Biology of advanced uveal melanoma and next steps for clinical therapeutics

Single-cell hdWGCNA reveals metastatic protective macrophages and development of deep learning model in uveal melanoma

BACKGROUND

Although there has been some progress in the treatment of primary uveal melanoma (UVM), distant metastasis remains the leading cause of death in patients. Monitoring, staging, and treatment of metastatic disease have not yet reached consensus. Although more than half of metastatic tumors (62%) are diagnosed within five years after primary tumor treatment, the remainder are only detected in the following 25 years. The mechanisms of UVM metastasis and its impact on prognosis are not yet fully understood.

METHODS

scRNA-seq data of UVM samples were obtained and processed, followed by cell type identification and characterization of macrophage subpopulations. High-dimensional weighted gene co-expression network analysis (HdWGCNA) was performed to identify key gene modules associated with metastatic protective macrophages (MPMφ) in primary samples, and functional analyses were conducted. Non-negative matrix factorization (NMF) clustering and immune cell infiltration analyses were performed using the MPMφ gene signatures. Machine learning models were developed using the identified metastatic protective macrophages related genes (MPMRGs) to distinguish primary from metastatic patients. A deep learning convolutional neural network (CNN) model was constructed based on MPMRGs and cell type associations. Lastly, a prognostic model was established using the MPMRGs and validated in independent cohorts.

RESULTS

Single-cell RNA-seq analysis revealed a unique immune microenvironment landscape in primary samples compared to metastatic samples, with an enrichment of macrophage cells. Using HdWGCNA, MPMφ and marker genes were identified. Functional analysis showed an enrichment of genes related to antigen processing progress and immune response. Machine learning and deep learning models based on key genes showed significant effectiveness in distinguishing between primary and metastatic patients. The prognostic model based on key genes demonstrated substantial predictive value for the survival of UVM patients.

CONCLUSION

Our study identified key macrophage subpopulations related to metastatic samples, which have a profound impact on shaping the tumor immune microenvironment. A prognostic model based on macrophage cell genes can be used to predict the prognosis of UVM patients.

Heterogeneity and molecular landscape of melanoma: implications for targeted therapy

Uveal cancer (UM) offers a complex molecular landscape characterized by substantial heterogeneity, both on the genetic and epigenetic levels. This heterogeneity plays a critical position in shaping the behavior and response to therapy for this uncommon ocular malignancy. Targeted treatments with gene-specific therapeutic molecules may prove useful in overcoming radiation resistance, however, the diverse molecular makeups of UM call for a patient-specific approach in therapy procedures. We need to understand the intricate molecular landscape of UM to develop targeted treatments customized to each patient's specific genetic mutations. One of the promising approaches is using liquid biopsies, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), for detecting and monitoring the disease at the early stages. These non-invasive methods can help us identify the most effective treatment strategies for each patient. Single-cellular is a brand-new analysis platform that gives treasured insights into diagnosis, prognosis, and remedy. The incorporation of this data with known clinical and genomics information will give a better understanding of the complicated molecular mechanisms that UM diseases exploit. In this review, we focused on the heterogeneity and molecular panorama of UM, and to achieve this goal, the authors conducted an exhaustive literature evaluation spanning 1998 to 2023, using keywords like "uveal melanoma, "heterogeneity". "Targeted therapies"," "CTCs," and "single-cellular analysis".

Uveal melanoma: Recent advances in immunotherapy

Uveal melanoma (UM) is the most common primary intraocular cancer in adults. The incidence in Europe and the United States is 6-7 per million population per year. Although most primary UMs can be successfully treated and locally controlled by irradiation therapy or local tumor resection, up to 50% of UM patients develop metastases that usually involve the liver and are fatal within 1 year. To date, chemotherapy and targeted treatments only obtain minimal responses in patients with metastatic UM, which is still characterized by poor prognosis. No standard therapeutic approaches for its prevention or treatment have been established. The application of immunotherapy agents, such as immune checkpoint inhibitors that are effective in cutaneous melanoma, has shown limited effects in the treatment of ocular disease. This is due to UM's distinct genetics, natural history, and complex interaction with the immune system. Unlike cutaneous melanomas characterized mainly by BRAF or NRAS mutations, UMs are usually triggered by a mutation in GNAQ or GNA11. As a result, more effective immunotherapeutic approaches, such as cancer vaccines, adoptive cell transfer, and other new molecules are currently being studied. In this review, we examine novel immunotherapeutic strategies in clinical and preclinical studies and highlight the latest insight in immunotherapy and the development of tailored treatment of UM.

Imipridones inhibit tumor growth and improve survival in an orthotopic liver metastasis mouse model of human uveal melanoma

Purpose

Uveal melanoma (UM) is a highly aggressive disease with very few treatment options. We previously demonstrated that mUM is characterized by high oxidative phosphorylation (OXPHOS). Here we tested the anti-tumor, signaling and metabolic effects of imipridones, CLPP activators which reduce OXPHOS indirectly and have demonstrated safety in patients.

Experimental Design

We assessed CLPP expression in UM patient samples. We tested the effects of imipridones (ONC201, ONC212) on the growth, survival, signaling and metabolism of UM cell lines in vitro, and for therapeutic effects in vivo in UM liver metastasis models.

Results

CLPP expression was confirmed in primary and mUM patient samples. ONC201/212 treatment of UM cell lines in vitro decreased OXPHOS effectors, inhibited cell growth and migration, and induced apoptosis. ONC212 increased metabolic stress and apoptotic pathways, inhibited amino acid metabolism, and induced cell death-related lipids. ONC212 also decreased tumor burden and increased survival in vivo in two UM liver metastasis models.

Conclusion

Imipridones are a promising strategy for further testing and development in mUM.

Recent approaches for the treatment of uveal melanoma: Opportunities and challenges

Uveal melanoma (UM) is the most prevalent primary intraocular cancer in adult population. Primary methods for treatment of UM involves surgery Proton Beam Therapy (PBT), Plaque Brachytherapy, phototherapy, and Charged Particle Radiation Therapy (CPT). It has been found that approximately 50 % of patients diagnosed with UM ultimately experience development of metastatic disease. Furthermore, it has been identified that majority of the patient experience metastasis in liver with a prevalence of 95 %. Management of metastatic UM (MUM) involves various therapeutic modalities, including systemic chemotherapy, molecular targeted therapy, immunotherapy and liver directed interventions. We outline gene mutation in UM and addresses various treatment modalities, including molecular targeted therapy, miRNA-based therapy, and immunotherapy. Additionally, inclusion of ongoing clinical trials aimed at developing novel therapeutic options for management of UM are also mentioned.

Efficacy of immune checkpoint inhibition in metastatic uveal melanoma: a systematic review and meta-analysis

Metastatic uveal melanoma (mUM) has historically been associated with short survival and limited effective treatments. Immune checkpoint inhibitors (ICIs) have been trialed in mUM; however, robust conclusions regarding their efficacy are difficult to draw given small study sizes and heterogeneous patient populations. Five databases were searched using a combination of 'ICI' and 'mUM' headings, and data on patient demographics, objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) were extracted. Pooled ORR was calculated using a random effects model and the inverse variance method. Available Kaplan-Meier OS and PFS curves were used to construct summary OS and PFS plots, from which median values were derived. Pooled ORR was 9.2% overall (95% CI 7.2-11.8) [4.1% for anti-CTLA4 (95% CI 2.1-7.7), 7.1% for anti-PD(L)1 (95% CI 4.5-10.9) and 13.5% for anti-CTLA4 plus anti-PD1 (95% CI 10.0-18.0)]. Median OS was 11.5 months overall (95% CI 9.5-13.8) [8.0 months for anti-CTLA4 (95% CI 5.5-9.9), 11.7 months for anti-PD(L)1 (95% CI 9.0-14.0) and 16.0 months for ipilimumab plus anti-PD1 (95% CI 11.5-17.7) ( P < 0.001)]. Median PFS was 3.0 months overall (95% CI 2.9-3.1). ICIs have limited efficacy in mUM and a recommendation for their use must consider the balance of benefit and risk for individual patients if no other options are available. Further biomarker profiling studies may be helpful in assessing which patients will benefit from ICIs, in particular the addition of ipilimumab to anti-PD1 therapy.

