bims-meladi 2021-06-20 papers

bims-meladi

Biomed News

on Melanocytes in development and disease

Issue of 2021‒06‒20
thirty-six papers selected by
Farah Jaber-Hijazi
University of the West of Scotland

BRN2 is a non-canonical melanoma tumor-suppressor.
Case Report: Rechallenge With BRAF and MEK Inhibitors in Metastatic Melanoma: A Further Therapeutic Option in Salvage Setting?
Cutaneous Melanoma Classification: The Importance of High-Throughput Genomic Technologies.
Prediction of Immune-Checkpoint Blockade Monotherapy Response in Patients With Melanoma Based on Easily Accessible Clinical Indicators.
Langerhans Cells as Morphologic Mimickers of Atypical Melanocytes on Reflectance Confocal Microscopy: A Case Report and Review of the Literature.
Inherited duplications of PPP2R3B predispose to nevi and melanoma via a C21orf91-driven proliferative phenotype.
Zwint facilitates melanoma progression by promoting c-Myc expression.
Identification of Genes Related to Immune Infiltration in the Tumor Microenvironment of Cutaneous Melanoma.
Phase I/II clinical trial of adoptive cell transfer of sorted specific T cells for metastatic melanoma patients.
First line immunotherapy extends brain metastasis free survival, improves overall survival, and reduces the incidence of brain metastasis in patients with advanced melanoma.
Gene Instability-Related lncRNA Prognostic Model of Melanoma Patients via Machine Learning Strategy.
AutoEncoder-Based Computational Framework for Tumor Microenvironment Decomposition and Biomarker Identification in Metastatic Melanoma.
Identification of Epithelial-Mesenchymal Transition-Related Prognostic lncRNAs Biomarkers Associated With Melanoma Microenvironment.
Identification of Prognostic alternative splicing signatures and their clinical significance in uveal melanoma.
E3 ubiquitin ligase HECTD2 mediates melanoma progression and immune evasion.
Evolutionary predictability of genetic versus nongenetic resistance to anticancer drugs in melanoma.
Construction of a Promising Tumor-Infiltrating CD8+ T Cells Gene Signature to Improve Prediction of the Prognosis and Immune Response of Uveal Melanoma.
Combination of chemotherapy with BRAF inhibitors results in effective eradication of malignant melanoma by preventing ATM-dependent DNA repair.
Successful encorafenib desensitization in a patient with recurrent metastatic melanoma.
Current Perspectives and Novel Strategies of NRAS-Mutant Melanoma.
The sentinel node invasion level (SNIL) as a prognostic parameter in melanoma.
Routine PET-CT scans provide early and accurate recurrence detection in asymptomatic stage IIB-III melanoma patients.
Single organelle measurements of melanosome pH using the novel ratiometric indicator RpHiMEL.
Identification of Precise Therapeutic Targets and Characteristic Prognostic Genes Based on Immune Gene Characteristics in Uveal Melanoma.
Dermoscopic Predictors of Tumor Thickness in Cutaneous Melanoma: A Retrospective Analysis of 245 Melanomas.
Computer-aided clinical image analysis for non-invasive assessment of tumor thickness in cutaneous melanoma.
Genetic counseling and testing for hereditary causes of melanoma can lead to earlier detection of skin cancer and other malignancies.
Overall survival in metastatic melanoma correlates with pembrolizumab exposure and T cell exhaustion markers.
Cost-Effectiveness Analysis of Adjuvant Therapy for BRAF-Mutant Resected Stage III Melanoma in Medicare Patients.
Immu-Mela: An open resource for exploring immunotherapy-related multidimensional genomic profiles in melanoma.
Electrofulguration assisted dermabrasion is comparable to manual dermabrasion in patients undergoing autologous non-cultured epidermal cell suspension for treatment of stable vitiligo: A randomised controlled trial.
Targeting the mercapturic acid pathway for the treatment of melanoma.
The induction of immunogenic cell death by photodynamic therapy in B16F10 cells in vitro is affected by the concentration of the photosensitizer.
Transcriptomic profiling of tumor microenvironment reveals distinct immune subgroups of metastatic melanoma and its potential implications for immunotherapy.
Emerging role of Tissue Resident Memory T cells in vitiligo: From pathogenesis to therapeutics.
In Situ Tumor Vaccination with Nanoparticle Co-Delivering CpG and STAT3 siRNA to Effectively Induce Whole-Body Antitumor Immune Response.

Nat Commun. 2021 06 17. 12(1): 3707

BRN2 is a non-canonical melanoma tumor-suppressor.

Michael Hamm, Pierre Sohier, Valérie Petit, Jérémy H Raymond, Véronique Delmas, Madeleine Le Coz, Franck Gesbert, Colin Kenny, Zackie Aktary, Marie Pouteaux, Florian Rambow, Alain Sarasin, Nisamanee Charoenchon, Alfonso Bellacosa, Luis Sanchez-Del-Campo, Laura Mosteo, Martin Lauss, Dies Meijer, Eirikur Steingrimsson, Göran B Jönsson, Robert A Cornell, Irwin Davidson, Colin R Goding, Lionel Larue.

While the major drivers of melanoma initiation, including activation of NRAS/BRAF and loss of PTEN or CDKN2A, have been identified, the role of key transcription factors that impose altered transcriptional states in response to deregulated signaling is not well understood. The POU domain transcription factor BRN2 is a key regulator of melanoma invasion, yet its role in melanoma initiation remains unknown. Here, in a BrafV600E PtenF/+ context, we show that BRN2 haplo-insufficiency promotes melanoma initiation and metastasis. However, metastatic colonization is less efficient in the absence of Brn2. Mechanistically, BRN2 directly induces PTEN expression and in consequence represses PI3K signaling. Moreover, MITF, a BRN2 target, represses PTEN transcription. Collectively, our results suggest that on a PTEN heterozygous background somatic deletion of one BRN2 allele and temporal regulation of the other allele elicits melanoma initiation and progression.

DOI: https://doi.org/10.1038/s41467-021-23973-5
Front Oncol. 2021 ;11 645008

Case Report: Rechallenge With BRAF and MEK Inhibitors in Metastatic Melanoma: A Further Therapeutic Option in Salvage Setting?

Anna Stagno, Sabrina Vari, Alessio Annovazzi, Vincenzo Anelli, Michelangelo Russillo, Francesco Cognetti, Virginia Ferraresi.

  Background: The combination of BRAF and MEK inhibitors represents the standard of care treatment for patients with metastatic BRAF-mutated melanoma, notwithstanding the high frequency of emergent resistance. Moreover, therapeutic options outside clinical trials are scarce when patients have progressed after both targeted therapy and therapy with immune checkpoint inhibitors. In this article, we report our experience with targeted therapy rechallenging with BRAF and MEK inhibitors in patients with metastatic BRAF-mutated melanoma after progression with kinase inhibitors and immunotherapy.Methods: Four patients with metastatic BRAF-mutated melanoma were rechallenged with BRAF and MEK inhibitors after progression with targeted therapy and subsequent immunotherapy (checkpoint inhibitors).
Results: Two patients (one of them was heavily pretreated) had partial response over 36 months (with local treatment on oligoprogression disease) and 10 months, respectively. A third patient with multisite visceral disease and high serum levels of lactate dehydrogenase had a short-lived clinical benefit rapidly followed by massive progression of disease (early progressor). The fourth patient, currently on treatment with BRAF/MEK inhibitors, is showing a clinical benefit and radiological stable disease over 3 months of therapy. Adverse events were manageable, similar to those reported during the first targeted therapy; the treatment was better tolerated at rechallenge compared with the first treatment by two out of four patients.

Keywords:  BRAF V600 mutation; BRAF inhibitor; MEK inhibitor; drug resistance; metastatic melanoma; rechallenge; targeted therapy

DOI:  https://doi.org/10.3389/fonc.2021.645008
Front Oncol. 2021 ;11 635488

Cutaneous Melanoma Classification: The Importance of High-Throughput Genomic Technologies.

Cristian Scatena, Daniela Murtas, Sara Tomei.

