Immune escape mechanisms of intraocular tumors

Biological characteristics and clinical management of uveal and conjunctival melanoma

Uveal and conjunctival melanomas are relatively rare tumors; nonetheless, they pose a significant risk of mortality for a large number of affected individuals. The pathogenesis of melanoma at different sites is very similar, however, the prognosis for patients with ocular melanoma remains unfavourable, primarily due to its distinctive genetic profile and tumor microenvironment. Regardless of considerable advances in understanding the genetic characteristics and biological behaviour, the treatment of uveal and conjunctival melanoma remains a formidable challenge. To enhance the prospect of success, collaborative efforts involving medical professionals and researchers in the fields of ocular biology and oncology are essential. Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors. Despite advancements in the development of effective melanoma therapeutic strategies, all current treatments for uveal melanoma (UM) and conjunctival melanoma (CoM) remain unsatisfactory, resulting in a poor long-term prognosis. Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors. A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy, with various potential therapeutic targets currently under consideration. Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents, with the hope of improving the prognosis for patients with metastatic disease.

Malignancies with a tendency to metastasize to the eyelid or ocular structures

Metastatic tumors to the eye and eyelid are generally seen in patients with disseminated metastases in the setting of advanced disease. Occasionally, they can present as the first sign of occult malignancy. The choroid is the most common site of intraocular metastases secondary to its dense vascular supply. Similar to the eye, metastatic tumors to the eyelid can present with a variety of clinical findings and are most often seen in patients with a known history of cancer. The most common skin malignancy that can spread to ocular structures is cutaneous melanoma, whereas the most common noncutaneous malignancy is breast cancer followed by lung cancer. In pediatric patients, metastatic disease to the eye is rare and can be seen in neuroblastoma and Ewing sarcoma. The overall prognosis of metastatic lesions involving the eye and eyelid is typically poor, with a mean survival of months. Ophthalmologists play an important role in the diagnosis of metastatic disease of the eye and eyelid; therefore, it is imperative for patients to undergo a complete ophthalmic examination and systemic workup if they have new-onset vision changes and a known history of cancer. Early diagnosis and management with systemic and local therapies can maximize quality of life and preserve vision.

Implications of LAG3 and CTLA4 immune checkpoints beyond PD-1/PD-L1 as a potential target in determining the prognosis of uveal melanoma patients

BackgroundResponse rate of PD-1/PD-L1 immunotherapeutic blockade agents in uveal melanoma (UM) is poor. Lymphocyte activation gene 3 (LAG3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) are the two promising immune checkpoint targets. Therefore, our aim was to explore at how these proteins were expressed in tumour tissue and serum, as well as their prognostic implications in UM.

METHODS

The expression of LAG3, CTLA-4, CD3, CD4, CD8 and FOXP3 was determined by immunohistochemistry in 54 enucleated UM tissue samples. mRNA expression level of LAG3 and CTLA-4 was determined by quantitative real-time PCR and corroborated by western blotting. Furthermore, soluble form of LAG3, CTLA-4 and CCR8 expression in serum was measured in 40 UM patients using ELISA.

RESULT

The expression of LAG3, CTLA-4, CD3, CD4, CD8 and FOXP3 was observed in 30%, 33%, 41%, 35%, 50% and 39% of the cases, respectively. Loss of nBAP1 expression was significantly correlated with CD8+expression (p=0.012) but not with tumour infiltrating lymphocytes. LAG3 and CTLA-4 mRNA levels were higher in UM compared with normal uveal tissues. Higher LAG3 expression with CD8+expression was associated with lower metastasis-free survival (MFS) (p=0.049), but not with CTLA-4 in UM patients. MFS rate was reduced in patients having lower levels of CCR8 protein (p=0.050) and increased level of LAG3 protein (p=0.001).

CONCLUSION

Our findings suggest that higher levels of LAG3 in UM with histopathologically high-risk parameters predict high metastatic potential and that it could be used as a targeted immunotherapy alone or in combination with PD-1/PD-L1 blockade agents.

Construction of oxidative phosphorylation-related prognostic risk score model in uveal melanoma

BACKGROUND

Uveal melanoma (UVM) is a malignant intraocular tumor in adults. Targeting genes related to oxidative phosphorylation (OXPHOS) may play a role in anti-tumor therapy. However, the clinical significance of oxidative phosphorylation in UVM is unclear.

METHOD

The 134 OXPHOS-related genes were obtained from the KEGG pathway, the TCGA UVM dataset contained 80 samples, served as the training set, while GSE22138 and GSE39717 was used as the validation set. LASSO regression was carried out to identify OXPHOS-related prognostic genes. The coefficients obtained from Cox multivariate regression analysis were used to calculate a risk score, which facilitated the construction of a prognostic model. Kaplan-Meier survival analysis, logrank test and ROC curve using the time "timeROC" package were conducted. The immune cell frequency in low- and high-risk group was analyzed through Cibersort tool. The specific genomic alterations were analyzed by "maftools" R package. The differential expressed genes between low- or high-risk group were analyzed and performed Gene Ontology (GO) and GSEA. Finally, we verified the function of CYC1 in UVM by gene silencing in vitro.

RESULTS

A total of 9 OXPHOS-related prognostic genes were identified, including NDUFB1, NDUFB8, ATP12A, NDUFA3, CYC1, COX6B1, ATP6V1G2, ATP4B and NDUFB4. The UVM prognostic risk model was constructed based on the 9 OXPHOS-related prognostic genes. The prognosis of patients in the high-risk group was poorer than low-risk group. Besides, the ROC curve demonstrated that the area under the curve of the model for predicting the 1 to 5-year survival rate of UVM patients were all more than 0.88. External validation in GSE22138 and GSE39717 dataset revealed that these 9 genes could also be utilized to evaluate and predict the overall survival of patients with UVM. The risk score levels related to immune cell frequency and specific genomic alterations. The DEGs between the low- and high- risk group were enriched in tumor OXPHOS and immune related pathway. In vitro experiments, CYC1 silencing significantly inhibited UVM cell proliferation and invasion, induced cell apoptosis.

CONCLUSION

In sum, a prognostic risk score model based on oxidative phosphorylation-related genes in UVM was developed to enhance understanding of the disease. This prognostic risk score model may help to find potential therapeutic targets for UVM patients. CYC1 acts as an oncogene role in UVM.

Updates in the Management of Uveal Melanoma

ABSTRACT

Uveal melanoma (UM), arising from intraocular melanocytes, poses a complex clinical challenge with a substantial risk of distant metastasis, often to the liver. Molecular profiling, encompassing genetic, cytogenetic, gene expression, and immunological subsets, plays a pivotal role in determining prognoses. The evolving landscape includes promising systemic treatments, such as tebentafusp, a novel immune-modulating bispecific fusion protein, and targeted therapies. Combined regional and systemic approaches, including immune checkpoint inhibitors and innovative liver-directed therapy, are also under investigation. Although recent progress has improved outcomes, ongoing research aims to address the unique challenges of UM and develop effective therapies, particularly for HLA-A*02:01-negative patients who represent a significant unmet medical need. This review comprehensively discusses the molecular characteristics of UM, risk stratification methods, and the current and future spectrum of regional and systemic therapeutic modalities.

Driver mutations in GNAQ and GNA11 genes as potential targets for precision immunotherapy in uveal melanoma patients

Uveal melanoma (UM) is the most common ocular malignancy in adults. Nearly 95% of UM patients carry the mutually exclusive mutations in the homologous genes GNAQ (amino acid change Q209L/Q209P) and GNA11 (aminoacid change Q209L). UM is located in an immunosuppressed organ and does not suffer immunoediting. Therefore, we hypothesize that driver mutations in GNAQ/11 genes could be recognized by the immune system. Genomic and transcriptomic data from primary uveal tumors were collected from the TCGA-UM dataset (n = 80) and used to assess the immunogenic potential for GNAQ/GNA11 Q209L/Q209P mutations using a variety of tools and HLA type information. All prediction tools showed stronger GNAQ/11 Q209L binding to HLA than GNAQ/11 Q209P. The immunogenicity analysis revealed that Q209L is likely to be presented by more than 73% of individuals in 1000 G databases whereas Q209P is only predicted to be presented in 24% of individuals. GNAQ/11 Q209L showed a higher likelihood to be presented by HLA-I molecules than almost all driver mutations analyzed. Finally, samples carrying Q209L had a higher immune-reactive phenotype. Regarding cancer risk, seven HLA genotypes with low Q209L affinity show higher frequency in uveal melanoma patients than in the general population. However, no clear association was found between any HLA genotype and survival. Results suggest a high potential immunogenicity of the GNAQ/11 Q209L variant that could allow the generation of novel therapeutic tools to treat UM like neoantigen vaccinations.

