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Pigment Cell & Melanoma Research

Wiley

Preprints posted in the last 90 days, ranked by how well they match Pigment Cell & Melanoma Research's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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Nanopore sequencing identifies a new Tyr::CreERT2 allele circulating in existing mouse stocks

Pomfret, L.; Nugawela, A.; Wilkinson, E.; Shih, B. B.-J.; Mort, R.

2026-07-30 genetics 10.64898/2026.07.29.741227 medRxiv
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The Tyr::CreERT2 transgenic mouse lines are essential tools for conditional gene manipulation in melanocytes and are widely used in melanoma research. Two independent lines are in common use: the Bosenberg line and the Larue line. Precise knowledge of transgene integration sites is critical for designing complex genetic crosses, yet the integration sites for these lines have only recently been characterised by whole genome sequencing. Here we report that a Tyr::CreERT2 mouse stock routinely used in BrafCA;Ptenflox melanoma models carries a previously undescribed integration on Chromosome 1, distinct from the previously reported Chromosome 2 integration. Using long-read nanopore sequencing, we mapped the integration to an intergenic locus between Alppl2 and Alpi, revealing a 2,430 bp genomic deletion at the insertion site. We developed position-specific junction PCR and qPCR assays to genotype this allele and confirmed that offspring are born at Mendelian ratios. Given that this stock is associated with elevated spontaneous melanoma penetrance, accurate characterisation of this allele has direct implications for the many laboratories employing this widely distributed melanoma model. SIGNIFICANCEThis study identifies a previously undescribed Tyr::CreERT2 transgene integration on Chromosome 1 in JAX strain 013590, a line widely used across the melanoma research community. Accurate characterisation of this allele has direct practical implications for the many laboratories that rely on this model for studies of melanoma initiation and progression.

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Rhpn2 promotes zebrafish melanoma development and aggressiveness in vivo

Alavi, M.; Gybels, A.; Gulizia, L.; Konobrocka, K.; Hovhannisyan, G.; Bekar, S.; Perazzolo, C.; Singh, S. P.; Pirson, I.

2026-07-09 cancer biology 10.64898/2026.07.03.736252 medRxiv
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Melanoma, one of the most metastatic and multidrug resistant cancer, is the first leading cause of death from skin cancer. This complex disease requires identification of additional cooperating events that contribute to progression, invasion and metastasis to reinforce therapeutics. RhoGTPases play key roles in cancer development and metastasis. Rhophilin-2 (RHPN2), a Rho effector, is amplified in various human cancers and its role in melanoma remains unexplored. Here, we combined knock-down experiments in human melanoma cells, with knock-out and overexpression experiments in zebrafish to uncover the roles of RHPN2 in melanoma development. We show that in human melanoma cells RHPN2 contributes to growth, and to clonogenic, migratory and invasive properties of the cells. Using NRASQ61L and BRAFV600E zebrafish models, we provide the first in vivo evidence that Rhpn2 promotes melanoma onset and development. Histological analysis of the Rhpn2 deficient tumors showed decreased cellular density and absence of primary cilia structures at the invasive tumor/stroma borders. Transcriptomic profiling of the Rhpn2-KO melanoma revealed increased expression of the IFN1-responsive genes and modulation of genes involved in lipid metabolism and cilia function. Together these findings position RHPN2 as a modulator of melanoma, offering new perspectives in considering it as a target to impair the development of the tumor.

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Topical application of a cryptochrome and REV-ERB inhibitor on human skin increases epidermal XPA and WEE1 expression

Cvammen, W.;Kemp, M.

2026-06-26 Molecular Biology 10.64898/2026.06.25.734574 medRxiv
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The time of day of UV exposure impacts both erythema and cancer development. To investigate whether UV-relevant clock-controlled gene expression can be modulated pharmacologically, we treated human skin explants with a combination of a cryptochoursome inhibitor and REV-ERB antagonist and then examined changes in gene expression of a limited number of core clock and clock-regulated genes. mRNA levels of both the DNA repair factor XPA and cell cycle checkpoint kinase WEE1 were found to be significantly increased by treatment. This pilot study suggests that clock-controlled gene expression can be altered pharmacologically to possibly alter skin responses to UV radiation.

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A Versatile, Spectrophotometer-Based, Quantitative, Visual, Bias-Reducing Method for Human Skin Colour Measurement and Classification

Dadzie, O. E.; Sturm, R. A.; Ali, S.; Fajuyigbe, D.; Petit, A.; Jablonski, N.; Yu, G.