  Cutaneous melanoma is an aggressive tumor responsible for 90% of mortality related to skin cancer. In the recent years, the discovery of driving mutations in melanoma has led to better treatment approaches. The last decade has seen a genomic revolution in the field of cancer. Such genomic revolution has led to the production of an unprecedented mole of data. High-throughput genomic technologies have facilitated the genomic, transcriptomic and epigenomic profiling of several cancers, including melanoma. Nevertheless, there are a number of newer genomic technologies that have not yet been employed in large studies. In this article we describe the current classification of cutaneous melanoma, we review the current knowledge of the main genetic alterations of cutaneous melanoma and their related impact on targeted therapies, and we describe the most recent high-throughput genomic technologies, highlighting their advantages and disadvantages. We hope that the current review will also help scientists to identify the most suitable technology to address melanoma-related relevant questions. The translation of this knowledge and all actual advancements into the clinical practice will be helpful in better defining the different molecular subsets of melanoma patients and provide new tools to address relevant questions on disease management. Genomic technologies might indeed allow to better predict the biological - and, subsequently, clinical - behavior for each subset of melanoma patients as well as to even identify all molecular changes in tumor cell populations during disease evolution toward a real achievement of a personalized medicine.

Keywords:  DNA; genomics; melanoma; mutations; next-generation sequencing

DOI:  https://doi.org/10.3389/fonc.2021.635488
Front Oncol. 2021 ;11 659754

Prediction of Immune-Checkpoint Blockade Monotherapy Response in Patients With Melanoma Based on Easily Accessible Clinical Indicators.

Hwa Kyung Byun, Jee Suk Chang, Minkyu Jung, Woong Sub Koom, Kee Yang Chung, Byung Ho Oh, Mi Ryung Roh, Kyung Hwan Kim, Choong-Kun Lee, Sang Joon Shin.

  Background: Immune checkpoint blocker (ICB) has shown significant clinical activity in melanoma. However, there are no clinically approved biomarkers to aid patient selection. We aimed to identify patients with advanced or metastatic melanoma who are likely to benefit from ICB monotherapy using easily accessible clinical indicators.Materials and Methods: We retrospectively reviewed the records of 134 patients with advanced or metastatic melanoma who received ICB monotherapy between 2014 and 2018. Prognostic factors of overall survival (OS) and progression-free survival (PFS) were determined using Cox regression analysis.
Results: During the median follow-up of 13.7 months, the median OS and PFS were 18.4 and 3.4 months, respectively. Visceral/central nervous system (CNS) metastasis (OS: adjusted hazards ratio [HR], 1.82; p=.014; PFS: HR, 1.59; p=.024), lymphopenia (<1000 cells/µL) within 3 months (OS: HR, 1.89, p=.006; PFS: HR, 1.70; p=.010), and elevated baseline lactate dehydrogenase (LDH) level (OS: HR, 2.61; p<.001; PFS: HR, 2.66; p<.001) were independent prognostic factors for both poor OS and PFS. Development of immune-related adverse events (irAE; e.g., hypothyroidism or vitiligo) within 6 months showed a trend toward better OS in multivariable analysis (HR, 0.37; p=.058). Patients with normal LDH levels and no visceral/CNS metastasis had a substantially better OS than the others (median, 40.4 vs. 13.6 months; p<.001). Among others, patients who developed irAE within 6 months achieved long-term OS (median, 43.6 vs. 13.1 months; p=.008). A decision tree was suggested using four risk factors, and the risk stratification provided significant distinction between the survival curves.
Conclusion: The four easily accessible clinical indicators associated with better treatment outcomes after ICB monotherapy in patients with advanced or metastatic melanoma were LDH level, the extent of disease, lymphopenia, and irAE. The combined use of these indicators can be clinically useful in improving risk stratification of patients treated with ICB monotherapy.

Keywords:  immune checkpoint blockade; lymphopenia; melanoma; overall survival; predictor

DOI:  https://doi.org/10.3389/fonc.2021.659754
Dermatol Pract Concept. 2021 May;11(3): e2021078

Langerhans Cells as Morphologic Mimickers of Atypical Melanocytes on Reflectance Confocal Microscopy: A Case Report and Review of the Literature.

Nadiya Chuchvara, Lauren Berger, Catherine Reilly, Amin Maghari, Babar K Rao.

  Pagetoid spread of melanocytes in the epidermis is a common indicator of melanocytic atypia, both histopathologically and with reflectance confocal microscopy (RCM). Specifically on RCM, large, bright, atypical dendritic and/or roundish cells are characteristic of melanoma. However, intraepidermal Langerhans cells (ILC) create the potential for diagnostic ambiguity on RCM. We describe one case of a pigmented facial lesion that was initially diagnosed as lentigo maligna (LM) due to numerous atypical perifollicular dendritic cells on RCM. Additionally, we present the findings of a literature review for similar reported cases conducted by searching the following terms on PubMed: reflectance confocal microscopy, RCM, lentigo maligna, melanoma, Langerhans cells, dendritic cells, and atypical cells. In our case, the lesion was determined to be a solar lentigo on histopathology. Immunohistochemistry (IHC) with CD1a identified the atypical-appearing cells as ILC, as it did in 54 reported cases of benign lesions (benign melanocytic nevus, Sutton/halo nevus, labial melanotic macule, and solar lentigo) misdiagnosed as malignant on RCM (melanoma, lip melanoma, lentigo maligna, and LM melanoma). According to our case and the literature, both ILC and atypical melanocytes can present with atypical-appearing dendritic and/or roundish cells under RCM. Currently, there is no method to distinguish the two without IHC. Therefore, the presence of pagetoid cells should continue to alert the confocalist of a potential neoplastic process, prompting biopsy, histopathologic diagnosis, and IHC differentiation.

Keywords:  Langerhans cells; RCM; atypical cells; dendritic cells; reflectance confocal microscopy

DOI:  https://doi.org/10.5826/dpc.1103a78
Genet Med. 2021 Jun 18.

Inherited duplications of PPP2R3B predispose to nevi and melanoma via a C21orf91-driven proliferative phenotype.

Satyamaanasa Polubothu, Davide Zecchin, Lara Al-Olabi, Daniël A Lionarons, Mark Harland, Stuart Horswell, Anna C Thomas, Lilian Hunt, Nathan Wlodarchak, Paula Aguilera, Sarah Brand, Dale Bryant, Cristina Carrera, Hui Chen, Greg Elgar, Catherine A Harwood, Michael Howell, Lionel Larue, Sam Loughlin, Jeff MacDonald, Josep Malvehy, Sara Martin Barberan, Vanessa Martins da Silva, Miriam Molina, Deborah Morrogh, Dale Moulding, Jérémie Nsengimana, Alan Pittman, Joan-Anton Puig-Butillé, Kiran Parmar, Neil J Sebire, Stephen Scherer, Paulina Stadnik, Philip Stanier, Gemma Tell, Regula Waelchli, Mehdi Zarrei, Susana Puig, Véronique Bataille, Yongna Xing, Eugene Healy, Gudrun E Moore, Wei-Li Di, Julia Newton-Bishop, Julian Downward, Veronica A Kinsler.

PURPOSE: Much of the heredity of melanoma remains unexplained. We sought predisposing germline copy-number variants using a rare disease approach.METHODS: Whole-genome copy-number findings in patients with melanoma predisposition syndrome congenital melanocytic nevus were extrapolated to a sporadic melanoma cohort. Functional effects of duplications in PPP2R3B were investigated using immunohistochemistry, transcriptomics, and stable inducible cellular models, themselves characterized using RNAseq, quantitative real-time polymerase chain reaction (qRT-PCR), reverse phase protein arrays, immunoblotting, RNA interference, immunocytochemistry, proliferation, and migration assays.
RESULTS: We identify here a previously unreported genetic susceptibility to melanoma and melanocytic nevi, familial duplications of gene PPP2R3B. This encodes PR70, a regulatory unit of critical phosphatase PP2A. Duplications increase expression of PR70 in human nevus, and increased expression in melanoma tissue correlates with survival via a nonimmunological mechanism. PPP2R3B overexpression induces pigment cell switching toward proliferation and away from migration. Importantly, this is independent of the known microphthalmia-associated transcription factor (MITF)-controlled switch, instead driven by C21orf91. Finally, C21orf91 is demonstrated to be downstream of MITF as well as PR70.
CONCLUSION: This work confirms the power of a rare disease approach, identifying a previously unreported copy-number change predisposing to melanocytic neoplasia, and discovers C21orf91 as a potentially targetable hub in the control of phenotype switching.

DOI: https://doi.org/10.1038/s41436-021-01204-y
Exp Ther Med. 2021 Aug;22(2): 818

Zwint facilitates melanoma progression by promoting c-Myc expression.

Kuanhou Mou, Jian Zhang, Xin Mu, Lijuan Wang, Wenli Liu, Rui Ge.

