homeostasis, inflammation, immunity and cancer. YAP/TAZ, the downstream effectors of Hippo pathway, usually act as coactivators and are dependent on other transcription factors to mediate their transcriptional outputs. In this review, we will first provide an overview on the core components and regulations of Hippo pathway in mammals, and then systematically summarize the identified transcriptional factors or partners that are responsible for the transcriptional output of YAP/TAZ in stem cell and differentiation. More than that, we will discuss the potential applications and future directions based on these findings.

Systemic and liver-directed therapies in metastatic uveal melanoma: state-of-the-art and novel perspectives

Metastatic uveal melanoma (MUM) is the most common form of noncutaneous melanoma. It is different from its cutaneous counterpart and is characterized by a very poor prognosis. Despite groundbreaking improvements in the treatment of cutaneous melanoma, there have been few advances in the treatment of MUM, and standard treatments for MUM have not been defined. We performed a systematic review focusing our attention on all interventional studies, ongoing or already published, concerning the treatment of MUM. We present results from studies of chemotherapy, targeted therapy, immunotherapy and liver-directed therapies. Although the results in this setting have been disappointing until now, trials investigating novel immunotherapeutic strategies alone and in combination with targeted agents and liver-directed therapies are ongoing.

Targeting the YAP/TAZ Pathway in Uveal and Conjunctival Melanoma With Verteporfin

Purpose

The purpose of this study was to determine whether YAP/TAZ activation in uveal melanoma (UM) and the susceptibility of melanoma cell lines to YAP/TAZ inhibition by verteporfin (VP) is related to the tumor's genetic background.

Methods

Characteristics of 144 patients with enucleated UM were analyzed together with mRNA expression levels of YAP/TAZ-related genes (80 patients from the The Cancer Genome Atlas [TCGA] project and 64 patients from Leiden, The Netherlands). VP was administered to cell lines 92.1, OMM1, Mel270, XMP46, and MM28 (UM), CRMM1 and CRMM2 (conjunctival melanoma), and OCM3 (cutaneous melanoma). Viability, growth speed, and expression of YAP1-related proteins were assessed.

Results

In TCGA data, high expression of YAP1 and WWTR1 correlated with the presence of monosomy 3 (P = 0.009 and P < 0.001, respectively) and BAP1-loss (P = 0.003 and P = 0.001, respectively) in the primary UM; metastasis development correlated with higher expression of YAP1 (P = 0.05) and WWTR1 (P = 0.003). In Leiden data, downstream transcription factor TEAD4 was increased in cases with M3/BAP1-loss (P = 0.002 and P = 0.006) and related to metastasis (P = 0.004). UM cell lines 92.1, OMM1, and Mel270 (GNAQ/11-mutation, BAP1-positive) and the fast-growing cell line OCM3 (BRAF-mutation) showed decreased proliferation after exposure to VP. Two slow-growing UM cell lines XMP46 and MM28 (GNAQ/11-mutation, BAP1-negative) were not sensitive to VP, and neither were the two conjunctival melanoma cell lines (BRAF/NRAS-mutation).

Conclusions

High risk UM showed an increased expression of YAP/TAZ-related genes. Although most UM cell lines responded in vitro to VP, BAP1-negative and conjunctival melanoma cell lines did not. Not only the mutational background, but also cell growth rate is an important predictor of response to YAP/TAZ inhibition by VP.

Molecular characteristics of uveal melanoma and intraocular tumors

Malignant melanomas within the eye present different types of metabolic and metastatic behavior. Uveal melanoma (UM) affects a quarter of a million individuals in the USA; however, the molecular pathogenesis is not well understood. Although UV radiation is a risk factor in cutaneous melanomas, it is not crucial for UM progression. Apart from chromosomal abnormalities, numerous major tumorigenic signaling pathways, including the PI3K/Akt, MAPK/ERK, Ras-association domain family 1 isoform A and Yes-associated protein/transcriptional co-activator with PDZ-binding motif signaling pathways, are associated with intraocular tumors. The present review describes the current insights regarding these signaling pathways that regulate the cell cycle and apoptosis, and could be used as potential targets for the treatment of UMs.

