Intra- and intertumoral heterogeneity of liver metastases in a patient with uveal melanoma revealed by single-cell RNA sequencing

WNT11 Promotes immune evasion and resistance to Anti-PD-1 therapy in liver metastasis

Liver metastasis (LM) poses a significant challenge in cancer treatment, with limited available therapeutic options and poor prognosis. Understanding the dynamics of tumor microenvironment (TME) and immune interactions is crucial for developing effective treatments. We find that WNT11 promoted CD8+ T-cell exclusion and suppression, which was correlated with poor prognosis in LM. Mechanistically, WNT11-overexpressing tumor cells directly reduce CD8+ T-cell recruitment and activity by decreasing CXCL10 and CCL4 expression through CAMKII-mediated β-catenin/AFF3 downregulation. WNT11-overexpressing tumor cells promote immunosuppressive macrophage polarization by inducing IL17D expression via the CAMKII/NF-κB pathway, which result in CD8+ T-cell suppression. Moreover, CAMKII inhibition increases the efficacy of anti-PD-1 therapy in mouse model of LM. Serum expression of WNT11 is identified as a potential minimally invasive biomarker in the management of colorectal cancer-LM with immunotherapy. Our findings highlight WNT11/CAMKII axis as a critical regulator of the TME and a promising target for immunotherapy in patients with LM.

Dysfunction of Endothelial Cell-Mediated Intercellular Communication and Metabolic Pathways in Age-Related Macular Degeneration

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, but the therapies are not satisfactory. This study aimed to find AMD specific features through the analysis of high-throughput sequencing.

METHODS

In this study, we integrated six projects containing single-cell RNA sequencing (scRNA-seq) data to perform a comprehensive analysis for AMD samples in the tissues of retina and retinal pigment epithelium/choroid, and in the positions of macula and periphery. Differentially expressed genes (DEGs) were analyzed and crucial signaling pathways were identified across cell types and between the macula and periphery. The intercellular signaling transduction among cell types were inferred by "CellChat" to build cell-cell communication network under normal and AMD conditions, and verified at the transcriptional level. The CD31+ endothelial cells were obtained to evaluate the enrichment of KEGG pathways in atrophic and neovascular AMD, and GSVA was adopted to discover differential metabolic signals in each AMD type.

RESULTS

Thirteen major cell types were identified in the integrated scRNA-seq data. Although no disease-specific cell type or differential cell proportion was found, DEGs and enriched pathways were shown in cell-type- and position-dependent manners. Severe impairment of endothelial cell-mediated cell interactions was found in the signaling transduction network of the macula, and compromised cell interactions were observed in the periphery. Furthermore, distinct signaling pathways and metabolic states were uncovered in atrophic and neovascular AMD. Striking reduction in energy metabolism, lipid metabolism, and oxidative stress was indicated in the atrophic AMD.

CONCLUSION

Conclusively, we discover aberrant signals and metabolic pathways in AMD samples, providing insight into mechanisms and potential therapeutic targets for the AMD treatment.

Single-cell and bulk transcriptome analysis reveals tumor cell heterogeneity and underlying molecular program in uveal melanoma

BACKGROUND

Uveal melanoma (UM) is a rare and deadly eye cancer with high metastatic potential. Despite the predominance of malignant cells within the tumor microenvironment, the heterogeneity and underlying molecular features remain to be fully characterized.

METHODS

We analyzed single-cell transcriptomic profiling of 37,660 malignant cells from 17 UM tumors. A consensus non-negative factorization algorithm was used to decipher transcriptional programs underlying tumor cell-intrinsic heterogeneity. Tumor-infiltrated immune cells were computationally estimated from bulk transcriptomes and bioinformatics methods. A gene signature was derived for subtyping and prognostic stratification and validated in multicenter cohorts.

RESULTS

ScRNA-seq analysis revealed the existence of diverse subpopulations and transcriptional variability among malignant cells within and between tumors. Furthermore, we observed that the heterogeneity of malignant cell states and compositions correlated with genomic, immunological, and clinical characteristics. By identifying gene expression programs associated with malignant cell heterogeneity at the single cell level, UM samples were classified into two distinct intra-tumoral subtypes (ITMHlo and ITMHhi) with different prognoses and immune microenvironments. Finally, a machine learning-derived 9-gene signature was developed to translate single-cell information into bulk tissue transcriptomes for patient stratification and was validated in multicenter cohorts.

CONCLUSIONS

Our study provides insight into understanding the intra-tumoral heterogeneity of UM and its potential impact on patient stratification.