  ZW10 interactor (Zwint) is upregulated in various types of tumors and exerts a carcinogenic effect. However, little is known about the expression profile, function and molecular mechanisms of action of Zwint in melanoma. Therefore, the aim of the present study was to investigate the expression levels of Zwint in melanoma cell lines and tissues. It was revealed that Zwint was highly expressed in melanoma samples. Functional experiments indicated that Zwint knockdown suppressed the proliferation and migration of A375 melanoma cells. Further mechanistic studies demonstrated that Zwint knockdown decreased the protein expression levels of c-Myc, MMP-2, Slug, mTOR, phosphorylated (p)-mTOR, p-p38 and fibronectin, while it increased the protein expression levels of E-cadherin and MMP-9. Among these genes, c-Myc, MMP-2 and Slug were overexpressed to investigate their effects on cell proliferation following Zwint knockdown. The results demonstrated that overexpression of c-Myc, but not MMP-2 or Slug, rescued the effects of Zwint knockdown on melanoma cell proliferation and migration. Taken together, the results of the present study suggested that Zwint may act as an oncogene in melanoma by regulating c-Myc expression.

Keywords:  ZW10 interactor; c-Myc; melanoma; migration; proliferation

DOI:  https://doi.org/10.3892/etm.2021.10250
Front Oncol. 2021 ;11 615963

Identification of Genes Related to Immune Infiltration in the Tumor Microenvironment of Cutaneous Melanoma.

Rujia Qin, Wen Peng, Xuemin Wang, Chunyan Li, Yan Xi, Zhaoming Zhong, Chuanzheng Sun.

  Cutaneous melanoma (CM) is the leading cause of skin cancer deaths and is typically diagnosed at an advanced stage, resulting in a poor prognosis. The tumor microenvironment (TME) plays a significant role in tumorigenesis and CM progression, but the dynamic regulation of immune and stromal components is not yet fully understood. In the present study, we quantified the ratio between immune and stromal components and the proportion of tumor-infiltrating immune cells (TICs), based on the ESTIMATE and CIBERSORT computational methods, in 471 cases of skin CM (SKCM) obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) were analyzed by univariate Cox regression analysis, least absolute shrinkage, and selection operator (LASSO) regression analysis, and multivariate Cox regression analysis to identify prognosis-related genes. The developed prognosis model contains ten genes, which are all vital for patient prognosis. The areas under the curve (AUC) values for the developed prognostic model at 1, 3, 5, and 10 years were 0.832, 0.831, 0.880, and 0.857 in the training dataset, respectively. The GSE54467 dataset was used as a validation set to determine the predictive ability of the prognostic signature. Protein-protein interaction (PPI) analysis and weighted gene co-expression network analysis (WGCNA) were used to verify "real" hub genes closely related to the TME. These hub genes were verified for differential expression by immunohistochemistry (IHC) analyses. In conclusion, this study might provide potential diagnostic and prognostic biomarkers for CM.

Keywords:  CIBERSORT; ESTIMATE; cutaneous melanoma; prognosis; protein–protein interaction; tumor microenvironment; tumor- infiltrating immune cells; weighted gene co-expression network analysis

DOI:  https://doi.org/10.3389/fonc.2021.615963
Cancer Immunol Immunother. 2021 Jun 12.

Phase I/II clinical trial of adoptive cell transfer of sorted specific T cells for metastatic melanoma patients.

Brigitte Dréno, Amir Khammari, Agnès Fortun, Virginie Vignard, Soraya Saiagh, Tiffany Beauvais, Nicolas Jouand, Sylvain Bercegay, Sylvain Simon, François Lang, Nathalie Labarrière.

  Adoptive cell transfer (ACT) of tumor-specific T lymphocytes represents a relevant therapeutic strategy to treat metastatic melanoma patients. Ideal T-cells should combine tumor specificity and reactivity with survival in vivo, while avoiding autoimmune side effects. Here we report results from a Phase I/II clinical trial (NCT02424916, performed between 2015 and 2018) in which 6 metastatic HLA-A2 melanoma patients received autologous antigen-specific T-cells produced from PBMC, after peptide stimulation in vitro, followed by sorting with HLA-peptide multimers and amplification. Each patient received a combination of Melan-A and MELOE-1 polyclonal specific T-cells, whose specificity and anti-tumor reactivity were checked prior to injection, with subcutaneous IL-2. Transferred T-cells were also characterized in terms of functional avidity, diversity and phenotype and their blood persistence was evaluated. An increase in specific T-cells was detected in the blood of all patients at day 1 and progressively disappeared from day 7 onwards. No serious adverse events occurred after this ACT. Clinically, five patients progressed and one patient experienced a partial response following therapy. Melan-A and MELOE-1 specific T-cells infused to this patient were diverse, of high avidity, with a high proportion of T lymphocytes co-expressing PD-1 and TIGIT but few other exhaustion markers. In conclusion, we demonstrated the feasibility and safety of ACT with multimer-sorted Melan-A and MELOE-1 specific T cells to metastatic melanoma patients. The clinical efficacy of such therapeutic strategy could be further enhanced by the selection of highly reactive T-cells, based on PD-1 and TIGIT co-expression, and a combination with ICI, such as anti-PD-1.

Keywords:  Adoptive cell transfer; MELOE-1; Melan-A; Melanoma; TCR

DOI:  https://doi.org/10.1007/s00262-021-02961-0
Cancer Rep (Hoboken). 2021 Jun 17. e1419

First line immunotherapy extends brain metastasis free survival, improves overall survival, and reduces the incidence of brain metastasis in patients with advanced melanoma.

Xuechen Wang, Benjamin Haaland, Siwen Hu-Lieskovan, Howard Colman, Sheri L Holmen.

  BACKGROUND: Recent advances in targeted therapy and immunotherapy have improved the prognosis of melanoma patients but brain metastasis remains a major challenge. Currently, it is unclear how existing therapies can be best used to prevent or treat brain metastasis in melanoma patients.AIMS: We aimed to assess brain metastasis free survival (BMFS), overall survival (OS), incidence of brain metastases, and sequencing strategies of immunotherapy and targeted therapy in patients with BRAF-mutated advanced melanoma.
METHODS AND RESULTS: We retrospectively analyzed 683 patients with BRAF-mutated advanced melanoma treated with first line (1L) immunotherapy (N = 266) or targeted therapy (N = 417). The primary outcome was BMFS. Secondary outcomes included OS of all patients and incidence of brain metastases in patients without documented brain metastases prior to 1L therapy. The median BMFS was 13.7 months [95% confidence interval (CI): 12.4-16.0] among all patients. The median BMFS for patients receiving 1L immunotherapy was 41.9 months [95% CI: 22.8-not reached (NR)] and targeted therapy was 11.0 months (95% CI: 8.8-12.5). Median OS results were qualitatively similar to BMFS results. The cumulative incidence of brain metastases for patients receiving 1L targeted therapy was higher than for patients receiving 1L immunotherapy (P < .001). Patients receiving 1L anti-CTLA4 plus anti-PD1 combination immunotherapy only or followed by second line (2L) targeted therapy had better BMFS (HR 0.40, 95% CI: 0.24-0.67, P = .001), improved OS (HR 0.49, 95% CI: 0.30-0.81, P = .005), and reduced incidence of brain metastases (HR 0.47, 95% CI: 0.24-0.67, P = .047) than patients receiving 1L combination BRAF and MEK targeted therapy followed by 2L immunotherapy.
CONCLUSION: Patients with advanced BRAF mutant melanoma treated with 1L immunotherapy have significantly longer BMFS and OS, and reduced incidence of brain metastases, compared with those treated with 1L targeted therapy. Further studies evaluating the ability of immunotherapy and targeted therapy to improve OS and prevent brain metastases are warranted.

Keywords:  first line therapy; immunology; melanoma; metastasis; target therapy

DOI:  https://doi.org/10.1002/cnr2.1419
J Oncol. 2021 ;2021 5582920

Gene Instability-Related lncRNA Prognostic Model of Melanoma Patients via Machine Learning Strategy.

Kexin Yan, Yutao Wang, Yining Shao, Ting Xiao.

