Search

Background: The COVID‐19 lockdown had a dramatic impact on primary care access and resulted in postponed skin cancer screenings. This raises concerns for a diagnostic delay on primary cutaneous melanomas, which can subsequently increase morbidity and mortality. Objectives: The aim of the study was to investigate the impact of the COVID‐19‐related restrictions on the melanoma diagnosis in five European skin cancer reference centres in Switzerland, Germany, Austria and Italy. Methods: A total of 7865 cutaneous melanoma cases were collected between 01 September 2018 and 31 August 2021. The time period was stratified into pre‐COVID (pre‐lockdown) and post‐COVID (lockdown and post‐lockdown) according to the established restrictions in each country. The data collection included demographic, clinical and histopathological data from histologically confirmed cutaneous melanomas. Personal and family history of melanoma, and presence of immunosuppression were used to assess the diagnosis delay in high‐risk individuals. Results: There was an overall increase of the Breslow tumour thickness (mean 1.25 mm vs. 1.02 mm) during the post‐COVID period, as well as an increase in the proportion of T3‐T4 melanomas, rates of ulceration and the number of mitotic rates ≥2 (all, p < 0.001). Patients with immunosuppression and personal history of melanoma showed a decrease in the mean log10‐transformed Breslow during lockdown and post‐COVID. In the multivariate analysis, age at melanoma diagnosis (p < 0.01) and personal history of melanoma (p < 0.01) showed significant differences in the mean Breslow thickness. Conclusions: The study confirms the diagnostic delay in cutaneous melanomas due to the COVID‐19 lockdown. High‐risk individuals, such as patients with personal history of melanoma and elderly individuals, were more hesitant to restart their regular skin cancer screenings post‐COVID. Further studies with longer follow‐up are required to evaluate the consequences of this diagnostic delay in long‐term outcomes. [ABSTRACT FROM AUTHOR]

Background: Washing red blood cell (RBC) units prior to transfusion is indicated for certain patients. In the United States, units stored at 1°C-6°C or transported at 1°C-10°C are available for issue up to 24 h, if not used immediately. The washing procedure commonly utilizes room temperature saline resulting in units starting out above the allowed temperature range. This leads to wastage if units are issued and returned too quickly before having a chance to equilibrate in a transport cooler.Study Design and Methods: Here we performed an experimental study of washed RBC quality comparing "ideal" storage conditions in a blood bank refrigerator to a "real-world" simulation of unit transport, including holding in a transport cooler. Twelve RBC units were washed and allocated evenly into either condition.Results: Measurements at 0, 1, 3, 6, 12, and 24 h post-washing revealed that placement in a transport cooler was associated with higher unit temperature prior to 12 h (p = .013) with a maximum difference of 9.3°C. Despite this difference, several measures of unit quality including extracellular potassium, pH, lactate, and free hemoglobin were indistinguishable between conditions (p = .382, .224, .286, .691, respectively). We selected half of the tested units from our irradiated inventory and confirmed increased potassium leak (p < .001) and accumulation of free hemoglobin (p = .012) in irradiated units.Discussion: Washed units stored under approved transport conditions are acceptable to return to inventory up to 24 h after washing and we provide a prediction interval-based temperature threshold for rejecting these units, permitting reduced waste. [ABSTRACT FROM AUTHOR]

