Survival in uveal melanoma patients is linked to genetic variation at HERC2 SNP rs12913832.

PURPOSE: Uveal melanoma (UM) is a rare disease, with the highest incidence in people with a fair skin and light eyes. Eye colour is largely genetically determined and defined by a set of single nucleotide polymorphisms (SNPs). We set out to determine whether we could identify a SNP that is related to prognosis. DESIGN: We sequenced DNA from peripheral blood mononuclear cells of 392 patients with UM and obtained the genotype of six common eye colour-related SNPs. Clinical and histopathologic tumour characteristics, tumour chromosome status, and patient survival were compared among patients with different genotypes. SUBJECTS: 392 patients who underwent enucleation for UM at the Leiden University Medical Center, Leiden, The Netherlands. METHODS: We isolated DNA from peripheral blood leukocytes of 392 patients with UM and performed sequencing, using six eye colour SNPs from the HIrisPlex-S assay. The genotypes extracted from the sequencing data were uploaded onto the Hirisplex webtool (https://hirisplex.erasmusmc.nl/) for eye colour prediction. We tested the association of eye colour SNPs with tumour characteristics and chromosome aberrations using Pearson's chi-square test and Mann-Whitney U test and survival with Kaplan-Meier curves with log-rank test and Cox regression. MAIN OUTCOME MEASURES: UM-related survival. RESULTS: Of the total cohort of 392 patients with analysable genotype data, 307 (78%) were assigned to have blue eyes, 74 (19%) brown eyes and 11 (3%) could not be assigned to either blue or brown. Patients with a genetically-blue eye colour had a worse survival (p = 0.04). This was related to one genotype: patients with the G/G genotype of rs12913832 (HERC2) which codes for blue eye colour had a worse prognosis (p = 0.017), which was related to more often having high-risk tumours (monosomy of chromosome 3, p = 0.04) than patients with an A/G or A/A genotype. CONCLUSION: The G/G genotype of rs12913832 (HERC2), which is related to blue eye colour, is not only a genetic factor related to the risk to develop a UM, but is also linked to a worse prognosis, due to an association with a higher risk of developing a high-risk UM (carrying monosomy of chromosome 3).

Protein and mRNA Expression in Uveal Melanoma Cell Lines Are Related to GNA and BAP1 Mutation Status.

Purpose: Cell lines are being used in preclinical uveal melanoma (UM) research. Because not all cell lines harbor typical GNAQ or GNA11 hotspot mutations, we aimed at better classifying them and determining whether we could find genetic causes to explain the protein and mRNA expression profiles of the cell lines. Methods: We studied protein and mRNA expression of 14 UM cell lines and determined the presence of single nucleotide variants and small insertions and deletions with next-generation sequencing and copy number alterations with a single nucleotide polymorphism array. The lists of differentially expressed proteins and genes were merged, and shared lists were created, keeping only terms with concordant mRNA and protein expression. Enrichment analyses were performed on the shared lists. Results: Cell lines Mel285 and Mel290 are separate from GNA-mutated cell lines and show downregulation of melanosome-related markers. Both lack typical UM mutations but each harbors four putatively deleterious variants in CTNNB1, PPP1R10, LIMCH1, and APC in Mel285 and ARID1A, PPP1R10, SPG11, and RNF43 in Mel290. The upregulated terms in Mel285 and Mel290 did not point to a convincing alternative origin. Mel285 shows loss of chromosomes 1p, 3p, partial 3q, 6, and partial 8p, whereas Mel290 shows loss of 1p and 6. Expression in the other 12 cell lines was related to BAP1 expression. Conclusions: Although Mel285 and Mel290 have copy number alterations that fit UM, multi-omics analyses show that they belong to a separate group compared to the other analyzed UM cell lines. Therefore, they may not be representative models to test potential therapeutic targets for UM.

Au(I) complexes installed on a self-assembled peptide efficiently catalyze intramolecular cyclization reactions.

