Propranolol exhibits activity against hemangiomas independent of beta blockade.

Propranolol is a widely used beta blocker that consists of a racemic mixture of R and S stereoisomers. Only the S stereoisomer has significant activity against the beta-adrenergic receptor. A fortuitous clinical observation was made in an infant who received propranolol for cardiac disease, and regression of a hemangioma of infancy was noted. This has led to the widespread use of propranolol for the treatment of large and life-threatening hemangiomas of infancy. Infants receiving propranolol require monitoring to ensure that they do not suffer from side effects related to beta blockade. The exact mechanism of activity of propranolol in hemangioma of infancy is unknown. In this study, we treated hemangioma stem cells with both beta blockade active S- and inactive R-propranolol and looked for genes that were coordinately regulated by this treatment. Among the genes commonly downregulated, Angiopoietin-like 4 (ANGPTL4) was among the most regulated. We confirmed that propranolol isomers downregulated ANGPTL4 in endothelial cells, with greater downregulation of ANGPTL4 using the beta blockade inactive R-propranolol. ANGPTL4 is present in human hemangiomas of infancy. Finally, R-propranolol inhibited the growth of bEnd.3 hemangioma cells in vivo. The implication of this is that hemangioma growth can be blocked without the side effects of beta blockade. Given that humans have been exposed to racemic propranolol for decades and thus to R-propranolol, clinical development of R-propranolol for hemangiomas of infancy and other angiogenic diseases is warranted.

Palladium based nanoparticles for the treatment of advanced melanoma.

IGF1R and CD44 are overexpressed in most advanced melanomas so we designed chemotherapeutic nanoparticles to target those receptors. Tris(dibenzylideneacetone)dipalladium (Tris DBA-Pd) is a novel inhibitor of N-myristoyltransferase 1 (NMT-1) and has proven in vivo activity against melanoma. However, poor solubility impairs its effectiveness. To improve its therapeutic efficacy and overcome drug resistance in advanced melanomas, we synthesized Tris DBA-Pd hyaluronic acid nanoparticles (Tris DBA-Pd HANP) and evaluated them against in vivo xenografts of LM36R, an aggressive BRAF mutant human melanoma resistant to BRAF inhibitors. We treated xenografted mice in four arms: empty HANPs, free Tris DBA-Pd, Tris DBA-Pd HANPs, and Tris DBA-Pd HANPs with IGF1R antibody. The Tris DBA-Pd HANP group was the most responsive to treatment and showed the greatest depletion of CD44-positive cells on IHC. Surprisingly, the HANP containing IGF1R antibody was less effective than particles without antibody, possibly due to steric hindrance of IGF1R and CD44 binding. Tris DBA-Pd nanoparticles are an effective therapy for CD44-positive tumors like melanoma, and further development of these nanoparticles should be pursued.

Genomic Assessment of Blitz Nevi Suggests Classification as a Subset of Blue Nevus Rather Than Spitz Nevus: Clinical, Histopathologic, and Molecular Analysis of 18 Cases.

Blitz nevi/tumors are a distinct subset of melanocytic neoplasia which show mixed morphologic features of Spitz and blue nevus. Genomically, most blue nevi have GNAQ or GNA11 mutations while most Spitzoid neoplasms have either an HRAS mutation or translocations involving MET, ROS, BRAF, ALK1, NTRK1, and RET. The criteria used for the assessment of malignancy in blue and Spitzoid lesions are different, and these lesions have different prognostic markers. In this study, we assess the clinical, morphological, and genomic changes in 18 cases of Blitz nevi/tumors to better characterize this subset of neoplasms and determine their optimal genomic classification. Most lesions occurred on the extremities followed by the head and neck region typical of blue nevi. Histology showed most cases having a prominent plexiform growth pattern with cells aggregating around the adnexal structures and neurovascular bundles also typical of blue nevi. Using next generation sequencing, we detected the presence of somatic mutations in GNAQ or GNA11 in 4 of 7 cases (57%) of Blitz nevi with sufficient DNA available for sequencing. Normal skin samples in these 4 cases were sequenced to confirm that the GNAQ or GNA11 mutations were somatic mutations. All 4 cases were negative for immunohistochemical assessment for wild-type BRAF, RET, ALK, and NTRK1 and mutational analysis of HRAS was also negative in all cases. Hence, our study suggests that Blitz nevi/tumors are a distinct subset which genomically are best classified as a subset of blue nevi.

Distinct Patterns of Acral Melanoma Based on Site and Relative Sun Exposure.