Background: Melanoma is a common tumor characterized by a high mortality rate in its late stage. After metastasis, current treatment methods are relatively ineffective. Many studies have shown that long noncoding RNA (lncRNA) may participate in gene mutation and genomic instability in cancer.Methods: We downloaded transcriptome data, mutation data, and clinical follow-up data of melanoma patients from The Cancer Genome Atlas. We divided samples into groups according to the number of somatic cell mutations and then performed a differential analysis to screen out the differentially expressed genes. We then divided samples into genomic unstable and genomic stable groups. We compared lncRNA expression profiles in these groups and constructed a protein-coding genes network coexpressed with selected lncRNA to analyze the pathways enriched by these genes. Two machine learning methods, least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE), were applied to conduct the lncRNA-related prognostic model. Afterward, we performed survival analysis, risk correlation analysis, independent prognostic analysis, and clinical subgroup model validation. Finally, through wound healing assay and transwell assay, the function of AATBC was verified by A375 cell lines.
Results: We screened 61 prognostic-related lncRNAs and constructed an lncRNA-mRNA coexpression network based on these lncRNAs. Seven lncRNAs were selected as common characteristic factors based on the two machine learning methods. The model formula was as follows: risk score = 0.085∗AATBC + 0.190∗ AC026689.1-0.117∗AC083799.1 + 0.036∗ AC091544.6-0.039∗ LINC01287-0.291∗ SPRY4.AS1 + 0.056∗ ZNF667.AS1. The seven lncRNAs in this formula are key candidates. Cell experiments have verified that knocking down AATBC in A375 cell lines can reduce the proliferation and invasion ability of melanoma cells.
Conclusion: The lncRNA we identified provides a new way to study lncRNA's role in the genomic instability of melanoma. Our findings may provide essential candidate biomarkers for the diagnosis and treatment of melanoma.

DOI: https://doi.org/10.1155/2021/5582920
Front Genet. 2021 ;12 665065

AutoEncoder-Based Computational Framework for Tumor Microenvironment Decomposition and Biomarker Identification in Metastatic Melanoma.

Yanding Zhao, Yadong Dong, Yongqi Sun, Chao Cheng.

  Melanoma is one of the most aggressive cancer types whose prognosis is determined by both the tumor cell-intrinsic and -extrinsic features as well as their interactions. In this study, we performed systematic and unbiased analysis using The Cancer Genome Atlas (TCGA) melanoma RNA-seq data and identified two gene signatures that captured the intrinsic and extrinsic features, respectively. Specifically, we selected genes that best reflected the expression signals from tumor cells and immune infiltrate cells. Then, we applied an AutoEncoder-based method to decompose the expression of these genes into a small number of representative nodes. Many of these nodes were found to be significantly associated with patient prognosis. From them, we selected two most prognostic nodes and defined a tumor-intrinsic (TI) signature and a tumor-extrinsic (TE) signature. Pathway analysis confirmed that the TE signature recapitulated cytotoxic immune cell related pathways while the TI signature reflected MYC pathway activity. We leveraged these two signatures to investigate six independent melanoma microarray datasets and found that they were able to predict the prognosis of patients under standard care. Furthermore, we showed that the TE signature was also positively associated with patients' response to immunotherapies, including tumor vaccine therapy and checkpoint blockade immunotherapy. This study developed a novel computational framework to capture the tumor-intrinsic and -extrinsic features and identified robust prognostic and predictive biomarkers in melanoma.

Keywords:  SKCM; biomarker; gene expression profile; immunotherapy; tumor microenvironment

DOI:  https://doi.org/10.3389/fgene.2021.665065
Front Cell Dev Biol. 2021 ;9 679133

Identification of Epithelial-Mesenchymal Transition-Related Prognostic lncRNAs Biomarkers Associated With Melanoma Microenvironment.

Bo Xiao, Liyan Liu, Zhuoyuan Chen, Aoyu Li, Pingxiao Wang, Cheng Xiang, Yi Zeng, Hui Li, Tao Xiao.

  Melanoma is the most common cancer of the skin, associated with a worse prognosis and distant metastasis. Epithelial-mesenchymal transition (EMT) is a reversible cellular biological process that plays significant roles in diverse tumor functions, and it is modulated by specific genes and transcription factors. The relevance of EMT-related lncRNAs in melanoma has not been determined. Therefore, RNA expression data and clinical features were collected from the TCGA database (N = 447). Melanoma samples were randomly assigned into the training (315) and testing sets (132). An EMT-related lncRNA signature was constructed via comprehensive analyses of lncRNA expression level and corresponding clinical data. The Kaplan-Meier analysis showed significant differences in overall survival in patients with melanoma in the low and high-risk groups in two sets. Receiver operating characteristic (ROC) curves were used to measure the performance of the model. Cox regression analysis indicated that the risk score was an independent prognostic factor in two sets. Besides, a nomogram was constructed based on the independent variables. Gene Set Enrichment Analysis (GSEA) was applied to evaluate the potential biological functions in the two risk groups. Furthermore, the melanoma microenvironment was evaluated using ESTIMATE and CIBERSORT algorithms in the risk groups. This study indicates that EMT-related lncRNAs can function as potential independent prognostic biomarkers for melanoma survival.

Keywords:  epithelial to mesenchymal transition; lncRNA; melanoma; prognostic; tumor microenvironment

DOI:  https://doi.org/10.3389/fcell.2021.679133
Exp Eye Res. 2021 Jun 12. pii: S0014-4835(21)00232-3. [Epub ahead of print] 108666

Identification of Prognostic alternative splicing signatures and their clinical significance in uveal melanoma.

Wen-Chuan Zhou, Ping Fei, Jing Li.

  As a posttranscriptional regulatory mechanism, alternative splicing (AS) has the potential to generate a large amount of protein diversity from limited genes. The purpose of our study was to assess the usefulness of prognostic splicing events as novel diagnostic and therapeutic signatures for uveal melanoma (UM). The datasets, clinical traits and AS data of UM were obtained from The Cancer Genome Atlas (TCGA) database and TCGA SpliceSeq database. Using bioinformatics analysis, we identified 1047 AS events as candidate AS events closely related to prognosis from 920 parent genes. The gene enrichment analysis indicated that these genes were mainly enriched in cellular components (CC) including cytosol, nucleoplasm, cytoplasm and ribosome, and in molecular functions (MF), including protein binding and poly(A) RNA binding. Furthermore, we selected all survival-associated splicing events to generate prognostic signatures, which included 4 exon skip (ES) events (DNASE1L1-90581-ES, NUDT1-78611-ES, BIN1-55198-ES, SEPN1-1195-ES) and 1 alternate promoter (AP) event (DPYSL2-83132-AP). The AS prognostic model was confirmed as independent overall survival (OS)-related factors (p = 0.014). A total of 17 splicing factors (SFs) involved in the regulation of AS were identified as related to the OS of UM patients. Our pooled data highlighted the usefulness and importance of AS biomarkers, which provided a potential strategy for the diagnosis and treatment of UM.

Keywords:  Alternative splicing; Bioinformatic analysis; Prognostic model; Uveal melanoma

DOI:  https://doi.org/10.1016/j.exer.2021.108666
Oncogene. 2021 Jun 18.

E3 ubiquitin ligase HECTD2 mediates melanoma progression and immune evasion.

Eleonora Ottina, Veera Panova, Laura Doglio, Anastasiya Kazachenka, Georgina Cornish, Joanna Kirkpatrick, Jan Attig, George R Young, Kevin Litchfield, Tom Lesluyes, Peter Van Loo, Charles Swanton, James MacRae, Thomas Tüting, George Kassiotis.

The ubiquitin-proteasome system maintains protein homoeostasis, underpins the cell cycle, and is dysregulated in cancer. However, the role of individual E3 ubiquitin ligases, which mediate the final step in ubiquitin-mediated proteolysis, remains incompletely understood. Identified through screening for cancer-specific endogenous retroviral transcripts, we show that the little-studied E3 ubiquitin ligase HECTD2 exerts dominant control of tumour progression in melanoma. HECTD2 cell autonomously drives the proliferation of human and murine melanoma cells by accelerating the cell cycle. HECTD2 additionally regulates cancer cell production of immune mediators, initiating multiple immune suppressive pathways, which include the cyclooxygenase 2 (COX2) pathway. Accordingly, higher HECTD2 expression is associated with weaker anti-tumour immunity and unfavourable outcome of PD-1 blockade in human melanoma and counteracts immunity against a model tumour antigen in murine melanoma. This central, multifaceted role of HECTD2 in cancer cell-autonomous proliferation and in immune evasion may provide a single target for a multipronged therapy of melanoma.

DOI: https://doi.org/10.1038/s41388-021-01885-4
Cancer Cell. 2021 Jun 07. pii: S1535-6108(21)00281-6. [Epub ahead of print]

Evolutionary predictability of genetic versus nongenetic resistance to anticancer drugs in melanoma.

Oskar Marin-Bejar, Aljosja Rogiers, Michael Dewaele, Julia Femel, Panagiotis Karras, Joanna Pozniak, Greet Bervoets, Nina Van Raemdonck, Dennis Pedri, Toon Swings, Jonas Demeulemeester, Sara Vander Borght, Stefan Lehnert, Francesca Bosisio, Joost J van den Oord, Isabelle Vanden Bempt, Diether Lambrechts, Thierry Voet, Oliver Bechter, Helen Rizos, Mitchell P Levesque, Eleonora Leucci, Amanda W Lund, Florian Rambow, Jean-Christophe Marine.