Whole-genome CRISPR screening identifies PI3K/AKT as a downstream component of the oncogenic GNAQ-focal adhesion kinase signaling circuitry

G proteins and G protein-coupled receptors activate a diverse array of signal transduction pathways that promote cell growth and survival. Indeed, hot spot-activating mutations in GNAQ/GNA11, encoding Gαq proteins, are known to be driver oncogenes in uveal melanoma (UM), for which there are limited effective therapies currently available. Focal adhesion kinase (FAK) has been recently shown to be a central mediator of Gαq-driven signaling in UM, and as a result, is being explored clinically as a therapeutic target for UM, both alone and in combination therapies. Despite this, the repertoire of Gαq/FAK-regulated signaling mechanisms have not been fully elucidated. Here, we used a whole-genome CRISPR screen in GNAQ-mutant UM cells to identify mechanisms that, when overactivated, lead to reduced sensitivity to FAK inhibition. In this way, we found that the PI3K/AKT signaling pathway represented a major resistance driver. Our dissection of the underlying mechanisms revealed that Gαq promotes PI3K/AKT activation via a conserved signaling circuitry mediated by FAK. Further analysis demonstrated that FAK activates PI3K through the association and tyrosine phosphorylation of the p85 regulatory subunit of PI3K and that UM cells require PI3K/AKT signaling for survival. These findings establish a novel link between Gαq-driven signaling and the stimulation of PI3K as well as demonstrate aberrant activation of signaling networks underlying the growth and survival of UM and other Gαq-driven malignancies.

Targeting IRS-1/2 in Uveal Melanoma Inhibits In Vitro Cell Growth, Survival and Migration, and In Vivo Tumor Growth

Uveal melanoma originating in the eye and metastasizing to the liver is associated with poor prognosis and has only one approved therapeutic option. We hypothesized that liver-borne growth factors may contribute to UM growth. Therefore, we investigated the role of IGF-1/IGF-1R signaling in UM. Here, we found that IRS-1, the insulin receptor substrate, is overexpressed in both UM cells and tumors. Since we previously observed that IGF-1R antibody therapy was not clinically effective in UM, we investigated the potential of NT157, a small molecule inhibitor of IRS-1/2, in blocking this pathway in UM. NT157 treatment of multiple UM cell lines resulted in reduced cell growth and migration and increased apoptosis. This treatment also significantly inhibited UM tumor growth in vivo, in the chicken egg chorioallantoic membrane (CAM) and subcutaneous mouse models, validating the in vitro effect. Mechanistically, through reverse phase protein array (RPPA), we identified significant proteomic changes in the PI3K/AKT pathway, a downstream mediator of IGF-1 signaling, with NT157 treatment. Together, these results suggest that NT157 inhibits cell growth, survival, and migration in vitro, and tumor growth in vivo via inhibiting IGF-1 signaling in UM.

Oncogenic Gq/11 signaling acutely drives and chronically sustains metabolic reprogramming in uveal melanoma

Metabolic reprogramming has been shown to occur in uveal melanoma (UM), the most common intraocular tumor in adults. Mechanisms driving metabolic reprogramming in UM are poorly understood. Elucidation of these mechanisms could inform development of new therapeutic strategies for metastatic UM, which has poor prognosis because existing therapies are ineffective. Here, we determined whether metabolic reprogramming is driven by constitutively active mutant α-subunits of the heterotrimeric G proteins Gq or G11 (Gq/11), the oncogenic drivers in ∼90% of UM patients. Using PET-computed tomography imaging, microphysiometry, and GC/MS, we found that inhibition of oncogenic Gq/11 with the small molecule FR900359 (FR) attenuated glucose uptake by UM cells in vivo and in vitro, blunted glycolysis and mitochondrial respiration in UM cell lines and tumor cells isolated from patients, and reduced levels of several glycolytic and tricarboxylic acid cycle intermediates. FR acutely inhibited glycolysis and respiration and chronically attenuated expression of genes in both metabolic processes. UM therefore differs from other melanomas that exhibit a classic Warburg effect. Metabolic reprogramming in UM cell lines and patient samples involved protein kinase C and extracellular signal-regulated protein kinase 1/2 signaling downstream of oncogenic Gq/11. Chronic administration of FR upregulated expression of genes involved in metabolite scavenging and redox homeostasis, potentially as an adaptive mechanism explaining why FR does not efficiently kill UM tumor cells or regress UM tumor xenografts. These results establish that oncogenic Gq/11 signaling is a crucial driver of metabolic reprogramming in UM and lay a foundation for studies aimed at targeting metabolic reprogramming for therapeutic development.

Cystatin C and cystatin SN as possible soluble tumor markers in malignant uveal melanoma

Background

The aim of the study was to determine the concentration of endogenous cystatin C and cystatin SN, as potential tumor biomarkers, in the serum and biological fluids of the eye in both healthy controls and patients with uveal melanoma.

Patients and methods

The concentration of both cystatins was determined in the intraocular fluid (IOF), tear fluid, and serum of patients with uveal melanoma and compared to baseline measurements in IOF, tears, serum, cerebral spinal fluid, saliva and urine of healthy controls.

Results

The concentration of cystatin C in all the biological matrices obtained from healthy controls significantly exceeded the concentration of cystatin SN and was independent of gender. Cystatin C concentrations in the tear fluid of patients with uveal melanoma (both the eye with the malignancy, as well as the contralateral, non-affected eye), were significantly greater than cystatin C concentrations in the tear fluid of healthy controls and was independent of tumor size. The concentration of cystatin SN in IOF of patients with uveal melanoma was significantly less than the corresponding concentration of cystatin SN in healthy controls.

Conclusions

The ratio of cystatins (CysC:CysSN) in both the serum and tear fluid, as well as the concentration of cystatin SN in IOF, would appear to strongly suggest the presence of uveal melanoma. It is further suggested that multiple diagnostic criteria be utilized if a patient is suspected of having uveal melanoma, such as determination of the cystatin C and cystatin SN concentrations in serum, tears, and IOF, ocular fundus and ultrasound imaging, and biopsy with histopathological evaluation.

Case Report: Two Genetically Distinct Choroidal Melanomas in the Same Eye Treated with Endolaser Therapy

SIGNIFICANCE

This case report highlights the merits of using fine needle aspiration biopsy to obtain gene expression profiling of individual choroidal melanomas when more than one tumor arises in the same eye. It is also the first such case to document laser ablation therapy as the primary treatment.

PURPOSE

This report describes a case of two primary choroidal melanomas with different genetic profiles in the same eye.

CASE REPORT

An 80-year-old man presented to the office with a neoplasm of uncertain behavior in the left eye. The patient's visual acuity and IOP in the left eye, respectively, at the time of his first visit to the office were 20/25 and 8 mmHg. A dilated fundus examination revealed that there were two choroidal lesions in the left eye. The macular lesion was classified as type 1A, and the ciliochoroidal lesion was classified as type 1B. The patient underwent a vitrectomy of the left eye, followed by endolaser ablation of the tumors. The patient was also injected with bevacizumab. To date, the patient is free of known metastasis. Most recently, his visual acuity and IOP in the left eye were 20/30 and 14 mmHg, respectively.

CONCLUSIONS

Although rare, multiple melanomas in the same eye may have differing genetic profiles, which may alter prognosis and management, depending on the class of tumor detected.

Next-Generation Immunotherapy Approaches in Melanoma

PURPOSE OF REVIEW

For patients with metastatic melanoma, immune checkpoint inhibition has drastically changed outcomes. Here, we review the current and next generations of immune-based anti-cancer therapeutics for patients with metastatic melanoma.

RECENT FINDINGS

The need for new anti-cancer therapeutics in patients with metastatic melanoma who have progression of disease despite immune checkpoint blockade is evident. Several novel agents are expected to have FDA approval within the next few years, as they have yielded impressive responses. Despite these optimistic agents, the field of immuno-oncology continues to expand and produce agents with novel mechanisms of action. The next generation of immunotherapy is based upon years of thoroughly researched immuno-oncology. Many of these agents are currently being evaluated in early phase clinical trials, and much of the preliminary data looks promising.