2026-07-31 dermatology 10.64898/2026.07.27.26358883 medRxiv
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We evaluated an inexpensive portable hand-held spectrophotometer for skin colour measurement and classification. Under standardised conditions, skin reflectance and colorimetric data were collected from 40 participants of diverse ancestral backgrounds at three anatomical sites: forehead (FH), right posterior forearm (FA), and right upper inner arm (RUA). Demographic and ancestral data, Fitzpatrick Skin Phototype classification, standardised iPhone 13 images, and visual and device-based skin colour matches were also obtained. Participants spanned the five-point EHSCS scale; visually matched Pantone SkinTone colours numbered 25 for FH, 33 for FA, and 28 for RUA. ITA values derived from colorimetric data were used to generate site-specific classifications using the five-point EHSCS, seven-point ITA scale incorporating Del Bino categories, and ten-point MST categories defined by Ulrich or Lipnick. This versatile spectrophotometer-based approach supports affordable, reproducible, race-, ethnicity-, and ancestry-independent skin colour measurement and classification across multiple scales for dermatologists and other users.

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Staurosporine drives non-canonical melanocyte maturation by coupling β-catenin signaling to actin-dependent dendrite remodeling

Xu, K.; Yang, L.; Lai, S.; Yang, F.; Kuroda, Y.; Tsuruta, D.; Katayama, I.

2026-06-10 cell biology 10.64898/2026.06.05.730514 medRxiv
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Skin pigmentation relies on the coordinated regulation of melanin production and dendritic morphology to ensure effective pigment distribution. While staurosporine is widely used as a proapoptotic agent in malignant cells, its effects on normal human melanocytes have not been fully characterized. Here, we investigated the impact of staurosporine on melanocyte biology and identify it as a potent inducer of non-canonical melanocyte maturation at sub-cytotoxic concentrations. In primary human neonatal melanocytes, staurosporine treatment enhances melanogenesis and promotes pronounced dendritic remodeling, leading to functional maturation distinct from its apoptotic effects in melanoma cells. Phenotypic analyses demonstrate increased pigment production and expanded dendritic networks that support efficient pigmentation. Molecular characterization indicates that these effects are associated with coordinated activation of {beta}-catenin signaling and actin-dependent cytoskeletal remodeling. The physiological relevance of these findings was further examined in vivo. Topical application of staurosporine to normal guinea pig skin increased baseline pigmentation without detectable inflammation. In addition, staurosporine accelerated repigmentation in a rhododendrol-induced leukoderma model by restoring functionally mature melanocyte populations and enhancing nuclear localization of {beta}-catenin. Together, these results identify staurosporine as a non-canonical modulator of melanocyte maturation and highlight the coordinated regulation of pigment production and dendritic remodeling as a key process supporting pigmentation in acquired hypopigmentary conditions. SummaryO_LIStaurosporine promotes non-canonical maturation of human melanocytes at sub-cytotoxic concentrations. C_LIO_LITreatment enhances both melanogenesis and dendritic remodeling, supporting functional pigmentation. C_LIO_LIStaurosporine increases baseline skin pigmentation in vivo without inducing inflammation. C_LIO_LIRepigmentation is accelerated in a rhododendrol-induced leukoderma model through restoration of mature melanocyte populations. C_LIO_LIThese findings highlight coordinated regulation of pigment production and dendritic morphology as a potential strategy to promote pigmentation in acquired hypopigmentary conditions. C_LI SignificanceLoss of melanocyte dendricity and functional maturation is a shared feature of multiple acquired hypopigmentary disorders, including vitiligo and chemical-induced leukoderma. This study demonstrates that staurosporine promotes dendritic remodeling and pigmentation in normal human melanocytes and enhances repigmentation in vivo. By identifying a melanocyte-intrinsic, ultraviolet-independent maturation program, our findings provide a biological framework for strategies aimed at restoring functional melanocytes in depigmented skin.

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Uveal and cutaneous melanoma share a common mutation with distinct prognostic implications: A bioinformatic study

Razmjooei, F.; Ashayeri, H.; Jafarzadeh, Z.; Dabbaghabdollahi, P.; Jafarizadeh, A.

