Self‐resolving superficial primary cutaneous mucormycosis in a 7‐week‐old infant

A 7‐week‐old girl, born at 30 weeks' gestational age, presented to clinic for evaluation of a crop of vesicular lesions that were noted after removal of a bandage that had been in place for 4 days. A punch biopsy of the lesion revealed fungal elements that were later identified as Rhizopus spp. The lesion began to self‐resolve, and no further treatment was needed, with full resolution of the lesion by 1 month after presentation. Clinicians should be aware of the variable presentations of mucormycosis and consider fungal infection in the differential diagnosis when evaluating vulnerable patients with skin eruptions.     

Dihydroavenanthramide D prevents UV‐irradiated generation of reactive oxygen species and expression of matrix metalloproteinase‐1 and ‐3 in human dermal fibroblasts

Ultraviolet B (UVB) radiation induces photoageing by upregulating the expression of matrix metalloproteinases (MMPs) in human skin cells. Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component in oats. Although anti‐inflammatory, anti‐atherosclerotic and antioxidant effects have been reported, the antiphotoageing effects of DHAvD are yet to be understood. In this study, we investigated the inhibitory effects of DHAvD on UVB‐induced production of reactive oxygen species (ROS) and expression of MMPs, and its molecular mechanism in UVB‐irradiated human dermal fibroblasts. Western blot and real‐time PCR analyses revealed that DHAvD inhibited UVB‐induced MMP‐1 and MMP‐3 expression. It also significantly blocked UVB‐induced ROS generation in fibroblasts. Additionally, DHAvD attenuated UVB‐induced phosphorylation of MAPKs, activation of NF‐κB and AP‐1. DHAvD regulates UVB‐irradiated MMP expression by inhibiting ROS‐mediated MAPK/NF‐κB and AP‐1 activation. DHAvD may be a useful candidate for preventing UV light‐induced skin photoageing.     

Melanoma mimicking Rosai‐Dorfman disease

Despite well‐defined clinical and histopathological features of melanoma, atypical presentations mimicking other skin disorders can result in a delayed diagnosis or misdiagnosis and subsequent inappropriate treatment. Rosai‐Dorfman disease (RDD) is a rare histiocytic disorder with unique clinical and histopathological features. We report a case of melanoma treated with cryotherapy that mimicked RDD both clinically and histopathologically. We compare this RDD‐like melanoma to classic RDD, outlining the importance of clinicopathological correlation prior to treatment, as well as the potential pitfalls in diagnosis after cryotherapy of pigmented lesions.     

NADPH oxidase is a novel target of delphinidin for the inhibition of UVB‐induced MMP‐1 expression in human dermal fibroblasts

We investigated the reported antiphotoaging effects of the major anthocyanidin delphidin and sought to identify its specific molecular target during UVB‐induced MMP‐1 expression. Delphinidin treatment significantly inhibited UVB‐induced MMP‐1 expression in primary cultured human dermal fibroblasts (HDF), an effect associated with the suppression of MKK4‐JNK1/2, MKK3/6‐p38 and MEK‐ERK1/2 phosphorylation. Further investigation revealed that delphinidin significantly inhibited UVB‐induced ROS production and NOX activity. Interestingly, the inhibitory effect of delphinidin on UVB‐induced NOX activity was stronger than that of apocynin, a pharmaceutical NOX inhibitor. Fractioned cell analysis results using a Western blot assay showed that this effect occurred through the inhibition of UVB‐induced P47^phox (a NOX subunit) translocation from the cytosol to the membrane. Pull down assays demonstrated that delphinidin binds directly to P47^phox in vitro. Collectively, our results suggest that delphinidin targets NOX, resulting in the suppression of UVB‐induced MMP‐1 expression in human dermal fibroblasts.     

Characterization and longitudinal monitoring of melanoma growth in ret‐transgenic mice using a single‐sequence MRI protocol

Spontaneous melanoma models in transgenic mice are increasingly used in preclinical research as they most closely match the progression of melanoma in humans. While optical inspection only allows analysis of tumors located on the skin, the accurate measurement and growth of subcutaneous tumors have not been adequately assessed. To improve the measurement accuracy of melanoma tumors, we used a fast single‐sequence MRI protocol at 9.4 Tesla for longitudinal characterization of a ret‐transgenic mouse model. Repeated MRI (average acquisition time 30 min per animal) of the trunk (excluding head and distal limbs) in six siblings revealed an increase in the mean total tumor volume (TTV) from 102.0 ± 80.5 mm³ at 35 days of age to 434.8 ± 154.9 mm³ by 77 days. The main tumor load was located within the pelvis (>40%), followed by the proximal hind limbs and groins (>30%). The smallest detectable tumor measured 0.07 mm³. Inter‐rater reliability between a radiologist and a veterinarian analysing MRI data was 0.993 for TTV and 0.840 for number of tumors (both p < 0.001). We thus conclude that because of the high variance of TTV of same‐aged mice, MRI should be used (i) to establish treatment groups matched for TTV and (ii) for longitudinal examination of the TTV in mice over the course of treatments.     