Emerging strategies to treat rare and intractable subtypes of melanoma

Melanoma is the deadliest form of skin cancer, possessing a diverse landscape of subtypes with distinct molecular signatures and levels of aggressiveness. Although immense progress has been achieved therapeutically for patients with the most common forms of this disease, little is known of how to effectively treat patients with rarer subtypes of melanoma. These subtypes include acral lentiginous (the rarest form of cutaneous melanoma; AL), uveal, and mucosal melanomas, which display variations in distribution across (a) the world, (b) patient age-groups, and (c) anatomic sites. Unfortunately, patients with these relatively rare subtypes of melanoma typically respond worse to therapies approved for the more common, non-AL cutaneous melanoma and do not have effective alternatives, and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in these high-risk melanoma subtypes represents one of the greatest challenges of the field. This review aims to collate and highlight effective preclinical and/or clinical strategies against these rare forms of melanoma.

Uveal melanoma: progress in molecular biology and therapeutics

Uveal melanoma (UM) is the most common intraocular malignancy in adults. So far, no systemic therapy or standard treatment exists to reduce the risk of metastasis and improve overall survival of patients. With the increased knowledge regarding the molecular pathways that underlie the oncogenesis of UM, it is expected that novel therapeutic approaches will be available to conquer this disease. This review provides a summary of the current knowledge of, and progress made in understanding, the pathogenesis, genetic mutations, epigenetics, and immunology of UM. With the advent of the omics era, multi-dimensional big data are publicly available, providing an innovation platform to develop effective targeted and personalized therapeutics for UM patients. Indeed, recently, a great number of therapies have been reported specifically for UM caused by oncogenic mutations, as well as other etiologies. In this review, special attention is directed to advancements in targeted therapies. In particular, we discuss the possibilities of targeting: GNAQ/GNA11, PLCβ, and CYSLTR2 mutants; regulators of G-protein signaling; the secondary messenger adenosine diphosphate (ADP)-ribosylation factor 6 (ARF6); downstream pathways, such as those involving mitogen-activated protein kinase/MEK/extracellular signal-related kinase, protein kinase C (PKC), phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR), Trio/Rho/Rac/Yes-associated protein, and inactivated BAP1; and immune-checkpoint proteins cytotoxic T-lymphocyte antigen 4 and programmed cell-death protein 1/programmed cell-death ligand 1. Furthermore, we conducted a survey of completed and ongoing clinical trials applying targeted and immune therapies for UM. Although drug combination therapy based on the signaling pathways involved in UM has made great progress, targeted therapy is still an unmet medical need.

Lower Levels of Adiponectin and Its Receptor Adipor1 in the Uveal Melanomas With Monosomy-3

Purpose

Adiponectin is an insulin-sensitizing and anticarcinogenic hormone that is encoded by a gene on chromosome 3. Here, we analyzed the expression of adiponectin and its receptor Adipor1 in primary uveal melanoma (UM) with regard to the monosomy-3 status and clinical factors, as well as the physiological response of UM cells to adiponectin.

Methods

Immunohistochemistry was performed on the primary UM of 34 patients. Circulating melanoma cells (CMC) were isolated by immunomagnetic enrichment. Monosomy-3 was evaluated by Immuno-FISH. Gene expression was analyzed using the RNAseq data of The Cancer Genome Atlas study. Cultures of choroidal melanocytes and UM were established from the samples of two patients. The proliferative potential of the UM cell lines Mel-270 and OMM-2.5 was determined by immunocytochemistry, immunoblotting, cell cycle analysis, nucleolar staining, and adenosine triphosphate (ATP) levels.

Results

UM with monosomy-3 exhibited a lower immunoreactivity for adiponectin and Adipor1, which was associated with monosomy-3-positive CMC and the development of extraocular growth or metastases. Both proteins were more abundant in the irradiated tumors and present in the cultured cells. Gene expression profile indicated the impairment of adiponectin-mediated signaling in the monosomy-3 tumors. Adiponectin induced a significant decline in the ATP levels, Ki-67 expression, cells in the G2/M phase, and nucleolar integrity in UM cultures.

Conclusions

Adiponectin deficiency appears to enhance the metastatic potential of the UM cells with monosomy-3 and the termination of tumor dormancy. Counteracting insulin resistance and improving the serum adiponectin levels might therefore be a valuable approach to prevent or delay the UM metastases.

