The metabolism of melanin synthesis-From melanocytes to melanoma.

Melanin synthesis involves the successful coordination of metabolic pathways across multiple intracellular compartments including the melanosome, mitochondria, ER/Golgi, and cytoplasm. While pigment production offers a communal protection from UV damage, the process also requires anabolic and redox demands that must be carefully managed by melanocytes. In this report we provide an updated review on melanin metabolism, including recent data leveraging new techniques, and technologies in the field of metabolism. We also discuss the many aspects of melanin synthesis that intersect with metabolic pathways known to impact melanoma phenotypes and behavior. By reviewing the metabolism of melanin synthesis, we hope to highlight outstanding questions and opportunities for future research that could improve patient outcomes in pigmentary and oncologic disease settings.

Clinical Features and Outcomes of Black Patients With Melanoma.

Importance: Melanoma in Black individuals has an annual incidence of approximately 1 in 100 000 people. Most studies of melanoma in Black patients have used population databases, which lack important, precise clinical details. Objective: To identify patient-level and tumor-level characteristics of melanoma in Black patients. Design, Setting, and Participants: This case series included Black patients with melanoma at 2 tertiary care centers (University of Texas Southwestern [UTSW] Medical Center and Parkland Health), affiliated with a single institution, UTSW in Dallas, Texas. Self-reported Black patients with a histopathologic diagnosis of melanoma were identified between January 2006 and October 2022. Main Outcomes and Measures: The main variables were demographics, clinical characteristics, personal and family medical history, immunosuppression history, comorbidities, histopathology reports, molecular/genetic studies, imaging reports, melanoma treatments and responses, time to progression, metastatic sites, and survival rates. Results: A total of 48 Black patients with melanoma (median [range] age at diagnosis, 62 [23-86] years; 30 [63%] female) were included in the study. Of 40 primary cutaneous melanomas, 30 (75%) were located on acral skin, despite only 10 of 30 (33%) being histologically classified as acral lentiginous melanomas. Compared with those with acral disease, patients with nonacral cutaneous melanomas were more likely to be immunocompromised (4 of 10 [40%] vs 2 of 30 [7%]) or have a personal history of cancer (6 of 10 [60%] vs 5 of 30 [17%]), with all 3 patients with superficial spreading melanoma having a history of both. No patients had more than 1 confirmed primary melanoma. Overall, 13 Black patients (27%) with melanoma developed stage IV disease, of whom 12 died because of disease progression. Those diagnosed with advanced acral melanoma, mucosal/ocular melanoma, or melanoma of unknown primary lacked actionable sequence variations, were nonresponsive to immunotherapy, and had the poorest outcomes. No patients with nonacral cutaneous melanomas developed distant metastases or died of melanoma. Conclusions and Relevance: This single-institution case series highlights several features of melanoma in Black patients that have not been captured in existing population-level registries, including precise anatomic sites, immune status, family and personal cancer history, and genetics. Multi-institutional registries would improve understanding of melanoma in Black patients.

Pathogenic mitochondrial DNA mutations inhibit melanoma metastasis.

Mitochondrial DNA (mtDNA) mutations are frequently observed in cancer, but their contribution to tumor progression is controversial. To evaluate the impact of mtDNA variants on tumor growth and metastasis, we created human melanoma cytoplasmic hybrid (cybrid) cell lines transplanted with wildtype mtDNA or pathogenic mtDNA encoding variants that partially or completely inhibit oxidative phosphorylation. Homoplasmic pathogenic mtDNA cybrids reliably established tumors despite dysfunctional oxidative phosphorylation. However, pathogenic mtDNA variants disrupted spontaneous metastasis of subcutaneous tumors and decreased the abundance of circulating melanoma cells in the blood. Pathogenic mtDNA did not induce anoikis or inhibit organ colonization of melanoma cells following intravenous injections. Instead, migration and invasion were reduced, indicating that limited circulation entry functions as a metastatic bottleneck amidst mtDNA dysfunction. Furthermore, analysis of selective pressure exerted on the mitochondrial genomes of heteroplasmic cybrid lines revealed a suppression of pathogenic mtDNA allelic frequency during melanoma growth. Collectively, these findings demonstrate that functional mtDNA is favored during melanoma growth and enables metastatic entry into the blood.