Self-assembled peptides are used for diverse applications in the biomedical and technological fields. The morphology and function of the assembled systems are dictated by the peptide sequence and length. In this work, a supramolecular catalyst was obtained upon self-assembly of the diphenylalanine peptide conjugated to a triphenylphosphine Au(I) complex in acetonitrile. The assembled molecules were characterized by spectroscopic techniques and by scanning electron microscopy. The activity of the catalyst was tested on two substrates in cyclization reactions. The morphology and the dimensions of the assembled systems vary depending on the presence of a carboxyl versus an amide C-terminal end. The catalyst efficiently promotes intramolecular cyclization reactions. Results obtained encourage the use of self-assembled peptides for the obtainment of new and efficient catalysts.

Chimeric Antigen Receptor T Cell with an Inducible Caspase-9 Suicide Gene Eradicates Uveal Melanoma Liver Metastases via B7-H3 Targeting.

PURPOSE: Uveal melanoma (UM) is the most common intraocular malignant tumor. Despite successful treatment of the primary tumor, about 50% of patients will recur with systemic diseases for which there are no effective treatment strategies. Here we investigated the preclinical efficacy of a chimeric antigen receptor (CAR) T-cell-based immunotherapy targeting B7-H3. EXPERIMENTAL DESIGN: B7-H3 expression on primary and metastatic human UM samples and cell lines was assessed by RNA sequencing, flow cytometry, and immunohistochemistry. Antitumor activity of CAR T cells targeting B7-H3 was tested in vitro with UM cell lines, patient-derived organotypic tumor spheroids from patients with metastatic UM, and in immunodeficient and humanized murine models. RESULTS: B7-H3 is expressed at high levels in >95% UM tumor cells in vitro and in vivo. We generated a B7-H3 CAR with an inducible caspase-9 (iCas9) suicide gene controlled by the chemical inducer of dimerization AP1903, which effectively kills UM cells in vitro and eradicates UM liver metastases in murine models. Delivery of iCas9.B7-H3 CAR T cells in experimental models of UM liver metastases demonstrates a durable antitumor response, even upon tumor rechallenge or in the presence of a significant metastatic disease burden. We demonstrate effective iCas9.B7-H3 CAR T-cell elimination in vitro and in vivo in response to AP1903. Our studies demonstrate more effective tumor suppression with iCas9.B7-H3 CAR T cells as compared to a B7-H3-targeted humanized monoclonal antibody. CONCLUSIONS: These studies support a phase I clinical trial with iCas9.B7-H3 CAR T cells to treat patients with metastatic UM.

Stereochemical Behavior of Pyrrolo-Pyrazole Peptidomimetics Promoting Phase-Selective Supramolecular Organogels.

Supramolecular gels were developed by taking advantage of an assembly of small dipeptides containing pyrrolo-pyrazole scaffolds. The dipeptides were prepared through a robust and ecofriendly synthetic approach from the commercially available starting materials of diazoalkanes and maleimides. By playing with the functionalization of the scaffold, the choice of the natural amino acid, and the stereochemistry, we were able to obtain phase-selective gels. In particular, one peptidomimetic showed gelation ability and thermoreversibility in aromatic solvents at very low concentrations. Rheology tests showed a typical viscoelastic solid profile, indicating the formation of strong gels that were stable under high mechanical deformation. NMR studies were performed, allowing us to determine the conformational and stereochemical features at the base of the supramolecular interactions.

Uveal melanoma: Current evidence on prognosis, treatment and potential developments.

Uveal Melanoma (UM) is a rare disease, yet it is the most common primary intraocular malignancy in adult patients. Despite continuous advancements and research, the risk of metastasis remains high. It is possible to stratify patients according to their risk of metastases using a variety of known risk factors. Even though there is no gold standard for the prognostication of patients with uveal melanoma, it is becoming increasingly clear that combining histo-pathological, patient-related and molecular prognostic markers allows a more accurate prediction of the metastatic risk than by using one parameter. Primary UM in the eye are treated very effectively with eye-sparing radiation-based techniques or enucleation. However, it is not yet possible to prevent or treat metastases with the current therapeutic options. Nonetheless, the efforts to find new therapeutic targets continue and progress is being made, especially in the field of targeted therapy, as exemplified by the anti-gp100 bispecific molecule Tebentafusp. This review delves into the history of uveal melanoma, its incidence, presentation and diagnosis, the known prognostic factors and the treatment options, both for the primary tumour and for metastases. We show that different populations may have different risks for developing UM, and that each country should evaluate their own patients.

