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Sample records for melanocyte malignant transformation1

  1. Tissue Inhibitor of Metalloproteinase 1 Expression Associated with Gene Demethylation Confers Anoikis Resistance in Early Phases of Melanocyte Malignant Transformation1

    PubMed Central

    Ricca, Tatiana I; Liang, Gangning; Suenaga, Ana Paula M; Han, Sang W; Jones, Peter A; Jasiulionis, Miriam G

    2009-01-01

    Although anoikis resistance has been considered a hallmark of malignant phenotype, the causal relation between neoplastic transformation and anchorage-independent growth remains undefined. We developed an experimental model of murine melanocyte malignant transformation, where a melanocyte lineage (melan-a) was submitted to sequential cycles of anchorage blockade, resulting in progressive morphologic alterations, and malignant transformation. Throughout this process, cells corresponding to premalignant melanocytes and melanoma cell lines were established and show progressive anoikis resistance and increased expression of Timp1. In melan-a melanocytes, Timp1 expression is suppressed by DNA methylation as indicated by its reexpression after 5-aza-2′-deoxycytidine treatment. Methylation-sensitive single-nucleotide primer extension analysis showed increased demethylation in Timp1 in parallel with its expression along malignant transformation. Interestingly, TIMP1 expression has already been related with negative prognosis in some human cancers. Although described as a MMP inhibitor, this protein has been associated with apoptosis resistance in different cell types. Melan-a cells overexpressing Timp1 showed increased survival in suspension but were unable to form tumors in vivo, whereas Timp1-overexpressing melanoma cells showed reduced latency time for tumor appearance and increased metastatic potential. Here, we demonstrated for the first time an increment in Timp1 expression since the early phases of melanocyte malignant transformation, associated to a progressive gene demethylation, which confers anoikis resistance. In this way, Timp1 might be considered as a valued marker for melanocyte malignant transformation. PMID:19956395

  2. From Melanocyte to Metastatic Malignant Melanoma

    PubMed Central

    Bandarchi, Bizhan; Ma, Linglei; Navab, Roya; Seth, Arun; Rasty, Golnar

    2010-01-01

    Malignant melanoma is one of the most aggressive malignancies in human and is responsible for almost 60% of lethal skin tumors. Its incidence has been increasing in white population in the past two decades. There is a complex interaction of environmental (exogenous) and endogenous, including genetic, risk factors in developing malignant melanoma. 8–12% of familial melanomas occur in a familial setting related to mutation of the CDKN2A gene that encodes p16. The aim of this is to briefly review the microanatomy and physiology of the melanocytes, epidemiology, risk factors, clinical presentation, historical classification and histopathology and, more in details, the most recent discoveries in biology and genetics of malignant melanoma. At the end, the final version of 2009 AJCC malignant melanoma staging and classification is presented. PMID:20936153

  3. Ancient melanocytic nevus: a simulator of malignant melanoma.

    PubMed

    Kerl, Helmut; Wolf, Ingrid H; Kerl, Katrin; Cerroni, Lorenzo; Kutzner, Heinz; Argenyi, Zsolt B

    2011-04-01

    Ancient melanocytic nevus (AN) is an unusual but distinctive melanocytic neoplasm within the spectrum of simulators of malignant melanoma. This report describes 13 patients with AN where a long follow-up information was available. Histopathology is characterized by 2 populations of melanocytes, namely, one with large pleomorphic cells and the other with small melanocytes. A few mitotic figures may be present exceptionally. MIB-1 (Ki67) proliferation marker reveals an overall low nuclear labeling index. Additional important findings are stromal degenerative changes. AN must be especially differentiated from dermal melanoma arising in a nevus. PMID:21399448

  4. The effect of white light on normal and malignant murine melanocytes: A link between opsins, clock genes, and melanogenesis.

    PubMed

    de Assis, L V M; Moraes, M N; da Silveira Cruz-Machado, S; Castrucci, A M L

    2016-06-01

    The skin possesses a photosensitive system comprised of opsins whose function is not fully understood, and clock genes which exert an important regulatory role in skin biology. Here, we evaluated the presence of opsins in normal (Melan-a cells) and malignant (B16-F10 cells) murine melanocytes. Both cell lines express Opn2, Opn4--for the first time reported in these cell types--as well as S-opsin. OPN4 protein was found in a small area capping the cell nuclei of B16-F10 cells kept in constant dark (DD); twenty-four hours after the white light pulse (WLP), OPN4 was found in the cell membrane. Despite the fact that B16-F10 cells expressed less Opn2 and Opn4 than Melan-a cells, our data indicate that the malignant melanocytes exhibited increased photoresponsiveness. The clock gene machinery is also severely downregulated in B16-F10 cells as compared to Melan-a cells. Per1, Per2, and Bmal1 expression increased in B16-F10 cells in response to WLP. Although no response in clock gene expression to WLP was observed in Melan-a cells, gene correlational data suggest a minor effect of WLP. In contrast to opsins and clock genes, melanogenesis is significantly upregulated in malignant melanocytes in comparison to Melan-a cells. Tyrosinase expression increased after WLP only in B16-F10 cells; however no increase in melanin content after WLP was seen in either cell line. Our findings may prove useful in the treatment and the development of new pharmacological approaches of depigmentation diseases and skin cancer. PMID:26947915

  5. BAP1 and BRAFV600E expression in benign and malignant melanocytic proliferations.

    PubMed

    Piris, Adriano; Mihm, Martin C; Hoang, Mai P

    2015-02-01

    BAP1 (BRCA1-associated protein 1) is a tumor suppressor gene whose mutations have recently been reported to increase susceptibility for the development of uveal melanoma, cutaneous atypical and epithelioid melanocytic lesions, clear cell renal cell carcinoma, and other tumors. Screening for BAP1 mutation/loss/inactivation and BRAFV600E mutation can be done by immunohistochemistry. We investigated BAP1 and BRAFV600E expression in 193 sporadic melanocytic lesions (11 dermal nevi, 20 congenital nevi, 40 primary and nondesmoplastic melanomas, 40 desmoplastic melanomas, 23 metastatic melanomas, 17 Spitz nevi, 19 atypical Spitz nevi, 8 atypical Spitz tumors, 14 proliferative nodules arising in congenital nevi, 1 nevus during pregnancy) and 30 melanocytic lesions from 3 patients with family history of uveal melanoma and BAP1 germline mutation. Most sporadic melanocytic lesions exhibited positive BAP1 nuclear staining, except for 1 proliferative nodule arising in congenital nevus, 1 desmoplastic, 1 nevoid, and 2 metastatic melanomas. BRAFV600E positivity was demonstrated in 80% of dermal, 5% of congenital, 6% of Spitz, and 5.5% of atypical Spitz nevi; 29% of proliferative nodules arising in congenital nevi; and 24% of primary and nondesmoplastic and 35% of metastatic melanomas. Combined BAP1 loss and BRAFV600E staining was seen in 67% of BAP1 tumor syndrome-associated lesions and in none of the sporadic melanocytic proliferations including Spitz and atypical Spitz nevi and atypical Spitz tumors, with the exception of 1 primary melanoma. The combined BAP1-BRAFV600E+ immunoprofile appears to be a constant feature of BAP1 tumor syndrome-associated melanocytic lesions, and the designation of Spitz nevi or variants thereof appears to be inaccurate for this group of lesions. PMID:25479927