2026-08-11 genetic and genomic medicine 10.64898/2026.08.07.26359988 medRxiv
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Background: Uveal melanoma (UM) and cutaneous melanoma (CM) both originate from the same cell line. This proposes the possibility of a shared mechanism between entities, requiring explicit investigation. Methods: Data from GWAS Catalog and DisGeNET were used to identify shared variation-disease associations (VDAs) between UM and CM. The results were validated using the Ensembl database. In the next step, the STRING database was used to identify the protein-protein interaction. Results: Subsequently, 109 unique VDAs were identified for UM and 880 for CM. However, only 2 VDAs were found to be shared among UM and CM in different ethnic groups. These shared VDAs were rs12203592 of the IRF4 gene, rs12913832 of the HECT and RLD domain-containing E3 ubiquitin protein ligase 2 (HERC2) gene. Notably, PPI network assessment through STRING showcased that OCA2 and IRF4 directly interacted with HERC2. Conclusion: While HERC2 acts as a poor prognostic factor in uveal melanoma, IRF4 status is a key prognostic indicator in both UM and CM. Identifying IRF4 allele contributions enables a better understanding of melanoma pathogenesis and fosters the development of disease-specific approaches.

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SERCA2b loss of function drives pigmentation by inducing adaptive ER stress and enhancing mitochondrial calcium uptake: significance in pathological hyperpigmentation associated with Darier’s Disease

Sharma, A.;Saurav, S.;Sharma, P.;Agrawal, A.;Sharma, N.;Rajan, G.;Bhalla, D.;Pandhi, D.;Yenamandra, V.;Tanwar, J.;Motiani, R.

2026-06-23 Cell Biology 10.64898/2026.06.22.733702 medRxiv
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Pigmentation is a critical protective mechanism that safeguards the skin against UV-induced damage, whereas dysregulated pigmentation predisposes to pigmentary disorders and skin malignancies. Although calcium signaling has emerged as an important regulator of melanogenesis, the identity of the calcium-handling proteins and the molecular mechanisms linking calcium dynamics to pigmentation remain poorly understood. Here, we identify the ER calcium pump SERCA2b as a negative regulator of pigmentation through modulation of ER stress and mitochondrial calcium uptake. We demonstrate that SERCA2b expression inversely correlates with pigmentation levels, and gain- and loss-of-function studies establish SERCA2b as a suppressor of melanogenesis. Mechanistically, SERCA2b depletion induces adaptive ER stress, enhances ER-mitochondrial proximity, and promotes mitochondrial calcium uptake. Notably, mutations in SERCA2b are associated with Darier disease, a condition characterized by hyperpigmented skin lesions, although the underlying mechanism remains unknown. To address this, we generated SERCA2b mutants corresponding to variants identified in Indian Dariers disease patients and examined their effects on pigmentation, ER stress, and mitochondrial calcium dynamics. The mutant phenotypes closely recapitulated SERCA2b loss-of-function effects, demonstrating that adaptive ER stress and enhanced mitochondrial calcium signaling underlie hyperpigmentation associated with Dariers disease. Importantly, treatment with 4-phenylbutyrate (4-PBA), an FDA-approved ER stress alleviator, rescued mutant-induced hyperpigmentation, reduced ER stress, and normalized mitochondrial calcium uptake. Collectively, our findings uncover a previously unrecognized role of SERCA2b in skin pigmentation, establish a mechanistic link between SERCA2b mutations and hyperpigmentation, and identify adaptive ER stress pathways as potential therapeutic target for pigmentary disorders.

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State tanning bed availability is associated with early-onset Melanoma incidence in the Midwest and Southern United States

Graffam, D.; Semprini, J.

2026-08-24 dermatology 10.64898/2026.08.21.26361039 medRxiv
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Despite known carcinogenic properties, indoor tanning remains popular among young adults and may contribute to early-onset melanoma. Our study aims to compare early-onset melanoma incidence by state availability of tanning beds. We analyzed population-based melanoma incidence data (2019-2023) from the National Program of Cancer Registries and calculated Incidence Rate Ratios (IRR) using verified state-level quintiles of tanning bed availability. Overall, in the Midwest/South regions, melanoma incidence increased with greater tanning-bed availability, from 8.7 cases per 100,000 population in Quintile 1 to 14.8 cases per 100,000 population in Quintile 5 (IRR = 1.69; CI = 1.65-1.74). No such relationship was found in the Northeast/West regions. In conclusion, we found that in Southern and Midwest states, increased availability of tanning beds was associated with higher early-onset melanoma in non-Hispanic White males and females, in both metro and non-metro counties. Policies which reduce tanning bed availability in high utilization regions may have potential to reduce early-onset melanoma.