Tumor Pigmentation Does Not Affect Light-Activated Belzupacap Sarotalocan Treatment but Influences Macrophage Polarization in a Murine Melanoma Model.

Purpose: Pigmentation in uveal melanoma is associated with increased malignancy and is known as a barrier for photodynamic therapy. We investigated the role of pigmentation in tumor behavior and the response to light-activated Belzupacap sarotalocan (Bel-sar) treatment in a pigmented (wild type) and nonpigmented (tyrosinase knock-out [TYR knock-out]) cell line in vitro and in a murine model. Methods: The B16F10 (TYR knock-out) was developed using CRISPR/Cas9. After the treatment with light-activated Bel-sar, cytotoxicity and exposure of damage-associated molecular patterns (DAMPs) were measured by flow cytometry. Treated tumor cells were co-cultured with bone marrow-derived macrophages (BMDMs) and dendritic cells (DCs) to assess phagocytosis and activation. Both cell lines were injected subcutaneously in syngeneic C57BL/6 mice. Results: Knock-out of the tyrosinase gene in B16F10 led to loss of pigmentation and immature melanosomes. Pigmented tumors contained more M1 and fewer M2 macrophages compared with amelanotic tumors. Bel-sar treatment induced near complete cell death, accompanied with enhanced exposure of DAMPs in both cell lines, resulting in enhanced phagocytosis of BMDMs and maturation of DCs. Bel-sar treatment induced a shift to M1 macrophages and delayed tumor growth in both in vivo tumor models. Following treatment, especially the pigmented tumors and their draining lymph nodes contained IFN-gamma positive CD8+T cells. Conclusions: Pigmentation influenced the type of infiltrating macrophages in the tumor, with more M1 macrophages in pigmented tumors. Belzupacap sarotalocan treatment induced immunogenic cell death and tumor growth delay in pigmented as well as in nonpigmented models and stimulated M1 macrophage influx in both models.

PRAME Expression: A Target for Cancer Immunotherapy and a Prognostic Factor in Uveal Melanoma.

Purpose: Uveal melanoma (UM) is a rare disease with a high mortality, and new therapeutic options are being investigated. Preferentially Expressed Antigen in Melanoma (PRAME) is a cancer testis antigen, expressed in the testis, but also in cancers, including uveal melanoma. PRAME is considered a target for immune therapy in several cancers, and PRAME-specific T cell clones have been shown to kill UM cells. Methods: We studied the literature on PRAME expression in hematological and solid malignancies, including UM, and its role as a target for immunotherapy. The distribution of tumor features was compared between PRAME-high and PRAME-low UM in a 64-patient cohort from the Leiden University Medical Center (LUMC) and in the Cancer Genome Atlas (TCGA) cohort of 80 cases and differential gene expression analysis was performed in the LUMC cohort. Results: PRAME is expressed in many malignancies, it is frequently associated with a negative prognosis, and can be the target of T cell receptor (TCR)-transduced T cells, a promising treatment option with high avidity and safety. In UM, PRAME is expressed in 26% to 45% of cases and is correlated with a worse prognosis. In the LUMC and the TCGA cohorts, high PRAME expression was associated with larger diameter, higher Tumor-Node-Metastasis (TNM) stage, more frequent gain of chromosome 8q, and an inflammatory phenotype. Conclusions: We confirm that PRAME is associated with poor prognosis in UM and has a strong connection with extra copies of 8q. We show that PRAME-specific immunotherapy in an adjuvant setting is promising in treatment of malignancies, including UM.

Phosphine-Catalyzed Domino Regio- and Stereo-Selective Hexamerization of 2-(Bromomethyl)acrylates to 1,2-Bis(cyclohexenyl)ethenyl Derivatives.

A phosphine-catalyzed domino assembly of six units of 2-bromomethyl acrylates afforded polyalkenyl adducts containing two cyclohexenyl rings. This reaction occurs under mild conditions providing the final product by formation of seven carbon-carbon bonds and four stereocenters. Experimental and computational studies support an initial dimerization of the substrate, which in turn trimerizes involving two totally regio- and stereocontrolled Diels-Alder cycloadditions. The yield of the hexamerization of the 2-bromomethyl acrylates depends on the size of the ester function. The protocol has also proved to be practicable on a gram scale.