Tumor Immune Microenvironment Characterization Identifies Prognosis and Immunotherapy-Related Gene Signatures in Melanoma

Background

The tumor microenvironment (TME) involves infiltration of multiple immune cell subsets, which could influence the prognosis and clinical characteristics. The increasing evidence on the role of tumor-infiltrating lymphocytes (TILs) in primary and metastatic melanomas supports that the immune system is involved in the progression and outcomes of melanoma. However, the immune infiltration landscape in melanoma has not been systematically elucidated.

Methods

In this study, we used CIBERSORT and ESTIMATE algorithms to analyze immune infiltration pattern of 993 melanoma samples. Then we screened differential expression genes (DEGs) related to immune subtypes and survival. The immune cell infiltration (ICI) score was constructed by using principal-component analysis (PCA) based on immune signature genes from DGEs. Gene set enrichment analysis (GSEA) was applied to explore high and low ICI score related pathways. Finally, the predictive ability of ICI score was evaluated in survival prognosis and immunotherapy benefit.

Result

We identified three ICI clusters and three gene clusters associated with different immune subtypes and survival outcomes. Then the ICI score was constructed, and we found that high ICI score exhibited activated immune characteristics and better prognosis. High ICI score was significantly enriched in immune pathways and highly expressed immune signature genes. More importantly, we confirmed that melanoma patients with high ICI score had longer overall survival and rate of response to immunotherapy.

Conclusion

We presented a comprehensive immune infiltration landscape in melanoma. Our results will facilitate understanding of the melanoma tumor microenvironment and provide a new immune therapy strategy.

Population pharmacokinetics and exposure-response of selumetinib and its N-desmethyl metabolite in pediatric patients with neurofibromatosis type 1 and inoperable plexiform neurofibromas

PURPOSE

Selumetinib (ARRY-142886) is a potent, selective, MEK1/2 inhibitor approved in the US for the treatment of children (≥ 2 years) with neurofibromatosis type 1 (NF1) and symptomatic, inoperable plexiform neurofibromas (PN). We characterized population pharmacokinetics (PK) of selumetinib and its active N-desmethyl metabolite, evaluated exposure-safety/efficacy relationships, and assessed the proposed therapeutic dose of 25 mg/m² bid based on body surface area (BSA) in this patient population.

METHODS

Population PK modeling and covariate analysis (demographics, formulation, liver enzymes, BSA, patients/healthy volunteers) were based on pooled PK data from adult healthy volunteers (n = 391), adult oncology patients (n = 83) and pediatric patients with NF1-PN (n = 68). Longitudinal selumetinib/metabolite exposures were predicted with the final model. Exposure-safety/efficacy analyses were applied to pediatric patients (dose levels: 20, 25, 30 mg/m² bid).

RESULTS

Selumetinib and metabolite concentration-time courses were modeled using a joint compartmental model. Typical selumetinib plasma clearance was 11.6 L/h (95% CI 11.0-12.2 L/ h). Only BSA had a clinically relevant (> 20%) impact on exposure, supporting BSA-based administration in children. Selumetinib and metabolite exposures in responders (≥ 20% PN volume decrease from baseline) and non-responders were largely overlapping, with medians numerically higher in responders. No clear relationships between exposure and safety events were established; exposure was not associated with key adverse events (AEs) including rash acneiform, diarrhea, vomiting, and nausea.

CONCLUSION

Findings support continuous selumetinib 25 mg/m² bid in pediatric patients. Importantly, the updated dosing nomogram ensures that patients will receive a clinically active, yet tolerable, dose regardless of differences in BSA and allows dose reductions, if necessary.

High EIF4E2 expression is an independent prognostic risk factor for poor overall survival and recurrence-free survival in uveal melanoma

Uveal melanoma (UM), as the most common primary intraocular carcinoma, is a relatively rare but lethal tumor. Upregulated eukaryotic translation initiation factor 4E family member 2 (EIF4E2) promotes the progression of multiple human carcinomas. However, its role remains unclear in UM. To identify the prognostic value of EIF4E2 in UM, we downloaded RNA-sequencing data along with clinical information from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. EIF4E2 mRNA was significantly increased in three different subgroups in the TCGA-UM dataset. High mRNA expression was correlated with shorter overall survival (OS) and shorter recurrence-free survival (RFS). Moreover, we constructed a prognostic signature using Cox regression analyses in our training cohort TCGA-UM dataset as follows: risk score = 0.04335 × Age +0.49639 × expression of EIF4E2. Based on the risk score, each patient was classified as high-risk or low-risk. Additional survival analyses suggested that patients in the high-risk score group had an unfavorable OS compared with patients in the low-risk score group, which was validated in two external GEO datasets, including GSE84976 and GSE22138. Functional enrichment analysis demonstrated that UM was correlated with hypoxia-related functions. Gene set enrichment analysis (GSEA) indicated significant enrichments of the p53 and Notch pathways. In addition, EIF4E2 was genetically altered in 12.5% (10/80) of UM patients. Epigenetically, higher expression of cg03852847 was correlated with longer OS and longer RFS. In conclusion, our findings demonstrated that high EIF4E2 expression is an independent prognostic risk factor for UM patients. EIF4E2 might play an important role in hypoxia-related signaling pathways during UM progression. Both genetic and epigenetic alterations may contribute to UM pathogenesis. These findings could offer individualized clinical prognostication and potential novel treatment targets for UM patients.

Combined Inhibition of Gαq and MEK Enhances Therapeutic Efficacy in Uveal Melanoma

PURPOSE

All uveal melanoma and a fraction of other melanoma subtypes are driven by activation of the G-protein alpha-q (Gαq) pathway. Targeting these melanomas has proven difficult despite advances in the molecular understanding of key driver signaling pathways in the disease pathogenesis. Inhibitors of Gαq have shown promising preclinical results, but their therapeutic activity in distinct Gαq mutational contexts and in vivo have remained elusive.

EXPERIMENTAL DESIGN

We used an isogenic melanocytic cellular system to systematically examine hotspot mutations in GNAQ (e.g., G48V, R183Q, Q209L) and CYSLTR2 (L129Q) found in human uveal melanoma. This cellular system and human uveal melanoma cell lines were used in vitro and in in vivo xenograft studies to assess the efficacy of Gαq inhibition as a single agent and in combination with MEK inhibition.

RESULTS

We demonstrate that the Gαq inhibitor YM-254890 inhibited downstream signaling and in vitro growth in all mutants. In vivo, YM-254890 slowed tumor growth but did not cause regression in human uveal melanoma xenografts. Through comprehensive transcriptome analysis, we observed that YM-254890 caused inhibition of the MAPK signaling with evidence of rebound by 24 hours and combination treatment of YM-254890 and a MEK inhibitor led to sustained MAPK inhibition. We further demonstrated that the combination caused synergistic growth inhibition in vitro and tumor shrinkage in vivo.

CONCLUSIONS

These data suggest that the combination of Gαq and MEK inhibition provides a promising therapeutic strategy and improved therapeutic window of broadly targeting Gαq in uveal melanoma.See related commentary by Neelature Sriramareddy and Smalley, p. 1217.

Transcriptional analysis of metastatic uveal melanoma survival nominates NRP1 as a therapeutic target

Uveal melanoma is a rare form of melanoma with particularly poor outcomes in the metastatic setting. In contrast with cutaneous melanoma, uveal melanoma lacks BRAF mutations and demonstrates very low response rates to immune-checkpoint blockade. Our objectives were to study the transcriptomics of metastatic uveal melanoma with the intent of assessing gene pathways and potential molecular characteristics that might be nominated for further exploration as therapeutic targets. We initially analyzed transcriptional data from The Cancer Genome Atlas suggesting PI3K/mTOR and glycolysis as well as IL6 associating with poor survival. From tumor samples collected in a prospective phase II trial (A091201), we performed a transcriptional analysis of human metastatic uveal melanoma observing a novel role for epithelial-mesenchymal transition associating with survival. Specifically, we nominate and describe initial functional validation of neuropillin-1 from uveal melanoma cells as associated with poor survival and as a mediator of proliferation and migration for uveal melanoma in vitro. These results immediately nominate potential next steps in clinical research for patients with metastatic uveal melanoma.