Heterogeneity of GNAQ/11 mutation inversely correlates with the metastatic rate in uveal melanoma

PURPOSE

To determine whether the GNAQ/11 mutation correlated with the outcome of patients with uveal melanoma (UM) when genetic heterogeneity was considered.

METHODS

We performed a retrospective study of sixty-seven patients with UM. The heterogeneity of GNAQ/11 was examined by using droplet digital PCR. The correlation between metastasis and heterogeneity of the GNAQ/11 mutation was analysed. Disease free survival curves were constructed using the Kaplan-Meier method, and the Wilcoxon log-rank test was used to compare the curves.

RESULTS

The GNAQ/11 mutation ratio was varied between each case. Among these patients, 28.35% of them harboured homogeneous mutation of GNAQ/11, 62.69% present heterogeneous mutation and 8.96% didn't present either GNAQ or GNA11 mutation. The tumour with heterogeneous mutation of GNAQ/11 has a higher metastatic rate than that with homogeneous mutation (13/29 vs 1/18, p=0.027). In Kaplan-Meier analysis, metastasis-free survival was not significantly associated with either homogeneous or heterogeneous mutation of GNAQ/11.

CONCLUSION

The mutation ratio of GNAQ/11 in UM was quite variable. The tumour with heterogeneous mutation of GNAQ/11 is more likely to develop a poor prognosis than that with homogeneous mutation of GNAQ/11.

Targeted Therapy of Uveal Melanoma: Recent Failures and New Perspectives

Among Uveal Melanoma (UM) driver mutations, those involving GNAQ or GNA11 genes are the most frequent, while a minor fraction of tumors bears mutations in the PLCB4 or CYSLTR2 genes. Direct inhibition of constitutively active oncoproteins deriving from these mutations is still in its infancy in UM, whereas BRAFV600E-targeted therapy has obtained relevant results in cutaneous melanoma. However, UM driver mutations converge on common downstream signaling pathways such as PKC/MAPK, PI3K/AKT, and YAP/TAZ, which are presently considered as actionable targets. In addition, BAP1 loss, which characterizes UM metastatic progression, affects chromatin structure via histone H2A deubiquitylation that may be counteracted by histone deacetylase inhibitors. Encouraging results of preclinical studies targeting signaling molecules such as MAPK and PKC were unfortunately not confirmed in early clinical studies. Indeed, a general survey of all clinical trials applying new targeted and immune therapy to UM displayed disappointing results. This paper summarizes the most recent studies of UM-targeted therapies, analyzing the possible origins of failures. We also focus on hyperexpressed molecules involved in UM aggressiveness as potential new targets for therapy.

Direct targeting of Gαq and Gα11 oncoproteins in cancer cells

Somatic gain-of-function mutations of GNAQ and GNA11, which encode α subunits of heterotrimeric Gαq/11 proteins, occur in about 85% of cases of uveal melanoma (UM), the most common cancer of the adult eye. Molecular therapies to directly target these oncoproteins are lacking, and current treatment options rely on radiation, surgery, or inhibition of effector molecules downstream of these G proteins. A hallmark feature of oncogenic Gαq/11 proteins is their reduced intrinsic rate of hydrolysis of guanosine triphosphate (GTP), which results in their accumulation in the GTP-bound, active state. Here, we report that the cyclic depsipeptide FR900359 (FR) directly interacted with GTPase-deficient Gαq/11 proteins and preferentially inhibited mitogenic ERK signaling rather than canonical phospholipase Cβ (PLCβ) signaling driven by these oncogenes. Thereby, FR suppressed the proliferation of melanoma cells in culture and inhibited the growth of Gαq-driven UM mouse xenografts in vivo. In contrast, FR did not affect tumor growth when xenografts carried mutated B-RafV600E as the oncogenic driver. Because FR enabled suppression of malignant traits in cancer cells that are driven by activating mutations at codon 209 in Gαq/11 proteins, we envision that similar approaches could be taken to blunt the signaling of non-Gαq/11 G proteins.

An Ensemble Method to Predict Target Genes and Pathways in Uveal Melanoma

Objective: This work proposes to predict target genes and pathways for uveal melanoma (UM) based on an ensemble method and pathway analyses.