  6. Transcription analysis in the MeLiM swine model identifies RACK1 as a potential marker of malignancy for human melanocytic proliferation

    PubMed Central

    Egidy, Giorgia; Julé, Sophia; Bossé, Philippe; Bernex, Florence; Geffrotin, Claudine; Vincent-Naulleau, Silvia; Horak, Vratislav; Sastre-Garau, Xavier; Panthier, Jean-Jacques

    2008-01-01

    Background Metastatic melanoma is a severe disease. Few experimental animal models of metastatic melanoma exist. MeLiM minipigs exhibit spontaneous melanoma. Cutaneous and metastatic lesions are histologically similar to human's. However, most of them eventually spontaneously regress. Our purpose was to investigate whether the MeLiM model could reveal markers of malignancy in human melanocytic proliferations. Results We compared the serial analysis of gene expression (SAGE) between normal pig skin melanocytes and melanoma cells from an early pulmonary metastasis of MeLiM minipigs. Tag identification revealed 55 regulated genes, including GNB2L1 which was found upregulated in the melanoma library. In situ hybridisation confirmed GNB2L1 overexpression in MeLiM melanocytic lesions. GNB2L1 encodes the adaptor protein RACK1, recently shown to influence melanoma cell lines tumorigenicity. We studied the expression of RACK1 by immunofluorescence and confocal microscopy in tissues specimens of normal skin, in cutaneous and metastatic melanoma developped in MeLiM minipigs and in human patients. In pig and human samples, the results were similar. RACK1 protein was not detected in normal epidermal melanocytes. By contrast, RACK1 signal was highly increased in the cytoplasm of all melanocytic cells of superficial spreading melanoma, recurrent dermal lesions and metastatic melanoma. RACK1 partially colocalised with activated PKCαβ. In pig metastases, additional nuclear RACK1 did not associate to BDNF expression. In human nevi, the RACK1 signal was low. Conclusion RACK1 overexpression detected in situ in human melanoma specimens characterized cutaneous and metastatic melanoma raising the possibility that RACK1 can be a potential marker of malignancy in human melanoma. The MeLiM strain provides a relevant model for exploring mechanisms of melanocytic malignant transformation in humans. This study may contribute to a better understanding of melanoma pathophysiology and to

  7. Induction of different morphologic features of malignant melanoma and pigmented lesions after transformation of murine melanocytes with bFGF-cDNA and H-ras, myc, neu, and E1a oncogenes.

    PubMed Central

    Ramon y Cajal, S.; Suster, S.; Halaban, R.; Filvaroff, E.; Dotto, G. P.

    1991-01-01

    Malignant melanomas show a remarkable degree of heterogeneity because of different morphologic features, biologic behavior, and prognosis. In this communication, the authors attempted to correlate morphologic heterogeneity of melanomas with transformation by different activated oncogenes; they studied the histologic features of melanocytic lesions induced by murine melanocytes transformed by basic fibroblast growth factor (b-FGF-cDNA) or H-ras, neu, myc, and E1a oncogenes, and the lesions were compared with those observed in human pathology. Tumors formed after grafting onto syngenic mice or subcutaneous injections in nude mice were studied. In syngenic mice, benign melanocytic lesions reminiscent of intradermal nevus were observed with melanocytes transformed with b-FGF-cDNA, and myc and E1a oncogenes. Benign lesions were also formed by neu-transformed melanocytes when they were grafted concomitantly with keratinocytes, whereas malignant tumors were formed by the same cells when grafted alone or together with fibroblasts. In contrast, H-ras melanocytes always formed malignant tumors. In nude mice, b-FGF-transformed melanocytes induced benign lesions, whereas transformed melanocytes by the other oncogenes formed malignant tumors with distinctive and homogeneous morphologic features that depended on the transforming oncogene. Melanomas with either epithelioid cell, spindle cell, small round cell, and anaplastic cell growth patterns could be distinguished after transformation with H-ras, neu, E1a, and myc oncogenes, respectively. These various histologic types are analogous to those that may be observed in human melanomas, even within the same tumor. These studies suggest a possible molecular mechanism for tumor heterogeneity in which distinct oncogenes or oncogenelike activities can be activated in different tumors or discrete parts of the same tumor. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1992762

  8. Expression of the c-Met/HGF receptor in human melanocytic neoplasms: demonstration of the relationship to malignant melanoma tumour progression.

    PubMed Central

    Natali, P. G.; Nicotra, M. R.; Di Renzo, M. F.; Prat, M.; Bigotti, A.; Cavaliere, R.; Comoglio, P. M.

    1993-01-01

    The c-MET proto-oncogene encodes the receptor for the Hepatocyte Growth Factor/Scatter Factor, which is known to mediate mitogenic, motogenic and invasive responses of several cell types. We have analysed by immunohistochemistry and biochemically the expression of c-MET in benign and malignant melanocytic lesions. The Met/HGF receptor which in the melanocytic lineage displays the structural features of the authentic receptor was undetectable in tissue melanocytes and in nevocytic nevi. Only four out of 23 primary melanomas scored positive. Expression was increased to a significant level in 17 out of the 44 metastatic lesions examined. The c-MET expression was homogeneous in multiple metastases from the same patients. Comparative analyses showed both lack of correlation with the expression of the tumour progression associated ICAM-1 adhesion molecule and, in 23% of cases, co-expression with the c-KIT encoded receptor. These findings show that the c-MET gene is expressed at late stages of melanoma progression and suggest that the presence of Met/HGF receptor may contribute to the acquisition of an invasive phenotype. Images Figure 1 Figure 2 PMID:8104462

  9. Value of melanocytic-associated immunohistochemical markers in the diagnosis of malignant melanoma: a review and update.

    PubMed

    Ordóñez, Nelson G

    2014-02-01

    Since the identification of S100 protein as an immunohistochemical marker that could be useful in the diagnosis of melanoma in the early 1980s, a large number of other melanocytic-associated markers that could potentially be used to assist in the differential diagnosis of these tumors have also been investigated. A great variation exists, however, among these markers, not only in their expression in some subtypes of melanoma, particularly desmoplastic melanoma, but also in their specificity because some of them can also be expressed in nonmelanocytic neoplasms, including various types of soft tissue tumors and carcinomas. This article reviews the information that is currently available on the practical value of some of the markers that have more often been recommended for assisting in the diagnosis of melanomas, including those that have only recently become available. PMID:23648379

  10. In vivo assessment of optical properties of melanocytic skin lesions and differentiation of melanoma from non-malignant lesions by high-definition optical coherence tomography.