  Therapy resistance arises from heterogeneous drug-tolerant persister cells or minimal residual disease (MRD) through genetic and nongenetic mechanisms. A key question is whether specific molecular features of the MRD ecosystem determine which of these two distinct trajectories will eventually prevail. We show that, in melanoma exposed to mitogen-activated protein kinase therapeutics, emergence of a transient neural crest stem cell (NCSC) population in MRD concurs with the development of nongenetic resistance. This increase relies on a glial cell line-derived neurotrophic factor-dependent signaling cascade, which activates the AKT survival pathway in a focal adhesion kinase (FAK)-dependent manner. Ablation of the NCSC population through FAK inhibition delays relapse in patient-derived tumor xenografts. Strikingly, all tumors that ultimately escape this treatment exhibit resistance-conferring genetic alterations and increased sensitivity to extracellular signal-regulated kinase inhibition. These findings identify an approach that abrogates the nongenetic resistance trajectory in melanoma and demonstrate that the cellular composition of MRD deterministically imposes distinct drug resistance evolutionary paths.

Keywords:  FAK signaling; cutaneous melanoma; minimal residual disease; neural crest stem cells; nongenetic reprogramming; patient-derived tumor xenografts; single-cell sequencing; therapy resistance

DOI:  https://doi.org/10.1016/j.ccell.2021.05.015
Front Cell Dev Biol. 2021 ;9 673838

Construction of a Promising Tumor-Infiltrating CD8+ T Cells Gene Signature to Improve Prediction of the Prognosis and Immune Response of Uveal Melanoma.

Yifang Sun, Jian Wu, Yonggang Yuan, Yumin Lu, Ming Luo, Ling Lin, Shengsheng Ma.

  Background: CD8+ T cells work as a key effector of adaptive immunity and are closely associated with immune response for killing tumor cells. It is crucial to understand the role of tumor-infiltrating CD8+ T cells in uveal melanoma (UM) to predict the prognosis and response to immunotherapy.Materials and Methods: Single-cell transcriptomes of UM with immune-related genes were combined to screen the CD8+ T-cell-associated immune-related genes (CDIRGs) for subsequent analysis. Next, a prognostic gene signature referred to tumor-infiltrating CD8+ T cells was constructed and validated in several UM bulk RNA sequencing datasets. The risk score of UM patients was calculated and classified into high- or low-risk subgroup. The prognostic value of risk score was estimated by using multivariate Cox analysis and Kaplan-Meier survival analysis. Moreover, the potential ability of gene signature for predicting immunotherapy response was further explored.
Results: In total, 202 CDIRGs were screened out from the single-cell RNA sequencing of GSE139829. Next, a gene signature containing three CDIRGs (IFNGR1, ANXA6, and TANK) was identified, which was considered as an independent prognostic indicator to robustly predict overall survival (OS) and metastasis-free survival (MFS) of UM. In addition, the UM patients were classified into high- and low-risk subgroups with different clinical characteristics, distinct CD8+ T-cell immune infiltration, and immunotherapy response. Gene set enrichment analysis (GSEA) showed that immune pathways such as allograft rejection, inflammatory response, interferon alpha and gamma response, and antigen processing and presentation were all positively activated in low-risk phenotype.
Conclusion: Our work gives an inspiration to explain the limited response for the current immune checkpoint inhibitors to UM. Besides, we constructed a novel gene signature to predict prognosis and immunotherapy responses, which may be regarded as a promising therapeutic target.

Keywords:  CD8+ T cells; immune-related genes; immunotherapy; prognosis; uveal melanoma

DOI:  https://doi.org/10.3389/fcell.2021.673838
Oncogene. 2021 Jun 17.

Combination of chemotherapy with BRAF inhibitors results in effective eradication of malignant melanoma by preventing ATM-dependent DNA repair.

Josune Alonso-Marañón, Alberto Villanueva, Josep Maria Piulats, María Martínez-Iniesta, Laura Solé, Juan Martín-Liberal, Sonia Segura, Ramon M Pujol, Mar Iglesias, Anna Bigas, Fernando Gallardo, Lluís Espinosa.

Invasive malignant melanoma (MM) is an aggressive tumor with no curative therapy in advanced stages. Chemotherapy has not demonstrated its efficacy in MM and current treatment for tumors carrying the most frequent BRAFV600E mutation consists of BRAF inhibitors alone or in combination with MAPK pathway inhibitors. We previously found that BRAF inhibition prevents activation of the DNA-damage repair (DDR) pathway in colorectal cancer thus potentiating the effect of chemotherapy. We now show that different chemotherapy agents inflict DNA damage in MM cells, which is efficiently repaired, associated with activation of the ATM-dependent DDR machinery. Pharmacologic inhibition of BRAF impairs ATM and DDR activation in these cells, leading to sustained DNA damage. Combination treatments involving DNA-damaging agents and BRAF inhibitors increase tumor cell death in vitro and in vivo, and impede MM regrowth after treatment cessation. We propose to reconsider the use of chemotherapy in combination with BRAF inhibitors for MM treatment.

DOI: https://doi.org/10.1038/s41388-021-01879-2
Melanoma Res. 2021 Jun 14.

Successful encorafenib desensitization in a patient with recurrent metastatic melanoma.

Grace D Cullen, Heidi D Finnes, Svetomir N Markovic, Gerald W Volcheck.

Type I hypersensitivity reactions (HSR) to dabrafenib are rare but have been previously described. We present a case where a 72-year-old woman with recurrent, metastatic BRAF-mutated melanoma developed a type I HSR to dabrafenib. We, therefore, developed a desensitization protocol with encorafenib, a similar class agent, to allow the patient to continue with treatment. Patients with a history of HSR to dabrafenib may be considered for encorafenib desensitization when other therapeutic options are limited.

DOI: https://doi.org/10.1097/CMR.0000000000000757
Onco Targets Ther. 2021 ;14 3709-3719

Current Perspectives and Novel Strategies of NRAS-Mutant Melanoma.

Alejandro Garcia-Alvarez, Carolina Ortiz, Eva Muñoz-Couselo.

  Melanoma is the deadliest cutaneous cancer. Activating mutations in NRAS are found in 20% of melanomas. NRAS-mutant melanoma is more aggressive and, therefore, has poorer outcomes, compared to non-NRAS-mutant melanoma. Despite promising preclinical data, to date immune checkpoint inhibitors remain the standard of care for locally advanced unresectable or metastatic NRAS melanoma. Data for efficacy of immunotherapy for NRAS melanoma mainly come from retrospective cohorts with divergent conclusions. MEK inhibitors have been the most developed targeted therapy approach. Although associated with an increase in progression-free survival, MEK inhibitors do not provide any benefit in terms of overall survival. Combination strategies with PI3K-AKT-mTOR pathway and CDK4/6 inhibitors seem to increase MEK inhibitors' benefit. Nevertheless, results from clinical trials are still prelaminar. A greater comprehension of the biology and intracellular interactions of NRAS-mutant melanoma will outline novel impactful strategies which could improve prognosis of these subgroup of patients.

Keywords:  MEK inhibitor; NRAS mutation; immunotherapy; metastatic melanoma

DOI:  https://doi.org/10.2147/OTT.S278095
Mod Pathol. 2021 Jun 15.

The sentinel node invasion level (SNIL) as a prognostic parameter in melanoma.

Lutz Kretschmer, Christina Mitteldorf, Simin Hellriegel, Andreas Leha, Alexander Fichtner, Philipp Ströbel, Michael P Schön, Felix Bremmer.

Sentinel lymph node (SN) tumor burden is becoming increasingly important and is likely to be included in future N classifications in melanoma. Our aim was to investigate the prognostic significance of melanoma infiltration of various anatomically defined lymph node substructures. This retrospective cohort study included 1250 consecutive patients with SN biopsy. The pathology protocol required description of metastatic infiltration of each of the following lymph node substructures: intracapsular lymph vessels, subcapsular and transverse sinuses, cortex, paracortex, medulla, and capsule. Within the SN with the highest tumor burden, the SN invasion level (SNIL) was defined as follows: SNIL 1 = melanoma cells confined to intracapsular lymph vessels, subcapsular or transverse sinuses; SNIL 2 = melanoma infiltrating the cortex or paracortex; SNIL 3 = melanoma infiltrating the medulla or capsule. We classified 338 SN-positive patients according to the non-metric SNIL. Using Kaplan-Meier estimates and Cox models, recurrence-free survival (RFS), melanoma-specific survival (MSS) and nodal basin recurrence rates were analyzed. The median follow-up time was 75 months. The SNIL divided the SN-positive population into three groups with significantly different RFS, MSS, and nodal basin recurrence probabilities. The MSS of patients with SNIL 1 was virtually identical to that of SN-negative patients, whereas outgrowth of the metastasis from the parenchyma into the fibrous capsule or the medulla of the lymph node indicated a very poor prognosis. Thus, the SNIL may help to better assess the benefit-risk ratio of adjuvant therapies in patients with different SN metastasis patterns.