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Short-term psychosocial outcomes following disclosure of glaucoma polygenic risk score (INSiGHT Study)

Maxwell, G. E.; Allen, R.; Hodge, L.; Kelley, S.; Craig, J. E.; Cohen-Woods, S.; Souzeau, E.

2026-07-01 genetic and genomic medicine 10.64898/2026.06.24.26356219 medRxiv
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Early glaucoma detection and treatment are critical to prevent irreversible blindness. Glaucoma polygenic risk scores (PRS) offer an effective approach for stratifying disease risk and are increasingly available in clinical practice. However, the psychosocial impact of receiving glaucoma PRS results is currently unknown. As such, this study investigated short-term psychosocial outcomes of disclosing glaucoma PRS to individuals over 50 years from the general population. Individuals from the bottom 10%, middle 45 to 55%, and top 10% of PRS scores were invited to receive their results and complete surveys before and 2 weeks after receiving results to assess anxiety, test-related distress, decisional regret, recall and understanding. Of invited participants, 51.7% (136/263) enrolled with 133 completing both surveys. Two weeks after disclosure, PRS recall was high (78.2%), although PRS knowledge remained limited. Privacy concerns were moderate, not differing across PRS groups (X^2 = 4.17, p = .124). Small reductions in glaucoma-related anxiety (z = -2.93, p = .003), generalised anxiety (z = -3.75, p < .001) and stress (z = -2.49, p = .013) were observed following disclosure. While scores remained within normal ranges, higher glaucoma-related anxiety (t = -2.36, p = .020), higher negative emotions (X^2 = 20.80, p < .001), and lower positive experience (F = 5.70, p = .004) were seen for high-risk participants compared to lower-risk participants. Decisional regret was low and did not differ across PRS groups (X^2 = 0.28, p = .869). These findings support the psychosocial safety of glaucoma PRS testing while highlighting the need for improved education and longer-term follow-up to support clinical implementation.

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Doxycycline Modulates Uveal-Melanoma-Associated Marker Expression in BAP1-Repressed Human Ocular Organoids

Blenkinsop, T. A.; Chiu, E. A.

2026-07-28 cancer biology 10.64898/2026.07.26.740828 medRxiv
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Uveal Melanoma (UM) is the most common eye cancer, with a metastatic mortality rate of 80%. Only 1-3% of patients have detectable UM at metastasis, and UM exhibits punctuated early growth. Doxycycline has recently been shown to inhibit metabolic processes exploited by cancer cells and reduce cancer cell growth in models of liver cancer. We hypothesized doxycycline may also be effective in UM and therefore tested doxycycline treatment in an eye organoid model of uveal melanoma. Using a stem cell line whereby BAP1 can be knocked down with a tetracycline-inducible system, we differentiated this line into a whole eye organoid model termed self-formed ectodermal autonomous multi-zone of ocular cells (SEAM). We found an enhanced proliferation in neural crest cells within the SEAM colonies. To identify the neural crest cells, we conducted single-cell RNA sequencing (scRNA-seq) analysis utilizing the Seurat R toolkit to pinpoint genes within neural crest clusters. To confirm the results of the in silico scRNA-seq analysis, genes with notable functions and differential expression in the neural crest cluster in relation to UM proliferation, angiogenesis, and oxidative phosphorylation were analyzed through immunofluorescence and RT-qPCR. Based on the scRNA-seq analysis, immunofluorescence, and RT-qPCR, the novel BAP1 KD (UM phenotype) model was found to replicate UM-relevant gene and protein expressions effectively, so the BAP1 KD (UM phenotype) was then treated with doxycycline to evaluate its effect on UM metastasis. Subsequent analysis found that doxycycline significantly inhibited UM growth, angiogenesis, and oxidative phosphorylation in the BAP1 KD (UM phenotype) model more than that of the control model, perhaps due to doxycycline targeting higher regions with more mitochondrial activity, indicating doxycyclines therapeutic potential in treating UM.

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Inhibition Of Ligand-Dependent Bmp Signaling Blunts Melanoma Growth

Gramann, A.;Ejemel, M.;Venkatesan, A.;Ferreira, L.;Zammitti, C.;Wiseheart, D.;Wang, Y.;Brehm, M.;Ceol, C.