    PubMed

    Boone, M A L M; Suppa, M; Dhaenens, F; Miyamoto, M; Marneffe, A; Jemec, G B E; Del Marmol, V; Nebosis, R

    2016-01-01

    One of the most challenging problems in clinical dermatology is the early detection of melanoma. Reflectance confocal microscopy (RCM) is an added tool to dermoscopy improving considerably diagnostic accuracy. However, diagnosis strongly depends on the experience of physicians. High-definition optical coherence tomography (HD-OCT) appears to offer additional structural and cellular information on melanocytic lesions complementary to that of RCM. However, the diagnostic potential of HD-OCT seems to be not high enough for ruling out the diagnosis of melanoma if based on morphology analysis. The aim of this paper is first to quantify in vivo optical properties such as light attenuation in melanocytic lesions by HD-OCT. The second objective is to determine the best critical value of these optical properties for melanoma diagnosis. The technique of semi-log plot whereby an exponential function becomes a straight line has been implemented on HD-OCT signals coming from four successive skin layers (epidermis, upper papillary dermis, deeper papillary dermis and superficial reticular dermis). This permitted the HD-OCT in vivo measurement of skin entrance signal (SES), relative attenuation factor normalized for the skin entrance signal (µ raf1) and half value layer (z 1/2). The diagnostic accuracy of HD-OCT for melanoma detection based on the optical properties, µ raf1 , SES and z 1/2 was high (95.6, 82.2 and 88.9 %, respectively). High negative predictive values could be found for these optical properties (96.7, 89.3 and 96.3 %, respectively) compared to morphologic assessment alone (89.9 %), reducing the risk of mistreating a malignant lesion to a more acceptable level (3.3 % instead of 11.1 %). HD-OCT seems to enable the combination of in vivo morphological analysis of cellular and 3-D micro-architectural structures with in vivo analysis of optical properties of tissue scatterers in melanocytic lesions. In vivo HD-OCT analysis of optical properties permits melanoma

  11. Giant Congenital Melanocytic Nevi and Neurocutaneous Melanosis

    PubMed Central

    Araújo, Catarina; Pardal, Francisco; Brito, Celeste

    2015-01-01

    Introduction. The major medical concern with giant congenital melanocytic nevi CMN is high risk of developing cutaneous melanoma, leptomeningeal melanoma, and neurocutaneous melanocytosis. Case Report. A 30-year-old woman with a giant congenital melanocytic nevus covering nearly the entire right thoracodorsal region and multiple disseminated melanocytic nevi presented with neurological symptoms. Cerebral magnetic resonance imaging revealed a large expansive lesion in the left frontal region. Postsurgically pathological diagnosis revealed characteristics of melanoma. Immunohistochemical examination showed S100(+), HMB45(+), MelanA(+), and MiTF(+). She received radiotherapy with temozolomide followed by two more chemotherapy cycles with temozolomide. She followed a rapidly progressive course, reflecting widespread leptomeningeal infiltration, and she died of multiorgan failure seven months after diagnosis of cerebral melanoma. Discussion. This patient was diagnosed as having a neurocutaneous melanosis with malignant widespread leptomeningeal infiltration. Diffuse spinal involvement is unusual and is described in only another patient. PMID:25722729

  12. Giant congenital melanocytic nevus in a bulgarian newborn.

    PubMed

    Chokoeva, A A; Fioranelli, M; Roccia, M G; Lotti, T; Wollina, U; Tchernev, G

    2016-01-01

    Giant congenital melanocytic nevus (GCMN) is a rare disorder affecting 1 in 200,000–500,000 live births. Central nervous system defects such as spina bifida, meningocele, Dandy Walker malformation may accompany it and thus cause significant morbidity. Despite the related risk for malignant transformation, GCMNs may be associated with neurocutaneous melanosis, a rare syndrome in which a giant CMN or multiple smaller CMNs are accompanied by melanocytic deposition in the brain and the spinal cord. We present a case of a 5-day-old newborn with giant congenital melanocytic nevus on his back, as we discuss the diagnostic and treatment approach. PMID:27373137

  13. Hyperspectral imaging of melanocytic lesions.

    PubMed

    Gaudi, Sudeep; Meyer, Rebecca; Ranka, Jayshree; Granahan, James C; Israel, Steven A; Yachik, Theodore R; Jukic, Drazen M

    2014-02-01

    Hyperspectral imaging (HSI) allows the identification of objects through the analysis of their unique spectral signatures. Although first developed many years ago for use in terrestrial remote sensing, this technology has more recently been studied for application in the medical field. With preliminary data favoring a role for HSI in distinguishing normal and lesional skin tissues, we sought to investigate the potential use of HSI as a diagnostic aid in the classification of atypical Spitzoid neoplasms, a group of lesions that often leave dermatopathologists bewildered. One hundred and two hematoxylin and eosin-stained tissue samples were divided into 1 of 4 diagnostic categories (Spitz nevus, Spitz nevus with unusual features, atypical Spitzoid neoplasm, and Spitzoid malignant melanoma) and 1 of 2 control groups (benign melanocytic nevus and malignant melanoma). A region of interest was selected from the dermal component of each sample, thereby maximizing the examination of melanocytes. Tissue samples were examined at ×400 magnification using a spectroscopy system interfaced with a light microscope. The absorbance patterns of wavelengths from 385 to 880 nm were measured and then analyzed within and among groups. All tissue groups demonstrated 3 common absorbance spectra at 496, 533, and 838 nm. Each sample group contained at least one absorption point that was unique to that group. The Spitzoid malignant melanoma category had the highest number of total and unique absorption points for any sample group. The data were then clustered into 12 representative spectral classes. Although each of the sample groups contained all 12 spectral vectors, they did so in differing proportions. These preliminary results reveal differences in the spectral signatures of the Spitzoid lesions examined in this study. Further investigation into a role for HSI in classifying atypical Spitzoid neoplasms is encouraged. PMID:24247577