DOI: https://doi.org/10.1038/s41379-021-00835-5
Eur J Surg Oncol. 2021 Jun 06. pii: S0748-7983(21)00573-4. [Epub ahead of print]

Routine PET-CT scans provide early and accurate recurrence detection in asymptomatic stage IIB-III melanoma patients.

Neel Maria Helvind, Catalina Aurora Aros Mardones, Lisbet Rosenkrantz Hölmich, Helle Westergren Hendel, Pernille Envold Bidstrup, Jens Ahm Sørensen, Annette Hougaard Chakera.

  INTRODUCTION: The use of routine imaging with 18F-FDG PET-CT (PET-CT) in melanoma surveillance is debated and evidence of its diagnostic value and yield in asymptomatic patients is limited. Denmark introduced nationwide routine surveillance with PET-CT in high-risk patients in 2016. The aim of this study was to examine the sensitivity, specificity, negative and positive predictive values, numbers-needed-to-scan and clinical impact of routine PET-CT in the surveillance of asymptomatic stage IIB-III melanoma patients.MATERIALS AND METHODS: Data was retrieved from the population-based Danish Melanoma Database and patient records. All patients diagnosed with stage IIB-III melanoma at two University Hospitals in 2016 and 2017 were included. Patients underwent surveillance with clinical examinations and PET-CT scans at 6, 12, 24 and 36 months.
RESULTS: In 138 patients, 243 routine PET-CTs were performed within a median follow-up time of 17.7 months. Routine PET-CT detected recurrence at least once in 25 patients (18.1%), including distant recurrence in 19 patients (13.8%). Stage IIB patients had the lowest recurrence rate (11.1%). Numbers-needed-to-scan to detect one distant recurrence was 12.8 patients and median time-to-recurrence was 6.8 months. Sensitivity was 100%, specificity was 94.7% and negative and positive predictive values were 100% and 74.4%, respectively. False positive findings prompted 22 additional investigations (of which ten invasive) in 17 patients (12.3%).
CONCLUSION: Routine PET-CT has a high sensitivity and specificity when used in high-risk melanoma surveillance. Time-to-recurrence and stage-specific recurrence rates indicate high gain of early routine imaging at six months especially for stage IIC and III patients.

Keywords:  18F-FDG PET-CT; Asymptomatic recurrence; Melanoma; Routine imaging; Surveillance

DOI:  https://doi.org/10.1016/j.ejso.2021.06.011
Methods Enzymol. 2021 ;pii: S0076-6879(21)00116-6. [Epub ahead of print]654 315-344

Single organelle measurements of melanosome pH using the novel ratiometric indicator RpHiMEL.

Jessica L Scales, Donald C Koroma, Elena Oancea.

  Melanocytes are specialized cells that produce melanin pigments responsible for skin, hair, and eye pigmentation. The synthesis and storage of melanin occurs in unique lysosome-related organelles called melanosomes, which regulate melanin production via complex regulatory mechanisms. Maintenance of the melanosome luminal ionic environment and pH is crucial for proper function of the main melanogenic enzymes. Defects in genes encoding pH-regulating melanosomal proteins result in oculocutaneous albinism, which is characterized by hypopigmentation, impaired vision, and increased susceptibility to skin and eye cancers. We recently uncovered several ion channels and transporters that modulate melanin synthesis by acidifying or neutralizing the luminal pH of melanosomes. However, our understanding of how melanosomes and other related organelles maintain their luminal pH is far from complete. The study of melanosome pH regulation requires robust imaging and quantification tools. Despite recent advances in the development of such methods, many limitations remain, particularly for quantitative analysis of individual organelle pH. In this chapter, we will provide an overview of the available methods used for melanosome pH determination, including their advantages, limitations, and challenges. To address the critical, unmet need for reliable melanosome pH quantification tools, we engineered a novel genetically encoded, ratiometric pH sensor for melanosomes that we named RpHiMEL. Here, we describe the design and optimization of RpHiMEL, and provide a pH quantification method for individual melanosomes in live cells. We demonstrate that RpHiMEL is a highly versatile tool with the potential to advance our understanding of pH regulation in melanosomes and related organelles.

Keywords:  Genetically encoded pH indicator; Intracellular ion channel; Intracellular transporter; Lysosomes; Melanocyte; Melanosome; Nectarine fluorescent protein; Organelle pH; Ratiometric pH indicator; RpHiMEL; Single melanosome tracking; iRFP fluorescent protein

DOI:  https://doi.org/10.1016/bs.mie.2021.03.003
Front Cell Dev Biol. 2021 ;9 666462

Identification of Precise Therapeutic Targets and Characteristic Prognostic Genes Based on Immune Gene Characteristics in Uveal Melanoma.

Zhenxi Zhang, Jingyu Su, Li Li, Wenjing Du.

  The tumor microenvironment is an important factor for the immunotherapy of tumor patients. The sequenced transcriptome data can be used to describe the tumor microenvironment and various immune subtypes. We exploited published data on patients with uveal melanoma (UVM) to identify immune subtypes. Based on the immune-related gene sets of 80 patients with UVM in the TCGA database, we used consensus clustering to identify two immune subgroups. In the two immune subtypes, we analyzed clinical characteristics and immune infiltration. Class1 has low immune infiltration, contains memory B cells, Th2 cells, Th17 cells, eosinophils, natural killer cells, and has a better prognosis. Class2 has higher immune infiltration. CD8+ T cells, Th1 cells, MDSCs, and Dendritic cells are enriched in class2, which has strong cytolytic activity, high expression of immune checkpoint genes, and poor outcome. Moreover, we have developed and verified an immune characteristic model that can predict the prognosis of patients well. Through this model, we screened prostaglandin-endoperoxide synthase 2 (PTGS2) as the therapeutic target of UVM. Treatment of choroidal melanoma cell line (OCM1) cells with celecoxib (an inhibitor of PTGS2) effectively inhibits cell growth, proliferation, and promotes apoptosis. Our results show the immunological heterogeneity of UVM patients and also provide an ideal therapeutic target for the future treatment design of patients.

Keywords:  PTGS2; immune classification; precision therapy; prognosis; tumor microenvironment; uveal melanoma

DOI:  https://doi.org/10.3389/fcell.2021.666462
Dermatol Pract Concept. 2021 May;11(3): e2021059

Dermoscopic Predictors of Tumor Thickness in Cutaneous Melanoma: A Retrospective Analysis of 245 Melanomas.

Enrique Rodríguez-Lomba, Belén Lozano-Masdemont, Lula María Nieto-Benito, Elisa Hernández de la Torre, Ricardo Suárez-Fernández, José Antonio Avilés-Izquierdo.

  Introduction: The literature regarding the association of dermoscopic structures with Breslow thickness in melanoma is scarce, limited to small case series, and mostly outdated.Objective: This study determined the dermoscopic patterns, colors and structures that are associated with melanoma in situ, thin melanomas (<0.8 mm) and thick melanomas potentially requiring sentinel lymph node biopsy according to current guidelines (≥0.8 mm).
Methods: A retrospective evaluation of 245 dermoscopic images of primary cutaneous melanoma located on the trunk or limbs was performed by consensus of 2 dermoscopists.
Results: Red-pink, blue-gray and white color, blue-white veil, shiny white streaks, irregular vessels, blue-black pigmentation, milky red areas, pseudolacunae, ulceration and rainbow pattern were associated with thickness ≥0.8 mm, whereas atypical pigmented network, regression and hypopigmented areas were significantly associated with early melanomas.
Limitations: This is a retrospective study performed in a single institution. Melanomas of special sites were excluded from our evaluation. Dermoscopy is based on subjective evaluations that depend largely on the observers' experience.
Conclusions: The identification of certain dermoscopic structures and colors might help in the discrimination between thin and thick melanomas.

Keywords:  Breslow index; dermatoscopy; dermoscopy; epiluminescence microscopy; melanoma; tumor thickness

DOI:  https://doi.org/10.5826/dpc.1103a59
BMC Res Notes. 2021 Jun 14. 14(1): 232

Computer-aided clinical image analysis for non-invasive assessment of tumor thickness in cutaneous melanoma.