Acral melanoma is distinct from melanoma of other cutaneous sites, yet there is considerable variation within this category. To better define this variation, we assessed melanomas occurring on dorsal (n = 21), volar (n = 9), and subungual/interdigital (n = 13) acral skin as well as acral nevi (n = 24) for clinical, histologic, and molecular features. Melanomas on dorsal acral surfaces demonstrated clear differences compared with volar and subungual/interdigital melanomas. The latter two groups exhibited significantly less frequent BRAF mutations (P = 0.01), were significantly less likely to have the superficial spreading histologic subtype (P = 0.01), occurred in older patients (P = 0.05), and had more frequent involvement in non-Caucasians (P = 0.01). These differences can be explained by differing levels of UV exposure. Subungual/interdigital melanomas had the most diverse group of oncogenic mutations including PIK3CA (2/13), STK11 (2/13), EGFR (1/13), FGFR3 (1/13), and PTPN11 (1/13). In addition, subungual/interdigital melanomas had a significantly higher frequency of copy number aberrations (67%) than other subgroups (P = 0.02), particularly in CDK4 and cyclin D1, and were less likely to have BRAF mutations or a superficial spreading histologic subtype (P = 0.05) compared with volar acral melanomas. Although based on a limited sample size, differences between volar and subungual/interdigital melanomas in our study may be the result of differing levels of UV exposure.

Genotypic and Phenotypic Features of BAP1 Cancer Syndrome: A Report of 8 New Families and Review of Cases in the Literature.

Importance: Patients with germline mutations in BAP1 may develop several flesh-colored melanocytic BAP1-mutated atypical intradermal tumors (MBAITs). These tumors generally develop earlier than other BAP1-associated tumors, highlighting an important role for dermatologists in identifying and screening patients with a history suggestive of a germline mutation. Objective: To describe 8 new families with germline mutations in BAP1 and provide a comprehensive review of reported cases. Design, Settings and Participants: Patients were identified in an outpatient dermatology clinical setting over a 6-month period (10 mutation carriers from 8 families) and through a literature review using PubMed (205 patients). Exposures: Mutations were identified through next-generation sequencing of saliva or blood samples, and RNA was extracted from fibroblasts cultured from a patient with an intronic variant to determine the impact of the mutation on the coding sequence. Main Outcomes and Measures: All 215 patients were assessed for personal and/or family history and genotype. These findings were compiled and assessed for any association between genotype and phenotype. Results: Overall, this study included 215 patients (108 women, 91 men, and 16 gender unspecified; median [range] age, 46.5 [10.0-79.0] years). Nine of the 10 patients who were identified in the outpatient dermatology setting were found to have MBAITs on clinical examination. Forty of 53 patients (75%) identified in the literature review who underwent total-body skin examinations (TBSE) were found to have MBAITs, suggesting a high penetrance in patients who have undergone TBSE. The most prevalent malignancies among BAP1 mutation carriers were uveal melanoma (n = 60 [28%]), mesothelioma (n = 48 [22%]), cutaneous melanoma (n = 38 [18%]), and renal cell carcinoma (n = 20 [9%]). A total of 71 unique mutations in BAP1 have been reported. Conclusions and Relevance: Our results indicate that germline mutations in both coding and noncoding regions throughout the BAP1 gene can impair protein function, leading to an increased risk for several associated malignancies. Four of the 8 probands we present had no history of BAP1-associated malignancies and were assessed for germline mutations when found to have MBAITs on dermatologic examination. Dermatologists can identify patients with a high likelihood of the BAP1 cancer syndrome through personal and family history and TBSE for the presence of possible MBAITs.

A single-institution assessment of superficial spreading melanoma (SSM) in the pediatric population: Molecular and histopathologic features compared with adult SSM.

BACKGROUND: The epidemiology of pediatric melanoma is distinct from that seen in adults. This is more distinguishable when pediatric patients are separated into prepubertal and adolescent groups. OBJECTIVE: In this study, we compared epidemiologic, clinical, histologic, and molecular characteristics of pediatric superficial spreading melanoma (SSM) in prepubertal and adolescent patients to that in adults. METHOD: We reviewed our database for pediatric melanomas, comparing SSM data between pediatric and adult cases for pathologic stage at presentation, ratio of radial to vertical growth phase, average Breslow depth and mitotic index, and frequency of fluorescence in situ hybridization (FISH) positivity. RESULTS: Of 84 pediatric melanomas, 38 were SSM, and 5 of the latter (6%) were prepubertal. There were no significant differences when pediatric and adult SSM were compared for stage at presentation, ratio of radial to vertical growth phase, average Breslow depth and mitotic count, or frequency of FISH positivity. A significant difference was detected for SSM arising from a precursor nevus (80% of pediatric cases versus 30% of adult cases). LIMITATIONS: Follow-up time was limited for both cohorts. CONCLUSIONS: SSM melanoma is infrequent in childhood, particularly in the prepubertal years. Features such as tumor stage, Breslow depth, mitotic activity, and FISH positivity suggest morphologic and molecular characteristics similar to those of adult SSM.