Oncogenic BRAF and NRAS mutations drive human melanoma initiation. We used transgenic zebrafish to model NRAS‐mutant melanoma, and the rapid tumor onset allowed us to study candidate tumor suppressors. We identified P38α‐MAPK14 as a potential tumor suppressor in The Cancer Genome Atlas melanoma cohort of NRAS‐mutant melanomas, and overexpression significantly increased the time to tumor onset in transgenic zebrafish with NRAS‐driven melanoma. Pharmacological activation of P38α‐MAPK14 using anisomycin reduced in vitro viability of melanoma cultures, which we confirmed by stable overexpression of p38α. We observed that the viability of MEK inhibitor resistant melanoma cells could be reduced by combined treatment of anisomycin and MEK inhibition. Our study demonstrates that activating the p38α‐MAPK14 pathway in the presence of oncogenic NRAS abrogates melanoma in vitro and in vivo. Significance: The significance of our study is in the accountability of NRAS mutations in melanoma. We demonstrate here that activation of p38α‐MAPK14 pathway can abrogate NRAS‐mutant melanoma which is contrary to the previously published role of p38α‐MAPK14 pathway in BRAF mutant melanoma. These results implicate that BRAF and NRAS‐mutant melanoma may not be identical biologically. We also demonstrate the translational benefit of our study by using a small molecule compound‐anisomycin (already in use for other diseases in clinical trials) to activate p38α‐MAPK14 pathway. [ABSTRACT FROM AUTHOR]

Aims: Despite their low individual metastatic potential, thin melanomas (≤1 mm Breslow thickness) contribute significantly to melanoma mortality overall. Therefore, identification of prognostic biomarkers is particularly important in this subgroup of melanoma. Prompted by preclinical results, we investigated cyclin D1 protein and Ki‐67 expression in in‐situ, metastatic and non‐metastatic thin melanomas. Methods and results: Immunohistochemistry was performed on 112 melanoma specimens, comprising 22 in situ, 48 non‐metastatic and 42 metastatic thin melanomas. Overall, epidermal and dermal cyclin D1 and Ki‐67 expression were semiquantitatively evaluated by three independent investigators and compared between groups. Epidermal Ki‐67 expression did not differ statistically in in‐situ and invasive melanoma (P = 0.7). Epidermal cyclin D1 expression was significantly higher in thin invasive than in in‐situ melanoma (P = 0.003). No difference was found in cyclin D1 expression between metastatic and non‐metastatic invasive tumours. Metastatic and non‐metastatic thin melanomas did not show significant differences in epidermal expression of Ki‐67 and cyclin D1 (P = 0.148 and P = 0.611, respectively). In contrast, strong dermal expression of Ki‐67 was more frequent in metastatic than non‐metastatic samples (28.6 versus 8.3%, respectively, P = 0.001). The prognostic value of dermal Ki‐67 expression was confirmed by multivariate analysis (P = 0.047). Conclusion: We found an increased expression of cyclin D1 in invasive thin melanomas compared to in‐situ melanomas, which supports a potential role of this protein in early invasion in melanoma, as suggested by preclinical findings. Moreover, our results confirm that high dermal Ki‐67 expression is associated with an increased risk of development of metastasis in thin melanoma and could possibly serve as a prognostic biomarker in clinical practice, especially if combined with additional methods. [ABSTRACT FROM AUTHOR]

NRAS mutations are the most common alterations among RAS isoforms in cutaneous melanoma, with patients harboring these aggressive tumors having a poor prognosis and low survival rate. The main line of treatment for these patients is MAPK pathway‐targeted therapies, such as MEK inhibitors, but, unfortunately, the response to these inhibitors is variable due to tumor resistance. Identifying genetic modifiers involved in resistance toward MEK‐targeted therapy may assist in the development of new therapeutic strategies, enhancing treatment response and patient survival. Our whole‐genome CRISPR‐Cas9 knockout screen identified the target Kelch domain‐containing F‐Box protein 42 (FBXO42) as a factor involved in NRAS‐mutant melanoma‐acquired resistance to the MEK1/2 inhibitor trametinib. We further show that FBXO42, an E3 ubiquitin ligase, is involved in the TAK1 signaling pathway, possibly prompting an increase in active P38. In addition, we demonstrate that combining trametinib with the TAK1 inhibitor, takinib, is a far more efficient treatment than trametinib alone in NRAS‐mutant melanoma cells. Our findings thus show a new pathway involved in NRAS‐mutant melanoma resistance and provide new opportunities for novel therapeutic options. [ABSTRACT FROM AUTHOR]