Targeting β-catenin using XAV939 nanoparticle promotes immunogenic cell death and suppresses conjunctival melanoma progression

Many tumors dysregulate Wnt/β-catenin pathway to promote stem-cell-like phenotype, tumorigenesis, immunosuppression, and resistance to targeted cancer immunotherapies. Therefore, targeting this pathway is a promising therapeutic approach to suppress tumor progression and elicit robust anti-tumor immunity. In this study, using a nanoparticle formulation for XAV939 (XAV-Np), a tankyrase inhibitor that promotes β-catenin degradation, we investigated the effect of β-catenin inhibition on melanoma cell viability, migration, and tumor progression using a mouse model of conjunctival melanoma. XAV-Nps were uniform and displayed near-spherical morphology with size stability for upto 5 days. We show that XAV-Np treatment of mouse melanoma cells significantly suppresses cell viability, tumor cell migration, and tumor spheroid formation compared to control nanoparticle (Con-Np) or free XAV939-treated groups. Further, we demonstrate that XAV-Np promotes immunogenic cell death (ICD) of tumor cells with a significant extracellular release or expression of ICD molecules, including high mobility group box 1 protein (HMGB1), calreticulin (CRT), and adenosine triphosphate (ATP). Finally, we show that local intra-tumoral delivery of XAV-Nps during conjunctival melanoma progression significantly suppresses tumor size and conjunctival melanoma progression compared to Con-Nps-treated animals. Collectively, our data suggest that selective inhibition of β-catenin in tumor cells using nanoparticle-based targeted delivery represents a novel approach to suppress tumor progression through increased tumor cell ICD.

Immunotherapy for ocular melanoma: a bibliometric and visualization analysis from 1991 to 2022

Background

In recent years, new therapeutic options to overcome the mechanisms of tumor immune suppression be effective in the treatment of cutaneous melanoma. These approaches have also been applied in ocular melanoma. The aim of this study is to present the current status and research hotspots of immunotherapy for ocular melanoma from a bibliometric perspective and to explore the field of immunotherapy for malignant ocular melanoma research.

Methods

In this study, the Web of Science Core Collection database (WoSCC) and Pubmed were selected to search the literature related to immunotherapy of ocular melanoma. Using VOSviewer, CiteSpace, the R package "bibliometrix," and the bibliometric online platform through the construction and visualization of bibliometric networks, the country/region, institution, journal, author, and keywords were analyzed to predict the most recent trends in research pertaining to ocular melanoma and immunotherapy.

Results

A total of 401 papers and 144 reviews related to immunotherapy of ocular melanoma were included. The United States is the main driver of research in the field, ranking first in terms of the number of publications, total citations, and H-index. The UNIVERSITY OF TEXAS SYSTEM is the most active institution, contributing the most papers. Jager, Martine is the most prolific author, and Carvajal, Richard is the most frequently cited author. CANCERS is the most published journal in the field and J CLIN ONCOL is the most cited journal. In addition to ocular melanoma and immunotherapy, the most popular keywords were "uveal melanoma" and "targeted therapy". According to keyword co-occurrence and burst analysis, uveal melanoma, immunotherapy, melanoma, metastases, bap1, tebentafusp, bioinformatics, conjunctival melanoma, immune checkpoint inhibitors, ipilimumab, pembrolizumab, and other research topics appear to be at the forefront of this field's research and have the potential to remain a hot research topic in the future.

Conclusion

This is the first bibliometric study in the last 30 years to comprehensively map the knowledge structure and trends in the field of research related to ocular melanoma and immunotherapy. The results comprehensively summarize and identify research frontiers for scholars studying immunotherapy associated with ocular melanoma.

Enhancing the immune effect of oHSV-1 therapy through TLR3 signaling in uveal melanoma

PURPOSE

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults, with patients having a low overall survival rate. Oncolytic viruses (OVs) have been shown effective as monotherapy or combined with immunotherapy in the treatment of UM. Oncolytic herpes simplex type I virus (oHSV-1) was found to alter gene expression and immune function in UMs. We investigated whether a combination treatment would be more effective in treating UM and reactive immune cells.

METHODS

RNA sequencing analysis were used to identify the effect of oHSV-1 infection in UM cells and protein changes were validated by western blot. Cell viability assays were performed through UM cell lines (MUM2B, 92.1, and MP41) and retinal pigment epithelial cell line (ARPE-19) to identify the efficacy and safety of the combination treatment. Western blot, qRT-PCR, cell viability assay and immunocytochemistry were performed to discover the reactivation of immune cells (U937 and HMC3).

RESULTS

Through RNA sequencing analysis and in vitro molecular biology assays, this study tested the ability of oHSV-1 combined with the TLR3 agonist poly(I:C) to re-activate the TLR3 meditated NF-ƙB signaling pathway and further increase the anti-tumor activity of UM cells and macrophages, including the stimulation of macrophage polarization and proliferation.

CONCLUSIONS

These findings indicate that the treatment of UM with a combination of oHSV-1 and poly(I:C) generates immune responses and enhances anti-tumoral activity, suggesting the need for further investigations and clinical trials of this combination.

Integrating single-cell analysis and machine learning to create glycosylation-based gene signature for prognostic prediction of uveal melanoma

BACKGROUND

Increasing evidence suggests a correlation between glycosylation and the onset of cancer. However, the clinical relevance of glycosylation-related genes (GRGs) in uveal melanoma (UM) is yet to be fully understood. This study aimed to shed light on the impact of GRGs on UM prognosis.

METHODS

To identify the most influential genes in UM, we employed the AUCell and WGCNA algorithms. The GRGs signature was established by integrating bulk RNA-seq and scRNA-seq data. UM patients were separated into two groups based on their risk scores, the GCNS_low and GCNS_high groups, and the differences in clinicopathological correlation, functional enrichment, immune response, mutational burden, and immunotherapy between the two groups were examined. The role of the critical gene AUP1 in UM was validated through in vitro and in vivo experiments.

RESULTS

The GRGs signature was comprised of AUP1, HNMT, PARP8, ARC, ALG5, AKAP13, and ISG20. The GCNS was a significant prognostic factor for UM, and high GCNS correlated with poorer outcomes. Patients with high GCNS displayed heightened immune-related characteristics, such as immune cell infiltration and immune scores. In vitro experiments showed that the knockdown of AUP1 led to a drastic reduction in the viability, proliferation, and invasion capability of UM cells.

CONCLUSION

Our gene signature provides an independent predictor of UM patient survival and represents a starting point for further investigation of GRGs in UM. It offers a novel perspective on the clinical diagnosis and treatment of UM.

BAG2 Is a Novel Prognostic Biomarker and Promising Immunotherapy Target in Uveal Melanoma

BACKGROUND

The importance of BAG2 in malignancy is gradually being recognized, however, information on its role in uveal melanoma (UVM) is limited. We aimed to elucidate its function and potential mechanism of action in UVM.

METHODS

Using the Cancer Genome Atlas (TCGA) and GEO-related datasets, we analyzed the differential expression of BAG2 in tumors, combined with clinical information and methylation data to analyze the prognostic value of BAG2, differential methylation and its association with UVM metastasis. In addition, correlation analysis explored the immunological characteristics of BAG2 in UVM and the response to immunotherapy. Finally, a prognostic model of ferroptosis- related genes was constructed and validated.