BAP1 mutant uveal melanoma is stratified by metabolic phenotypes with distinct vulnerability to metabolic inhibitors

Cancer cell metabolism is a targetable vulnerability; however, a precise understanding of metabolic heterogeneity is required. Inactivating mutations in BRCA1-associated protein 1 (BAP1) are associated with metastasis in uveal melanoma (UM), the deadliest adult eye cancer. BAP1 functions in UM remain unclear. UM patient sample analysis divided BAP1 mutant UM tumors into two subgroups based on oxidative phosphorylation (OXPHOS) gene expression suggesting metabolic heterogeneity. Consistent with patient data, transcriptomic analysis of BAP1 mutant UM cell lines also showed OXPHOShigh or OXPHOSlow subgroups. Integrated RNA sequencing, metabolomics, and molecular analyses showed that OXPHOShigh BAP1 mutant UM cells utilize glycolytic and nucleotide biosynthesis pathways, whereas OXPHOSlow BAP1 mutant UM cells employ fatty acid oxidation. Furthermore, the two subgroups responded to different classes of metabolic suppressors. Our findings indicate that targeting cancer metabolism is a promising therapeutic option for BAP1 mutant UM; however, tailored approaches may be required due to metabolic heterogeneities.

LncRNA LINC00518 Acts as an Oncogene in Uveal Melanoma by Regulating an RNA-Based Network

Simple Summary

Uveal melanoma (UM) is the most frequent primary tumor of the eye in adults. Although molecular alterations on protein-coding genes have been associated with the development of UM, the role of non-coding RNAs and their competitive endogenous networks remain poorly investigated. Starting from a computational analysis on UM expression dataset deposited in The Cancer Genome Atlas, we identified the long non-coding RNA LINC00518 as a potential oncogene. We then experimentally evaluated LINC00518 and its supposed RNA signaling in human biopsies and in vitro functional assays. The results obtained suggest that LINC00518, under potential transcriptional control by MITF, regulates an RNA–RNA network promoting cancer-related processes (i.e., cell proliferation and migration). These findings open the way to the characterization of the unknown RNA signaling associated with UM and pave the way to the exploitation of a potential target for RNA-based therapeutics.

Abstract

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults; little is known about the contribution of non-coding RNAs (ncRNAs) to UM pathogenesis. Competitive endogenous RNA (ceRNA) networks based on RNA–RNA interactions regulate physiological and pathological processes. Through a combined approach of in silico and experimental biology, we investigated the expression of a set of long non-coding RNAs (lncRNAs) in patient biopsies, identifying LINC00518 as a potential oncogene in UM. The detection of LINC00518 dysregulation associated with several in vitro functional assays allowed us to investigate its ceRNA regulatory network and shed light on its potential involvement in cancer-related processes, such as epithelial to mesenchymal transition (EMT) and CoCl₂-induced hypoxia-like response. In vitro transient silencing of LINC00518 impaired cell proliferation and migration, and affected mRNA expression of LINGO2, NFIA, OTUD7B, SEC22C, and VAMP3. A “miRNA sponge” and “miRNA protector” model have been hypothesized for LINC00518-induced regulation of mRNAs. In vitro inhibition of MITF suggested its role as a potential activator of LINC00518 expression. Comprehensively, LINC00518 may be considered a new oncogene in UM and a potential target for RNA-based therapeutic approaches.

Update on uveal melanoma: Translational research from biology to clinical practice (Review)

Uveal melanoma is the most common type of intraocular cancer with a low mean annual incidence of 5‑10 cases per million. Tumours are located in the choroid (90%), ciliary body (6%) or iris (4%) and of 85% are primary tumours. As in cutaneous melanoma, tumours arise in melanocytes; however, the characteristics of uveal melanoma differ, accounting for 3‑5% of melanocytic cancers. Among the numerous risk factors are age, sex, genetic and phenotypic predisposition, the work environment and dermatological conditions. Management is usually multidisciplinary, including several specialists such as ophthalmologists, oncologists and maxillofacial surgeons, who participate in the diagnosis, treatment and complex follow‑up of these patients, without excluding the management of the immense emotional burden. Clinically, uveal melanoma generates symptoms that depend as much on the affected ocular globe site as on the tumour size. The anatomopathological study of uveal melanoma has recently benefited from developments in molecular biology. In effect, disease classification or staging according to molecular profile is proving useful for the assessment of this type of tumour. Further, the improved knowledge of tumour biology is giving rise to a more targeted approach to diagnosis, prognosis and treatment development; for example, epigenetics driven by microRNAs as a target for disease control. In the present study, the main epidemiological, clinical, physiopathological and molecular features of this disease are reviewed, and the associations among all these factors are discussed.

Correlation between the Expression of Angiogenic Factors and Stem Cell Markers in Human Uveal Melanoma

Uveal melanoma (UM) is the most common malignant tumor of the eye with extremely high metastatic potential. UM tumor cells can disseminate only hematogenously, thus, angiogenic signals have a particular role in the prognosis of the disease. Although the presence of cancer stem cells (CSCs) in densely vascularized UMs has been reported previously, their role in the process of hematogenous spread of UM has not been studied. In this study, we investigated the regulation of angiogenesis in UM in correlation with the presence of CSCs. Seventy UM samples were collected to analyze the expression of CSC markers and angiogenic factors. The expression of CSC markers was studied by RT-PCR, Western blotting techniques and IHC-TMA technique. RT-PCR showed high expression of CSC markers, particularly nestin, FZD6 and SOX10 and somewhat lower expression of NGFR. The protein expression of FZD6, HIF-1α and VEGFA was further evaluated in 52 UM samples by the IHC-TMA technique. We report here for the first time a significant correlation between FZD6 and VEGFA expression in UM samples. The observed correlation between FZD6 and VEGFA suggests the presence of CSCs in UM that are associated with the vascularization process.

A Phase II Study of Glembatumumab Vedotin for Metastatic Uveal Melanoma

Glembatumumab vedotin (CDX-011, GV) is a fully human Immunoglobulin G2 monoclonal antibody directed against glycoprotein NMB coupled via a peptide linker to monomethyl auristatin E (MMAE), a potent cytotoxic microtubule inhibitor. This phase II study evaluated the overall response rate and safety of GV, glycoprotein NMB (GPNMB) expression, and survival in patients with metastatic uveal melanoma. Eligible patients with metastatic uveal melanoma who had not previously been treated with chemotherapy received GV 1.9 mg/kg every three weeks. The primary endpoint was the objective response rate (ORR). Secondary endpoints included GPNMB expression, progression-free survival (PFS), overall survival (OS), and toxicity analysis. GPNMB expression was assessed pre- and post-treatment via immunohistochemistry for patients with available tumor tissue. Out of 35 patients who received treatment, two patients had confirmed partial responses (PRs; 6%), and 18 patients had a stable disease (SD; 51%) as the best objective response. 38% of the patients had stable disease >100 days. The grade 3 or 4 toxicities that occurred in two or more patients were neutropenia, rash, hyponatremia, and vomiting. The median progression-free survival was 3.1 months (95% CI: 1.5–5.6), and the median overall survival was 11.9 months (95% CI 9.0–16.9) in the evaluable study population. GV is well-tolerated in metastatic uveal melanoma. The disease control rate was 57% despite a low objective response rate. Exploratory immune correlation studies are underway to provide insight into target saturation, combination strategies, and antigen release.

Heterotrimeric Gq proteins as therapeutic targets?