Abstract: Methadone (Met) mainly acts as a μ‐opioid receptor agonist. Recent evidence pointing towards the role of Met in sensitization of certain cancer cell lines to chemotherapeutic agents has promoted the hypothesis that Met may be a useful adjuvant to cancer chemotherapy. We wanted to address whether Met has, alone or in combination with a chemotherapeutic agent, an effect on melanoma cell viability in vitro. Only a small fraction (4.3%) of our 102 melanoma biobank cell lines with RNA‐sequencing data showed expression of the main receptor for Met (OPRM1). We assessed the viability of melanoma cell lines with high, medium or low/no OPRM1 expression (OPRM1high, OPRM1med, OPRM1neg) 72 hours after treatment with Met alone or combined with cisplatin (Cis). Our analyses show that Met alone did not affect cell viability. While Cis/Met treatment did not have an effect on viability of OPRM1med or OPRM1neg cell lines, it resulted in a slightly decreased cell viability of OPRM1high cells. Clinically, concurrent temozolomide/Met treatment did not have an effect in our single‐case report of a patient suffering from uveal melanoma. Taken together, our findings do not provide evidence for recommending Met as an adjuvant to chemotherapy in patients with melanoma. [ABSTRACT FROM AUTHOR]

There is growing evidence that the metastatic spread of melanoma is driven not by a linear increase in tumorigenic aggressiveness, but rather by switching back and forth between two different phenotypes of metastatic potential. In vitro these phenotypes are respectively defined by the characteristics of strong proliferation/weak invasiveness and weak proliferation/strong invasiveness. Melanoma cell phenotype is tightly linked to gene expression. Taking advantage of this, we have developed a gene expression-based tool for predicting phenotype called Heuristic Online Phenotype Prediction. We demonstrate the predictive utility of this tool by comparing phenotype-specific signatures with measurements of characteristics of melanoma phenotype-specific biology in different melanoma cell lines and short-term cultures. We further show that 86% of 536 tested melanoma lines and short-term cultures are significantly associated with the phenotypes we describe. These findings reinforce the concept that a two-state system, as described by the phenotype switching model, underlies melanoma progression. [ABSTRACT FROM AUTHOR]

MAPK inhibitors (MAPKi) show outstanding clinical response rates in melanoma patients harbouring BRAF mutations, but resistance is common. The ability of melanoma cells to switch from melanocytic to mesenchymal phenotypes appears to be associated with therapeutic resistance. High‐throughput, subcellular proteome analyses and RNAseq on two panels of primary melanoma cells that were either sensitive or resistant to MAPKi revealed that only 15 proteins were sufficient to distinguish between these phenotypes. The two proteins with the highest discriminatory power were PTRF and IGFBP7, which were both highly upregulated in the mesenchymal‐resistant cells. Proteomic analysis of CRISPR/Cas‐derived PTRF knockouts revealed targets involved in lysosomal activation, endocytosis, pH regulation, EMT, TGFβ signalling and cell migration and adhesion, as well as a significantly reduced invasive index and ability to form spheres in 3D culture. Overexpression of PTRF led to MAPKi resistance, increased cell adhesion and sphere formation. In addition, immunohistochemistry of patient samples showed that PTRF expression levels were a significant biomarker of poor progression‐free survival, and IGFBP7 levels in patient sera were shown to be higher after relapse. Synopsis: Therapy resistance towards BRAF inhibition and relapse in skin cancer are frequently associated with cellular phenotype switching, but the molecular control of this plasticity and discriminating markers remain unclear. Multidimensional expression profiling of resistant and sensitive primary melanoma reveals functional biomarkers and potential targets associated with poor progression‐free survival. Combined proteome and transcriptome analyses identify a core set of 15 MAPKi resistance‐associated proteins.PTRF and IGFBP7 are upregulated in resistant mesenchymal‐type melanoma cells.Depletion of PTRF results in downregulation of lysosomal endocytosis targets and EMT signaling.Overexpression of PTRF induces MAPKi‐resistance, increased cell adhesion and sphere formation.PTRF expression correlates with poor progression‐free survival under MAPKi treatment. [ABSTRACT FROM AUTHOR]