  14. The ultrastructure of conjunctival melanocytic tumors.

    PubMed Central

    Jakobiec, F A

    1984-01-01

    The ultrastructure of conjunctival melanocytic lesions in 49 patients was evaluated to find significant differences between benign and malignant cells. The patients studied included 9 with benign epithelial (racial) melanosis, 2 with pigmented squamous cell papillomas, 16 with conjunctival nevi, 18 with primary acquired melanosis, and 11 with invasive nodules of malignant melanoma. In benign epithelial melanosis, dendritic melanocytes were situated along the basement membrane region of the conjunctival epithelium, with one basilar dendritic melanocyte lodged among every five or six basilar keratinocytes. The dendritic melanocytes extended arborizing cellular processes between the basilar and among the suprabasilar keratinocytes, which manifested considerable uptake of melanin granules into their cytoplasm. The benign dendritic melanocytes possessed nuclei with clumped heterochromatin at the nuclear membrane, small, tightly wound nucleoli, and large, elongated, fully melaninized melanin granules. In two patients with benign hyperplasia of the dendritic melanocytes, occasional dendritic melanocytes were located in a suprabasilar position, but were always separated from each other by keratinocytes or their processes. In the two black patients with benign pigmented squamous papillomas, the benign dendritic melanocytes were located hapharzardly at all levels of the acanthotic epithelium and not just along the basement membrane region. Melanin uptake by the proliferating keratinocytes was minimal. In benign melanocytic nevi of the conjunctiva, nevus cells within the intraepithelial junctional nests displayed a more rounded cellular configuration; short villi and broader cellular processes suggestive of abortive dendrites were found. The nuclear chromatin pattern was clumped at the nuclear membrane, but the nucleoli were somewhat larger than those of benign dendritic melanocytes in epithelial melanosis. The melanosomes were smaller and rounder than those in dendritic

  15. What are melanocytes really doing all day long...?

    PubMed

    Plonka, P M; Passeron, T; Brenner, M; Tobin, D J; Shibahara, S; Thomas, A; Slominski, A; Kadekaro, A L; Hershkovitz, D; Peters, E; Nordlund, J J; Abdel-Malek, Z; Takeda, K; Paus, R; Ortonne, J P; Hearing, V J; Schallreuter, K U

    2009-09-01

    Everyone knows and seems to agree that melanocytes are there to generate melanin - an intriguing, but underestimated multipurpose molecule that is capable of doing far more than providing pigment and UV protection to skin (1). What about the cell that generates melanin, then? Is this dendritic, neural crest-derived cell still serving useful (or even important) functions when no-one looks at the pigmentation of our skin and its appendages and when there is essentially no UV exposure? In other words, what do epidermal and hair follicle melanocytes do in their spare time - at night, under your bedcover? How much of the full portfolio of physiological melanocyte functions in mammalian skin has really been elucidated already? Does the presence or absence of melanocytes matter for normal epidermal and/or hair follicle functions (beyond pigmentation and UV protection), and for skin immune responses? Do melanocytes even deserve as much credit for UV protection as conventional wisdom attributes to them? In which interactions do these promiscuous cells engage with their immediate epithelial environment and who is controlling whom? What lessons might be distilled from looking at lower vertebrate melanophores and at extracutaneous melanocytes in the endeavour to reveal the 'secret identity' of melanocytes? The current Controversies feature explores these far too infrequently posed, biologically and clinically important questions. Complementing a companion viewpoint essay on malignant melanocytes (2), this critical re-examination of melanocyte biology provides a cornucopia of old, but under-appreciated concepts and novel ideas on the slowly emerging complexity of physiological melanocyte functions, and delineates important, thought-provoking questions that remain to be definitively answered by future research. PMID:19659579

  16. Melanocytic Nevus of the Tarsal Conjunctiva

    PubMed Central

    Yazıcı, Bülent; Bilge, Ayşe Dolar; Yağcı, Ayşe; Naqadan, Faisal; Altıntepe, Filiz

    2016-01-01

    Background: Melanocytic nevus is a rare occurrence in the tarsal conjunctiva and only 7 well-described cases have been reported previously in the English literature. Case Report: The medical records of 4 patients with tarsal conjunctival melanocytic nevus were reviewed, together with the relevant literature. All patients (3 women and 1 man; age range: 17 – 40 years) had been referred with a suspicion of melanoma. There was one tarsal nevus in the lower eyelid in 3 patients and 2 nevi in the upper eyelid in 1 patient. All lesions were darkly pigmented with irregular borders and were associated with a history of a recent growth in size. An intralesional cyst was present in 1 nevus only. After surgical excision, no recurrence or complication occurred during the follow-up period (range: 7 – 48 months). Conclusion: Tarsal melanocytic nevus has been described in detail in 11 cases, including these 4 cases, in the English literature. The lesion arose from the lower eyelid in all cases except one. Tarsal melanocytic nevi may frequently display clinical features suggesting melanoma, such as advanced patient age, recent growth, dark and irregular pigmentation, nodularity, hypervascularity, and the absence of an intralesional cyst. After total excision, nevus recurrence or malignant transformation has not been reported.

  17. Worldwide cutaneous malignant melanoma incidences analyzed by sex, age, and skin type over time (1955–2007): Is HPV infection of androgenic hair follicular melanocytes a risk factor for developing melanoma exclusively in people of European-ancestry?

    PubMed Central

    Merrill, Stephen J.; Subramanian, Madhan; Godar, Dianne E.

    2016-01-01

    ABSTRACT The cutaneous malignant melanoma (CMM) incidence has been increasing in an exponential manner in certain populations around the world for over 7 decades. To help illuminate the etiology, we performed worldwide temporal (1955–2007) CMM incidence analysis by sex, age (0–14, 15–29, 30–49, 50–69, 70–85+), and skin type on 6 continents using data from the International Agency for Research on Cancer. We observe an exponential increase in the CMM incidence over time and an increase of about 2 orders of magnitude between age groups 0–14 and 15–29 exclusively in European-ancestry populations around the world independent of skin type (I–III or III–IV). Other populations like the Chinese (III-IV) had much lower CMM incidences that either remained stable or temporally decreased but did not display a dramatic increase between the youngest age groups. The dramatic increase in the incidence between the youngest age groups found only in European-ancestry populations suggests one of the most important risk factors for CMM may be developing androgenic hair, the occurrence of which appears to correlate with the distribution of CMM over male and female body sites. Besides that potential new risk factor, the increasing CMM incidence with increasing age, known not to be from cumulative UV doses, may be associated with age-related changes to skin, i.e., thinning epidermis causing lower vitamin D3 levels, and hair, i.e., whitening from higher reactive oxygen species. The temporal exponential increasing CMM incidence in European-ancestry populations may be due to Human Papilloma Virus infection of follicular hair melanocytes, found in CMM biopsies. PMID:27588159

  18. Worldwide cutaneous malignant melanoma incidences analyzed by sex, age, and skin type over time (1955-2007): Is HPV infection of androgenic hair follicular melanocytes a risk factor for developing melanoma exclusively in people of European-ancestry?