Heterotrimeric G proteins are the core upstream elements that transduce and amplify the cellular signals from G protein-coupled receptors (GPCRs) to intracellular effectors. GPCRs are the largest family of membrane proteins encoded in the human genome and are the targets of about one-third of prescription medicines. However, to date, no single therapeutic agent exerts its effects via perturbing heterotrimeric G protein function, despite a plethora of evidence linking G protein malfunction to human disease. Several recent studies have brought to light that the Gq family-specific inhibitor FR900359 (FR) is unexpectedly efficacious in silencing the signaling of Gq oncoproteins, mutant Gq variants that mostly exist in the active state. These data not only raise the hope that researchers working in drug discovery may be able to potentially strike Gq oncoproteins from the list of undruggable targets, but also raise questions as to how FR achieves its therapeutic effect. Here, we place emphasis on these recent studies and explain why they expand our pharmacological armamentarium for targeting Gq protein oncogenes as well as broaden our mechanistic understanding of Gq protein oncogene function. We also highlight how this novel insight impacts the significance and utility of using G(q) proteins as targets in drug discovery efforts.

The targeted LHRH analog AEZS-108 alters expression of genes related to angiogenesis and development of metastasis in uveal melanoma

Uveal melanoma (UM) is the most common malignant tumor of the eye. Recently, we have established that 46% of UM specimens express LHRH receptors. This finding supports the idea of a LHRH receptor-targeted therapy of UM patients. Cytotoxic analog of LHRH, AEZS-108 exhibits effective anti-cancer activity in LHRH-receptor positive cancers. AEZS-108 is a hybrid molecule, composed of a synthetic peptide carrier and the cytotoxic doxorubicin (DOX). In the present study, we investigated AEZS-108 induced cytotoxicity and the altered mRNA expression profile of regulatory factors related to angiogenesis and metastasis in LHRH receptor positive OCM3 cells. Our results show that AEZS-108 upregulates the expression of MASPIN/SERPINB5 tumor suppressor gene, which is downregulated in normal uvea and UM specimens independently from the LHRH receptor-ligand interaction. AEZS-108 also substantially downregulates hypoxia-inducible factor 1 alpha (HIF1A) expression. In order to investigate the mechanism of the induction of MASPIN by AEZS-108, OCM3 cells were treated with free DOX, D-Lys⁶ LHRH analog, or AEZS-108. qRT- PCR analysis revealed in OCM3 cells that AEZS-108 is a more potent inducer of MASPIN than free DOX. In conclusion, we show for the first time that AEZS-108 has a major impact in the regulation of angiogenesis thus plays a potential role in tumor suppression. Taken together, our results support the development of novel therapeutic strategies for UM focusing on LHRH receptors.

Randomized Phase II Trial and Tumor Mutational Spectrum Analysis from Cabozantinib versus Chemotherapy in Metastatic Uveal Melanoma (Alliance A091201)

PURPOSE

The surface receptor MET is highly expressed on primary uveal melanoma; MET inhibitors demonstrated early clinical signals of efficacy in slowing uveal melanoma growth. The primary objective of our study was to compare the progression-free survival rate at 4 months (PFS4) of patients with uveal melanoma treated with cabozantinib or chemotherapy.

PATIENTS AND METHODS

Patients with metastatic uveal melanoma and RECIST measurable disease were randomized 2:1 to receive either cabozantinib (arm 1) versus temozolomide or dacarbazine (arm 2) with restaging imaging every two cycles. Cross-over from arm 2 to cabozantinib after progression was allowed (arm 2X). Available tumor specimens were analyzed by whole-exome sequencing (WES) and results were correlated with outcome.

RESULTS

Forty-six eligible patients were accrued with 31, 15, and 9 in arms 1, 2, and 2X, respectively. Median lines of prior therapy, including hepatic embolization, were two. Rates of PFS4 in arm 1 and arm 2 were 32.3% and 26.7% (P = 0.35), respectively, with median PFS time of 60 and 59 days (P = 0.964; HR = 0.99). Median overall survival (OS) was 6.4 months and 7.3 months (P = 0.580; HR = 1.21), respectively. Grade 3-4 Common Terminology Criteria for Adverse Events were present in 61.3%, 46.7%, and 37.5% in arms 1, 2, and 2X, respectively. WES demonstrated a mean tumor mutational burden of 1.53 mutations/Mb and did not separate OS ≤ or >1 year (P = 0.14). Known mutations were identified by WES and novel mutations were nominated.

CONCLUSIONS

MET/VEGFR blockade with cabozantinib demonstrated no improvement in PFS but an increase in toxicity relative to temozolomide/dacarbazine in metastatic uveal melanoma.

TNF-Alpha Inhibition and Other Immunosuppressants in the Development of Uveal and Cutaneous Melanoma

OBJECTIVE

To investigate an association between tumor necrosis factors-alpha (TNFα) inhibitors or other immunosuppressants and the development of uveal and cutaneous melanoma.

PATIENTS AND METHODS

We performed a retrospective incidence and case-control analysis of patients in Olmsted County, MN, who were diagnosed with uveal or cutaneous melanoma from January 1, 2000, to December 31, 2014. Incidence was adjusted by age and gender to the 2010 US white population. Controls were matched by sex and age to cases at time of diagnosis of melanoma.

RESULTS

There were 1221 cases of melanoma (33 uveal, 1188 cutaneous). Combined incidence of uveal and cutaneous melanoma per 100,000 person-years varied by gender (male > female), age (older > younger), and time period: 2010 to 2014 (77.9, 95% confidence interval [CI], 71.1-84.7) ≈ 2005 to 2009 (78.0, 95% CI, 70.9-85.0) > 2000 to 2004 (42.5, 95% CI, 36.9-48.1, P<.001). TNFa inhibitor prescription was not associated with significantly increased risk of melanoma vs controls (1.06% vs 0.41%, P=.06). Immunosuppressive agents, high-dose corticosteroids, and topical immunosuppressants were associated with melanoma (odds ratio [OR] 1.42 CI, 1.03-1.95, 3.30 CI, 2.44-4.48, and 1.87 CI, 1.06-3.28, respectively). An increased number of patients with uveal melanoma received immune modulating agents vs controls, but this was not statistically significant (P=.36). Autoimmune disease itself was not correlated with melanoma (P=.73).

CONCLUSION

Exposure to immunosuppressive agents is associated with melanoma. TNFa inhibition and autoimmune disease alone do not significantly increase risk of melanoma. In patients receiving immunosuppressive treatments, physicians should consider monitoring with dilated ophthalmic and full-body skin examinations. Further studies are needed to assess the impact of TNFa inhibitors on development of melanoma, particularly in uveal melanoma.

microRNA-374 inhibits proliferation and promotes apoptosis of mouse melanoma cells by inactivating the Wnt signalling pathway through its effect on tyrosinase

Melanoma is one of the most malignant skin tumours with constantly increasing incidence worldwide. Previous studies have demonstrated that microRNA‐374 (miR‐374) is a novel biomarker for cancer therapy. Therefore, this study explores whether miR‐374 targeting tyrosinase (TYR) affects melanoma and its underlying mechanism. We constructed subcutaneous melanoma models to carry out the following experiments. The cells were transfected with a series of miR‐374 mimics, miR‐374 inhibitors or siRNA against TYR. Dual luciferase reporter gene assay was used for the verification of the targeting relationship between miR‐374 and TYR. Reverse transcription quantitative polymerase chain reaction and western blot analysis were conducted to determine the expression of miR‐374, TYR, β‐catenin, B‐cell leukaemia 2 (Bcl‐2), Bcl‐2 associated X protein (Bax), Low‐density lipoprotein receptor‐related protein 6 (LRP6), Leucine‐rich repeat G protein‐coupled receptor 5 (LGR5) and CyclinD1. Cell proliferation, migration, invasion, cell cycle distribution and apoptosis were evaluated using cell counting kit‐8 assay, scratch test, transwell assay and flow cytometry respectively. TYR was proved as a putative target of miR‐374 as the evidenced by the result. It was observed that up‐regulated miR‐374 or down‐regulated TYR increased expression of Bax and decreased expressions of TYR, β‐catenin, LRP6, Bcl‐2, CyclinD1 and LGR5, along with diminished cell proliferation, migration, invasion and enhanced apoptosis. Meanwhile, cells with miR‐374 inhibitors showed an opposite trend. These findings indicated that up‐regulated miR‐374 could inhibit the expression of TYR to suppress cell proliferation, migration, invasion and promote cell apoptosis in melanoma cells by inhibiting the Wnt signalling pathway.