Melanoma‐derived IL‐1 converts vascular endothelium to a proinflammatory and procoagulatory phenotype via NFκB activation

Spreading of melanoma is associated with efficient extravasation of circulating tumor cells from the vascular system into distant target organs. This process is accompanied and supported by proinflammatory and procoagulatory conditions. In this study, we analysed the ability of human melanoma cell lines to activate endothelial cells (ECs) in vitro. Some melanoma cells, that is, MV3, were shown to trigger an prompt calcium‐flux‐dependent, procoagulatory endothelial response that was accompanied by luminal release of ultra‐large von Willebrand factor (ULVWF) fibres that were immobilized to the endothelial surface layer. In contrast to MV3‐derived supernatant, prolonged treatment of ECs with WM9‐derived supernatant mediated a pronounced activation of nuclear factor kappa B (NFκB). NFκB activation in ECs was dependent on both IL‐1α and IL‐1β secreted from melanoma cells. Melanoma‐derived IL‐1 mediated an upregulation of proinflammatory cytokines IL‐6 and IL‐8, the intercellular adhesion molecule‐1 (ICAM‐1), the vascular cell adhesion molecule‐1 (VCAM‐1) and the procoagulatory tissue factor (TF) in ECs. Our data show that melanoma cells activate ECs either directly and within seconds or by an IL‐1‐mediated NFκB activation. Both pathways of EC activation convert the regular repressive function of ECs on inflammation and coagulation to a proinflammatory and procoagulatory surface that supports tumor progression.     

Genetic alterations in RAS‐regulated pathway in acral lentiginous melanoma

Studies integrating clinicopathological and genetic features have revealed distinct patterns of genomic aberrations in Melanoma. Distributions of BRAF or NRAS mutations and gains of several oncogenes differ among melanoma subgroups, while 9p21 deletions are found in all melanoma subtypes. In the study, status of genes involved in cell cycle progression and apoptosis was evaluated in a panel of 17 frozen primary acral melanomas. NRAS mutations were found in 17% of the tumors. In contrast, BRAF mutations were not found. Gains of AURKA gene (20q13.3) were detected in 37.5% of samples, gains of CCND1 gene (11q13) or TERT gene (5p15.33) in 31.2% and gains of NRAS gene (1p13.2) in 25%. Alterations in 9p21 were identified in 69% of tumors. Gains of 11q13 and 20q13 were mutually exclusive, and 1p13.2 gain was associated with 5p15.33. Our findings showed that alterations in RAS‐related pathways are present in 87.5% of acral lentiginous melanomas.     

BRAF,KIT and NRAS mutations and expression of c‐KIT,phosphorylated extracellular signal‐regulated kinase and phosphorylated AKT in Japanese melanoma patients

To clarify the status of gene mutation and activation of growth signal in melanoma of Japanese patients in vivo, we analyzed the mutation of BRAF exon 15, NRAS exon 2, and KIT exons 9, 11, 13, 17 and 18 in melanoma cells obtained by laser capture microdissection, and performed direct sequencing in 20 cases of acral lentiginous melanoma (ALM) and 17 cases of superficial spreading melanoma (SSM). In the study of the mutation of BRAF, pyrosequencing was also done. To examine the cell proliferation signaling, immunohistochemistry for phosphorylated extracellular signal‐regulated kinase (pERK), phosphorylated AKT (phosphorylated AKT) and c‐KIT was done. The mutation of BRAF p.V600E was detected in 13 cases of ALM (65.0%) and 12 cases of SSM (70.6%). No NRAS mutation was found in all cases. The mutation in exons 9, 11, and 18 of KIT was detected in nine cases. The mutation of BRAF and KIT showed no correlation with clinical stage, lymph node metastasis, tumor thickness, ulceration and histology. pERK and pAKT was observed in small population of melanoma cells and there was no correlation with gene mutation. Our results indicate that the mutations of BRAF and KIT exist in Japanese melanoma patients, however, the cell growth signaling may be regulated by not only these mutated genes, but by other unknown regulatory factors, which may affect the prognosis of melanoma.     

Anti‐early endosome antigen 1 autoantibodies were detected in a pemphigus‐like patient but not in the majority of pemphigus diseases

Although the major autoantigens in classic pemphigus are desmogleins, sera from various types of pemphigus react with a number of other molecules, including desmocollins and plakin proteins. However, other novel pemphigus‐related autoantigens remain to be identified. In this study, i mmunoblotting for serum from an atypical autoimmune bullous disease patient identified an unknown 175 kDa protein. Subsequent studies using two‐dimensional gel electrophoresis, immunoblotting and mass‐spectrometry identified the 175 kDa protein as early endosome antigen 1 (EEA1). This finding was confirmed by subsequent immunological studies, including indirect immunofluorescence of skin and cultured keratinocytes, two‐dimensional gel electrophoresis and immunoblotting with anti‐EEA1 polyclonal antibody, and preabsorption with EEA1 recombinant protein. Finally, we developed a novel BIOCHIP assay using full‐length EEA1 recombinant protein to detect anti‐EEA1 antibodies. However, none of 35 sera from various types of pemphigus showed anti‐EEA1 antibodies in the BIOCHIP assay, with the exception of the serum from the index case. In addition, various findings in the index case did not suggest pathogenic role of anti‐EEA1 autoantibodies. Therefore, although we successfully identified the 175 kDa protein reacted by a serum of an atypical pemphigus‐like patient as EEA1, novel BIOCHIP study for other pemphigus sera indicated that EEA1 is not a common and pathogenic autoantigen in pemphigus.