RESULTS

BAG2 is significantly downregulated in multiple cancers including UVM. Prognostic analysis showed that BAG2 was an independent prognostic factor for UVM. Abnormal methylation of BAG2 may affect the metastasis of UVM and be significantly associated with poor prognosis. Immune analysis clarified that BAG2 was significantly associated with UVM immune cell infiltration and multiple immune checkpoints, and low expression of BAG2 was more beneficial in immunotherapy. In addition, the prognostic model of ferroptosis we constructed has good performance in predicting overall survival and metastasis-free survival of UVM.

CONCLUSIONS

BAG2 is an independent prognostic factor for UVM and may be a potential immune checkpoint for UVM.

KDELR3 Is a Prognostic Biomarker Related to the Immune Infiltration and Chemoresistance of Anticancer Drugs in Uveal Melanoma

Uveal melanoma (UM) is an intraocular malignancy in adults in which approximately 50% of patients develop metastatic diseases and have a poor clinical outcome. Immunotherapies are quickly becoming a need, and recent research has produced some amazing achievements in this area. In the current investigation, an attempt was made to evaluate the prognostic usefulness of KDELR3 in UM, particularly its connection with tumor-infiltrating lymphocytes (TILs). The expression patterns of mRNAs and related clinical data of 80 UM patients were obtained from The Cancer Genome Atlas (TCGA). By using RT-PCR, we were able to investigate whether or not UM cells and D78 cells expressed KDELR3. The Kaplan-Meier approach, as well as univariate and multivariate tests, was utilized in order to investigate the potential predictive significance of KDELR3 expression. The associations between KDELR3 and TILs and immunological checkpoints were analyzed in order to evaluate the effect that KDELR3 may have on UM immunotherapy. On the basis of the differential expression of KDELR3, a distribution of the half-maximal inhibitory concentration (IC50) of various targeted medicines was observed. In this study, we found that the expression of KDELR3 was distinctly increased in most types of tumors. In addition, KDELR3 was highly expressed in UM cells. Moreover, patients with high KDELR3 expression exhibited a shorter overall survival and disease-free survival than those with low KDELR3 expression. Multivariate analyses confirmed that KDELR3 expression was an independent prognostic factor for overall survival and disease-free survival in patients with UM. Furthermore, KDELR3 expression was demonstrated to be positively correlated with macrophage M1, T cell CD8, T cell follicular helper, dendritic cell resting, and T cell CD4 memory activated. Meanwhile, the expression of KDELR3 was related to several immune checkpoints. The IC50 of AP-24534, BHG712, bleomycin, camptothecin, cisplatin, cytarabine, GSK1070916, and tipifarnib was higher in the KDELR3 high-expression group. In conclusion, KDELR3 may be applied as a potential diagnostic and prognostic biomarker for UM patients.

Recent Advances and Challenges in Uveal Melanoma Immunotherapy

Simple Summary

Uveal melanoma is the most common primary intraocular malignancy in adults. Although it can be controlled locally, half of the patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Existing therapies, such as chemotherapy and targeted therapies, induce only minimal responses. This review focuses on newly published research on immunotherapy. We highlight expanding treatments and their clinical outcomes, as well as propose promising new treatments and feasible checkpoints. Based on these findings, we provide innovative insights into feasible strategies for the treatment of patients with uveal melanoma.

Abstract

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Compared to cutaneous melanoma (CM), which mainly harbors BRAF or NRAS mutations, UM predominantly harbors GNAQ or GNA11 mutations. Although primary UM can be controlled locally, approximately 50% of patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Unfortunately, chemotherapy and targeted therapies only induce minimal responses in patients with metastatic UM, with a median survival time of only 4–5 months after metastasis detection. Immunotherapy agents, such as immune checkpoint inhibitors, have achieved pioneering outcomes in CM but have shown limited effects in UM. Researchers have explored several feasible checkpoints to identify options for future therapies. Cancer vaccines have shown little in the way of therapeutic benefit in patients with UM, and there are few ongoing trials providing favorable evidence, but adoptive cell transfer-related therapies seem promising and deserve further investigation. More recently, the immune-mobilizing monoclonal T-cell receptor against the cancer molecule tebentafusp showed impressive antitumor effects. Meanwhile, oncolytic viruses and small molecule inhibitors have also gained ground. This review highlights recent progress in burgeoning treatments and provides innovative insights on feasible strategies for the treatment of UM.

Circulating immune profile can predict survival of metastatic uveal melanoma patients: results of an exploratory study

Metastatic uveal melanoma (UM) is a poor prognosis malignancy. Immunotherapy is commonly employed, despite the low activity, considering the lack of other effective systemic treatments. In this study, the prognostic and predictive role of soluble immune checkpoints and inflammatory cytokines/chemokines in 22 metastatic UM patients was evaluated. Baseline levels of these molecules were assessed, as well as their changes during anti-PD-1 therapy. The correlation between soluble immune checkpoints/cytokines/chemokines and survival was analyzed. A comparison between circulating immune profile of metastatic cutaneous melanoma (CM), for which immunotherapy is a mainstay of treatment, and UM during anti-PD-1 therapy was also performed. Three immune molecules resulted significantly higher in metastatic UM patients with survival <6 months versus patients with survival ≥6 months: IL-8, HVEM and IDO activity. Considering these three molecules, we obtained a baseline score able to predict patients’ survival. The same three molecules, together with soluble(s) CD137, sGITR and sCD27, resulted significantly lower in patients with survival >30 months. We also observed an increase of sCD137, sCD28, sPD-1, sPD-L2 sLAG3, sCD80 and sTim3 during anti-PD-1 treatment, as well as IDO activity, IP-10 and CCL2. Several of these molecules were significantly higher in UM compared to CM patients during anti-PD-1 therapy. The analysis of circulating immune molecules allows to identify patients with poor prognosis despite immunotherapy and patients with long survival treated with an anti-PD-1 agent. The different serum concentration of these molecules during anti-PD-1 therapy between UM and CM reflects the different efficacy of immune checkpoint inhibitors.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Regulation of epigenetic homeostasis in uveal melanoma and retinoblastoma

Uveal melanoma (UM) and retinoblastoma (RB), which cause blindness and even death, are the most frequently observed primary intraocular malignancies in adults and children, respectively. Epigenetic studies have shown that changes in the epigenome contribute to the rapid progression of both UM and RB following classic genetic changes. The loss of epigenetic homeostasis plays an important role in oncogenesis by disrupting the normal patterns of gene expression. The targetable nature of epigenetic modifications provides a unique opportunity to optimize treatment paradigms and establish new therapeutic options for both UM and RB with these aberrant epigenetic modifications. We aimed to review the research findings regarding relevant epigenetic changes in UM and RB. Herein, we 1) summarize the literature, with an emphasis on epigenetic alterations, including DNA methylation, histone modifications, RNA modifications, noncoding RNAs and an abnormal chromosomal architecture; 2) elaborate on the regulatory role of epigenetic modifications in biological processes during tumorigenesis; and 3) propose promising therapeutic candidates for epigenetic targets and update the list of epigenetic drugs for the treatment of UM and RB. In summary, we endeavour to depict the epigenetic landscape of primary intraocular malignancy tumorigenesis and provide potential epigenetic targets in the treatment of these tumours.

Do Extracellular RNAs Provide Insight into Uveal Melanoma Biology?

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults, showing a high mortality due to metastasis. Although it is considered a rare disease, a growing number of papers have reported altered levels of RNAs (i.e., coding and non-coding RNAs) in cancerous tissues and biological fluids from UM patients. The presence of circulating RNAs, whose dysregulation is associated with UM, paved the way to the possibility of exploiting it for diagnostic and prognostic purposes. However, the biological meaning and the origin of such RNAs in blood and ocular fluids of UM patients remain unexplored. In this review, we report the state of the art of circulating RNAs in UM and debate whether the amount and types of RNAs measured in bodily fluids mirror the RNA alterations from source cancer cells. Based on literature data, extracellular RNAs in UM patients do not represent, with rare exceptions, a snapshot of RNA dysregulations occurring in cancerous tissues, but rather the complex and heterogeneous outcome of a systemic dysfunction, including immune system activity, that modifies the mechanisms of RNA delivery from several cell types.