Prevention of Skin Cancers With Topical Calcipotriol and Fluorouracil in Patients With Xeroderma Pigmentosum.

This case report describes treatment regimens with topical calcipotriol plus fluorouracil for 2 patients with xeroderma pigmentosum.

Effects of pair migratory behavior on breeding phenology and success in a partially migratory shorebird population.

In migratory systems, variation in individual phenology can arise through differences in individual migratory behaviors, and this may be particularly apparent in partial migrant systems, where migrant and resident individuals are present within the same population. Links between breeding phenology and migratory behavior or success are generally investigated at the individual level. However, for breeding phenology in particular, the migratory behaviors of each member of the pair may need to be considered simultaneously, as breeding phenology will likely be constrained by timing of the pair member that arrives last, and carryover effects on breeding success may vary depending on whether pair members share the same migratory behavior or not. We used tracking of marked individuals and monitoring of breeding success from a partially migrant population of Eurasian oystercatchers (Haematopus ostralegus) breeding in Iceland to test whether (a) breeding phenology varied with pair migratory behavior; (b) within-pair consistency in timing of laying differed among pair migratory behaviors; and (c) reproductive performance varied with pair migratory behavior, timing of laying, and year. We found that annual variation in timing of laying differed among pair migratory behaviors, with resident pairs being more consistent than migrant and mixed pairs, and migrant/mixed pairs breeding earlier than residents in most years but later in one (unusually cold) year. Pairs that laid early were more likely to replace their clutch after nest loss, had higher productivity and higher fledging success, independent of pair migratory behavior. Our study suggests that the links between individual migratory behavior and reproductive success can vary over time and, to a much lesser extent, with mate migratory behavior and can be mediated by differences in laying dates. Understanding these cascading effects of pair phenology on breeding success is likely to be key to predicting the impact of changing environmental conditions on migratory species.

The future of oncology policy.

To ensure the previous progress seen in cancer survival rates continues as we move through the 21st Century it is important to determine future effective policy related to oncology healthcare delivery and funding. Recent successes with, for example, the COVID vaccine response, the decision-making agility exhibited by governments and healthcare systems and the effective use of telehealth and real-world evidence highlight the progress that can be made with pooled efforts and innovative thinking. This shared approach is the basis for the European Beating Cancer Plan which outlines action points for governments and health systems for the period 2021-2025. It focuses on a whole government approach, centred on patients, maximising the potential of new technologies and insights across policy areas including employment, education, transport and taxation, enabling the tackling of cancer drivers in schools, workplaces, research labs, towns and cities and rural communities. Despite the plan there are still concerns that oncology policy has not adequately responded to the pace of innovation and the unique challenges generated by innovative oncological technologies. There needs to be focus on: gaining consensus on the most appropriate methods to assess and price combination therapies and cell and gene therapies, developing effective outcome-based payment models for personalised medicine and developing consensus on the ideal approach for multiple indication pricing. Finally, future policy needs to ensure pharmaceutical companies and other research organisations are adequately rewarded for innovation to ensure continued R&D and the development of innovative oncological products.

The mammalian SKIV2L RNA exosome is essential for early B cell development.

The SKIV2L RNA exosome is an evolutionarily conserved RNA degradation complex in the eukaryotes. Mutations in the SKIV2L gene are associated with a severe inherited disorder, trichohepatoenteric syndrome (THES), with multisystem involvement but unknown disease mechanism. Here, we reported a THES patient with SKIV2L mutations showing severe primary B cell immunodeficiency, hypogammaglobulinemia, and kappa-restricted plasma cell dyscrasia but normal T cell and NK cell function. To corroborate these findings, we made B cell-specific Skiv2l knockout mice (Skiv2lfl/flCd79a-Cre), which lacked both conventional B-2 and innate-like B-1 B cells in the periphery and secondary lymphoid organs. This was linked to a requirement of SKIV2L RNA exosome activity in the bone marrow during early B cell development at the pro-B cell to large pre-B cell transition. Mechanistically, Skiv2l-deficient pro-B cells exhibited cell cycle arrest and DNA damage. Furthermore, loss of Skiv2l led to substantial out-of-frame V(D)J rearrangement of immunoglobulin heavy chain and severely reduced surface expression of µH, both of which are crucial for pre-BCR signaling and proliferative burst during early B cell development. Together, our data demonstrated a crucial role for SKIV2L RNA exosome in early B cell development in both human and mice by ensuring proper V(D)J recombination and Igh expression, which serves as the molecular basis for immunodeficiency associated with THES.