Immunotherapy response and resistance in patients with advanced uveal melanoma: a retrospective cohort study

Metastatic uveal melanoma (mUM) is associated with poor prognosis. Ipilimumab/nivolumab has shown antitumor efficacy in phase II studies. Tebentafusp resulted in longer overall survival (OS) compared to investigator`s choice in a phase III study. We sought to describe the radiological response patterns of mUM patients treated with immunotherapy. Patients with mUM treated with ipilimumab/nivolumab and tebentafusp between July 2018 and December 2022, with available radiological assessment per RECISTv1.1 and/or imPERCIST5, were retrospectively identified and included. Progression-free survival (PFS) and OS rates, liver-specific response and pathological assessment in available liver biopsies were evaluated. In the ipilimumab/nivolumab group, median PFS (mPFS) was 2.9 months (95% CI 2.2-28.6) and mOS 28.9 months (95% CI 12.7-NR). Complete (CMR) and partial (PMR) metabolic response per imPERCIST5, and partial response (PR) per RECISTv1.1 were associated with longer PFS and OS by trend, compared to morphologically and metabolically stable or progressive disease. In the tebentafusp group, mPFS was 2.7 months (95% CI 2.2-3) and mOS 18.6 months (95% CI 11.5-NR). PMR and PR were associated with longer PFS by trend. In both treatments, the overall treatment response was associated with the radiological response at the liver site. In available liver tumor biopsies, differences in pathological and radiological responses were noted. ImPERCIST5 and RECIST v1.1 are valuable tools in the radiological response assessment, but both methods display limitations. Accurate biomarkers to stratify patients at risk for disease progression and future translational studies to investigate mechanisms of response and resistance are required.

Patient-derived xenografts and single-cell sequencing identifies three subtypes of tumor-reactive lymphocytes in uveal melanoma metastases

Uveal melanoma (UM) is a rare melanoma originating in the eye's uvea, with 50% of patients experiencing metastasis predominantly in the liver. In contrast to cutaneous melanoma, there is only a limited effectiveness of combined immune checkpoint therapies, and half of patients with uveal melanoma metastases succumb to disease within 2 years. This study aimed to provide a path toward enhancing immunotherapy efficacy by identifying and functionally validating tumor-reactive T cells in liver metastases of patients with UM. We employed single-cell RNA-seq of biopsies and tumor-infiltrating lymphocytes (TILs) to identify potential tumor-reactive T cells. Patient-derived xenograft (PDX) models of UM metastases were created from patients, and tumor sphere cultures were generated from these models for co-culture with autologous or MART1-specific HLA-matched allogenic TILs. Activated T cells were subjected to TCR-seq, and the TCRs were matched to those found in single-cell sequencing data from biopsies, expanded TILs, and in livers or spleens of PDX models injected with TILs. Our findings revealed that tumor-reactive T cells resided not only among activated and exhausted subsets of T cells, but also in a subset of cytotoxic effector cells. In conclusion, combining single-cell sequencing and functional analysis provides valuable insights into which T cells in UM may be useful for cell therapy amplification and marker selection.

Single cell RNA-sequencing in uveal melanoma: advances in heterogeneity, tumor microenvironment and immunotherapy

Uveal melanoma (UM) is a highly aggressive and fatal tumor in the eye, and due the special biology of UM, immunotherapy showed little effect in UM patients. To improve the efficacy of immunotherapy for UM patients is of great clinical importance. Single-cell RNA sequencing(scRNA-seq) provides a critical perspective for deciphering the complexity of intratumor heterogeneity and tumor microenvironment(TME). Combing the bioinformatics analysis, scRNA-seq could help to find prognosis-related molecular indicators, develop new therapeutic targets especially for immunotherapy, and finally to guide the clinical treatment options.

ITGB2-ICAM1 axis promotes liver metastasis in BAP1-mutated uveal melanoma with retained hypoxia and ECM signatures

PURPOSE

Uveal melanoma (UM) with BAP1 inactivating mutations has a high risk of metastasis, but the mechanism behind BAP1 deficiency driving UM metastasis is unknown.

METHODS

We analyzed the single-cell RNA sequencing (scRNA-Seq) data comprised primary and metastatic UM with or without BAP1 mutations (MUTs) to reveal inter- and intra-tumor heterogeneity among different groups. Then, an immune-competent mouse liver metastatic model was used to explore the role of ITGB2-ICAM1 in BAP1-associated UM metastasis.

RESULTS

Cluster 1 tumor cells expressed high levels of genes linked to tumor metastasis, such as GDF15, ATF3, and CDKN1A, all of which are associated with poor prognosis. The strength of communication between terminally exhausted CD8+ T cells and GDF15hiATF3hiCDKN1Ahi tumor cells was enhanced in BAP1-mutated UM, with CellChat analysis predicting strong ITGB2-ICAM1 signaling between them. High expression of either ITGB2 or ICAM1 was a worse prognostic indicator. Using an immune-competent mouse liver metastatic model, we indicated that inhibiting either ICAM1 or ITGB2 prevented liver metastasis in the BAP1-mutated group in vivo. The inhibitors primarily inhibited hypoxia- and ECM-related pathways indicated by changes in the expression of genes such as ADAM8, CAV2, ENO1, PGK1, LOXL2, ITGA5, and VCAN. etc. CONCLUSION: This study suggested that the ITGB2-ICAM1 axis may play a crucial role for BAP1-associated UM metastasis by preserving hypoxia- and ECM- related signatures, which provide a potential strategy for preventing UM metastasis in patients with BAP1 mutation.