METHODS

The ensemble method integrated a correlation method (Pearson correlation coefficient, PCC), a causal inference method (IDA) and a regression method (Lasso) utilizing the Borda count election method. Subsequently, to validate the performance of PIL method, comparisons between confirmed database and predicted miRNA targets were performed. Ultimately, pathway enrichment analysis was conducted on target genes in top 1000 miRNA-mRNA interactions to identify target pathways for UM patients.

RESULTS

Thirty eight of the predicted interactions were matched with the confirmed interactions, indicating that the ensemble method was a suitable and feasible approach to predict miRNA targets. We obtained 50 seed miRNA-mRNA interactions of UM patients and extracted target genes from these interactions, such as ASPG, BSDC1 and C4BP. The 601 target genes in top 1,000 miRNA-mRNA interactions were enriched in 12 target pathways, of which Phototransduction was the most significant one.

CONCLUSION

The target genes and pathways might provide a new way to reveal the molecular mechanism of UM and give hand for target treatments and preventions of this malignant tumor.

Yes-Associated Protein (YAP) Promotes Tumorigenesis in Melanoma Cells Through Stimulation of Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1)

YAP is a critical protein in cancer development and can induce transformative phenotypes in mammary epithelial cells. Previous studies have provided evidence that YAP can contribute to the metastatic behavior of melanoma, since specific knockdown of YAP leads to reduced metastatic and invasive capacity in vitro. However, the mechanism by which YAP regulates the function of melanoma is unknown. Here, we identified that YAP has a positive impact on the expression of LRP1, which also plays critical roles in cancer. Mechanically, knockdown of YAP resulted in a significant down-regulation of LRP1 at both the protein and mRNA levels. Tissue microarray analysis (TMA) also showed a positive correlation between YAP and LRP1 expression. In addition, reduction of YAP-impaired pro-carcinogenic phenotypes could be partially reversed by simultaneous overexpression of LRP1, suggesting that LRP1 is functionally important in YAP-induced melanoma tumorigenesis. Furthermore, we found that LRP1 was regulated by YAP through a transcription- and promoter-dependent mechanism. Taken together, our results suggest that YAP regulates LRP1 through stimulation of the LRP1 promoter and that LRP1 may be an important target for influencing YAP in melanoma.

New concepts in the molecular understanding of uveal melanoma

PURPOSE OF REVIEW

Uveal melanoma is the most common primary intraocular malignancy, and its metastases are deadly. Significant work has been done to elucidate the molecular framework that causes uveal melanoma development and metastasis. This review is intended to highlight the most recent breakthroughs in the molecular understanding of uveal melanoma.

RECENT FINDINGS

Monosomy of chromosome 3 and class 2 gene-expression profile are well-known indicators of melanoma metastasis. However, some patients with disomy 3 and class 1 gene expression profiling (GEP) still develop metastasis. Disomy 3 tumors may be further classified based upon the presence of an SF3B1 mutation. The role of SF3B1 gene is unclear at this time but may be related to the development of late metastases among disomy 3 uveal melanoma. Class 1 GEP tumors have recently been subdivided into class 1a and class 1b, with class 1b tumors carrying a slightly higher risk of metastasis. Among patients with either class 1 or class 2 GEP, the expression of preferentially expressed antigen in melanoma (PRAME) is an independent risk factor for the development of metastasis. Mutation of GNAQ is the most commonly observed mutation in uveal melanoma, regardless of chromosome 3 status or GEP class. Inhibitors or GNAQ may be targets for therapeutic intervention in uveal melanoma. MicroRNA molecules are small noncoding RNA molecules that have been recently demonstrated to function in RNA silencing and posttranscriptional regulation of gene expression. These molecules may play a role in the development of uveal melanoma metastasis.

SUMMARY

New findings such as the presence or absence of PRAME, mutations in the SF3B1 gene and microRNA dysregulation have added new layers to our understanding of uveal melanoma. These new concepts will enhance our ability to prognosticate tumor metastasis and may provide targets for therapeutic intervention.