Highly efficient morpholine-based organocatalysts for the 1,4-addition reaction between aldehydes and nitroolefins: an unexploited class of catalysts.

Many studies have demonstrated how the pyrrolidine nucleus is more efficient than the corresponding piperidine or morpholine as organocatalysts in the condensation of aldehydes with electrophiles via enamine. Focussing on morpholine-enamines, their low reactivity is ascribed to the presence of oxygen on the ring and to the pronounced pyramidalisation of nitrogen, decreasing the nucleophilicity of the enamine. Thus, the selection of efficient morpholine organocatalysts appears to be a difficult challenge. Herein, we reported on the synthesis of new organocatalysts belonging to the class of ß-morpholine amino acids that were tested in a model reaction, i.e., the 1,4-addition reaction of aldehydes to nitroolefins. Starting from commercially available amino acids and epichlorohydrin, we designed an efficient synthesis for the aforementioned catalysts, controlling the configuration and the substitution pattern. Computational studies indeed disclosed the transition state of the reaction, explaining why, despite all the limitations of the morpholine ring for enamine catalysis, our best catalyst works efficiently, affording condensation products with excellent yields, diastereoselection and good-to-exquisite enantioselectivity.

Combined Mcl-1 and YAP1/TAZ inhibition for treatment of metastatic uveal melanoma.

Uveal melanoma is the most common intraocular tumor in adults, representing approximately 5% of all melanoma cases. Up to 50% of uveal melanoma patients develop metastases that are resistant to most of the commonly used antineoplastic treatments. Virtually all uveal melanoma tumors harbor activating mutations in GNAQ or GNA11 , encoding Gαq and Gα11, respectively. Constant activity of these proteins causes deregulation of multiple downstream signaling pathways including PKC, MAPK and YAP1/TAZ. While the importance of YAP1 signaling for the proliferation of uveal melanoma has recently been demonstrated, much less is known about the paralog of YAP1 transcriptional coactivator, named TAZ; however, similar to YAP1, TAZ is expected to be a therapeutic target in uveal melanoma. We performed a small-scale drug screen to discover a compound synergistically inhibiting uveal melanoma proliferation/survival in combination with YAP1/TAZ inhibition. We found that the combination of genetic depletion of YAP1/TAZ together with Mcl-1 inhibition demonstrates a synergistic inhibitory effect on the viability of uveal melanoma cell lines. Similarly, indirect attenuation of the YAP1/TAZ signaling pathway with an inhibitor of the mevalonate pathway, that is, the geranyl-geranyl transferase inhibitor GGTI-298, synergizes with Mcl-1 inhibition. This combination could be potentially used as a treatment for metastatic uveal melanoma.

Patient-derived zebrafish xenografts of uveal melanoma reveal ferroptosis as a drug target.

Uveal melanoma (UM) has a high risk to progress to metastatic disease with a median survival of 3.9 months after metastases detection, as metastatic UM responds poorly to conventional and targeted chemotherapy and is largely refractory to immunotherapy. Here, we present a patient-derived zebrafish UM xenograft model mimicking metastatic UM. Cells isolated from Xmm66 spheroids derived from metastatic UM patient material were injected into 2 days-old zebrafish larvae resulting in micro-metastases in the liver and caudal hematopoietic tissue. Metastasis formation could be reduced by navitoclax and more efficiently by the combinations navitoclax/everolimus and flavopiridol/quisinostat. We obtained spheroid cultures from 14 metastatic and 10 primary UM tissues, which were used for xenografts with a success rate of 100%. Importantly, the ferroptosis-related genes GPX4 and SLC7A11 are negatively correlated with the survival of UM patients (TCGA: n = 80; Leiden University Medical Centre cohort: n = 64), ferroptosis susceptibility is correlated with loss of BAP1, one of the key prognosticators for metastatic UM, and ferroptosis induction greatly reduced metastasis formation in the UM xenograft model. Collectively, we have established a patient-derived animal model for metastatic UM and identified ferroptosis induction as a possible therapeutic strategy for the treatment of UM patients.