2026-06-26 Cancer Biology 10.64898/2026.06.25.734518 medRxiv
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Treatments for advanced melanoma have markedly improved, but a significant proportion of patients still receive little to no survival benefit with standard-of-care therapies due to resistance and relapse1-5. The discovery and development of novel targets and therapies are needed to continue to improve patient outcomes in advanced melanoma. The identification of ligand-dependent BMP signaling that inhibits differentiation and promotes survival of melanoma cells suggests it is a potential therapeutic target that could complement current therapies6. Expression of the BMP ligand GDF6 (a.k.a BMP13) is responsible for this activity, and its expression is correlated with poor outcomes for melanoma patients. Here, we describe a novel monoclonal antibody targeting GDF6 that causes melanoma cell differentiation and death and blunts tumor growth in vivo. Together, these results indicate BMP-directed therapy has significant potential as a novel therapy for patients with advanced melanoma.

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The clinical utility of functional testing in fibroblasts to diagnose primary mitochondrial disease

Van Hove, J. L. K.; Friederich, M. W.; Van Hove, R. A.; Lee, J. C.; Knight, K. M.; Donovan, T. E.; Silveira, L.; Ganetzky, R.; Hirano, M.; Abdenur, J. E.; Butler, M. G.; Cassiman, D.; Cohen, B. H.; Elsea, S. H.; Enns, G. M.; Gahl, W. A.; Gavrilova, R.; Geddes, G. C.; Glamuzima, E. E.; Goldstein, A. C.; Haas, R. H.; Khan, A.; Kripps, K. A.; Larson, A.; Lehman, A. N.; Lichter-Konecki, U.; Mayr, J. A.; Morava, E.; Peterson, J. T.; Rosenfeld, J. A.; Saneto, R. P.; Scaglia, F.; Shelkowitz, E.; Simon, M. T.; Smet, J. E.; Smith, W. E.; Soler-Alfonso, C.; Tarnopolsky, M. A.; Van Coster, R. N. A.; Vanl

2026-06-15 genetic and genomic medicine 10.64898/2026.06.12.26355546 medRxiv
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Genome sequencing of the heterogeneous primary mitochondrial disorders (PMD) frequently reveals variants of uncertain significance that require functional tests for diagnosis, and does not identify variants in all patients. We analyzed mitochondrial enzyme assays, blue native polyacrylamide gel electrophoresis (BN-PAGE) with in-gel activity staining, complex I assembly blot, and select protein abundances in fibroblasts of a case series of 204 PMD patients divided into functional classes, in comparison to 51 controls and 53 differential diagnostic conditions. Overall, sensitivity and specificity for respiratory chain enzyme assays were 46% and 93% respectively, for BN-PAGE 40% and 98%, for complex I assembly assay 49% and 99%. The overall sensitivity of all tests was 76%, specificity 93%, with positive predictive value 96% and negative predictive value 67%. Categories with high sensitivity were isolated complex deficiencies, nuclear DNA-encoded mitochondrial protein synthesis defects, co-factor defects, and mitochondrial amino-acyl-tRNA synthetase conditions when aided by protein abundance. Mitochondrial DNA mutations and maintenance disorders showed poor sensitivities. Secondary dysfunctions were rare. A complete battery of functional tests showed strong diagnostic clinical utility in fibroblasts.

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Rod pathway blockade improves visual function in a mouse model of photoreceptor degeneration

Taylor, W. R.; Puthussery, T.; Kulkarni, M.; Gayet, J.; Cosio, K.; Zheng, A.

2026-07-21 systems biology 10.64898/2026.07.17.739110 medRxiv
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Retinitis pigmentosa (RP) refers to a group of inherited photoreceptor degenerations characterized by the initial death of rods and secondary loss of cones. In animal models of RP, the ganglion cells (GCs) exhibit increased spontaneous activity that can mask residual photoreceptor signals and reduce the efficacy of treatments for vision restoration. The A2 amacrine cells (ACs) are inhibitory interneurons that propagate aberrant activity to GCs, but it remains unclear whether rod or cone pathways drive altered A2-AC signaling or whether the relative contributions of these pathways change with disease progression. We examined the circuit mechanisms underlying aberrant activity in the rd10 mouse model and found that blocking rod pathway input to A2-ACs suppressed aberrant activity and improved the signal-to-noise ratio of residual cone-driven responses in On- GCs. The results also indicate that the On- but not the Off-pathway exhibits circuit-level compensation during the loss of photoreceptor input. The results suggest that pharmacological blockade of the rod pathway may improve residual cone-mediated function and improve the efficacy of vision restoration in rod-cone photoreceptor degenerations.