Heterogeneity and molecular landscape of melanoma: implications for targeted therapy

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

Uveal melanoma modeling in mice and zebrafish

Despite extensive research and refined therapeutic options, the survival for metastasized uveal melanoma (UM) patients has not improved significantly. UM, a malignant tumor originating from melanocytes in the uveal tract, can be asymptomatic and small tumors may be detected only during routine ophthalmic exams; making early detection and treatment difficult. UM is the result of a number of characteristic somatic alterations which are associated with prognosis. Although UM morphology and biology have been extensively studied, there are significant gaps in our understanding of the early stages of UM tumor evolution and effective treatment to prevent metastatic disease remain elusive. A better understanding of the mechanisms that enable UM cells to thrive and successfully metastasize is crucial to improve treatment efficacy and survival rates. For more than forty years, animal models have been used to investigate the biology of UM. This has led to a number of essential mechanisms and pathways involved in UM aetiology. These models have also been used to evaluate the effectiveness of various drugs and treatment protocols. Here, we provide an overview of the molecular mechanisms and pharmacological studies using mouse and zebrafish UM models. Finally, we highlight promising therapeutics and discuss future considerations using UM models such as optimal inoculation sites, use of BAP1mut-cell lines and the rise of zebrafish models.

Detection of metastases using circulating tumour DNA in uveal melanoma

BACKGROUND

Approximately 50% of uveal melanoma (UM) patients will develop metastatic disease depending on the genetic features of the primary tumour. Patients need 3-12 monthly scans, depending on their prognosis, which is costly and often non-specific. Circulating tumour DNA (ctDNA) quantification could serve as a test to detect and monitor patients for early signs of metastasis and therapeutic response.

METHODS

We assessed ctDNA as a biomarker in three distinct UM cohorts using droplet-digital PCR: (A) a retrospective analysis of primary UM patients to predict metastases; (B) a prospective analysis of UM patients after resolution of their primary tumour for early detection of metastases; and (C) monitoring treatment response in metastatic UM patients.

RESULTS

Cohort A: ctDNA levels were not associated with the development of metastases. Cohort B: ctDNA was detected in 17/25 (68%) with radiological diagnosis of metastases. ctDNA was the strongest predictor of overall survival in a multivariate analysis (HR = 15.8, 95% CI 1.7-151.2, p = 0.017). Cohort C: ctDNA monitoring of patients undergoing immunotherapy revealed a reduction in the levels of ctDNA in patients with combination immunotherapy.

CONCLUSIONS

Our proof-of-concept study shows the biomarker feasibility potential of ctDNA monitoring in for the clinical management of uveal melanoma patients.

Single-cell sequencing in primary intraocular tumors: understanding heterogeneity, the microenvironment, and drug resistance

Retinoblastoma (RB) and uveal melanoma (UM) are the most common primary intraocular tumors in children and adults, respectively. Despite continued increases in the likelihood of salvaging the eyeball due to advancements in local tumor control, prognosis remains poor once metastasis has occurred. Traditional sequencing technology obtains averaged information from pooled clusters of diverse cells. In contrast, single-cell sequencing (SCS) allows for investigations of tumor biology at the resolution of the individual cell, providing insights into tumor heterogeneity, microenvironmental properties, and cellular genomic mutations. SCS is a powerful tool that can help identify new biomarkers for diagnosis and targeted therapy, which may in turn greatly improve tumor management. In this review, we focus on the application of SCS for evaluating heterogeneity, microenvironmental characteristics, and drug resistance in patients with RB and UM.

Dysfunctional intercellular communication and metabolic signaling pathways in thin endometrium