Increased Histological Tumor Pigmentation in Uveal Melanoma Is Related to Eye Color and Loss of Chromosome 3/BAP1.

Purpose: Heavy pigmentation is known to be a prognostic risk factor in uveal melanoma (UM). We analyzed whether genetic tumor parameters were associated with tumor pigmentation and whether pigmentation should be included in prognostic tests. Design: Retrospective comparison of clinical, histopathological, and genetic features and survival in UM with different pigmentation. Participants: A total of 1058 patients with UM from a White European population with diverse eye colors enucleated between 1972 and 2021. Methods: Cox regression and log-rank tests were used for survival analysis; the chi-square test and Mann-Whitney U test were used for correlation analysis. Main Outcome Measures: Uveal melanoma-related survival based on tumor pigmentation and chromosome status, correlation of tumor pigmentation with prognostic factors. Results: The 5-year UM-related mortality was 8% in patients with nonpigmented tumors (n = 54), 25% with lightly pigmented tumors (n = 489), 41% with moderately pigmented tumors (n = 333), and 33% with dark tumors (n = 178) (P < 0.001). The percentage of tumors with monosomy 3 (M3) or 8q gain increased with increasing pigmentation (31%, 46%, 62%, and 70% having M3 [P < 0.001], and 19%, 43%, 61%, and 63% having 8q gain [P < 0.001] in the 4 increasing pigment groups, respectively). BRCA-associated protein 1 (BAP1) loss (known for 204 cases) was associated with increased tumor pigmentation (P = 0.001). Cox regression analysis on survival showed that when chromosome status and pigmentation were both included, pigmentation was not an independent prognostic indicator. Preferentially expressed antigen in melanoma (PRAME) expression was a significant prognostic marker in light tumors (P = 0.02) but not in dark tumors (P = 0.85). Conclusions: Patients with moderately and heavily pigmented tumors showed a significantly higher UM-related mortality than patients with unpigmented and light tumors (P < 0.001), supporting prior reports on the relation between increased tumor pigmentation and a worse prognosis. Although we previously showed that a dark eye color was associated with tumor pigmentation, we now show that the tumor's genetic status (chromosome 3 and 8q/BAP1 status) is also related to tumor pigmentation. When pigmentation and chromosome 3 status are both included in a Cox regression analysis, pigmentation is not an independent prognostic factor. However, evidence from this and previous studies shows that chromosome changes and PRAME expression have a stronger association with survival when they occur in light tumors than in dark ones. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references.

Microphthalmia-Associated Transcription Factor: A Differentiation Marker in Uveal Melanoma.

Microphthalmia-associated transcription factor (MITF) is an important regulator of melanogenesis and melanocyte development. In cutaneous melanoma, MITF loss has been linked to an increased expression of stem cell markers, a shift in epithelial-to-mesenchymal transition (EMT)-related factors, and increased inflammation. We explored the role of MITF in Uveal Melanoma (UM) using a cohort of 64 patients enucleated at the Leiden University Medical Center. We analysed the relation between MITF expression and clinical, histopathological and genetic features of UM, as well as survival. We performed differential gene expression and gene set enrichment analysis using mRNA microarray data, comparing MITF-low with MITF-high UM. MITF expression was lower in heavily pigmented UM than in lightly pigmented UM (p = 0.003), which we confirmed by immunohistochemistry. Furthermore, MITF was significantly lower in UM with monosomy 3/BAP1 loss than in those with disomy 3/no BAP1 loss (p < 0.001) and with 8q gain/amplification 8q (p = 0.02). Spearman correlation analysis showed that a low MITF expression was associated with an increase in inflammatory markers, hallmark pathways involved in inflammation, and epithelial-mesenchymal transition. Similar to the situation in cutaneous melanoma, we propose that MITF loss in UM is related to de-differentiation to a less favourable EMT profile and inflammation.

The multifunctional human ocular melanocortin system.