    PubMed

    Merrill, Stephen J; Subramanian, Madhan; Godar, Dianne E

    2016-01-01

    The cutaneous malignant melanoma (CMM) incidence has been increasing in an exponential manner in certain populations around the world for over 7 decades. To help illuminate the etiology, we performed worldwide temporal (1955-2007) CMM incidence analysis by sex, age (0-14, 15-29, 30-49, 50-69, 70-85+), and skin type on 6 continents using data from the International Agency for Research on Cancer. We observe an exponential increase in the CMM incidence over time and an increase of about 2 orders of magnitude between age groups 0-14 and 15-29 exclusively in European-ancestry populations around the world independent of skin type (I-III or III-IV). Other populations like the Chinese (III-IV) had much lower CMM incidences that either remained stable or temporally decreased but did not display a dramatic increase between the youngest age groups. The dramatic increase in the incidence between the youngest age groups found only in European-ancestry populations suggests one of the most important risk factors for CMM may be developing androgenic hair, the occurrence of which appears to correlate with the distribution of CMM over male and female body sites. Besides that potential new risk factor, the increasing CMM incidence with increasing age, known not to be from cumulative UV doses, may be associated with age-related changes to skin, i.e., thinning epidermis causing lower vitamin D3 levels, and hair, i.e., whitening from higher reactive oxygen species. The temporal exponential increasing CMM incidence in European-ancestry populations may be due to Human Papilloma Virus infection of follicular hair melanocytes, found in CMM biopsies. PMID:27588159

  19. Protein Expression Analysis of Melanocyte Differentiation Antigen TRP-2.

    PubMed

    Avogadri, Francesca; Gnjatic, Sacha; Tassello, Jodie; Frosina, Denise; Hanson, Nicole; Laudenbach, Megan; Ritter, Erika; Merghoub, Taha; Busam, Klaus J; Jungbluth, Achim A

    2016-03-01

    Melanocyte differentiation antigens, such as gp100, tyrosinase, and Melan-A and their corresponding antibodies HMB45, T311, and A103, are major diagnostic tools in surgical pathology. Little is known about tyrosinase-related protein 2 (TRP-2, or dopachrome tautomerase/DCT) another melanocyte differentiation antigen, which is an enzymatic component of melanogenesis. We identified a commercial reagent to TRP-2, monoclonal antibody (mAb) C-9 and undertook a comprehensive analysis to assess its specificity and usefulness for surgical pathology. Subsequently, we analyzed panels of normal tissues and tumors. We show that TRP-2 is regularly expressed in melanocytes of the normal skin. In cutaneous nevi, TRP-2 is present in junctional as well as in dermal nevocytes. In malignant tumors, C-9 reactivity is restricted to melanocytic and related lesions and present in 84% and 58% of primary and metastatic melanomas, respectively. Ten primary melanomas of the anorectal mucosa were all positive. Like the other melanocyte differentiation antigens, TRP-2 was absent in 6 desmoplastic melanomas. Also, only 2 of 9 angiomyolipomas were TRP-2 positive. We conclude that mAb C-9 is a valuable reagent for the analysis of TRP-2 expression in archival surgical pathology material. The expression pattern of TRP-2 in melanocytic and related lesions appears to parallel other melanocyte differentiation antigens, although the overall incidence is lower than other antigens, such as Melan-A or gp100. PMID:26894771

  20. Early diagnosis and successful treatment of paraneoplastic melanocytic proliferation

    PubMed Central

    Jansen, Joyce C G; Van Calster, Joachim; Pulido, Jose S; Miles, Sarah L; Vile, Richard G; Van Bergen, Tine; Cassiman, Catherine; Spielberg, Leigh H; Leys, Anita M

    2015-01-01

    Background Paraneoplastic melanocytic proliferation (bilateral diffuse uveal melanocytic proliferation, BDUMP) is a rare but devastating disease that causes progressive visual loss in patients who usually have an occult malignancy. Visual loss occurs as a result of paraneoplastic changes in the uveal tissue. Methods In a masked fashion, the serum of two patients with BDUMP was evaluated for the presence of cultured melanocyte elongation and proliferation (CMEP) factor using cultured human melanocytes. We evaluated the efficacy of plasmapheresis as a treatment modality early in the disease in conjunction with radiation and chemotherapy. Results The serum of the first case patient was investigated after plasmapheresis and did not demonstrate proliferation of cultured human melanocytes. The serum of the second case was evaluated prior to treatment with plasmapheresis and did induce this proliferation. These findings are in accordance with the diminution of CMEP factor after plasmapheresis. Treatment with plasmapheresis managed to stabilise the ocular disease progression in both patients. Conclusions In the past, visual loss due to paraneoplastic melanocytic proliferation was considered progressive and irreversible. We treated two patients successfully with plasmapheresis and demonstrated a relation between CMEP factor in the serum of these patients and proliferation of cultured melanocytes. PMID:25908835

  1. Melanocytes in the Skin – Comparative Whole Transcriptome Analysis of Main Skin Cell Types

    PubMed Central

    Reemann, Paula; Reimann, Ene; Ilmjärv, Sten; Porosaar, Orm; Silm, Helgi; Jaks, Viljar; Vasar, Eero; Kingo, Külli; Kõks, Sulev

    2014-01-01

    Melanocytes possess several functions besides a role in pigment synthesis, but detailed characteristics of the cells are still unclear. We used whole transcriptome sequencing (RNA-Seq) to assess differential gene expression of cultivated normal human melanocytes with respect to keratinocytes, fibroblasts and whole skin. The present results reveal cultivated melanocytes as highly proliferative cells with possible stem cell-like properties. The enhanced readiness to regenerate makes melanocytes the most vulnerable cells in the skin and explains their high risk of developing into malignant melanoma. PMID:25545474

  2. Malignant melanoma maxilla

    PubMed Central

    Devi, Seema; Sinha, Richi; Singh, Rakesh Kumar

    2015-01-01

    A malignant melanoma is a highly lethal melanocytic neoplasm. A neoplasm usually affects the skin. Malignant melanomas in the head and neck region are rare, accounting for less than 1% of all melanomas. Malignant melanoma of the nose and paranasal sinuses is an aggressive disease typically presenting at an advanced stage, with a 5-year survival rate ranging 20-30%. Melanomas are tumors arising from melanocytes, which are neuroectodermally derived cells located in the basal layers of the skin. This is a case report of a 35-year-old male, who presented with very aggressive disease and developed liver metastasis. PMID:26668467

  3. Intraoral malignant melanoma

    PubMed Central

    Babburi, Suresh; Subramanyam, R. V.; Aparna, V.; Sowjanya, P.