Demographic variation in space and time: implications for conservation targeting.

The dynamics of wild populations are governed by demographic rates which vary spatially and/or temporally in response to environmental conditions. Conservation actions for widespread but declining populations could potentially exploit this variation to target locations (or years) in which rates are low, but only if consistent spatial or temporal variation in demographic rates occurs. Using long-term demographic data for wild birds across Europe, we show that productivity tends to vary between sites (consistently across years), while survival rates tend to vary between years (consistently across sites), and that spatial synchrony is more common in survival than productivity. Identifying the conditions associated with low demographic rates could therefore facilitate spatially targeted actions to improve productivity or (less feasibly) forecasting and temporally targeting actions to boost survival. Decomposing spatio-temporal variation in demography can thus be a powerful tool for informing conservation policy and for revealing appropriate scales for actions to influence demographic rates.

Individual repeatability of avian migration phenology: A systematic review and meta-analysis.

Changes in phenology and distribution are being widely reported for many migratory species in response to shifting environmental conditions. Understanding these changes and the situations in which they occur can be aided by understanding consistent individual differences in phenology and distribution and the situations in which consistency varies in strength or detectability. Studies tracking the same individuals over consecutive years are increasingly reporting migratory timings to be a repeatable trait, suggesting that flexible individual responses to environmental conditions may contribute little to population-level changes in phenology and distribution. However, how this varies across species and sexes, across the annual cycle and in relation to study (tracking method, study design) and/or ecosystem characteristics is not yet clear. Here, we take advantage of the growing number of publications in movement ecology to perform a phylogenetic multilevel meta-analysis of repeatability estimates for avian migratory timings to investigate these questions. Of 2,433 reviewed studies, 54 contained suitable information for meta-analysis, resulting in 177 effect sizes from 47 species. Individual repeatability of avian migratory timings averaged 0.414 (95% confidence interval: 0.3-0.5) across landbirds, waterbirds and seabirds, suggesting consistent individual differences in migratory timings is a common feature of migratory systems. Timing of departure from the non-breeding grounds was more repeatable than timings of arrival at or departure from breeding grounds, suggesting that conditions encountered on migratory journeys and outcome of breeding attempts can influence individual variation. Population-level shifts in phenology could arise through individual timings changing with environmental conditions and/or through shifts in the numbers of individuals with different timings. Our findings suggest that, in addition to identifying the conditions associated with individual variation in phenology, exploring the causes of between-individual variation will be key in predicting future rates and directions of changes in migratory timings. We therefore encourage researchers to report the within- and between- individual variance components underpinning the reported repeatability estimates to aid interpretation of migration behaviour. In addition, the lack of studies in the tropics means that levels of repeatability in less strongly seasonal environments are not yet clear.

Individual consistency in migration strategies of a tropical seabird, the Round Island petrel.

BACKGROUND: In migratory species, the extent of within- and between-individual variation in migratory strategies can influence potential rates and directions of responses to environmental changes. Quantifying this variation requires tracking of many individuals on repeated migratory journeys. At temperate and higher latitudes, low levels of within-individual variation in migratory behaviours are common and may reflect repeated use of predictable resources in these seasonally-structured environments. However, variation in migratory behaviours in the tropics, where seasonal predictability of food resources can be weaker, remains largely unknown. METHODS: Round Island petrels (Pterodroma sp.) are tropical, pelagic seabirds that breed all year round and perform long-distance migrations. Using multi-year geolocator tracking data from 62 individuals between 2009 and 2018, we quantify levels of within- and between-individual variation in non-breeding distributions and timings. RESULTS: We found striking levels of between-individual variation in at-sea movements and timings, with non-breeding migrations to different areas occurring across much of the Indian Ocean and throughout the whole year. Despite this, repeat-tracking of individual petrels revealed remarkably high levels of spatial and temporal consistency in within-individual migratory behaviour, particularly for petrels that departed at similar times in different years and for those departing in the austral summer. However, while the same areas were used by individuals in different years, they were not necessarily used at the same times during the non-breeding period. CONCLUSIONS: Even in tropical systems with huge ranges of migratory routes and timings, our results suggest benefits of consistency in individual migratory behaviours. Identifying the factors that drive and maintain between-individual variation in migratory behaviour, and the consequences for breeding success and survival, will be key to understanding the consequences of environmental change across migratory ranges.