Marios Papadakis, Alexandros Paschos, Andreas Manios, Percy Lehmann, Georgios Manios, Hubert Zirngibl.

OBJECTIVE: Computerized clinical image analysis is shown to improve diagnostic accuracy for cutaneous melanoma but its effectiveness in preoperative assessment of melanoma thickness has not been studied. The aim of this study, is to explore how melanoma thickness correlates with computer-assisted objectively obtained color and geometric variables. All patients diagnosed with cutaneous melanoma with available clinical images prior to tumor excision were included in the study. All images underwent digital processing with an automated non-commercial software. The software provided measurements for geometrical variables, i.e., overall lesion surface, maximum diameter, perimeter, circularity, eccentricity, mean radius, as well as for color variables, i.e., range, standard deviation, coefficient of variation and skewness in the red, green, and blue color space.RESULTS: One hundred fifty-six lesions were included in the final analysis. The mean tumor thickness was 1.84 mm (range 0.2-25). Melanoma thickness was strongly correlated with overall surface area, maximum diameter, perimeter and mean lesion radius. Thickness was moderately correlated with eccentricity, green color and blue color. We conclude that geometrical and color parameters, as objectively extracted by computer-aided clinical image processing, may correlate with tumor thickness in patients with cutaneous melanoma. However, these correlations are not strong enough to reliably predict tumor thickness.

DOI: https://doi.org/10.1186/s13104-021-05650-4
Int J Dermatol. 2021 Jun 17.

Genetic counseling and testing for hereditary causes of melanoma can lead to earlier detection of skin cancer and other malignancies.

Albert E Zhou, Karl M Hoegler, Julie F Solimine.

DOI: https://doi.org/10.1111/ijd.15716
Pharmacol Res Perspect. 2021 Aug;9(4): e00808

Overall survival in metastatic melanoma correlates with pembrolizumab exposure and T cell exhaustion markers.

Vishal Navani, Moira C Graves, Giovana Celli Marchett, Hiren Mandaliya, Nikola A Bowden, Andre van der Westhuizen.

  Trial data support an absence of an exposure-survival relationship for pembrolizumab. As these relationships remain unexamined in a real-world setting, we determined them in metastatic melanoma prospectively in an observational study. Translational objectives included identifying biomarkers of progressive disease (PD). Checkpoint blockade naïve patients receiving 2 mg/kg Q3W pembrolizumab had pharmacokinetic and clinical outcome data collected. Trough, a valid surrogate for drug exposure, was assessed using ELISA. T-cell exhaustion and chemokine markers were determined using flow cytometry. Geometric means of exposures and biomarkers were tested against objective response groups using one-way ANOVA. The cohort was split by the median into high versus low pembrolizumab exposure groups. Kaplan-Meier progression-free survival (PFS) and overall survival (OS) curves were estimated for high versus low exposure, compared using the log rank test. The high pembrolizumab exposure group (n = 14) experienced substantially longer median OS (not reached vs. 48 months, p = .014), than the low exposure group (n = 14). A similar positive exposure PFS relationship was found (median not reached vs. 48 months, p = .045). The frequency of TIM-3 expression on CD4+ T cells was significantly higher in PD (mean 27.8%) than complete response (CR) (13.38%, p = .01) and partial response (12.4%, p = .05). There was a near doubling of CXCR6 and TIM-3 co-expression on CD4+ T cells in PD (mean 23.3%) versus CR (mean 11.4, p = .003) and partial response (9.8%, p = .0001). We describe positive exposure-PFS and exposure-OS relationships for pembrolizumab in metastatic melanoma. TIM-3, alongside co-expression of CXCR6 and TIM-3 on circulating CD4+ T cells are potential bio markers of treatment failure.

Keywords:  CXCR6; TIM-3; drug exposure; immune checkpoint blockade; metastatic melanoma; pembrolizumab; pharmacokinetics

DOI:  https://doi.org/10.1002/prp2.808
Ann Surg Oncol. 2021 Jun 15.

Cost-Effectiveness Analysis of Adjuvant Therapy for BRAF-Mutant Resected Stage III Melanoma in Medicare Patients.

Saam A Mojtahed, Nicole R Boyer, Saieesh A Rao, Thomas F Gajewski, Jennifer Tseng, Kiran K Turaga.

BACKGROUND: Adjuvant therapy for stage III melanoma improves several measures of patient survival. However, decisions regarding inclusion of adjuvant therapies in the formularies of public payers necessarily consider the cost-effectiveness of those treatments. The objective of this study is to evaluate the cost-effectiveness of four recently approved adjuvant therapies for BRAF-mutant stage III melanoma in the Medicare patient population.METHODS: In this cost-effectiveness analysis, a Markov microsimulation model was used to simulate the healthcare trajectory of patients randomized to receive either first-line targeted therapy (dabrafenib-trametinib) or immunotherapy (ipilimumab, nivolumab, or pembrolizumab). The base case was a 65-year-old Medicare patient with BRAF V600E-mutant resected stage III melanoma. Possible health states included recurrence-free survival, adverse events, local recurrence, distant metastases, and death. Transition probabilities were determined from published clinical trials. Costs were estimated from reimbursement rates reported by CMS and the Red Book drug price database. Primary outcomes were costs (US$), life years, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs). Model robustness was evaluated using one-way and probabilistic sensitivity analyses.
RESULTS: Dabrafenib-trametinib provided 1.83 QALYs over no treatment and 0.23 QALYs over the most effective immunotherapy, pembrolizumab. Dabrafenib-trametinib was associated with an ICER of $95,758/QALY over no treatment and $285,863/QALY over pembrolizumab. Pembrolizumab yielded an ICER of $68,396/QALY over no treatment and dominated other immunotherapies.
CONCLUSIONS: Pembrolizumab is cost-effective at a conventional willingness-to-pay (WTP) threshold, but dabrafenib-trametinib is not. Though dabrafenib-trametinib offers incremental QALYs, optimization of drug pricing is necessary to ensure dabrafenib-trametinib is accessible at an acceptable WTP threshold.

DOI: https://doi.org/10.1245/s10434-021-10288-4
J Genet Genomics. 2021 May 14. pii: S1673-8527(21)00101-6. [Epub ahead of print]

Immu-Mela: An open resource for exploring immunotherapy-related multidimensional genomic profiles in melanoma.

Jing Yang, Shilin Zhao, Jing Wang, Quanhu Sheng, Qi Liu, Yu Shyr.

  There are increasing studies aimed to reveal genomic hallmarks predictive of immune checkpoint blockade (ICB) treatment response, which generated a large number of data and provided an unprecedented opportunity to identify response-related features and evaluate their robustness across cohorts. However, those valuable data sets are not easily accessible to the research community. To take full advantage of existing large-scale immuno-genomic profiles, we developed Immu-Mela (http://bioinfo.vanderbilt.edu/database/Immu-Mela/), a multidimensional immuno-genomic portal that provides interactive exploration of associations between ICB responsiveness and multi-omics features in melanoma, including genetic, transcriptomics, immune cells, and single-cell populations. Immu-Mela also enables integrative analysis of any two genomic features. We demonstrated the value of Immu-Mela by identifying known and novel genomic features associated with ICB response. In addition, Immu-Mela allows users to upload their data sets (unrestricted to any cancer types) and co-analyze with existing data to identify and validate signatures of interest. Immu-Mela reduces barriers between researchers and complex genomic data, facilitating discoveries in cancer immunotherapy.

Keywords:  Biomarker; CTLA-4 blockade; Immune checkpoint; Immunotherapy; Melanoma; Multidimensional genomics; PD-1/PD-L1 blockade

DOI:  https://doi.org/10.1016/j.jgg.2021.03.016
J Cosmet Dermatol. 2021 Jun 16.

Electrofulguration assisted dermabrasion is comparable to manual dermabrasion in patients undergoing autologous non-cultured epidermal cell suspension for treatment of stable vitiligo: A randomised controlled trial.

Anubha Dev, Keshavamurthy Vinay, Muthu Kumaran Sendhil, Anuradha Bishnoi, Niharika Srivastava, Sunil Dogra, Davinder Parsad.