    2013-01-01

    Primary oral mucosal melanoma is a rare aggressive neoplasm and accounts for only 0.2-8% of all reported melanomas. It is a malignant neoplasm of melanocytes that may arise from a benign melanocytic lesion or de novo from melanocytes within normal skin or mucosa. It is considered to be the most deadly and biologically unpredictable of all human neoplasms, having the worst prognosis. In this article, we report a case of oral melanoma in a 52-year-old female patient with a chief complaint of black discolouration of the maxillary gingiva and palate. PMID:24249959

  4. Melanocytes and Their Diseases

    PubMed Central

    Yamaguchi, Yuji; Hearing, Vincent J.

    2014-01-01

    Human melanocytes are distributed not only in the epidermis and in hair follicles but also in mucosa, cochlea (ear), iris (eye), and mesencephalon (brain) among other tissues. Melanocytes, which are derived from the neural crest, are unique in that they produce eu-/pheo-melanin pigments in unique membrane-bound organelles termed melanosomes, which can be divided into four stages depending on their degree of maturation. Pigmentation production is determined by three distinct elements: enzymes involved in melanin synthesis, proteins required for melanosome structure, and proteins required for their trafficking and distribution. Many genes are involved in regulating pigmentation at various levels, and mutations in many of them cause pigmentary disorders, which can be classified into three types: hyperpigmentation (including melasma), hypopigmentation (including oculocutaneous albinism [OCA]), and mixed hyper-/hypopigmentation (including dyschromatosis symmetrica hereditaria). We briefly review vitiligo as a representative of an acquired hypopigmentation disorder. PMID:24789876

  5. Induction of nerve growth factor receptors on cultured human melanocytes

    SciTech Connect

    Peacocke, M.; Yaar, M.; Mansur, C.P.; Chao, M.V.; Gilchrest, B.A. )

    1988-07-01

    Normal differentiation and malignant transformation of human melanocytes involve a complex series of interactions during which both genetic and environmental factors play roles. At present, the regulation of these processes is poorly understood. The authors have induced the expression of nerve growth factor (NGF) receptors on cultured human melanocytes with phorbol 12-tetradecanoate 13-acetate and have correlated this event with the appearance of a more differentiated, dendritic morphology. Criteria for NGF receptor expression included protein accumulation and cell-surface immunofluorescent staining with a monoclonal antibody directed against the human receptor and induction of the messenger RNA species as determined by blot-hybridization studies. The presence of the receptor could also be induced by UV irradiation or growth factor deprivation. The NGF receptor is inducible in cultured human melanocytes, and they suggest that NGF may modulate the behavior of this neural crest-derived cell in the skin.

  6. VITILIGO AND THE MELANOCYTE RESERVOIR

    PubMed Central

    Falabella, Rafael

    2009-01-01

    Repigmentation of vitiligo depends on available melanocytes from three possible sources: from the hair follicle unit which is the main provider of pigment cells, from the border of vitiligo lesions, and from unaffected melanocytes within depigmented areas; pigment cells at these locations originate a perifollicular, border spreading and a diffuse repigmentation pattern. In order for repigmentation to take place under stimulation with diverse therapies, melanocytes should be present in appropriate numbers. Melanocyte tissue stem cells located in the niche at the bulge region of the hair follicle are the most important sources for providing immature pigment cells that undergo terminal differentiation and originate repigmentation, but cytokines, UVR and other molecules acting in melanogenesis with adequate regulation mechanisms contribute to successful recovery in vitiligo. The presence of keratinocyte stem cells in the interfollicular epidermis raises the question on the possibility of melanocyte stem cells in a similar location and the development of future strategies for therapeutic purposes. PMID:20101329

  7. Amelanotic Melanoma in the Vicinity of Acquired Melanocytic Nevi and not Arising from Agminated Melanocytic Nevi: Masquerading as Pyogenic Granuloma

    PubMed Central

    Rao, Angoori Gnaneshwar; Babu, V Ashok; Koppada, Divya; Haritha, M; Chandana, P; Swapna; Anoosha

    2016-01-01

    Amelanotic melanoma (AMM) presenting as pyogenic granuloma and occurring in the vicinity of acquired melanocytic nevi is rare. Herein, we report such a manifestation in a 68-year-old male who presented with the painful red nodule and multiple pigmented patches involving the left great toe. Histopathological examination of skin biopsy taken from the nodule with an immunohistochemical study using HMB45 and S-100 confirmed the diagnosis of AMM. Biopsy from the pigmented patch near the nodule showed features of melanocytic nevus. Investigative work up revealed metastatic deposits in the left inguinal lymph node with no evidence of systemic involvement, placing him in malignant melanoma Stage IIIC of American Joint Committee on Cancer (AJCC) tumor node metastasis system. The development of AMM in the vicinity of acquired melanocytic nevi and manifesting as granuloma pyogenicum is unique in this case. PMID:26955141

  8. Simulants of Malignant Melanoma

    PubMed Central

    Piérard-Franchimont, Claudine; Delvenne, Philippe

    2015-01-01

    During the recent period, dermoscopy has yielded improvement in the early disclosure of various atypical melanocytic neoplasms (AMN) of the skin. Beyond this clinical procedure, AMN histopathology remains mandatory for establishing their precise diagnosis. Of note, panels of experts in AMN merely report moderate agreement in various puzzling cases. Divergences in opinion and misdiagnosis are likely increased when histopathological criteria are not fine-tuned and when facing a diversity of AMN types. Furthermore, some AMN have been differently named in the literature including atypical Spitz tumor, metastasizing Spitz tumor, borderline and intermediate melanocytic tumor, malignant Spitz nevus, pigmented epithelioid melanocytoma or animal-type melanoma. Some acronyms have been further suggested such as MELTUMP (after melanocytic tumor of uncertain malignant potential) and STUMP (after Spitzoid melanocytic tumor of uncertain malignant potential). In this review, such AMN at the exclusion of cutaneous malignant melanoma (MM) variants, are grouped under the tentative broad heading skin melanocytoma. Such set of AMN frequently follows an indolent course, although they exhibit atypical and sometimes worrisome patterns or cytological atypia. Rare cases of skin melanocytomas progress to loco regional clusters of lesions (agminate melanocytomas), and even to regional lymph nodes. At times, the distinction between a skin melanocytoma and MM remains puzzling. However, multipronged immunohistochemistry and emerging molecular biology help profiling any malignancy risk if present. PMID:26779311

  9. Digital dermoscopic follow-up of 1544 melanocytic nevi.

    PubMed

    Rotaru, Maria; Nati, Angelica-Elena; Avrămoiu, Ioan; Grosu, Florin; Mălăescu, Gheorghe Dan