Revealing differential modules in uveal melanoma by analyzing differential networks

The aim of the present study was to investigate differential modules (DMs) between uveal melanoma (UM) and normal conditions by examining differential networks. Based on a gene expression profile collected from the ArrayExpress database, the inference of DMs involved three steps: The first step was construction of a differential co‑expression network (DCN); second, the module algorithm was adapted to identify the DMs presented in DCN; finally, the statistical significance of DMs were assessed based on the null score distribution of DMs generated using randomized networks. A DCN with 309 nodes and 3,729 edges was obtained, and 30 seed genes from the DCN were examined. Subsequently, one DM, which had 179 nodes and 3,068 edges, was investigated. By utilizing randomized networks, the P‑value for DM was 0.034, therefore, the DM was statically significant between UM and baseline conditions. In conclusion, the present study successfully identified one DM in UM based on DCN and module algorithm, and this DM may be beneficial in revealing the pathological mechanism of UM and provide insight for future investigation of UM.

Verteporfin induces apoptosis and eliminates cancer stem-like cells in uveal melanoma in the absence of light activation

Uveal melanoma (UM) is the most common primary ocular malignancy in adults. Currently, no beneficial systemic therapy is available; therefore, there is an urgent need for effective targeted therapeutic drugs. As verteporfin has shown anti-neoplastic activity in several types of cancers, here we hypothesized and investigated the efficacy of verteporfin against UM cells without light activation. MTS assay, flow cytometry analysis of apoptosis, Western blotting of relevant proteins, transwell migration and invasion assay, melanosphere culture, and measurement of ALDH⁺ populations, were used to evaluate the effects of verteporfin on UM cells. We found that verteporfin disrupted the interaction between YAP and TEAD4 in UM cells and decreased the expression of YAP targeted downstream genes. Verteporfin treatment decreased the cytoplasmic and nuclear levels of YAP and induced lysosome-dependent degradation of YAP protein. Verteporfin exhibited distinct inhibitory effect on the proliferation of four lines of UM cells (e.g., 92.1, Mel 270, Omm 1 and Omm 2.3), and induced apoptosis through the intrinsic pathway. Additionally, verteporfin suppressed migration and invasion of UM cells, impaired the traits of cancer stem-like cells (e.g., melanosphere formation capacity, and ALDH⁺ cell population). This study demonstrated the anti-neoplastic activity of verteporfin against UM cells in vitro, providing a rationale for evaluating this agent in clinical investigation.

Update on Ophthalmic Oncology 2014: Retinoblastoma and Uveal Melanoma

PURPOSE

The aim of this study was to review peer-reviewed articles on ophthalmic oncology (specifically retinoblastoma and uveal melanoma) published from January to December 2014.

DESIGN

This study is a literature review.

METHODS

The terms retinoblastoma and uveal melanoma were used in a MEDLINE literature search. Abstracts were studied, and the most relevant articles were selected for inclusion and further in-depth review.

RESULTS

In retinoblastoma, more eyes are being salvaged due to intravitreal melphalan. The year 2014 marks a deepening in our understanding of the biological basis of the disease and the cell of origin. Knowledge on the genetic underpinnings of uveal melanoma has broadened to include other pathways, interactions, and potential therapeutic targets.

CONCLUSIONS

In 2014, there were valuable advancements in our knowledge of retinoblastoma and uveal melanoma. Some of these resulted in improved patient management.

Class III-specific HDAC inhibitor Tenovin-6 induces apoptosis, suppresses migration and eliminates cancer stem cells in uveal melanoma

Uveal melanoma (UM) is the most common intraocular malignancy in adults. Despite improvements in surgical, radiation and chemotherapy treatments, the overall survival of UM and prognosis remain poor. In the present study, we hypothesized that Sirtuin 1 and 2 (SIRT1/2), class III histone deacetylases (HDACs), were critical in controlling the destiny of bulk tumor cells and cancer stem cells (CSCs) of UM. We testified this hypothesis in four lines of UM cells (92.1, Mel 270, Omm 1 and Omm 2.3). Our results showed that inhibition of SIRT1/2 by Tenovin-6 induced apoptosis in UM cells by activating the expression of tumor suppressor genes such as p53 and elevating reactive oxygen species (ROS). Tenovin-6 inhibited the growth of UM cells. Tenovin-6 and vinblastine was synergistic in inducing apoptosis of UM cell line 92.1 and Mel 270. Furthermore, Tenovin-6 eliminated cancer stem cells in 92.1 and Mel 270 cells. In conclusion, our findings suggest that Tenovin-6 may be a promising agent to kill UM bulk tumor cells and CSCs.