Loss of glucose 6-phosphate dehydrogenase function increases oxidative stress and glutaminolysis in metastasizing melanoma cells.

The pentose phosphate pathway is a major source of NADPH for oxidative stress resistance in cancer cells but there is limited insight into its role in metastasis, when some cancer cells experience high levels of oxidative stress. To address this, we mutated the substrate binding site of glucose 6-phosphate dehydrogenase (G6PD), which catalyzes the first step of the pentose phosphate pathway, in patient-derived melanomas. G6PD mutant melanomas had significantly decreased G6PD enzymatic activity and depletion of intermediates in the oxidative pentose phosphate pathway. Reduced G6PD function had little effect on the formation of primary subcutaneous tumors, but when these tumors spontaneously metastasized, the frequency of circulating melanoma cells in the blood and metastatic disease burden were significantly reduced. G6PD mutant melanomas exhibited increased levels of reactive oxygen species, decreased NADPH levels, and depleted glutathione as compared to control melanomas. G6PD mutant melanomas compensated for this increase in oxidative stress by increasing malic enzyme activity and glutamine consumption. This generated a new metabolic vulnerability as G6PD mutant melanomas were more dependent upon glutaminase than control melanomas, both for oxidative stress management and anaplerosis. The oxidative pentose phosphate pathway, malic enzyme, and glutaminolysis thus confer layered protection against oxidative stress during metastasis.

The effect of food prescription programs on chronic disease management in primarily low-income populations: A systematic review and meta-analysis.

Background: Having low-income limits one's ability to purchase foods that are high in nutritional value (e.g. vegetables and fruits (V/F)). Higher V/F intake is associated with less diet-related chronic disease. Food pharmacy programs are potential solutions to providing V/F to low-income populations with or at-risk for chronic disease. Aim: This systematic review aimed to determine the effect of food pharmacy programs, including interventions targeting populations at-risk for chronic disease. Methods: We searched Pubmed and Google Scholar databases for studies reporting on food pharmacy interventions and outcomes (hemoglobin A1c, body mass index (BMI), V/F intake, and blood pressure). We calculated pooled mean differences using a random-effects model. Seventeen studies met our inclusion criteria; 13 studies used a pre/post study design, three used a randomized controlled trial, and one was a post-survey only. Results: We found that the pooled mean daily servings of V/F (0.77; 95% CI: 0.30 to 1.24) was higher and BMI (-0.40; 95% CI: -0.50 to -0.31) was lower with food pharmacy interventions We did not find any differences in the pooled mean differences for hemoglobin A1c or systolic blood pressure. Conclusion: Findings posit that food pharmacy programs delivered to primarily low-income individuals with comorbidities may be a promising solution to improving V/F intake and possibly overall diet in these populations.

A Short Isoform of Spermatogenic Enzyme GAPDHS Functions as a Metabolic Switch and Limits Metastasis in Melanoma.

Despite being the leading cause of cancer deaths, metastasis remains a poorly understood process. To identify novel regulators of metastasis in melanoma, we performed a large-scale RNA sequencing screen of 48 samples from patient-derived xenograft (PDX) subcutaneous melanomas and their associated metastases. In comparison with primary tumors, expression of glycolytic genes was frequently decreased in metastases, whereas expression of some tricarboxylic acid (TCA) cycle genes was increased in metastases. Consistent with these transcriptional changes, melanoma metastases underwent a metabolic switch characterized by decreased levels of glycolytic metabolites and increased abundance of TCA cycle metabolites. A short isoform of glyceraldehyde-3-phosphate dehydrogenase, spermatogenic (GAPDHS) lacking the N-terminal domain suppressed metastasis and regulated this metabolic switch. GAPDHS was downregulated in metastatic nodules from PDX models as well as in human patients. Overexpression of GAPDHS was sufficient to block melanoma metastasis, whereas its inhibition promoted metastasis, decreased glycolysis, and increased levels of certain TCA cycle metabolites and their derivatives including citrate, fumarate, malate, and aspartate. Isotope tracing studies indicated that GAPDHS mediates this shift through changes in pyruvate carboxylase activity and aspartate synthesis, both metabolic pathways critical for cancer survival and metastasis. Together, these data identify a short isoform of GAPDHS that limits melanoma metastasis and regulates central carbon metabolism. SIGNIFICANCE: This study characterizes metabolic changes during cancer metastasis and identifies GAPDHS as a novel regulator of these processes in melanoma cells.