Uveal Melanoma Metastasis

Uveal melanoma (UM) is characterized by relatively few, highly incident molecular alterations and their association with metastatic risk is deeply understood. Nevertheless, this knowledge has so far not led to innovative therapies for the successful treatment of UM metastases or for adjuvant therapy, leaving survival after diagnosis of metastatic UM almost unaltered in decades. The driver mutations of UM, mainly in the G-protein genes GNAQ and GNA11, activate the MAP-kinase pathway as well as the YAP/TAZ pathway. At present, there are no drugs that target the latter and this likely explains the failure of mitogen activated kinase kinase inhibitors. Immune checkpoint blockers, despite the game changing effect in cutaneous melanoma (CM), show only limited effects in UM probably because of the low mutational burden of 0.5 per megabase and the unavailability of antibodies targeting the main immune checkpoint active in UM. The highly pro-tumorigenic microenvironment of UM also contributes to therapy resistance. However, T-cell redirection by a soluble T-cell receptor that is fused to an anti-CD3 single-chain variable fragment, local, liver specific therapy, new immune checkpoint blockers, and YAP/TAZ specific drugs give new hope to repeating the success of innovative therapy obtained for CM.

LAG3 and Its Ligands Show Increased Expression in High-Risk Uveal Melanoma

Uveal melanoma (UM) is a rare ocular malignancy which originates in the uveal tract, and often gives rise to metastases. Potential targets for immune checkpoint inhibition are lymphocyte-activation gene 3 (LAG3) and its ligands. We set out to analyse the distribution of these molecules in UM. The expression of mRNA was determined using an Illumina array in 64 primary UM from Leiden. The T lymphocyte fraction was determined by digital droplet PCR. In a second cohort of 15 cases from Leiden, mRNA expression was studied by Fluidigm qPCR, while a third cohort consisted of 80 UM from TCGA. In the first Leiden cohort, LAG3 expression was associated with the presence of epithelioid cells (p = 0.002), monosomy of chromosome 3 (p = 0.004), and loss of BAP1 staining (p = 0.001). In this Leiden cohort as well as in the TCGA cohort, LAG3 expression correlated positively with the expression of its ligands: LSECtin, Galectin-3, and the HLA class II molecules HLA-DR, HLA-DQ, and HLA-DP (all p < 0.001). Furthermore, ligands Galectin-3 and HLA class II were increased in monosomy 3 tumours and the expression of LAG3 correlated with the presence of an inflammatory phenotype (T cell fraction, macrophages, HLA-A and HLA-B expression: all p < 0.001). High expression levels of LAG3 (p = 0.01), Galectin-3 (p = 0.001), HLA-DRA1 (p = 0.002), HLA-DQA1 (p = 0.04), HLA-DQB2 (p = 0.03), and HLA-DPA1 (p = 0.007) were associated with bad survival. We conclude that expression of the LAG ligands Galectin-3 and HLA class II strongly correlates with LAG3 expression and all are increased in UM with Monosomy 3/BAP1 loss. The distribution suggests a potential benefit of monoclonal antibodies against LAG3 or Galectin-3 as adjuvant treatment in patients with high-risk UM.

Identification and validation of tumor microenvironment-related lncRNA prognostic signature for uveal melanoma

AIM

To investigate the role of tumor microenvironment (TME)-related long non-coding RNA (lncRNA) in uveal melanoma (UM), probable prognostic signature and potential small molecule drugs using bioinformatics analysis.

METHODS

UM expression profile data were downloaded from the Cancer Genome Atlas (TCGA) and bioinformatics methods were used to find prognostic lncRNAs related to UM immune cell infiltration. The gene expression profile data of 80 TCGA specimens were analyzed using the single sample Gene Set Enrichment Analysis (ssGSEA) method, and the immune cell infiltration of a single specimen was evaluated. Finally, the specimens were divided into high and low infiltration groups. The differential expression between the two groups was analyzed using the R package 'edgeR'. Univariate, multivariate and Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analyses were performed to explore the prognostic value of TME-related lncRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analyses were also performed. The Connectivity Map (CMap) data set was used to screen molecular drugs that may treat UM.

RESULTS

A total of 2393 differentially expressed genes were identified and met the criteria for the low and high immune cell infiltration groups. Univariate Cox analysis of lncRNA genes with differential expression identified 186 genes associated with prognosis. Eight prognostic markers of TME-included lncRNA genes were established as potentially independent prognostic elements. Among 269 differentially expressed lncRNAs, 69 were up-regulated and 200 were down-regulated. Univariate Cox regression analysis of the risk indicators and clinical characteristics of the 8 lncRNA gene constructs showed that age, TNM stage, tumor base diameter, and low and high risk indices had significant prognostic value. We screened the potential small-molecule drugs for UM, including W-13, AH-6809 and Imatinib.

CONCLUSION

The prognostic markers identified in this study are reliable biomarkers of UM. This study expands our current understanding of the role of TME-related lncRNAs in UM genesis, which may lay the foundations for future treatment of this disease.

A Comprehensive Understanding of Choroidal Metastasis from Lung Cancer

The incidence of lung cancer with intraocular metastasis is low, of which choroidal metastasis is the most painful metastatic lesion. The clinical symptoms resulting from choroidal metastasis from lung cancer easily detected although they are rarely identified prior to the diagnosis of the primary malignancy. The quality of life of patients is inevitably impaired. Some lung cancer patients complain of ocular symptoms as the first manifestation of lung cancer. Early diagnosis and treatment can significantly overcome or delay the visual impairment and improve prognosis. The main therapeutic modalities include systemic and local treatments, while observation is also a treatment option. Currently, the feasibility and effectiveness of various treatment options are controversial worldwide. Herein, we summarize the underlying mechanisms, epidemiology, clinical features, auxiliary examinations, diagnosis, and recent treatment options for intraocular metastases.

MiRNAs Correlate with HLA Expression in Uveal Melanoma: Both Up- and Downregulation Are Related to Monosomy 3

Simple Summary

Uveal melanoma (UM) is a rare ocular malignancy that often gives rise to metastases. Tumours with an inflammatory phenotype have an especially bad prognosis. As an increased HLA expression and the presence of tumour-infiltrating lymphocytes and macrophages may be regulated by miRNAs, we set out to investigate whether any miRNAs are associated with inflammatory parameters in this malignancy. Some miRNAs were increased in UM with a high HLA expression and high T cell numbers, while others were decreased, showing two opposing patterns; however, both patterns were related to the tumour’s chromosome 3/BAP1 status. We conclude that specific miRNAs are related to the inflammatory phenotype and that these are differentially expressed between disomy 3/BAP1-positive versus monosomy 3/BAP1-negative UM.

Abstract

MicroRNAs are known to play a role in the regulation of inflammation. As a high HLA Class I expression is associated with a bad prognosis in UM, we set out to determine whether any miRNAs were related to a high HLA Class I expression and inflammation. We also determined whether such miRNAs were related to the UM’s genetic status. The expression of 125 miRNAs was determined in 64 primary UM from Leiden. Similarly, the mRNA expression of HLA-A, HLA-B, TAP1, BAP1, and immune cell markers was obtained. Expression levels of 24 of the 125 miRNAs correlated with expression of at least three out of four HLA Class I probes. Four miRNAs showed a positive correlation with HLA expression and infiltration with leukocytes, 20 a negative pattern. In the first group, high miRNA levels correlated with chromosome 3 loss/reduced BAP1 mRNA expression, in the second group low miRNA levels. The positive associations between miRNA-22 and miRNA-155 with HLA Class I were confirmed in the TCGA study and Rotterdam cohort, and with TAP1 in the Rotterdam data set; the negative associations between miRNA-125b2 and miRNA-211 and HLA-A, TAP1, and CD4 were confirmed in the Rotterdam set. We demonstrate two patterns: miRNAs can either be related to a high or a low HLA Class I/TAP1 expression and the presence of infiltrating lymphocytes and macrophages. However, both patterns were associated with chromosome 3/BAP1 status, which suggests a role for BAP1 loss in the regulation of HLA expression and inflammation in UM through miRNAs.