Dietary compounds and cutaneous malignant melanoma: recent advances from a biological perspective

Cutaneous malignant melanoma is a heterogeneous disease, being the consequence of specific genetic alterations along several molecular pathways. Despite the increased knowledge about the biology and pathogenesis of melanoma, the incidence has grown markedly worldwide, making it extremely important to develop preventive measures. The beneficial role of correct nutrition and of some natural dietary compounds in preventing malignant melanoma has been widely demonstrated. This led to numerous studies investigating the role of several dietary attitudes, patterns, and supplements in the prevention of melanoma, and ongoing research investigates their impact in the clinical management and outcomes of patients diagnosed with the disease. This article is an overview of recent scientific advances regarding specific dietary compounds and their impact on melanoma development and treatment.

Butyrophilin-Like 9 (BTNL9) Suppresses Invasion and Correlates with Favorable Prognosis of Uveal Melanoma

Background

Uveal melanoma (UM) is the most common intraocular malignancy, and the prognosis of patients with advanced stage of UM is very dismal. The T cell receptor ectopic expression of butyrophilin-like 9 (BTNL9) has been observed in several types of cancers, but the expression and clinical significance of BTNL9 in UM is unclear.

Material/Methods

In our study, we detected the expression of BTNL9 in 6 pairs of UM tissues and adjacent tissues using quantitative real-time polymerase chain reaction (qRT-PCR), and further investigated BTNL9 expression with immunohistochemistry (IHC) in a retrospective cohort consisted of 62 UM patients. The correlations between BNTL9 expression and clinicopathological factors were analyzed with Fisher’s test, and the prognostic significance of BTNL9 was evaluated with univariate analysis and multivariate analysis. Using experiments in vitro, we investigated the function of BTNL9 in UM proliferation and invasion.

Results

BTNL9 mRNAs in adjacent tissues were remarkably higher than in UM tissues. The percentages of BTNL9 low expression and high expression were 56.45% and 43.55%, respectively. High expression of BTNL9 was significantly associated with favorable prognosis of UM. BTNL9 expression was identified as a prognostic biomarker predicting better outcome of UM patients. Moreover, BTNL9 could suppress invasion instead of proliferation in melanoma cell line.

Conclusions

BTNL9 was a favorable prognostic factor of UM and it could suppress invasion of UM, suggesting that BTNL9 detection could help stratify high-risk patients with UM after operation and guide more precise surveillance and treatment.

miR-224-5p inhibits proliferation, migration, and invasion by targeting PIK3R3/AKT3 in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Accumulating investigations have identified the aberrant expression of miRNAs (microRNAs) in UM, such as miR-181, miR-20a, miR-144, miR-146a. The purpose of this study is to investigate the biological function of miR-224-5p in UM. The expression of miR-224-5p, PIK3R3, and AKT3 in 30 tumor tissues and paired adjacent noncancerous tissues were analyzed using Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell proliferation assay, transwell assay, and wound healing assay were used to measure the effects of miR-224-5p on the motility of UM in vitro. Western blot analysis and luciferase assays were used to detect the expression of PIK3R3 and AKT3 as miR-224-5p downstream targets. The results of Western blot analysis and qRT-PCR assays indicated that the expression of miR-224-5p was lower in UM tissues compared to normal tissue, while the expression of PIK3R3 and AKT3 were simultaneously increased. Upregulation of miR-224-5p significantly inhibited capacities of proliferation, invasion, and migration of OCM-1A cells and decreased expression of PIK3R3 and AKT3. Luciferase assay demonstrated PIK3R3 and AKT3 as downstream targets of miR-224-5p. Moreover, upregulating PIK3R3 and AKT3 restrained miR-224-5p-induced inhibition of the motility of OCM-1A cells. Thus, our study proved that miR-224-5p was involved in proliferation, invasion, and migration of UM cells via regulation the expression of PIK3R3 and AKT3. And the results also established a miR-224-5p/PIK3R3/PI3K/AKT axis in the regulation of UM progression, providing an experimental basis for further exploring the miR-224-5p as a therapeutic and diagnosis target for patients with UM.

Prognostic significance of deregulated microRNAs in uveal melanomas

Uveal melanoma (UM) represents the most frequent primary tumor of the eye. Despite the development of new drugs and screening programs, the prognosis of patients with UM remains poor and no effective prognostic biomarkers are yet able to identify high-risk patients. Therefore, in the present study, microRNA (miRNA or miR) expression data, contained in the TCGA UM (UVM) database, were analyzed in order to identify a set of miRNAs with prognostic significance to be used as biomarkers in clinical practice. Patients were stratified into 2 groups, including tumor stage (high-grade vs. low-grade) and status (deceased vs. alive); differential analyses of miRNA expression among these groups were performed. A total of 20 deregulated miRNAs for each group were identified. In total 7 miRNAs were common between the groups. The majority of common miRNAs belonged to the miR-506-514 cluster, known to be involved in UM development. The prognostic value of the 20 selected miRNAs related to tumor stage was assessed. The deregulation of 12 miRNAs (6 upregulated and 6 downregulated) was associated with a worse prognosis of patients with UM. Subsequently, miRCancerdb and microRNA Data Integration Portal bioinformatics tools were used to identify a set of genes associated with the 20 miRNAs and to establish their interaction levels. By this approach, 53 different negatively and positively associated genes were identified. Finally, DIANA-mirPath prediction pathway and Gene Ontology enrichment analyses were performed on the lists of genes previously generated to establish their functional involvement in biological processes and molecular pathways. All the miRNAs and genes were involved in molecular pathways usually altered in cancer, including the mitogen-activated protein kinase (MAPK) pathway. Overall, the findings of the presents study demonstrated that the miRNAs of the miR-506-514 cluster, hsa-miR-592 and hsa-miR-199a-5p were the most deregulated miRNAs in patients with high-grade disease compared to those with low-grade disease and were strictly related to the overall survival (OS) of the patients. However, further in vitro and translational approaches are required to validate these preliminary findings.

Avelumab in patients with previously treated metastatic melanoma: phase 1b results from the JAVELIN Solid Tumor trial

Background

We report phase 1b data from patients enrolled in the JAVELIN Solid Tumor clinical trial (NCT01772004) with unresectable stage IIIC or IV melanoma that had progressed after ≥1 line of therapy for metastatic disease.

Patients and methods

Patients received avelumab (10 mg/kg)—a human anti–PD-L1 antibody. Assessments included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety.

Results

As of December 31, 2016, 51 patients were treated and followed for a median of 24.2 months (range, 16.1–31.5). Most patients had cutaneous (n = 28 [54.9%]) or ocular (n = 16 [31.4%]) melanoma and had received a median of 2 prior lines of therapy (range, 0–4), including ipilimumab (n = 26 [51.0%]). The confirmed ORR was 21.6% (95% CI, 11.3–35.3; complete response, 7.8%; partial response, 13.7%). The median duration of response was not estimable (95% CI, 2.6 months-not estimable). Median PFS and OS were 3.1 months (95% CI, 1.4–6.3) and 17.2 months (95% CI, 6.6-not estimable), respectively. Subgroup analyses suggested meaningful clinical activity (ORR [95% CI]) in patients with non-ocular melanoma (31.4% [16.9–49.3]), PD-L1–positive tumors (42.1% [20.3–66.5]), or prior ipilimumab therapy (30.8% [14.3–51.8]). Thirty-nine patients (76.5%) had a treatment-related adverse event (TRAE), most commonly infusion-related reaction (29.4%), fatigue (17.6%), and chills (11.8%); 4 patients (7.8%) had a grade 3 TRAE. Five patients (9.8%) had an immune-related TRAE (all were grade 1/2). No grade 4 TRAEs or treatment-related deaths were reported.

Conclusion

Avelumab showed durable responses, promising survival outcomes, and an acceptable safety profile in patients with previously treated metastatic melanoma.

Trial registration

ClinicalTrials.gov identifier: NCT01772004.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0459-y) contains supplementary material, which is available to authorized users.