Background: The endometrial thickness is a key factor for successful implantation. Thin endometrium is associated with lower implantation rate and pregnancy rate. Lacking of a better understanding for the cellular and molecular mechanisms of thin endometrium, managing patients with thin endometrium still represents a major challenge for clinicians. Methods: In this study, we combined four single-cell RNA sequencing (scRNA-seq) and one bulk sequencing (bulk-seq) data for thin endometrium to perform an integrated analysis for endometrial cells in proliferating phase. Cell proportion and differentially expressed genes (DEGs) were analyzed to determine the disease-specific cell type and signaling pathways. The cell-cell communication among cell types were inferred by "CellChat" to illustrate the differential intercellular communication under normal and thin endometrium conditions. GSEA and GSVA were applied to identify dysfunctional signals and metabolic pathways before and after thin endometrium. Results: Integration of scRNA-seq identified eight cell types. The proportion of stromal cells showed a significant difference between normal and thin endometrial tissue. The DEGs in diverse cell types revealed enriched pathways in a cell-specific manner. Aberrant cell-cell signaling transduction was found in almost all cell types, especially in immune cells and epithelial cells. Furthermore, dysfunctional metabolic signaling pathways were induced in a cell-type dependent way. The down-regulation of carbohydrate metabolism and nucleotide metabolism was observed and the energy metabolism switch was indicated. Conclusion: Conclusively, we discover dysfunctional signals and metabolic pathways in thin endometrium, providing insight into mechanisms and therapeutic strategies for the atrophic endometrium.

Integration of Bulk RNA Sequencing and Single-Cell RNA Sequencing to Reveal Uveal Melanoma Tumor Heterogeneity and Cells Related to Survival

Molecular classification based on transcriptional characteristics is often used to study tumor heterogeneity. Human cancer has different cell populations with distinct transcription in tumors, and their heterogeneity is the focus of tumor therapy. Our purpose was to explore the tumor heterogeneity of uveal melanoma (UM) through RNA sequencing (RNA-seq) and single-cell RNA sequencing (scRNA-seq). Based on the consensus clustering assays of the prognosis-related immune gene set, the immune subtype (IS) of UM and its corresponding immune characteristics were comprehensively analyzed. The heterogeneous cell groups and corresponding marker genes of UM were identified from GSE138433 using scRNA-seq analysis. Pseudotime trajectory analysis and SCENIC analysis were conducted to explore the trajectory of cell differentiation and the regulatory network of single-cell transcription factors (TFs). Based on 37 immune gene sets, UM was divided into two different immune subtypes (IS1 and IS2). The two kinds of ISs have different characteristics in prognosis, immune-related molecules, immune score, and immune cell infiltration. According to 11,988 cells of scRNA-seq data from six UM samples, 11 cell clusters and 10 cell types were identified. The subsets of C1, C4, C5, C8, and C9 were related to the prognosis of UM, and different TF–target gene regulatory networks were involved. These five cell subsets differentiated into 3 different states. Our results provided valuable information about the heterogeneity of UM tumors and the expression patterns of TFs in different cell types.

Prognostic Biomarkers in Uveal Melanoma: The Status Quo, Recent Advances and Future Directions

Simple Summary

Although rare, uveal melanoma (UM) is the most common cancer that develops inside adult eyes. The prognosis is poor, since 50% of patients will develop lethal metastases in the first decade, especially to the liver. Once metastases are detected, life expectancy is limited, given that the available treatments are mostly unsuccessful. Thus, there is a need to find methods that can accurately predict UM prognosis and also effective therapeutic strategies to treat this cancer. In this manuscript, we initially compile the current knowledge on epidemiological, clinical, pathological and molecular features of UM. Then, we cover the most relevant prognostic factors currently used for the evaluation and follow-up of UM patients. Afterwards, we highlight emerging molecular markers in UM published over the last three years. Finally, we discuss the problems preventing meaningful advances in the treatment and prognostication of UM patients, as well as forecast new roadblocks and paths of UM-related research.

Abstract

Uveal melanoma (UM) is the most common malignant intraocular tumour in the adult population. It is a rare cancer with an incidence of nearly five cases per million inhabitants per year, which develops from the uncontrolled proliferation of melanocytes in the choroid (≈90%), ciliary body (≈6%) or iris (≈4%). Patients initially present either with symptoms like blurred vision or photopsia, or without symptoms, with the tumour being detected in routine eye exams. Over the course of the disease, metastases, which are initially dormant, develop in nearly 50% of patients, preferentially in the liver. Despite decades of intensive research, the only approach proven to mildly control disease spread are early treatments directed to ablate liver metastases, such as surgical excision or chemoembolization. However, most patients have a limited life expectancy once metastases are detected, since there are limited therapeutic approaches for the metastatic disease, including immunotherapy, which unlike in cutaneous melanoma, has been mostly ineffective for UM patients. Therefore, in order to offer the best care possible to these patients, there is an urgent need to find robust models that can accurately predict the prognosis of UM, as well as therapeutic strategies that effectively block and/or limit the spread of the metastatic disease. Here, we initially summarized the current knowledge about UM by compiling the most relevant epidemiological, clinical, pathological and molecular data. Then, we revisited the most important prognostic factors currently used for the evaluation and follow-up of primary UM cases. Afterwards, we addressed emerging prognostic biomarkers in UM, by comprehensively reviewing gene signatures, immunohistochemistry-based markers and proteomic markers resulting from research studies conducted over the past three years. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues of research in UM.

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.