CARD11 is a prognostic biomarker and correlated with immune infiltrates in uveal melanoma

Uveal melanoma (UVM), the most common primary intraocular malignancy, has a high mortality because of a high propensity to metastasize. Our study analyzed prognostic value and immune-related characteristics of CARD11 in UVM, hoping to provide a potential management and research direction. The RNA-sequence data of 80 UVM patients were downloaded from The Cancer Genome Atlas database and divided them into high- and low-expression groups. We analyzed the differentially expressed genes, enrichment analyses and the infiltration of immune cells using the R package and Gene-Set Enrichment Analysis. A clinical prediction nomogram and protein-protein interaction network were constructed and the first 8 genes were considered as the hub-genes. Finally, we constructed a competing endogenous RNA (ceRNA) network by Cytoscape and analyzed the statistical data via the R software. Here we found that CARD11 expression had notable correlation with UVM clinicopathological features, which was also an independent predictor for overall survival (OS). Intriguingly, CARD11 had a positively correlation to autophagy, cellular senescence and apoptosis. Infiltration of monocytes was significantly higher in low CARD11 expression group, and infiltration of T cells regulatory was lower in the same group. Functional enrichment analyses revealed that CARD11 was positively related to T cell activation pathways and cell adhesion molecules. The expressions of hub-genes were all increased in the high CARD11 expression group and the ceRNA network showed the interaction among mRNA, miRNA and lncRNA. These findings show that high CARD11 expression in UVM is associated with poor OS, indicating that CARD11 may serve as a potential biomarker for the diagnosis and prognosis of the UVM.

Bioinformatic Analysis Reveals Central Role for Tumor-Infiltrating Immune Cells in Uveal Melanoma Progression

Tumor-infiltrating immune cells are capable of effective cancer surveillance, and their abundance is linked to better prognosis in numerous tumor types. However, in uveal melanoma (UM), extensive immune infiltrate is associated with poor survival. This study aims to decipher the role of different tumor-infiltrating cell subsets in UM in order to identify potential targets for future immunotherapeutic treatment. We have chosen the TCGA-UVM cohort as a training dataset and GSE22138 as a testing dataset by mining publicly available databases. The abundance of 22 immune cell types was estimated using CIBERSORTx. Then, to determine the significance of tumor-infiltrating cell subsets in UM, we built a multicell type prognostic signature, which was validated in the testing cohort. The created signature was built upon the negative prognostic role of CD8+ T cells and M0 macrophages and the positive role of neutrophils. Based on the created signature score, we divided the patients into low- and high-risk groups. Kaplan-Meier, Cox, and ROC analyses demonstrated superior performance of our risk score compared to either clinical or pathologic characteristics of both cohorts. Further, we found the molecular pathways associated with cancer immunoevasion and metastasis to be enriched in the high-risk group, explaining both the lack of adequate immune surveillance despite increased infiltration of CD8+ T cells as well as the higher metastatic potential. Genes associated with tryptophan metabolism (IDO1 and KYNU) and metalloproteinases were among the most differentially expressed between the high- and low-risk groups. Our correlation analyses interpreted in context of published in vitro data strongly suggest the central role of CD8+ T cells in shifting the UM tumor microenvironment towards suppressive and metastasis-promoting. Therefore, we propose further investigations of IDO1 and metalloproteinases as novel targets for immunotherapy in lymphocyte-rich metastatic UM patients.

Conjunctival melanoma: New insights in tumour genetics and immunology, leading to new therapeutic options

Recent developments in oncology have led to a better molecular and cellular understanding of cancer, and the introduction of novel therapies. Conjunctival melanoma (CoM) is a rare but potentially devastating disease. A better understanding of CoM, leading to the development of novel therapies, is urgently needed. CoM is characterized by mutations that have also been identified in cutaneous melanoma, e.g. in BRAF, NRAS and TERT. These mutations are distinct from the mutations found in uveal melanoma (UM), affecting genes such as GNAQ, GNA11, and BAP1. Targeted therapies that are successful in cutaneous melanoma may therefore be useful in CoM. A recent breakthrough in the treatment of patients with metastatic cutaneous melanoma was the development of immunotherapy. While immunotherapy is currently sparsely effective in intraocular tumours such as UM, the similarities between CoM and cutaneous melanoma (including in their immunological tumour micro environment) provide hope for the application of immunotherapy in CoM, and preliminary clinical data are indeed emerging to support this use. This review aims to provide a comprehensive overview of the current knowledge regarding CoM, with a focus on the genetic and immunologic understanding. We elaborate on the distinct position of CoM in contrast to other types of melanoma, and explain how new insights in the pathophysiology of this disease guide the development of new, personalized, treatments.

How to Make Immunotherapy an Effective Therapeutic Choice for Uveal Melanoma

Simple Summary

Despite improvements in the early identification and successful control of primary uveal melanoma, 50% of patients will develop metastatic disease with only marginal improvements in survival. This review focuses on the tumor microenvironment and the cross-talk between tumor and immune cells in a tumor characterized by low mutational load, the induction of immune-suppressive cells, and the expression of alternative immune checkpoint molecules. The choice of combining different strategies of immunotherapy remains a feasible and promising option on selected patients.

Abstract

Uveal melanoma (UM), though a rare form of melanoma, is the most common intraocular tumor in adults. Conventional therapies of primary tumors lead to an excellent local control, but 50% of patients develop metastases, in most cases with lethal outcome. Somatic driver mutations that act on the MAP-kinase pathway have been identified, yet targeted therapies show little efficacy in the clinics. No drugs are currently available for the G protein alpha subunitsGNAQ and GNA11, which are the most frequent driver mutations in UM. Drugs targeting the YAP–TAZ pathway that is also activated in UM, the tumor-suppressor gene BRCA1 Associated Protein 1 (BAP1) and the Splicing Factor 3b Subunit 1 gene (SF3B1) whose mutations are associated with metastatic risk, have not been developed yet. Immunotherapy is highly effective in cutaneous melanoma but yields only poor results in the treatment of UM: anti-PD-1 and anti-CTLA-4 blocking antibodies did not meet the expectations except for isolated cases. Here, we discuss how the improved knowledge of the tumor microenvironment and of the cross-talk between tumor and immune cells could help to reshape anti-tumor immune responses to overcome the intrinsic resistance to immune checkpoint blockers of UM. We critically review the dogma of low mutational load, the induction of immune-suppressive cells, and the expression of alternative immune checkpoint molecules. We argue that immunotherapy might still be an option for the treatment of UM.

Translation of single-cell transcriptomic analysis of uveal melanomas to clinical oncology

Uveal melanoma (UM) is an aggressive and deadly neoplasm. In recent decades, great efforts have been made to obtain a more comprehensive understanding of genetics, genomics and molecular changes in UM, enabling the identification of key cellular processes and signalling pathways. Still, there is no effective treatment for the metastatic disease. Intratumoural heterogeneity (ITH) is thought to be one of the leading determinants of metastasis, therapeutic resistance and recurrence. Crucially, tumours are complex ecosystems, where cancer cells, and diverse cell types from their microenvironment engage in dynamic spatiotemporal crosstalk that allows cancer progression, adaptation and evolution. This highlights the urgent need to gain insight into ITH in UM and its intersection with the microenvironment to overcome treatment failure. Here we provide an overview of the studies and technologies to study ITH in human UMs and tumour micro-environmental composition. We discuss how to incorporate ITH into clinical consideration for the purpose of advocating for new clinical management. We focus on the application of single-cell transcriptomic analysis and propose that understanding the driving forces and functional consequences of the observed tumour heterogeneity holds promise for changing the treatment paradigm of metastatic UMs, surmounting resistance and improving patient prognosis.

Immunotherapy in uveal melanoma: novel strategies and opportunities for personalized treatment

INTRODUCTION

Uveal melanoma (UM) is the most common intraocular cancer and represents a discrete subtype of melanoma. Metastatic disease, which occurs in half of patients, has a dismal prognosis. Immunotherapy with immune checkpoint inhibitors has produced promising results in cutaneous melanoma but has failed to show analogous efficacy in metastatic UM. This is attributable to UM's distinct genetics and its complex interaction with the immune system. Hence, more efficacious immunotherapeutic approaches are under investigation.

AREAS COVERED

We discuss those novel immunotherapeutic strategies in clinical and preclinical studies for advanced disease and which are thought to overcome the hurdles set by UM in terms of immune recognition. We also highlight the need to determine predictive markers in relation to these strategies to improve clinical outcomes. We used a simple narrative analysis to summarize the data. The search methodology is located in the Introduction.