Proceedings of the Association for Research in Vision and Ophthalmology and Champalimaud Foundation Ocular Oncogenesis and Oncology Conference

The 2018 Ocular Oncogenesis and Oncology Conference was held through a partnership of the Association for Research in Vision and Ophthalmology (ARVO) and the Champalimaud Foundation. Twenty-one experts from international ocular oncology centers, from the Champalimaud Clinical Centre and the Champalimaud Foundation Cancer Research Program, and from patient advocacy organizations, delivered lectures on subjects that ranged from global ocular oncology, to basic research in mechanisms of ocular malignancy, to clinical research in ocular cancers, and to anticipated future developments in the area. The scientific program of the conference covered a broad range of ocular tumors-including uveal melanoma, retinoblastoma, ocular surface tumors, and adnexal and intraocular lymphomas-and pathogenesis and management were deliberated in the context of the broader systemic cancer discipline. In considering the latest basic and clinical research developments in ocular oncogenesis and oncology, and providing the opportunity for cross-talk between ocular cancer biologists, systemic cancer biologists, ocular oncologists, systemic oncologists, patients, and patient advocates, the forum generated new knowledge and novel insights for the field. This report summarizes the content of the invited talks at the 2018 ARVO-Champalimaud Foundation Ocular Oncogenesis and Oncology Conference.

Arylsulfonamide 64B Inhibits Hypoxia/HIF-Induced Expression of c-Met and CXCR4 and Reduces Primary Tumor Growth and Metastasis of Uveal Melanoma

PURPOSE

Uveal melanoma (UM) is the most prevalent and lethal intraocular malignancy in adults. Here, we examined the importance of hypoxia in UM growth and tested the antitumor effects of arylsulfonamide 64B, an inhibitor of the hypoxia-induced factor (HIF) pathway in animal models of UM and investigated the related mechanisms.

EXPERIMENTAL DESIGN

UM cells were implanted in the uvea of mice eyes and mice systemically treated with 64B. Drug effect on primary eye tumor growth, circulating tumor cells, metastasis formation in liver, and survival were examined. 64B effects on UM cell growth, invasion and hypoxia-induced expression of C-X-C chemokine receptor type 4 (CXCR4) and mesenchymal-epithelial transition factor (c-Met) were measured. Luciferase reporter assays, chromatin immunoprecipitation, co-immunoprecipitation, and cellular thermal shift assays were used to determine how 64B interferes with the HIF transcriptional complex.

RESULTS

Systemic administration of 64B had potent antitumor effects against UM in several orthotopic mouse models, suppressing UM growth in the eye (∼70% reduction) and spontaneous liver metastasis (∼50% reduction), and extending mice survival (P < 0.001) while being well tolerated. 64B inhibited hypoxia-induced expression of CXCR4 and c-Met, 2 key drivers of tumor invasion and metastasis. 64B disrupted the HIF-1 complex by interfering with HIF-1α binding to p300/CBP co-factors, thus reducing p300 recruitment to the MET and CXCR4 gene promoters. 64B could thermostabilize p300, supporting direct 64B binding to p300.

CONCLUSIONS

Our preclinical efficacy studies support the further optimization of the 64B chemical scaffold toward a clinical candidate for the treatment of UM.

miR-25 Promotes Melanoma Progression by regulating RNA binding motif protein 47

Melanoma is the most aggressive skin cancer, and accounts for the major part of skin cancer-related deaths in the world. In addition, the underlying mechanism of tumor progression in melanoma remains far from being elucidated. In this study, we have evaluated the function of miR-25 in melanoma. First, we examined the expression of miR-25 in four melanoma cell lines (A875, MV3, M14 and uacc-257) and in a normal melanocyte cell line (HEM-a). Then, we overexpressed miR-25 in M14 cells. Our results show that miR-25 promotes M14 cell proliferation and migration. We found that miR-25 up-regulates the PI3K/Akt/mTOR signaling pathway in these tumor cells. Furthermore, a luciferase-based reporter gene assay showed that miR-25 could directly target the RNA-binding motif protein 47 (RBM47). Taken together, our findings suggest that RBM47 is a promising target for the treatment of melanoma.

Atypical activation of the G protein Gαq by the oncogenic mutation Q209P

The causative role of G protein-coupled receptor (GPCR) pathway mutations in uveal melanoma (UM) has been well-established. Nearly all UMs bear an activating mutation in a GPCR pathway mediated by G proteins of the G_q/11 family, driving tumor initiation and possibly metastatic progression. Thus, targeting this pathway holds therapeutic promise for managing UM. However, direct targeting of oncogenic Gα_q/11 mutants, present in ∼90% of UMs, is complicated by the belief that these mutants structurally resemble active Gα_q/11 WT. This notion is solidly founded on previous studies characterizing Gα mutants in which a conserved catalytic glutamine (Gln-209 in Gα_q) is replaced by leucine, which leads to GTPase function deficiency and constitutive activation. Whereas Q209L accounts for approximately half of GNAQ mutations in UM, Q209P is as frequent as Q209L and also promotes oncogenesis, but has not been characterized at the molecular level. Here, we characterized the biochemical and signaling properties of Gα_q Q209P and found that it is also GTPase-deficient and activates downstream signaling as efficiently as Gα_q Q209L. However, Gα_q Q209P had distinct molecular and functional features, including in the switch II region of Gα_q Q209P, which adopted a conformation different from that of Gα_q Q209L or active WT Gα_q, resulting in altered binding to effectors, Gβγ, and regulators of G-protein signaling (RGS) proteins. Our findings reveal that the molecular properties of Gα_q Q209P are fundamentally different from those in other active Gα_q proteins and could be leveraged as a specific vulnerability for the ∼20% of UMs bearing this mutation.

Prognostic value of chromosomal imbalances, gene mutations, and BAP1 expression in uveal melanoma

Uveal melanoma (UM) exhibits recurring chromosomal abnormalities and gene driver mutations, which are related to tumor evolution/progression. Almost half of the patients with UM develop distant metastases, predominantly to the liver, and so far there are no effective adjuvant therapies. An accurate UM genetic profile could assess the individual patient's metastatic risk, and provide the basis to determine an individualized targeted therapeutic strategy for each UM patient. To investigate the presence of specific chromosomal and gene alterations, BAP1 protein expression, and their relationship with distant progression free survival (DPFS), we analyzed tumor samples from 63 UM patients (40 men and 23 women, with a median age of 64 years), who underwent eye enucleation by a single cancer ophthalmologist from December 2005 to June 2016. UM samples were screened for the presence of losses/gains in chromosomes 1p, 3, 6p, and 8q, and for mutations in GNAQ, GNA11, BAP1, SF3B1, and EIF1AX. BAP1 protein expression was detected by immunohistochemistry (IHC). Multivariate analysis showed that the presence of monosomy 3, 8q gain, and loss of BAP1 protein were significantly associated to DPFS, while BAP1 gene mutation was not, mainly due to the presence of metastatic UM cases with negative BAP1 IHC and no BAP1 mutation detected by Sanger sequencing. Loss of BAP1 protein expression and monosomy 3 represent the strongest predictors of metastases, and may have important implications for implementation of patient surveillance, properly designed clinical trials enrollment, and adjuvant therapy.

GNQ-209P Mutation in Metastatic Uveal Melanoma and Treatment Outcome

Metastatic prognosis in uveal melanoma is assessed by gene expression profiling (GEP) testing of the tumor cells, usually obtained by fine needle aspiration (FNA). GEP has demonstrated high accuracy in distinguishing class I and II tumors, both having different metastatic potential. Transcriptomic studies identified distinct mutations including somatic mutations in GNAQ and GNA11, detected in more than 80%, and contribute to the upregulation of the mitogen-activated protein kinase (MAPK) pathway and the development of uveal melanoma (UM). The role of these mutations in treatment selection and possible benefit from targeted therapy are somewhat unclear. However, until the discovery of novel agents, local versus systemic therapies remain options for treatment that can still be considered for disease control in certain cases. We report a series of patients with metastatic UM with distinct mutational profiles. One had significant liver metastases with proven GNQ-209P mutation on tissue biopsy while peripheral blood molecular profiling did not show these mutations. The other three cases had no GNQ-209P mutation. All cases received nab-paclitaxel (Abraxane) as a treatment drug, and we record their responses to treatment and their molecular-profiling results.