Immune privilege in the eye involves physical barriers, immune regulation and secreted proteins that together limit the damaging effects of intraocular immune responses and inflammation. The neuropeptide alpha-melanocyte stimulating hormone (α-MSH) normally circulates in the aqueous humour of the anterior chamber and the vitreous fluid, secreted by iris and ciliary epithelium, and retinal pigment epithelium (RPE). α-MSH plays an important role in maintaining ocular immune privilege by helping the development of suppressor immune cells and by activating regulatory T-cells. α-MSH functions by binding to and activating melanocortin receptors (MC1R to MC5R) and receptor accessory proteins (MRAPs) that work in concert with antagonists, otherwise known as the melanocortin system. As well as controlling immune responses and inflammation, a broad range of biological functions is increasingly recognised to be orchestrated by the melanocortin system within ocular tissues. This includes maintaining corneal transparency and immune privilege by limiting corneal (lymph)angiogenesis, sustaining corneal epithelial integrity, protecting corneal endothelium and potentially enhancing corneal graft survival, regulating aqueous tear secretion with implications for dry eye disease, facilitating retinal homeostasis via maintaining blood-retinal barriers, providing neuroprotection in the retina, and controlling abnormal new vessel growth in the choroid and retina. The role of melanocortin signalling in uveal melanocyte melanogenesis however remains unclear compared to its established role in skin melanogenesis. The early application of a melanocortin agonist to downregulate systemic inflammation used adrenocorticotropic hormone (ACTH)-based repository cortisone injection (RCI), but adverse side effects including hypertension, edema, and weight gain, related to increased adrenal gland corticosteroid production, impacted clinical uptake. Compared to ACTH, melanocortin peptides that target MC1R, MC3R, MC4R and/or MC5R, but not adrenal gland MC2R, induce minimal corticosteroid production with fewer adverse systemic effects. Pharmacological advances in synthesising MCR-specific targeted peptides provide further opportunities for treating ocular (and systemic) inflammatory diseases. Following from these observations and a renewed clinical and pharmacological interest in the diverse biological roles of the melanocortin system, this review highlights the physiological and disease-related involvement of this system within human eye tissues. We also review the emerging benefits and versatility of melanocortin receptor targeted peptides as non-steroidal alternatives for inflammatory eye diseases such as non-infectious uveitis and dry eye disease, and translational applications in promoting ocular homeostasis, for example, in corneal transplantation and diabetic retinopathy.

Non-Conventional Peptide Self-Assembly into a Conductive Supramolecular Rope.

Structures composed of alternating α and ß amino acids can give rise to peculiar secondary structural motifs, which could self-assemble into complex structures of controlled geometries. This work describes the self-assembly properties of an α,ß-peptide, containing three units of syn H2-(2-F-Phe)-h-PheGly-OH, able to self-organize on surfaces into a fascinating supramolecular rope. This material was characterized by AFM, electronic conduction and fluorescence measurements. Molecular dynamics simulations showed that this hexapeptide can self-assemble into an antiparallel ß-sheet layer, stabilized by intermolecular H-bonds, which, in turn, can self-assemble into many side-by-side layers, due to π-π interactions. As a matter of fact, we demonstrated that in this system, the presence of aromatic residues at the intramolecular interface promoted by the alternation of α,ß-amino-acids in the primary sequence, endorses the formation of a super-secondary structure where the aromatic groups are close to each other, conferring to the system good electron conduction properties. This work demonstrates the capability and future potential of designing and fabricating distinctive nanostructures and efficient bioelectronic interfaces based on an α,ß-peptide, by controlling structure and interaction processes beyond those obtained with α- or ß-peptides alone.

Preclinical Evaluation of Trabectedin in Combination With Targeted Inhibitors for Treatment of Metastatic Uveal Melanoma.