A clinical, histologic, and follow-up study of genital melanosis in men and women.

BACKGROUND: Genital melanosis may clinically mimic melanoma. Little is known about the potential risk for genital and nongenital melanoma in these patients. OBJECTIVE: In this retrospective cohort study, we analyzed clinical and histologic data from patients with genital melanosis to better characterize these lesions and the risk they confer for genital and nongenital melanoma. METHODS: In all, 41 patients were identified for a retrospective chart review and histologic analysis. RESULTS: Genital melanosis can clinically mimic melanoma but the typical age of onset is younger than for genital melanoma. A majority of lesions were found to stabilize or regress over time. Five patients were found to have a history of melanoma, only 1 of which was in the genital region. Lesions from these patients were more likely to show melanocytes with suprabasal movement (P = .0101) and to have a higher melanocyte count (P < .0462). LIMITATIONS: We present a relatively small cohort of patients with an average follow-up of only 30.5 months. CONCLUSION: Patients with genital melanosis, and in particular those with any level of histologic atypia in the genital melanosis lesion, may require careful total body skin examinations for the possibility of melanoma in any body site.

A Comparison of Morphologic and Molecular Features of BRAF, ALK, and NTRK1 Fusion Spitzoid Neoplasms.

Recent studies have identified translocations involving the kinase domains of ALK, NTRK1, BRAF, RET, and ROS in spitzoid neoplasms. Subsequent studies have also characterized morphologic features corresponding to ALK and NTRK1 translocations. In this study, we sought to further compare morphologic features across a range of 49 genetically defined spitzoid neoplasms with ALK, NTRK1, BRAF, or RET fusions to determine discriminating features. We also compared them with a group of 22 spitzoid neoplasms, which were confirmed to be negative for fusions in ALK, NTRK1, BRAF, and RET. Features with the highest discriminatory value included diameter of the lesion, dermal architecture, and certain cytomorphologic features. Specifically, cases with a large diameter (≥9 mm) and wedge-shaped, plexiform dermal architecture of nests of large, spindle-shaped cells were most likely to have an ALK fusion. NTRK1-fused cases were most likely of the fusions to have Kamino bodies and were typically arranged in smaller nests with smaller predominantly spindle-shaped cells, occasionally forming rosettes. BRAF fusion cases were the only fusion subtype to have a predominance of epithelioid cells, were less organized in nests, and commonly had a sheet-like growth pattern or dysplastic Spitz architecture. BRAF fusion cases were most likely to have high-grade nuclear atypia, to be diagnosed as spitzoid melanoma, to have a positive result by melanoma fluorescence in situ hybridization assay, and to develop copy number gains in the kinase domain of the fusion protein. On the basis of experience from this cohort, BRAF-fused cases appear most likely to progress to melanoma.

Lineage tracing of stem and progenitor cells of the murine corneal epithelium.

Accumulating evidence supports the dogma that the corneal epithelium is regenerated by stem cells located exclusively in the limbal niche, at the corneal periphery. Accordingly, limbal stem cells (LSCs) give rise to progenitors that proliferate and migrate centripetally to repopulate the corneal epithelium, which has a short turnover. Moreover, LSC loss leads to corneal opacity and blindness, while limbal grafting restores patients' vision. However, contradicting data suggested that the limbus does not participate in corneal homeostasis and that the cornea contains stem cells. As of today, only indirect evidence for limbal cell migration under homeostasis or injury has been demonstrated. Here, we performed lineage tracing experiments using R26R-Confetti mice to follow K14+ limbal/corneal epithelial cells stochastically induced to express one out of four fluorescent genes. In homeostasis, radial limbal stripes of slow migrating cells proceeded toward the corneal center while, infrequently, slow cycling limbal clones resembling quiescent stem cells were observed. Additionally, rare corneal clones that did not migrate centripetally, but survived for over 4 months, were inspected. In contrast to limbal stripes, corneal clusters had minor contribution to tissue replenishment in homeostasis. Corneal cells, however, significantly contributed to mild wound repair while large limbal streaks appeared within a week following severe wounding that coincided with partial loss of corneal transparency. This data suggest that the mouse limbus largely contributes to corneal renewal while corneal progenitor cells have a long turnover and, therefore, may be able to maintain the corneal epithelium for several months.