Cytoplasmic RNA quality control failure engages mTORC1-mediated autoinflammatory disease.

Inborn errors of nucleic acid metabolism often cause aberrant activation of nucleic acid sensing pathways, leading to autoimmune or autoinflammatory diseases. The SKIV2L RNA exosome is cytoplasmic RNA degradation machinery that was thought to be essential for preventing the self-RNA-mediated interferon (IFN) response. Here, we demonstrate the physiological function of SKIV2L in mammals. We found that Skiv2l deficiency in mice disrupted epidermal and T cell homeostasis in a cell-intrinsic manner independently of IFN. Skiv2l-deficient mice developed skin inflammation and hair abnormality, which were also observed in a SKIV2L-deficient patient. Epidermis-specific deletion of Skiv2l caused hyperproliferation of keratinocytes and disrupted epidermal stratification, leading to impaired skin barrier with no appreciable IFN activation. Moreover, Skiv2l-deficient T cells were chronically hyperactivated and these T cells attacked lesional skin as well as hair follicles. Mechanistically, SKIV2L loss activated the mTORC1 pathway in both keratinocytes and T cells. Both systemic and topical rapamycin treatment of Skiv2l-deficient mice ameliorated epidermal hyperplasia and skin inflammation. Together, we demonstrate that mTORC1, a classical nutrient sensor, also senses cytoplasmic RNA quality control failure and drives autoinflammatory disease. We also propose SKIV2L-associated trichohepatoenteric syndrome (THES) as a new mTORopathy for which sirolimus may be a promising therapy.

The frequency of assessment of progression in randomized oncology clinical trials.

BACKGROUND: Progression in tumor assessments is often detected at a follow-up appointment rather than when actual change in progression has occurred, which can bias PFS outcomes. AIM: We sought to evaluate the frequency of tumor assessment scans in clinical trials of anti-cancer interventions and to compare this to recommended (National Comprehensive Cancer Network) and real-world frequencies of tumor assessments. METHODS: In a cross-sectional analysis, we searched for articles published in the three top oncology journals between July 2017 and June 2020. We included articles that were RCTs of patients that had unresectable or metastatic solid tumors and used an intervention that was designed to be anti-tumor. We abstracted median PFS survival for each group, the PFS hazard ratio, frequency of tumor assessment scans, tumor type, intervention type, and information regarding the study. RESULTS: We found that, in the 182 comparisons (163 articles), less frequent tumor assessment (occurring more than 9 weeks between assessments) was associated with higher median PFS values for both the intervention group (p < .0001) and the control group (p < .0001). PFS hazard ratios for studies scanning for tumors every 10 or more weeks were no different than for studies scanning for tumors more frequently (p = .88). Data on the frequency of tumor assessments in the real world is sparse. CONCLUSION: We found that less frequent tumor assessment frequency was associated with longer median PFS in both intervention and control groups of clinical oncology trials but was not associated with differences in PFS hazard ratios. Future research is needed to compare real world to trial assessment.

Ten years later: a review of the US 2009 institute of medicine report on conflicts of interest and solutions for further reform.

Conflicts of interest (COIs) in healthcare are increasingly discussed in the literature, yet these relationships continue to influence healthcare. Research has consistently shown that financial COIs shape prescribing practices, medical education and guideline recommendations. In 2009, the Institute of Medicine (IOM, now the National Academy of Medicine) published Conflicts of Interest in Medical Research, Practice, and Education-one of the most comprehensive reviews of empirical research on COIs in medicine. Ten years after publication of theIOM's report, we review the current state of COIs within medicine. We also provide specific recommendations for enhancing scientific integrity in medical research, practice, education and editorial practices.