  BACKGROUND: Recipient site preparation is a crucial step in non-cultured epidermal cell suspension (NCES) as it facilitates proper uptake of the grafted melanocytes.OBJECTIVES: To compare the repigmentation rate of recipient sites prepared with manual dermabrasion (MD) versus electrofulguration assisted dermabrasion (EF) in patients undergoing NCES for treatment of stable vitiligo.
METHODS: This was a prospective randomised study including 26 patients of stable vitiligo (VIDA 0 or -1), each having two patches of size greater than 3x3 cm located symmetrically or at the same site or a single patch of 6x6 cm or larger. After randomisation of patches in the given patient, MD and EF were performed on recipient areas followed by NCES. The patients were followed up at 4 weekly intervals upto 24weeks and assessed for extent of repigmentation and adverse effects if any.
RESULTS: Greater than 75% repigmentation was observed in 69.3% of the patches prepared by MD as compared to 73.1% patches prepared by EF at the end of 24 weeks (p = 0.791). The mean improvement in target VASI was 64.0 % in the MD group as compared to 68.8% in the EF group (p = 0.21). Patches prepared by EF achieved successful repigmentation earlier as compared to patches prepared by MD (9.4 weeks vs 11.4 weeks, p=0.12).
CONCLUSION: Both MD and EF have comparable outcomes with respect to all parameters.

Keywords:  Colour match; Electrofulguration; Manual dermabrasion; Non-cultured epidermal cell suspension; Repigmentation; Vitiligo; radiosurgery; repigmentation

DOI:  https://doi.org/10.1111/jocd.14290
Cancer Lett. 2021 Jun 11. pii: S0304-3835(21)00287-1. [Epub ahead of print]518 10-22

Targeting the mercapturic acid pathway for the treatment of melanoma.

Sharad S Singhal, Saumya Srivastava, Tamara Mirzapoiazova, David Horne, Sanjay Awasthi, Ravi Salgia.

  The treatment of metastatic melanoma is greatly hampered by the simultaneous dysregulation of several major signaling pathways that suppress apoptosis and promote its growth and invasion. The global resistance of melanomas to therapeutics is also supported by a highly active mercapturic acid pathway (MAP), which is responsible for the metabolism and excretion of numerous chemotherapy agents. The relative importance of the MAP in melanoma survival was not recognized until demonstrated that B16 melanoma undergoes dramatic apoptosis and regression upon the depletion or inhibition of the MAP transporter protein RLIP. RLIP is a multi-functional protein that couples ATP hydrolysis with the movement of substances. As the rate-limiting step of the MAP, the primary function of RLIP in the plasma membrane is to catalyze the ATP-dependent efflux of unmetabolized drugs and toxins, including glutathione (GSH) conjugates of electrophilic toxins (GS-Es), which are the precursors of mercapturic acids. Clathrin-dependent endocytosis (CDE) is an essential mechanism for internalizing ligand-receptor complexes that promote tumor cell proliferation through autocrine stimulation (Wnt5a, PDGF, βFGF, TNFα) or paracrine stimulation by hormones produced by fibroblasts (IGF1, HGF) or inflammatory cells (IL8). Aberrant functioning of these pathways appears critical for melanoma cell invasion, metastasis, and evasion of apoptosis. This review focuses on the selective depletion or inhibition of RLIP as a highly effective targeted therapy for melanoma that could cause the simultaneous disruption of the MAP and critical peptide hormone signaling that relies on CDE.

Keywords:  BRAF; Drug resistance; Melanoma; RLIP; p53

DOI:  https://doi.org/10.1016/j.canlet.2021.06.004
Photodiagnosis Photodyn Ther. 2021 Jun 13. pii: S1572-1000(21)00219-2. [Epub ahead of print] 102392

The induction of immunogenic cell death by photodynamic therapy in B16F10 cells in vitro is affected by the concentration of the photosensitizer.

Morais José Athayde Vasconcelos, Almeida Letícia R, Rodrigues Mosar C, Azevedo Ricardo B, Muehlmann Luis A.

  Photodynamic therapy (PDT) can trigger immune responses against cancer cells. The induction of immunogenic cell death (ICD) is one of the possible mechanisms behind this event, but the protocol conditions necessary for a robust induction of ICD by PDT have not been studied. In this work, the immunogenicity of B16F10 melanoma cells treated with different PDT protocols was investigated. The exposure of damage-associated molecules (DAMPs), namely HMGB1, calreticulin and ATP, a hallmark of ICD, and the presence of apoptotic and necrotic cells were assessed after the application of PDT mediated by different concentrations of aluminum-phthalocyanine (AlPcNE) in vitro. Furthermore, the in vivo immunogenicity of PDT-treated B16F10 cells was investigated with an immunization-challenge model in C57BL/6 mice. The percentage of dead cells was directly proportional to the concentration of AlPcNE. The IC50, IC70 and IC90 concentrations of AlPcNE induced the exposure of DAMPs by B16F10 cells after PDT. In the in vivo model, however, only the B16F10 cells treated with PDT-AlPcNE at the IC50 or IC70 rendered C57BL/6 significantly more resistant to a subsequent challenge with viable B16F10 cells. Thus, the induction of ICD in B16F10 cells by PDT occurs only at a specific range of AlPcNE concentrations.

Keywords:  DAMP; Immunotherapy; Melanoma; aluminum-phthalocyanine; cancer

DOI:  https://doi.org/10.1016/j.pdpdt.2021.102392
J Genet Genomics. 2021 Apr 14. pii: S1673-8527(21)00088-6. [Epub ahead of print]

Transcriptomic profiling of tumor microenvironment reveals distinct immune subgroups of metastatic melanoma and its potential implications for immunotherapy.

Yixuan Huang, Peng Zhang.

DOI: https://doi.org/10.1016/j.jgg.2021.03.008
Autoimmun Rev. 2021 Jun 10. pii: S1568-9972(21)00140-3. [Epub ahead of print]20(8): 102868

Emerging role of Tissue Resident Memory T cells in vitiligo: From pathogenesis to therapeutics.

Firdosh Shah, Shivani Patel, Rasheedunnisa Begum, Mitesh Dwivedi.

  Vitiligo is an acquired depigmenting disorder which affects both skin and mucous membranes and autoimmunity has been strongly suggested to play a role in loss of melanocytes. The recurrence of skin macules at the same sites where they were observed prior to the treatment, suggests the existence of Tissue Resident Memory T cells (TRMs) that persist within the skin or peripheral tissues with a longer survivability. Emerging studies have shown that reactivation of these skin TRMs results into autoreactive TRM cells in various autoimmune diseases including vitiligo. This review focuses on different subsets (CD8+ TRMs and CD4+ TRMs) of TRM cells, their retention and survivability in the skin along with their pathomechanisms leading to melanocyte death and progression of vitiligo. In addition, the review describes the TRM cells as potential targets for developing effective therapeutics of vitiligo.

Keywords:  Autoimmunity; CD4(+) TRM; CD8(+) TRM; Homing receptors; Melanocyte; Tissue Resident Memory T Cells (TRM); Vitiligo

DOI:  https://doi.org/10.1016/j.autrev.2021.102868
Adv Mater. 2021 Jun 12. e2100628

In Situ Tumor Vaccination with Nanoparticle Co-Delivering CpG and STAT3 siRNA to Effectively Induce Whole-Body Antitumor Immune Response.

Worapol Ngamcherdtrakul, Moataz Reda, Molly A Nelson, Ruijie Wang, Husam Y Zaidan, Daniel S Bejan, Ngoc Ha Hoang, Ryan S Lane, Shiuh-Wen Luoh, Sancy A Leachman, Gordon B Mills, Joe W Gray, Amanda W Lund, Wassana Yantasee.

  The success of immunotherapy with immune checkpoint inhibitors (ICIs) in a subset of individuals has been very exciting. However, in many cancers, responses to current ICIs are modest and are seen only in a small subsets of patients. Herein, a widely applicable approach that increases the benefit of ICIs is reported. Intratumoral administration of augmenting immune response and inhibiting suppressive environment of tumors-AIRISE-02 nanotherapeutic that co-delivers CpG and STAT3 siRNA-results in not only regression of the injected tumor, but also tumors at distant sites in multiple tumor model systems. In particular, three doses of AIRISE-02 in combination with systemic ICIs completely cure both treated and untreated aggressive melanoma tumors in 63% of mice, while ICIs alone do not cure any mice. A long-term memory immune effect is also reported. AIRISE-02 is effective in breast and colon tumor models as well. Lastly, AIRISE-02 is well tolerated in mice and nonhuman primates. This approach combines multiple therapeutic agents into a single nanoconstruct to create whole-body immune responses across multiple cancer types. Being a local therapeutic, AIRISE-02 circumvents regulatory challenges of systemic nanoparticle delivery, facilitating rapid translation to the clinic. AIRISE-02 is under investigational new drug (IND)-enabling studies, and clinical trials will soon follow.

Keywords:  cancer immunotherapy; intratumoral therapy; melanoma; nanotechnology; translational research

DOI:  https://doi.org/10.1002/adma.202100628