    2015-01-01

    The use of dermatoscopy increases melanocytic nevi diagnostic accuracy, and is important for dermoscopic monitoring of atypical lesions, allowing to find significant changes in the earliest stage. Dermoscopic diagnosis of melanocytic nevi type in a group of patients and their follow-up with the assessment of changes occurred during dermoscopic monitoring. Dermoscopically, we followed the nevic size and pattern, the color and pigment distribution. Follow-up visits were scheduled depending on the type of the melanocytic lesions and the patient's compliance. The nevi that have shown significant dermoscopic changes were excised and histopathologically examined. The study was performed on a group of 92 patients, mostly females (56.5%), mean age of 29.1 years. Of the total of 1544 melanocytic nevi examined, 27.4% were atypical and 72.6% common nevi. The average dermoscopic examination interval was 14.1 months. During monitoring, 35.5% atypical nevi and 22.5% common nevi have modified, especially changes in pigmentation and color (31% atypical nevi and 9.9% common nevi) and the appearance of new dermoscopic structures (12.7% atypical nevi and common nevi 8.5%). Of the total nevi monitored, 3% showed significant changes and were excised and examined pathologically, without diagnose of any malignant transformation. In our study, dermoscopic changes appeared in atypical as well as in common nevi. The dermoscopic monitoring of melanocytic-pigmented lesions remains an accessible method of assessment the evolution of nevi and can reduce the risk of appearance of malignant melanoma in the general population. PMID:26743296

  10. Vasculogenic mimicry: lessons from melanocytic tumors.

    PubMed

    Spiliopoulos, Konstantinos; Peschos, Dimitrios; Batistatou, Anna; Ntountas, Ioannis; Agnantis, Niki; Kitsos, Georgios

    2015-01-01

    Tumor cell vasculogenic mimicry refers to the formation of tumor cell-lined vessels that contribute to tumor neovascularization and nutrient and oxygen supply. These tumor cells express many endothelial and stem cell markers, resulting in them having a unique phenotype. This phenomenon is observed in a variety of neoplasms, such as glioblastomas and sarcomas, as well as breast, ovarian, liver and lung carcinomas. It is also evident in melanocytic lesions, regardless of their benign or malignant nature. The biochemical and molecular events that regulate vasculogenic mimicry provide opportunities for development of novel forms of tumor-targeted treatments. Furthermore, the presence of this process in a tumor might have prognostic implications. PMID:25977376

  11. Traumatic iridial extrusion mimicking a conjunctival melanocytic neoplasm.

    PubMed

    Zoroquiain, Pablo; Ganimi, Maria Sb; Alghamdi, Sarah; Burnier, Julia V; Aldrees, Sultan S; Burnier, Miguel N

    2016-01-01

    Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis. PMID:26913071

  12. Traumatic iridial extrusion mimicking a conjunctival melanocytic neoplasm

    PubMed Central

    Zoroquiain, Pablo; Ganimi, Maria SB; Alghamdi, Sarah; Burnier, Julia V; Aldrees, Sultan S; Burnier, Miguel N

    2016-01-01

    Conjunctival melanoma is a rare malignant tumour of the eye. Its diagnosis represents a challenge for general pathologists due to low exposure to ocular biopsies and a broad differential diagnosis. In addition, conjunctival samples are often small and are associated with a high frequency of artefacts due to their processing. Here, we present the first case to date of a traumatic iridial extrusion masquerading as a conjunctival melanocytic neoplasm. An 83-year-old Asian man presented with a conjunctival-pigmented nodule surrounded by an area of diffuse pigmentation. Histopathology revealed in the nodule a well-demarcated lesion composed of spindle shaped melanocytes with thick-walled blood vessels. At higher magnification, the blood vessels were composed of thick walls with collagen fibres in an onion-skin-like arrangement. The histological findings were consistent with extruded iridial tissue. The map biopsies of the flat, pigmented lesion showed melanocytic cell proliferation with dendritic processes restricted to the lamina propria without any epithelial involvement, consistent with ocular melanocytosis. The diagnosis of conjunctival melanocytic lesions is challenging, and non-neoplastic conditions should always be included in the differential diagnosis. Pathologists should correlate clinicopathological findings and be familiar with the normal histology in order to achieve the correct diagnosis. PMID:26913071

  13. Genetics Home Reference: giant congenital melanocytic nevus

    MedlinePlus

    ... noncancerous skin patch (nevus) that is composed of pigment-producing cells called melanocytes . It is present from ... called neurocutaneous melanosis, which is the presence of pigment-producing skin cells (melanocytes) in the tissue that ...

  14. Differential diagnosis of heavily pigmented melanocytic lesions: challenges and diagnostic approach.

    PubMed

    Aung, Phyu P; Mutyambizi, Kudakwashe K; Danialan, Richard; Ivan, Doina; Prieto, Victor G

    2015-12-01

    The differential diagnosis of heavily pigmented melanocytic neoplasms includes melanoma (especially animal type), melanosis of partially or completely regressed melanoma, blue naevus (BN), pigmented Spitzoid lesions, recurrent naevus, combined naevus, pigmented spindle cell naevus, epithelioid blue naevus of the Carney complex/pigmented epithelioid melanocytoma, deep penetrating naevus, hyperpigmented scar after surgery of melanoma in which there are also melanophages and hyperpigmentation due to the minocycline, a tattoo or a hyperpigmented scar. Pathologists face challenges when evaluating a pigmented lesion, especially in a small superficial biopsy, because it is difficult to access important histopathological features to differentiate benign versus malignant melanocytic lesions. The histological features that favour a diagnosis of melanoma include dimension (>6 mm), asymmetry, poor circumscription, irregular confluent nests, confluent lentiginous junctional melanocytic proliferation, lack of maturation with descent in the dermis, suprabasal pagetoid melanocytes, asymmetrical distribution of melanin pigment, cytological atypia, dermal mitotic figures, asymmetrical dermal lymphocytic infiltrate and necrosis. PMID:26602414

  15. Optimal management of common acquired melanocytic nevi (moles): current perspectives

    PubMed Central

    Sardana, Kabir; Chakravarty, Payal; Goel, Khushbu

    2014-01-01

    Although common acquired melanocytic nevi are largely benign, they are probably one of the most common indications for cosmetic surgery encountered by dermatologists. With recent advances, noninvasive tools can largely determine the potential for malignancy, although they cannot supplant histology. Although surgical shave excision with its myriad modifications has been in vogue for decades, the lack of an adequate histological sample, the largely blind nature of the procedure, and the possibility of recurrence are persisting issues. Pigment-specific lasers were initially used in the Q-switched mode, which was based on the thermal relaxation time of the melanocyte (size 7 μm; 1 μsec), which is not the primary target in melanocytic nevus. The cluster of nevus cells (100 μm) probably lends itself to treatment with a millisecond laser rather than a nanosecond laser. Thus, normal mode pigment-specific lasers and pulsed ablative lasers (CO2/erbium [Er]:yttrium aluminum garnet [YAG]) are more suited to treat acquired melanocytic nevi. The complexities of treating this disorder can be overcome by following a structured approach by using lasers that achieve the appropriate depth to treat the three subtypes of nevi: junctional, compound, and dermal. Thus, junctional nevi respond to Q-switched/normal mode pigment lasers, where for the compound and dermal nevi, pulsed ablative laser (CO2/Er:YAG) may be needed. If surgical excision is employed, a wide margin and proper depth must be ensured, which is skill dependent. A lifelong follow-up for recurrence and melanoma is warranted in predisposed individuals, although melanoma is decidedly uncommon in most acquired melanocytic nevi, even though histological markers may be seen on evaluation. PMID:24672253