Embryonic Zebrafish: Different Phenotypes after Injection of Human Uveal Melanoma Cells

Although murine xenograft models for human uveal melanoma (UM) are available, they are of limited utility for screening large compound libraries for the discovery of new drugs. We need new preclinical models which can efficiently evaluate drugs that can treat UM metastases. The zebrafish embryonic model is ideal for drug screening purposes because it allows the investigation of potential antitumor properties of drugs within 1 week. The optical transparency of the zebrafish provides unique possibilities for live imaging of fluorescence-labelled cancer cells and their behavior. In addition, the adaptive immune response, which is responsible for the rejection of transplanted material, is not yet present in the early stages of fish development, and systemic immunosuppression is therefore not required to allow growth of tumor cells. We studied the behavior of UM cells following injection into zebrafish embryos and observed different phenotypes. We also analyzed cell migration, proliferation, formation of micrometastasis and interaction with the host microenvironment. Significant differences were noted between cell lines: cells derived from metastases showed more migration and proliferation than cells derived from the primary tumors. The addition of the c-Met inhibitor crizotinib to the water in which the larvae were kept reduced the migration and proliferation of UM cells expressing c-Met. This indicates the applicability of the zebrafish xenografts for testing novel inhibitory compounds and provides a fast and sensitive in vivo vertebrate model for preclinical drug screening to combat UM.

Gα13 mediates human cytomegalovirus-encoded chemokine receptor US28-induced cell death in melanoma

US28, a constitutively active G-protein-coupled receptor encoded by the human cytomegalovirus, leads to mechanistically unknown programmed cell death. Here we show that expression of wild-type US28 in human melanoma cells leads to apoptotic cell death via caspase 3 activation along with reduced cell proliferation. Reduced tumor growth upon US28 expression was observed in a xenograft mouse model. The signaling mute US28R129A showed a reduced antiproliferative effect. On evaluating different G-proteins coupled to US28 for signal transduction, Gα13 was identified as the main G-protein executing the apoptotic effect. Silencing of Gα13 but not Gαq resulted in a substantial increase in cell survival. Overexpression of Gα13 but not Gαq and their GTPase deficient forms Gα13Q226L and GαqQ209L, respectively, confirmed the requirement of Gα13 for US28 mediated cell death. Increasing expression of Gα13 alone induced cell death underscoring its relay function for US28 mediated decreased cell viability. Further reduced expression of Gα13 in melanoma cell lines isolated from advanced lesions and melanoma tissue was observed. These findings identified Gα13 as crucial for US28-induced cell death, substantiating that the effect of US28 on cell fate depends on preferred G-protein binding.

A Subset of Nuclear Receptors are Uniquely Expressed in Uveal Melanoma Cells

Uveal melanoma (UM) is recognized as the most common intraocular malignancy and the second most common form of melanoma. Nearly 50% of UM patients develop untreatable and fatal metastases. The 48-member nuclear receptor (NR) superfamily represents a therapeutically targetable group of transcription factors known for their regulation of key cancer pathways in numerous tumor types. Here, we profiled the expression of the 48 human NRs by qRT-PCR across a melanoma cell line panel including 5 UM lines, 9 cutaneous melanoma (CM) lines, and normal primary melanocytes. NR expression patterns identified a few key features. First, in agreement with our past studies identifying RXRg as a CM-specific marker, we found that UM cells also exhibit high levels of RXRg expression, making it a universal biomarker for melanoma tumors. Second, we found that LXRb is highly expressed in both UM and CM lines, suggesting that it may be a therapeutic target in a UM metastatic setting as it has been in CM models. Third, we found that RARg, PPARd, EAR2, RXRa, and TRa expressions could subdivide UM from CM. Previous studies of UM cancers identified key mutations in three genes: GNAQ, GNA11, and BRAF. We found unique NR expression profiles associated with each of these UM mutations. We then performed NR-to-NR and NR-to-genome expression correlation analyses to find potential NR-driven transcriptional programs activated in UM and CM. Specifically, RXRg controlled gene networks were identified that may drive melanoma-specific signaling and metabolism. ERRa was identified as a UM-defining NR and genes correlated with its expression confirm the role of ERRa in metabolic control. Given the plethora of available NR agonists, antagonists, and selective receptor modulators, pharmacologic manipulation of these NRs and their transcriptional outputs may lead to a more comprehensive understanding of key UM pathways and how we can leverage them for better therapeutic alternatives.