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A Translational Reference for Green Autofluorescence Imaging in the Rhesus Macaque Eye using the OcuMet Beacon

Ripolles-Garcia, A.; Lim, J.; Raposo, A. C.; Bailey, J. C.; Handel, K. W.; Khan, M. J.; Sutton, L. R.; Yu, J.; Dougherty, E. K.; Nguyen Jaggers, T.; Lam, B.; Valjalo, Y. N.; Thienpaitoon, R.; Muniz, N. A.; Giorgi, E.; Villafuerte-Trisolini, C. I.; Anderson, K.; Habbas-Nimer, N.; Rich, C. A.; Riegger, K.; Moshiri, A.; Leonard, B. C.; Yiu, G.; Thomasy, S. M.

2026-08-19 physiology 10.64898/2026.08.11.744247 medRxiv
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PurposeTo evaluate associations between green autofluorescence (GAF) and structural and functional measures relevant to retinal and optic neuropathies, and to establish normative GAF values across the optic nerve head (ONH), macula, and papillofoveal bundle (PFB) in rhesus macaques. MethodsEighty-two macaques with normal ONH morphology by spectral-domain optical coherence tomography (SD-OCT) were included with a mean {+/-} SD age of 12.76 {+/-} 7.18 (range 0.11-29.39) years. The GAF images were acquired in the ONH, macula and PFB with the OcuMet Beacon. In a subset of macaques (n=19), pattern electroretinogram (PERG) and photopic full-field ERG including the photopic negative response (PhNR) were recorded. ResultsThe GAF significantly increased with age in the ONH, macula and PFB. After adjusting by age, there were no sex differences, but IOP showed a positive association with macular GAF. At the ONH, higher GAF correlated with thinner retinal nerve fiber layer, inner and outer segment complex, and total retinal thickness. In the macula, inner nuclear layer thickness was positively associated with GAF, whereas outer plexiform layer and inner and outer segment complex were inversely associated. The PERG amplitudes inversely tracked ONH GAF. ConclusionsGAF rises with age and IOP, couples to retinal structure, and at the ONH, aligns with inner-retinal functional indices. This study provides a regional reference for GAF in rhesus macaques. Translational RelevanceNormative GAF data in healthy rhesus macaques provide a framework for interpreting this noninvasive signal in translational studies of retinal and optic nerve disease.

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Clinical phenotypes of uveal melanoma in patients with germline pathogenic/likely pathogenic BAP1 variants.

Abdallah, R.; Taylor, O. B.; McElroy, J.; Ramsey, K.; Byrne, L.; Elsayed, A. M.; Cebulla, C. M.; Abdel-Rahman, M. H.

2026-07-01 ophthalmology 10.64898/2026.06.29.26356877 medRxiv
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Germline pathogenic or likely pathogenic variants (GPVs) in BRCA-1 Associated Protein 1 (BAP1) are associated with a spectrum of tumors, including uveal melanoma (UM). Currently, UM patients with BAP1 GPVs are treated as high-risk class 2 tumors based on mostly empiric data. In the current study, we examined the clinical phenotype of a cohort of 29 UM patients with BAP1 GPVs. We also carried out a systematic review of the literature of UM patients with BAP1 GPVs. We observed that UM patients with BAP1 GPVs have significantly lower median age of diagnosis compared to median age reported in UM patients in the Surveillance, Epidemiology, and End Results Program (SEERS) database. Metastatic risk and overall survival in the UM BAP1 GPVs cohort were statistically significant from those in patients with class 1 tumors, but were comparable to those observed in UM patients with class 2 tumors. In UM BAP1 GPVs treated with radiation (n=12), no secondary cancers were observed in the field of radiation in a median 26.5 months (range, 4-119 months) follow up period. One patient experienced a separate growth of UM at a distinct location within the same eye. These data support managing UM in patients with BAP1 GPVs as aggressive class 2 tumors, following the currently established standard of care for these high-risk tumors.

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Model of naturally occurring refractive error (NORE) in mice

Bentley-Ford, M. R.; Palumaa, T.; Lou, L.; Jonnalagadda, A.; Bade, M. L.; Balamurugan, S.; Mazade, R.; Pardue, M. T.