EXPERT OPINION

Novel immunotherapeutic strategies focus on transforming immune excluded tumor microenvironment in metastatic UM to T cell inflamed. Preliminary results of approaches such as vaccines, adoptive cell transfer and other novel molecules are encouraging. Factors such as HLA compatibility and expression level of targeted antigens should be considered to optimize personalized management.

Additive Role of Immune System Infiltration and Angiogenesis in Uveal Melanoma Progression

Uveal melanoma (UM) is a malignant tumor that arises in the melanocytes of the uveal tract. It is the most frequent eye cancer, and despite new therapeutic approaches, prognosis is still poor, with up to 50% of patients developing metastasis with no efficient treatment options available. In contrast to cutaneous melanoma, UM is considered an “immune-cold” tumor due to the low mutational burden and the unique immunosuppressive microenvironment. To gain insight into the role of the UM microenvironment in regard to prognosis and metastatic progression, we have performed a pool analysis characterizing the UM microenvironment by using a bioinformatic approach. A variety of scores based on gene expression measuring stromal infiltration were calculated and used to assess association with prognosis. As a result, the highest immune and stromal scores were associated with poor prognosis. Specifically, stromal cells (fibroblasts and endothelial cells), T cells CD8+, natural killer (NK) cells, and macrophages M1 and M2 infiltration were associated with poor prognosis. Contrary to other tumors, lymphocytic infiltration is related to poor prognosis. Only B cells were associated with more favorable prognosis. UM samples scoring high in both angiogenesis (Angio) and antigen presentation (AP) pathways showed a poor prognosis suggesting an additive role of both functions. Almost all these tumors exhibited a chromosome 3 monosomy. Finally, an enrichment analysis showed that tumors classified as high Angio-high AP also activated metabolic pathways such as glycolysis or PI3K-AKT-MTOR. In summary, our pool analysis identified a cluster of samples with angiogenic and inflammatory phenotypes exhibiting poor prognosis and metabolic activation. Our analysis showed robust results replicated in a pool analysis merging different datasets from different analytic platforms.

Retinal Inflammation, Cell Death and Inherited Retinal Dystrophies

Inherited retinal dystrophies (IRDs) are a group of retinal disorders that cause progressive and severe loss of vision because of retinal cell death, mainly photoreceptor cells. IRDs include retinitis pigmentosa (RP), the most common IRD. IRDs present a genetic and clinical heterogeneity that makes it difficult to achieve proper treatment. The progression of IRDs is influenced, among other factors, by the activation of the immune cells (microglia, macrophages, etc.) and the release of inflammatory molecules such as chemokines and cytokines. Upregulation of tumor necrosis factor alpha (TNFα), a pro-inflammatory cytokine, is found in IRDs. This cytokine may influence photoreceptor cell death. Different cell death mechanisms are proposed, including apoptosis, necroptosis, pyroptosis, autophagy, excessive activation of calpains, or parthanatos for photoreceptor cell death. Some of these cell death mechanisms are linked to TNFα upregulation and inflammation. Therapeutic approaches that reduce retinal inflammation have emerged as useful therapies for slowing down the progression of IRDs. We focused this review on the relationship between retinal inflammation and the different cell death mechanisms involved in RP. We also reviewed the main anti-inflammatory therapies for the treatment of IRDs.

HDAC Inhibition Increases HLA Class I Expression in Uveal Melanoma

Simple Summary

Chemotherapy and immunotherapy are both used to treat malignancies. The immunotherapy of cancer often involves T cells, which recognise the antigens presented in HLA molecules. Uveal melanoma (UM) is an intraocular malignancy, which often gives rise to metastases. We determined whether high-risk tumours expressed the target of two drugs, histone deacetylase (HDAC) inhibitor Quisinostat and Tazemetostat, an inhibitor of Enhancer of zeste homologue 2 (EZH2). We observed that especially high-risk UM tumours (monosomy 3, gain of 8q, loss of BAP1) expressed several HDACs, and showed a high HLA Class I expression. We further tested whether these drugs influenced HLA Class I expression on three UM cell lines. The drug Quisinostat led to an upregulation of HLA protein and mRNA levels in three UM cell lines, while Tazemetostat had little effect. We concluded that the use of drugs that influence epigenetic regulators may impact immunotherapy approaches.

Abstract

The treatment of uveal melanoma (UM) metastases or adjuvant treatment may imply immunological approaches or chemotherapy. It is to date unknown how epigenetic modifiers affect the expression of immunologically relevant targets, such as the HLA Class I antigens, in UM. We investigated the expression of HDACs and the histone methyl transferase EZH2 in a set of 64 UMs, using an Illumina HT12V4 array, and determined whether a histone deacetylase (HDAC) inhibitor and EZH2 inhibitor modified the expression of HLA Class I on three UM cell lines. Several HDACs (HDAC1, HDAC3, HDAC4, and HDAC8) showed an increased expression in high-risk UM, and were correlated with an increased HLA expression. HDAC11 had the opposite expression pattern. While in vitro tests showed that Tazemetostat did not influence cell growth, Quisinostat decreased cell survival. In the three tested cell lines, Quisinostat increased HLA Class I expression at the protein and mRNA level, while Tazemetostat did not have an effect on the cell surface HLA Class I levels. Combination therapy mostly followed the Quisinostat results. Our findings indicate that epigenetic drugs (in this case an HDAC inhibitor) may influence the expression of immunologically relevant cell surface molecules in UM, demonstrating that these drugs potentially influence immunotherapy.

Prognostic significance of PD-1/PD-L1 expression in uveal melanoma: correlation with tumor-infiltrating lymphocytes and clinicopathological parameters

BACKGROUND

To understand how to improve the effect of immune checkpoint inhibitors in uveal melanoma (UM), we need a better understanding of the expression of PD-1 and PD-L1, their relation with the presence of tumor-infiltrating lymphocytes (TILs), and their prognostic relevance in UM patients.

MATERIALS AND METHODS

Expression of PD-1 and PD-L1 was assessed in 71 UM tissue samples by immunohistochemistry and quantitative real-time PCR (qRT-PCR), and further validated by western blotting. The effect of interferon gamma (IFN-γ) on PD-1/PD-L1 expression was determined on four UM cell lines.

RESULTS

Immunoreactivity of PD-1 was found in 30/71 cases and of PD-L1 in 44/71 UM samples. Tumor-infiltrating lymphocytes were found in 46% of UM tissues. PD-1 was expressed on TILs while tumor cells expressed PD-L1. UM with and without TILs showed expression of PD-1 in 69% and 18% cases, respectively (p = 0.001). Similarly, PD-L1 was found in 75% of UM with TILs and in 50% of cases without TILs, respectively (p = 0.03). DFS rate were lower in patients with TILs with expression of PD-1 and PD-L1, but the rate of DFS was higher with expression of PD-L1 in patients without TILs. After treatment of UM cell lines with IFN-γ, PD-1 expression was induced in all UM cell lines whereas PD-L1 expression was found at a lower level in untreated cells, while expression also increased following treatment with IFN-γ.

CONCLUSION

Our study suggests that increased infiltration with TILs promotes the aggressive behavior and suppresses the immune response of UM cells, thereby inhibiting immunotherapy.

Defective FasL expression is associated with increased resistance to melanoma liver metastases and enhanced natural killer cell activity

The objective was to determine if the absence of FasL signaling would affect melanoma liver metastases by influencing the antimelanoma properties of liver natural killer (NK) cells. Melanoma liver metastases were induced in wild-type C57BL/6 mice and the gld/gld mutant C57BL/6 mouse strain that expresses a defective form of FasL (CD95L) that fails to engage and signal via the Fas receptor (CD95). Liver metastases were produced by intrasplenic injection of B16LS9 melanoma cells. Liver NK cell activity directed against murine B16LS9 melanoma cells was determined in a 24 h in-vitro cytotoxicity assay. Liver NK cells, NK T cells, and the NK cell surface activation marker, NKG2D, were measured by flow cytometry. Mice expressing defective FasL displayed reduced, rather than enhanced, melanoma liver metastases that coincided with increased liver NK cell-mediated tumor cell cytotoxicity. Enhanced cytotoxicity was not mediated by perforin, tumor necrosis factor-α, or tumor necrosis-associated apoptosis-inducing ligand but was closely associated with elevated interferon-γ in the tumor-bearing liver. FasL-defective gld/gld mice also displayed reduced numbers of liver NK T cells, which have been previously implicated in suppression on liver NK cell activity. The absence of functional FasL in the liver correlates with a heightened, not diminished, resistance to melanoma liver metastases. The resistance to liver metastases coincides with a significant, albeit transient, increase in liver NK cytotoxicity and elevated levels of interferon-γ in the liver.

Uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. UMs are usually initiated by a mutation in GNAQ or GNA11, unlike cutaneous melanomas, which usually harbour a BRAF or NRAS mutation. The annual incidence in Europe and the USA is ~6 per million population per year. Risk factors include fair skin, light-coloured eyes, congenital ocular melanocytosis, ocular melanocytoma and the BAP1-tumour predisposition syndrome. Ocular treatment aims at preserving the eye and useful vision and, if possible, preventing metastases. Enucleation has largely been superseded by various forms of radiotherapy, phototherapy and local tumour resection, often administered in combination. Ocular outcomes are best with small tumours not extending close to the optic disc and/or fovea. Almost 50% of patients develop metastatic disease, which usually involves the liver, and is usually fatal within 1 year. Although UM metastases are less responsive than cutaneous melanoma to chemotherapy or immune checkpoint inhibitors, encouraging results have been reported with partial hepatectomy for solitary metastases, with percutaneous hepatic perfusion with melphalan or with tebentafusp. Better insight into tumour immunology and metabolism may lead to new treatments.

A Unique Regulation Region in the 3' UTR of HLA-G with a Promising Potential

Human leukocyte antigen G (HLA-G) is a non-classical human leukocyte antigen (HLA) class I protein that interacts with inhibitory receptors and is commonly overexpressed in various cancers, thereby establishing itself as an inhibitory checkpoint immune ligand. It is also expressed in trophoblast cells during pregnancy and protects the fetus from immune rejection. Despite its crucial role and its intriguing expression pattern, the regulation of HLA-G’s expression is only partially understood. HLA-G’s mRNA is expressed in many tissues but the protein expression is restricted only to the cells mentioned above. Therefore, we suggest that HLA-G is post-transcriptionally regulated. Here, we reveal a distinctive site present only in the 3′ Untranslated region (UTR) of HLA-G, which might explain its unique expression pattern. Consequently, we attempted to find binding factors such as RNA binding proteins (RBPs) and microRNAS (miRs) that regulate HLA-G expression by interacting with this distinct site present in its 3′ UTR. Our research indicates that this site should be further studied in order to reveal its significance.

The Role of Immune Checkpoint Blockade in Uveal Melanoma

Uveal melanoma (UM) represents the most common intraocular malignancy in adults and accounts for about 5% of all melanomas. Primary disease can be effectively controlled by several local therapy options, but UM has a high potential for metastatic spread, especially to the liver. Despite its clinical and genetic heterogeneity, therapy of metastatic UM has largely been adopted from cutaneous melanoma (CM) with discouraging results until now. The introduction of antibodies targeting CTLA-4 and PD-1 for immune checkpoint blockade (ICB) has revolutionized the field of cancer therapy and has achieved pioneering results in metastatic CM. Thus, expectations were high that patients with metastatic UM would also benefit from these new therapy options. This review provides a comprehensive and up-to-date overview on the role of ICB in UM. We give a summary of UM biology, its clinical features, and how it differs from CM. The results of several studies that have been investigating ICB in metastatic UM are presented. We discuss possible reasons for the lack of efficacy of ICB in UM compared to CM, highlight the pitfalls of ICB in this cancer entity, and explain why other immune-modulating therapies could still be an option for future UM therapies.

Uveal melanoma: Towards a molecular understanding

Uveal melanoma is an aggressive malignancy that originates from melanocytes in the eye. Even if the primary tumor has been successfully treated with radiation or surgery, up to half of all UM patients will eventually develop metastatic disease. Despite the common origin from neural crest-derived cells, uveal and cutaneous melanoma have few overlapping genetic signatures and uveal melanoma has been shown to have a lower mutational burden. As a consequence, many therapies that have proven effective in cutaneous melanoma -such as immunotherapy- have little or no success in uveal melanoma. Several independent studies have recently identified the underlying genetic aberrancies in uveal melanoma, which allow improved tumor classification and prognostication of metastatic disease. In most cases, activating mutations in the Gα11/Q pathway drive uveal melanoma oncogenesis, whereas mutations in the BAP1, SF3B1 or EIF1AX genes predict progression towards metastasis. Intriguingly, the composition of chromosomal anomalies of chromosome 3, 6 and 8, shown to correlate with an adverse outcome, are distinctive in the BAP1^mut, SF3B1^mut and EIF1AX^mut uveal melanoma subtypes. Expression profiling and epigenetic studies underline this subdivision in high-, intermediate-, or low-metastatic risk subgroups and suggest a different approach in the future towards prevention and/or treatment based on the specific mutation present in the tumor of the patients. In this review we discuss the current knowledge of the underlying genetic events that lead to uveal melanoma, their implication for the disease course and prognosis, as well as the therapeutic possibilities that arise from targeting these different aberrant pathways.

Innate immune response in retinal homeostasis and inflammatory disorders

Innate immune cells such as neutrophils, monocyte-macrophages and microglial cells are pivotal for the health and disease of the retina. For the maintenance of retinal homeostasis, these cells and immunosuppressive molecules in the eye actively regulate the induction and the expression of inflammation in order to prevent excessive activation and subsequent tissue damage. In the disease context, these regulatory mechanisms are modulated genetically and/or by environmental stimuli such as damage-associated molecular patterns (DAMPs), and a chronic innate immune response regulates or contributes to the formation of diverse retinal disorders such as uveitis, retinitis pigmentosa, retinal vascular diseases and retinal fibrosis. Here we summarize the recent knowledge regarding the innate immune response in both ocular immune regulation and inflammatory retinal diseases, and we describe the potential of the innate immune response as a biomarker and therapeutic target.

Immunological Backbone of Uveal Melanoma: Is There a Rationale for Immunotherapy?

No standard treatment has been established for metastatic uveal melanoma (mUM). Immunotherapy is commonly used for this disease even though UM has not been included in phase III clinical trials with checkpoint inhibitors. Unfortunately, only a minority of patients obtain a clinical benefit with immunotherapy. The immunological features of mUM were reviewed in order to understand if immunotherapy could still play a role for this disease.

Characterization of the Pathophysiological Role of CD47 in Uveal Melanoma

Uveal melanoma (UM) represents the most frequent primary intraocular tumor, however, limited therapeutic options are still available. We have previously shown that cluster of differentiation 47 (CD47) is significantly upregulated in UM cells following inflammatory stimuli and that it represents a predictor of disease progression. Here, we aimed to better characterize the pathophysiological role of CD47 in UM. We show that CD47 is not modulated at different cancer stages, although patients with the lowest expression of CD47 show significant better progression-free survival, after correcting for the presence of BAP1, GNAQ, and GNA11 mutations. By stratifying patients based on the expression of CD47 in the tumor, we observed that patients with high levels of CD47 have a significant increase in immune score as compared to patients with low levels of CD47. In particular, deconvolution analysis of infiltrating immune cell populations revealed that a significantly higher number of CD4+ and CD8+ T cells can be found in patients with high CD47 levels, with the most enriched populations being the Th2, Treg, and CD8+ Tcm cells. We also show that a large number of transcripts are significantly modulated between the groups of patients with high and low levels of CD47, with a significant enrichment of interferon IFN-alpha regulated genes. The results from this study may propel the development of anti-CD47 therapies for UM patients.