In-depth proteomic profiling of the uveal melanoma secretome

Uveal melanoma (UM), the most common primary intraocular tumour in adults, is characterised by a high frequency of metastases to the liver, typically with a fatal outcome. Proteins secreted from cancer cells (‘secretome’) are biologically important molecules thought to contribute to tumour progression. We examined the UM secretome by applying a label-free nanoLCMS/MS proteomic approach to profile proteins secreted into culture media by primary UM tumours with a high− (HR; n = 11) or low− (LR; n = 4) metastatic risk, compared to normal choroidal melanocytes (NCM) from unaffected post-mortem eyes. Across the three groups, 1843 proteins were identified at a 1% false discovery rate; 758 of these by at least 3 unique peptides, and quantified. The majority (539/758, 71%) of proteins were classified as secreted either by classical (144, 19%), non-classical (43, 6%) or exosomal (352, 46%) mechanisms. Bioinformatic analyzes showed that the secretome composition reflects biological differences and similarities of the samples. Ingenuity^® pathway analysis of the secreted protein dataset identified abundant proteins involved in cell proliferation-, growth- and movement. Hepatic fibrosis/hepatic stellate cell activation and the mTORC1-S6K signalling axis were among the most differentially regulated biological processes in UM as compared with NCM. Further analysis of proteins upregulated ≥ 2 in HR-UM only, identified exosomal proteins involved in extracellular matrix remodelling and cancer cell migration/invasion; as well as classically secreted proteins, possibly representing novel biomarkers of metastatic disease. In conclusion, UM secretome analysis identifies novel proteins and pathways that may contribute to metastatic development at distant sites, particularly in the liver.

Treatment of uveal melanoma: where are we now?

Uveal melanoma, a rare subset of melanoma, is the most common primary intraocular malignancy in adults. Despite effective primary therapy, nearly 50% of patients will develop metastatic disease. Outcomes for those with metastatic disease remain dismal due to a lack of effective therapies. The unique biology and immunology of uveal melanoma necessitates the development of dedicated management and treatment approaches. Ongoing efforts seek to optimize the efficacy of targeted therapy and immunotherapy in both the adjuvant and metastatic setting. This review provides a comprehensive, updated overview of disease biology and risk stratification, the management of primary disease, options for adjuvant therapy, and the current status of treatment strategies for metastatic disease.

Epigenetic reprogramming and aberrant expression of PRAME are associated with increased metastatic risk in Class 1 and Class 2 uveal melanomas

Background

We previously identified PRAME as a biomarker for metastatic risk in Class 1 uveal melanomas. In this study, we sought to define a threshold value for positive PRAME expression (PRAME+) in a large dataset, identify factors associated with PRAME expression, evaluate the prognostic value of PRAME in Class 2 uveal melanomas, and determine whether PRAME expression is associated with aberrant hypomethylation of the PRAME promoter.

Results

Among 678 samples analyzed by qPCR, 498 (73.5%) were PRAME- and 180 (26.5%) were PRAME+. Class 1 tumors were more likely to be PRAME-, whereas Class 2 tumors were more likely to be PRAME+ (P < 0.0001). PRAME expression was associated with shorter time to metastasis and melanoma specific mortality in Class 2 tumors (P = 0.01 and P = 0.02, respectively). In Class 1 tumors, PRAME expression was directly associated with SF3B1 mutations (P < 0.0001) and inversely associated with EIF1AX mutations (P = 0.004). PRAME expression was strongly associated with hypomethylation at 12 CpG sites near the PRAME promoter.

MATERIALS AND METHODS

Analyses included PRAME mRNA expression, Class 1 versus Class 2 status, chromosomal copy number, mutation status of BAP1, EIF1AX, GNA11, GNAQ and SF3B1, and genomic DNA methylation status. Analyses were performed on 555 de-identified samples from Castle Biosciences, 123 samples from our center, and 80 samples from the TCGA.

Conclusions

PRAME is aberrantly hypomethylated and activated in Class 1 and Class 2 uveal melanomas and is associated with increased metastatic risk in both classes. Since PRAME has been successfully targeted for immunotherapy, it may prove to be a companion prognostic biomarker.

Presentation, Treatment, and Prognosis of Secondary Melanoma within the Orbit

BACKGROUND

Ocular melanoma is a rare but often deadly malignancy that arises in the uvea, conjunctiva, or orbit. Uveal melanoma is the most common type, with conjunctival melanoma being the second most frequently observed. Melanoma accounts for 5-10% of metastatic or secondary orbital malignancies, but only a minute proportion of primary orbital neoplasia. The aim of this study was to characterize the clinical presentation, treatment, and prognosis in patients presenting with melanoma metastatic to, or secondary within, the orbit.

METHODS

A retrospective cohort study of patients presenting to a tertiary referral orbital unit from 1982 to 2016 was performed. Eighty-nine patients with biopsy-proven diagnosis of melanoma within the orbit were included in the study. The clinical notes, radiological imaging, histology, surgical notes, and outcome data for the patients were reviewed. The main outcome measures of interest were the interval between primary malignant melanoma and orbital presentation, survival after orbital presentation, and clinical parameters (such as gender, age at presentation, and treatment approach).

RESULTS

The commonest primary source of tumor was choroidal melanoma, with conjunctival and cutaneous melanomas being relatively common; eyelid and naso-sinus tumors occurred in a few cases. The mean age at presentation with orbital disease was 65 years (31-97 years). The interval between primary malignancy and orbital disease (either local spread/recurrence or true metastatic disease) showed wide variability, with almost one-third of patients having orbital disease at the time of primary diagnosis, but others presenting many years later; indeed, the longest orbital disease-free interval was over 34 years. Twenty-three patients were considered to have had late orbital metastases-that is, at more than 36 months after primary tumor. The median survival following presentation with orbital involvement was 24 months. Patients with tumors of cutaneous origin had worst survival, whereas those with conjunctival tumors had the best prognosis.

CONCLUSION

A high index of suspicion for orbital recurrence should be maintained in any patient with prior history of melanoma, however distant the primary tumor is in site or time. Furthermore, giving a prognosis for orbital melanoma remains problematic due to highly variable survival, and further investigation will be necessary to understand the likely genetic basis of this phenomenon.

Prospective Clinical and Pharmacological Evaluation of the Delcath System's Second-Generation (GEN2) Hemofiltration System in Patients Undergoing Percutaneous Hepatic Perfusion with Melphalan

Introduction

Percutaneous hepatic perfusion (PHP) with melphalan is an effective treatment for patients with hepatic metastases, but associated with high rates of bone marrow depression. To reduce systemic toxicity, improvements have been made to the filtration system. In pre-clinical studies, the Delcath System’s GEN2 filter was superior to the first-generation filters. In this clinical study, we analysed the pharmacokinetics and toxicity of PHP using the new GEN2 filter.

Methods and Materials

Starting February 2014, two prospective phase II studies were initiated in patients with hepatic metastases from ocular melanoma or colorectal cancer. In 10 PHP procedures performed in the first 7 enrolled patients, blood samples were obtained to determine filter efficiency and systemic drug exposure. PHP was performed with melphalan 3 mg/kg with a maximum of 220 mg. Complications were assessed according to CTCAE v4.03. Response was assessed according to RECIST 1.1.

Results

Pharmacokinetic analysis of blood samples showed an overall filter efficiency of 86% (range 71.1–95.5%). The mean filter efficiency decreased from 95.4% 10 min after the start of melphalan infusion to 77.5% at the end of the procedure (p = 0.051). Bone marrow depression was seen after up to 80.0% of 10 procedures, but was self-limiting and mostly asymptomatic. No hypotension-related complications or procedure-related mortality occurred.

Conclusion

The GEN2 filter has a higher melphalan filter efficiency compared to the first-generation filters and a more consistent performance. PHP with the GEN2 filter appears to have an acceptable safety profile, but this needs further validation in larger studies.