2026-07-06 genetics 10.64898/2026.07.01.735855 medRxiv
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Purpose: Animal models of myopia typically induce monocular refractive shifts via form deprivation (FD) or lens-induced myopia (LIM), modeling susceptibility to myopia, but with potentially limited applicability to childhood myopia. Here we describe a novel, genetically diverse mouse model of naturally occurring refractive error (NORE) with three distinct refractive phenotypes: hyperopic, myopic, and intermediate. Methods: C57BL/6J mice were mated to 129S2/SvPasCrl mice to create F1 or F2 offspring. Refractive errors in male and female F1 (N=21) and F2 (N=101) mice were assessed on postnatal days (P) 28 and 42 using photorefractometry. In a subset of mice (N=30 - 40), corneal radius of curvature, axial ocular dimensions, retinal and visual function were assessed. Results: F2 mice were classified as NORE with either hyperopic (RE [&ge;] 0 diopters (D) at P28 and P42), myopic (RE<0D at P28 and P42) or intermediate (RE<0D at P28 and RE [&ge;] 0D at P42) refractions based on individual trajectories. All ocular parameters changed with age, with significantly slower growth in axial length and vitreous chamber depth in the intermediate versus myopic mice (p<0.05). Lens thickness was smaller in the myopic group at P28. Differences in refraction were not attributed to variances in retinal function or dopamine signaling. Conclusions: NORE mice represent a novel, genetically diverse wild-type mouse model that, unlike traditional models, does not require interventions such as FD or LIM to induce myopia. NORE mice provide a valuable tool for future investigations of genetic and environmental mechanisms and targeted therapeutic strategies for refractive errors.

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The Unlabeled Organ: Adipose tissue and normativity in anatomy and physiology texts

Hermsmeyer, I. D. K.; MacDougald, O. A.; Orczykowski, M. E.

2026-07-17 scientific communication and education 10.64898/2026.07.14.736897 medRxiv
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Adipose tissue is a dynamic and essential organ system with roles in metabolism, endocrine signaling, immune function, thermoregulation, and structural support. Despite this, it has historically been framed as inert or pathological, raising questions about how it is represented in biomedical education. We evaluated the visual and textual representation of adipose tissue across widely used anatomy, physiology, and combined anatomy-physiology textbooks. Images were coded for presence, labeling, and degree of representation, and text mentions of "adipose" and "fat" were quantified across functional contexts. In anatomy textbooks, adipose tissue was frequently present (6.6-21.7% of images) but rarely labeled (<5% of all images; <25% of adipose-containing images). Representation was often minimal or incidental, and text descriptions were predominantly non-functional, with a preference for the term "fat." In physiology textbooks, adipose tissue was more often described in functional terms and more frequently referred to as "adipose," particularly in metabolic contexts, but appeared in relatively few images (<5%) and was typically minimally depicted. Combined anatomy-physiology texts showed intermediate patterns but retained low labeling rates and limited integration of structure and function. Across all textbook types, terminology varied by context, with "fat" more common in non-functional and obesity-related descriptions and "adipose" associated with metabolic functions, suggesting context-dependent bias in terminology. Overall, adipose tissue is present but inconsistently framed across visual and textual domains. This fragmentation may limit recognition of adipose tissue as an integrated organ system and may reinforce reductive or stigmatizing interpretations. Aligning educational representations with current scientific understanding is therefore essential to support a more accurate and integrated view of adipose tissue as a dynamic organ system.

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Identification of a Novel Alternatively Spliced CRYBA1 Transcript in Unilateral Childhood Cataract Associated with Persistent Fetal Vasculature

Sankaranarayanan, R.; Vasavada, A. R.; Agrawal, D.; Vasavada, S. A.; Vasavada, V. A.

2026-07-13 genetic and genomic medicine 10.64898/2026.07.08.26357271 medRxiv
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Purpose: To identify transcript-level variants in crystallin genes in paediatric patients with unilateral cataracts. Methods: Anterior capsulorhexis (n=12) from patients underwent surgical management of congenital unilateral cataracts was collected. Total RNA was isolated from lens epithelial cells, and complementary DNA (cDNA) was synthesized. Full-length RNA transcripts of 10 lens-specific crystallin genes were PCR-amplified and analysed via Sanger sequencing. Identified transcript variants were further validated using genomic DNA (gDNA) through Sanger sequencing. In addition, the full-length (~7,535 bp) CRYBA1 genomic region was sequenced using Oxford Nanopore Technology. Results: Aberrant low molecular weight (LMW) amplicons (~370 bp) of the CRYBA1 transcript were identified in three patients presented with unilateral cataract. Of 3 patients, 2 had persistent fetal vasculature (PFV) and 1 had pre-existing posterior capsular defect (PPCD). Sanger sequencing revealed a precise loss of exons 2 to 4 in the CRYBA1 RNA transcript. No coding, splice-site, or large deletion variants were detected in the genomic DNA of the patients or their parents. In silico analysis predicted two possible truncated proteins arising from these alternatively spliced transcripts: one comprising the first 11 amino acids of the N-terminal region with a loss of all Greek key motifs, and another comprising 90 amino acids encoded by exons 5 and 6, initiated from an alternative start codon in exon 5, and loss of Greek key motifs 1 & 2. Conclusion: The precise skipping of exons 2 to 4, consistent with canonical splicing signals (5-prime-GU...AG-3-prime), in the absence of genomic alterations, suggests the presence of alternatively spliced (AS) CRYBA1 transcripts in human lenses. This is the first report documenting AS-CRYBA1 transcripts in association with childhood cataracts with PFV and PPCD.