Investigation of indoleamine 2,3-dioxygenase 1 expression in uveal melanoma

The purpose of this study was to investigate indoleamine 2,3-dioxygenase 1 (IDO1) expression and its implications in uveal melanoma (UM). Bioinformatics analysis was performed on microarray data (GSE22138 and GSE27831) from the Gene Expression Omnibus (GEO) database to evaluate IDO1 expression in mRNA level. Ninety-two cases in the database were divided into the IDO1-high group (46 cases) and IDO1-low group (46 cases). Paraffin embedded tumor sections from 27 patients with UM were studied by immunofluorescence. The mRNA results showed that IDO1 expression was inversely correlated with tumor thickness (9.93 ± 3.33 mm in IDO1-high group vs. 11.56 ± 2.38 mm in IDO1-low group) (p = 0.016) and metastatic rate (30.4% in IDO1-high group vs. 69.6% in IDO1-low group, p < 0.001). The IDO1-high group showed higher immune cell gene expression: CD3D (6.56 ± 1.0 vs. 5.46 ± 0.53, p < 0.0001), CD4 (4.72 ± 0.4 vs. 4.2 ± 0.42, p < 0.0001), and CD68 (6.17 ± 1.23 vs. 5.53 ± 0.77, p = 0.015). Further analysis showed that immune-suppressive T regulatory cell genes (CD3D, CD4, IL2RA and FOXP3) were expressed in 67.4% (31/46) cases in the IDO1-high group and 23.91% (11/46) cases in the IDO1-low group. In addition, IDO1 and interferon gamma (IFNG) mRNA expression were strongly correlated (r = 0.70, p < 0.0001). The correlation analysis of different immune checkpoints showed that IDO1 was positively correlated with CD274(PDL1), but not CTLA4 or PDCD1.The disease-free survival (DFS) in the IDO1-high/IFNG-high group was better than that of the IDO1-low/IFNG-low group. The IDO1 immunostaining result showed that 2 cases in 18 UMs with Bruch's membrane (BM) rupture and 7 out of 9 cases without BM rupture were scored high (Grade 2-3) (p = 0.001). Comparing the immune cells staining results between IDO1-high group and IDO1-low group, higher percentage of patients in the former group had high levels of T cells and macrophages infiltration, but only the difference in macrophage was statistically significant (CD68, 77.78% vs. 27.78%, p = 0.04). The analysis based on GEO data and the result from immunostaining study are consistent with each other. In conclusion, the expression of IDO1 is probably induced by IFNγ from infiltrated immune cells in UM. BM rupture is an important indicator of IDO1 expression level and distribution pattern. The complex role of IDO1 may limit its therapeutic effect in UM.

Orbital metastases of invasive lobular breast carcinoma

Breast cancer is the main site of origin of orbital metastatic disease. Although invasive lobular breast carcinoma accounts for 10-15% of all breast cancer cases, it has been noticed that it metastasizes to the orbit more often compared to breast cancer of no special type (NST). The pathogenesis of this metastasis is not entirely understood; however, it seems that the unique tissue-specific characteristics of orbital microenvironment might contribute to metastatic disease in this particular site. Given the increasing survival of breast cancer patients and the prolonged metastatic potential of invasive lobular breast carcinoma, it is possible that the incidence of this rare metastasis might increase in the future. The purpose of this review is to present clinical manifestations, immunohistochemical characteristics and therapeutic options for orbital metastases from invasive lobular carcinoma.

Immune privilege: failure of immunotherapy in controlling metastatic cutaneous melanoma to the eye

This report concerns a 49-year-old female with cutaneous malignant melanoma and systemic metastases. These resolved following combination immunotherapy with ipilimumab and nivolumab. She subsequently experienced unilateral floaters, an increase in iris pigmentation and pigmentary glaucoma. The eye progressively lost vision and became painful due to iris neovascularization. The clinical diagnosis was of cutaneous melanoma metastatic to the vitreous, ciliary body and iris. Enucleation was performed for symptom control, with histopathology confirming the clinical diagnosis. The immune privilege of the eye may preclude ocular metastasis control with immunotherapy. Ocular symptoms in such patients merit referral to an ophthalmologist.

Programmed cell death ligand-1 expression in tumor and immune cells is associated with better patient outcome and decreased tumor-infiltrating lymphocytes in uveal melanoma

Programmed cell death-1/ligand (PD-1/PD-L1) interaction negatively regulates T cell activity. PD-L1 expression in tumor cells, antigen-presenting cells, and lymphocytes of the tumor microenvironment is associated with response to treatment with PD-1/PD-L1 inhibitors, but there is still debate on the cutoff value that correlates with responders. In uveal melanoma (UM), 40% of patients will develop liver metastases and, amongst them, 90% will succumb to their disease. The aim of this study was to analyze PD-L1 expression as a prognostic marker and as a possible therapeutic target for UM. Sixty-seven enucleated eyes from UM patients with relevant clinical information were analyzed. Univariate and multivariate analysis were used to evaluate association of PD-L1 with survival. PD-L1 expression was positive relatively to tumor cells, immune cells, and the tumor and tumor-infiltrating immune cell group scoring in 46, 34 and 55% of the cases, respectively. On univariate analysis, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with a longer metastasis-free survival (P = 0.04 and P = 0.007). However, on multivariate analysis, only the tumor and tumor-infiltrating immune cell group positivity was associated with longer metastasis-free survival (P = 0.01). Furthermore, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with decreased tumor-infiltrating lymphocytes (P = 0.02). PD-L1, when expressed in uveal melanoma, is associated with better patient outcome and decreased tumor-infiltrating lymphocytes. These results support the consideration of anti-PD-1/PD-L1 therapy in uveal melanoma. To determine the best cutoff value, further studies from patients enrolled in clinical trials treated with PD-1/PD-L1 inhibitors are necessary.

High expression of PD-1 and PD-L1 in ocular adnexal sebaceous carcinoma

Ocular adnexal sebaceous carcinoma (OASC) is an aggressive malignancy that frequently recurs locally and metastasizes. Surgical extirpation may produce significant aesthetic morbidity, and effective systemic therapies for locally advanced or metastatic disease are largely ineffective. Immune checkpoint inhibitors have shown efficacy in the management of several solid tumors where tumor cell PD-L1 expression correlates with improved response. To determine whether OASC might be amenable to immune checkpoint blockade, we performed comprehensive immune profiling for CD3, CD8, PD-1, FOXP3, and PD-L1 in 24 patients with primary OASC. The composition, distribution and density of the tumor associated immune infiltrate were quantified by automated image analysis and correlated with measures of clinical outcome. Tumor cells in 12 OASCs (50%) expressed PD-L1. Higher densities of CD3+ (p = 0.01), CD8+ (p = 0.006), and PD-1+ (p = 0.024) tumor-associated T cells were associated with higher T category (≥T3a per the 7th edition of the American Joint Committee on Cancer staging manual). Higher tumor cell expression of PD-L1 correlated with higher density of PD-1+ tumor-associated T cells (p = 0.021). Since a CD3+ CD8+ PD-1 + T-cell infiltrate represents a "suppressed T-cell phenotype" apparently permissive toward OASC progression, our findings provide a mechanistic rationale for the effective application of immune checkpoint blockade in OASC to abrogate PD-1/PD-L1 interaction and effectively unleash the immune infiltrate to treat higher-stage tumors.

Immunotherapy for the Treatment of Uveal Melanoma: Current Status and Emerging Therapies

PURPOSE OF REVIEW

Uveal melanoma is a distinct subset of melanoma with a biology and treatment approach that is unique from that of cutaneous melanoma. Here we will review the current data evaluating immunotherapies in both the adjuvant and metastatic settings in uveal melanoma.

RECENT FINDINGS

In the adjuvant setting, interferon demonstrated no survival benefit in uveal melanoma, and studies evaluating immune-based strategies such as vaccine therapy are ongoing. Anti-CTLA-4 and anti-PD-1/ PD-L1 blockade in uveal melanoma have been evaluated in several small prospective and/or retrospective studies with rare responses and no overall survival benefit demonstrated. Ongoing studies evaluating combination checkpoint inhibition and other antibody-based therapies are ongoing. Although immunotherapy with anti-CTLA-4 and anti-PD-1 agents has dramatically changed the treatment approach to cutaneous melanoma, its success in uveal melanoma has been much more limited. Clinical trial participation should be prioritized in patients with uveal melanoma.