Purpose: Uveal melanoma (UM) is considered a rare disease; yet, it is the most common intraocular malignancy in adults. Although the primary tumor may be efficiently managed, more than 50% of patients with UM develop distant metastases. The mortality at the first year after diagnosis of metastatic UM has been estimated at 81%, and the poor prognosis has not improved in the past years due to the lack of effective therapies. Methods: In order to search for novel therapeutic possibilities for metastatic UM, we performed a small-scale screen of targeted drug combinations. We verified the targets of the tested compounds by western blotting and PCR and clarified the mechanism of action of the selected combinations by caspase 3 and 7 activity assay and flow cytometry. The best two combinations were tested in a mouse patient-derived xenograft (PDX) UM model as putative therapeutics for metastatic UM. Results: Combinations of the multitarget drug trabectedin with either the CK2/CLK double-inhibitor CX-4945 (silmitasertib) or the c-MET/TAM (TYRO3, Axl, MERTK) receptor inhibitors foretinib and cabozantinib demonstrated synergistic effects and induced apoptosis (relative caspase 3 and 7 activity increased up to 20.5-fold in UM cell lines). In the case of the combination of foretinib and cabozantinib, inhibition of the TAM receptors, but not c-Met, was essential to inhibit the growth of UM cells. Monotreatment with trabectedin inhibited tumor growth by 42%, 49%, and 35% in the MM26, MM309, and MM339 PDX mouse models, respectively. Conclusions: Trabectedin alone or in combination with cabozantinib inhibited tumor growth in PDX UM mouse models. Blocking of MERTK, rather than TYRO3, activity inhibited UM cell growth and synergized with trabectedin.

MITF in Normal Melanocytes, Cutaneous and Uveal Melanoma: A Delicate Balance.

Microphthalmia-associated transcription factor (MITF) is an important regulator of melanogenesis and melanocyte development. Although it has been studied extensively in cutaneous melanoma, the role of MITF in uveal melanoma (UM) has not been explored in much detail. We review the literature about the role of MITF in normal melanocytes, in cutaneous melanoma, and in UM. In normal melanocytes, MITF regulates melanocyte development, melanin synthesis, and melanocyte survival. The expression profile and the behaviour of MITF-expressing cells suggest that MITF promotes local proliferation and inhibits invasion, inflammation, and epithelial-to-mesenchymal (EMT) transition. Loss of MITF expression leads to increased invasion and inflammation and is more prevalent in malignant cells. Cutaneous melanoma cells switch between MITF-high and MITF-low states in different phases of tumour development. In UM, MITF loss is associated with loss of BAP1 protein expression, which is a marker of poor prognosis. These data indicate a dual role for MITF in benign and malignant melanocytic cells.

Adding the Cancer Genome Atlas Chromosome Classes to American Joint Committee on Cancer System Offers More Precise Prognostication in Uveal Melanoma.

PURPOSE: Uveal melanoma (UM) is a rare disease and the most common primary intraocular malignancy in adults, with a high risk of metastases. Reliable prognostication systems are based on anatomic features, as in the tumor-node-metastasis staging of the American Joint Committee on Cancer (AJCC) system, or on genetic information, as in The Cancer Genome Atlas (TCGA) system. Prior evidence suggests that combining both systems may be beneficial. We evaluated the benefit of combining the TCGA and AJCC systems in a large cohort of patients. DESIGN: Retrospective case series of patients with UM. PARTICIPANTS: Nine hundred seventy-nine patients with a choroidal or ciliary body melanoma treated at the Wills Eye Hospital between 1998 and 2020, 94% of whom received eye-sparing treatment. METHODS: Tumors were classified into 4 TCGA groups based on chromosome copy number: A (disomy 3, normal 8q), B (disomy 3, any 8q gain), C (monosomy 3, 1 extra copy of 8q), and D (monosomy 3, multiple 8q gain). The eighth edition of the AJCC staging manual was used for AJCC staging. Cox regression and the log-rank test were used for survival analysis. MAIN OUTCOME MEASURE: Metastasis-free survival. RESULTS: Combining information of the 2 systems improved prognostication in intermediate groups: in TCGA group C, we saw an increased rate of metastasis in AJCC stage III (28%) compared with stage II (8.9%); the same was seen in AJCC stage II, going from TCGA group C (8.9%) to group D (46%), and in AJCC stage III, going from group C (28%) to group D (49%). In patients with AJCC stage II or III disease, loss of chromosome 3 and gain of 8q (TCGA groups C and D) significantly worsened the prognosis, with multiple 8q gain (TCGA group D) having a greater impact. CONCLUSIONS: Combining information from AJCC stages and TCGA groups yields a better predictive power even in this set of relatively small tumors. We propose that physicians take both systems into account whenever possible, especially in moderate-risk groups.