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Teaching adipose tissue as an organ system: addressing weight bias and enhancing anatomical understanding through AdipoAtlas

Hermsmeyer, I. D. K.; Sonneville, K. R.; Patterson, A. M. S.; Sherwood, R. M.; Orlikoff, E. R.; MacDougald, O. A.; Orczykowski, M. E.

2026-07-30 scientific communication and education 10.64898/2026.07.29.741583 medRxiv
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Adipose tissue (body fat) is increasingly recognized as a dynamic organ system essential to human health, with distinct depots that serve specialized biological functions. However, this understanding is not reflected in traditional human anatomy curricula, where adipose tissue is typically introduced only as connective tissue and treated in dissection as an obstacle to be removed rather than a structure worthy of study. Anatomy dissection courses have been identified as a source of negative weight bias in medical students, with students reporting disgust toward adipose tissue and frustration with its removal to visualize course-required anatomical structures. Here, we hypothesize that reframing adipose tissue as a functional organ system within anatomy curricula may improve students understanding of human anatomy and mitigate these negative perceptions. To test this, we created a human adipose atlas (AdipoAtlas) by identifying and photographing macroscopic adipose depots in an anatomical donor and organizing these images into an anatomical reference with evidence-based functional descriptions. The atlas was integrated into a human anatomy dissection course, followed by a survey assessing students perceptions of adipose tissue and attitudes related to weight bias, with a concurrent non-dissection anatomy course serving as a control. Students in the adipose-inclusive course reported more positive perceptions and improved understanding of adipose tissue as a multifunctional organ system, while responses related to weight-based discrimination and broader attitudes toward body size were similar between groups. These results support our hypothesis that integrating adipose tissue into anatomy education improves anatomical understanding and may reduce negative weight-related perceptions.

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Automated Melanoma Screening: A Machine Learning Pipeline for Mole Detection, Boundary Segmentation, and ABCD(E) Feature Extraction

Abdolahnejad, M.; Pascazi, E.; Lee, M.; Cheng, J.; Poon, F.; Kyeremeh, M.; Chan, H. O.; Joshi, R.; Hong, C.

2026-07-01 dermatology 10.64898/2026.06.29.26356601 medRxiv
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Early detection of suspicious moles remains the most effective means of reducing mortality from skin cancer, yet systematic screening is constrained by the time and expertise required for manual mole assessment. This paper presents an end-to-end computational pipeline that utilizes wide-angle skin photographs (including consumer-grade smartphone images) and produces quantitative ABCD (Asymmetry, Border irregularity, Color variegation, Diameter) feature scores for every detected mole. The pipeline operates in four stages: mole detection via adaptive thresholding and blob analysis, super-resolution enhancement using EDSR, false-positive filtering using a brightness-based statistical criterion, and lesion segmentation using the Boundary Attention Mapper (BAM). BAM generates high-resolution segmentation masks by fusing early-layer activations with GradCAM heatmaps from a trained EfficientNet-B7 classifier, achieving 90.45% accuracy on the ISIC2017 dataset, outperforming both conventional GradCAM (87.78%) and dedicated segmentation architectures, including DeepLabv3 and SAM v2 by more than 5 percentage points in Dice score. The EfficientNet-B7 backbone achieves a micro-average AUC of 0.97 across eight lesion classes, with a melanoma AUC of 0.99. Color quantification uses K-means clustering with a threshold calibrated on the PH2 dataset (MSE = 1.425). Applied to 87 wide-angle images, the mole detection module achieved an F1 score of 86%. The system outputs a structured CSV of per-lesion ABCD scores suitable for clinical triage and longitudinal tracking. A clinical validation study with dermatologists and surgeons is underway to assess concordance between automated and expert assessments.