  16. Optimal management of common acquired melanocytic nevi (moles): current perspectives.

    PubMed

    Sardana, Kabir; Chakravarty, Payal; Goel, Khushbu

    2014-01-01

    Although common acquired melanocytic nevi are largely benign, they are probably one of the most common indications for cosmetic surgery encountered by dermatologists. With recent advances, noninvasive tools can largely determine the potential for malignancy, although they cannot supplant histology. Although surgical shave excision with its myriad modifications has been in vogue for decades, the lack of an adequate histological sample, the largely blind nature of the procedure, and the possibility of recurrence are persisting issues. Pigment-specific lasers were initially used in the Q-switched mode, which was based on the thermal relaxation time of the melanocyte (size 7 μm; 1 μsec), which is not the primary target in melanocytic nevus. The cluster of nevus cells (100 μm) probably lends itself to treatment with a millisecond laser rather than a nanosecond laser. Thus, normal mode pigment-specific lasers and pulsed ablative lasers (CO2/erbium [Er]:yttrium aluminum garnet [YAG]) are more suited to treat acquired melanocytic nevi. The complexities of treating this disorder can be overcome by following a structured approach by using lasers that achieve the appropriate depth to treat the three subtypes of nevi: junctional, compound, and dermal. Thus, junctional nevi respond to Q-switched/normal mode pigment lasers, where for the compound and dermal nevi, pulsed ablative laser (CO2/Er:YAG) may be needed. If surgical excision is employed, a wide margin and proper depth must be ensured, which is skill dependent. A lifelong follow-up for recurrence and melanoma is warranted in predisposed individuals, although melanoma is decidedly uncommon in most acquired melanocytic nevi, even though histological markers may be seen on evaluation. PMID:24672253

  17. Sorafenib induced eruptive melanocytic lesions.

    PubMed

    Uhlenhake, Elizabeth E; Watson, Alice C; Aronson, Peter

    2013-05-01

    Sorafenib is a multikinase inhibitor FDA-approved for the treatment of advanced renal cell and hepatocellular carcinoma. Dermatologic side effects include hand-foot skin reaction, facial and scalp erythema and desquamation, splinter subungual hemorrhages, alopecia, pruritus, xerosis, keratoacanthomas, and squamous cell carcinomas. We report sudden eruption of melanocytic nevi diffusely in a patient receiving sorafenib. PMID:24011281

  18. LASP1, a Newly Identified Melanocytic Protein with a Possible Role in Melanin Release, but Not in Melanoma Progression

    PubMed Central

    Houben, Roland; Grunewald, Thomas G. P.; Goebeler, Matthias; Butt, Elke

    2015-01-01

    The LIM and SH3 protein 1 (LASP1) is a focal adhesion protein. Its expression is increased in many malignant tumors. However, little is known about the physiological role of the protein. In the present study, we investigated the expression and function of LASP1 in normal skin, melanocytic nevi and malignant melanoma. In normal skin, a distinct LASP1 expression is visible only in the basal epidermal layer while in nevi LASP1 protein is detected in all melanocytes. Melanoma exhibit no increase in LASP1 mRNA compared to normal skin. In melanocytes, the protein is bound to dynamin and mainly localized at late melanosomes along the edges and at the tips of the cell. Knockdown of LASP1 results in increased melanin concentration in the cells. Collectively, we identified LASP1 as a hitherto unknown protein in melanocytes and as novel partner of dynamin in the physiological process of membrane constriction and melanosome vesicle release. PMID:26061439

  19. A comparative review of melanocytic neoplasms.

    PubMed

    Smith, S H; Goldschmidt, M H; McManus, P M

    2002-11-01

    malignant melanocytic neoplasms or predicting survival time. PMID:12450197

  20. Congenital melanocytic nevus: two clinicopathological forms.

    PubMed

    Magaña, Mario; Sánchez-Romero, Elizabeth; Magaña, Pablo; Beck-Magaña, Andrés; Magaña-Lozano, Mario

    2015-01-01

    Congenital melanocytic nevus (CMN) is a hamartomatous disease for which many attempts at classification have been proposed. This disease is relevant not only because of its functional and esthetic implications but also because it is a well-documented precursor to malignant melanoma. We performed a clinical and pathological prospective study of 200 cases of CMN and were able to identify 2 different forms of CMN, each one with biological, clinical, and histopathological features and criteria that are consistent and repeatable. We propose to name them types I and II. Type I CMN is the most common, usually, if not always, a single lesion, it consists of a plaque that involves only 1 anatomic region and does not go beyond it; type I CNM grows in proportion to the growth of the child, melanoma rarely develops from it, and when it does it usually arises at the dermoepidermal junction. Its histopathology shows cords, strands, nests, and single units of melanocytes spreading between collagen bundles only in the dermis and frequently the epidermis too, but without trespassing to the hypodermis, that is, it is superficial. Type II CMN is always made up of many lesions, one of them being very large and surrounded by many lesions; histopathologically, it involves not only the skin but also deeper structures, sometimes bone and central nervous system; therefore, it is deep; when melanoma develops, it does in the dermal component and usually from the largest plaque. This type of CMN is the one that develops neurocutaneous melanocytosis. This system is not only easy and logical but it also has biologic advantages and the clinical-pathological correlation and criteria are repeatable by clinicians and pathologists. PMID:25140664

  1. The usefulness of c-Kit in the immunohistochemical assessment of melanocytic lesions

    PubMed Central

    Pilloni, L.; Bianco, P.; Difelice, E.; Cabras, S.; Castellanos, M.E.; Atzori, L.; Ferreli, C.; Mulas, P.; Nemolato, S.; Faa, G.

    2011-01-01

    C-Kit (CD117), the receptor for the stem cell factor, a growth factor for melanocyte migration and proliferation, has shown differential immunostaining in various benign and malignant melanocytic lesions. The purpose of this study is to compare c-Kit immunostaining in benign nevi and in primary and metastatic malignant melanomas, to determine whether c-Kit can aid in the differential diagnosis of these lesions. c-Kit immunostaining was performed in 60 cases of pigmented lesions, including 39 benign nevi (5 blue nevi, 5 intra-dermal nevi, 3 junctional nevi, 15 cases of primary compound nevus, 11 cases of Spitz nevus), 18 cases of primary malignant melanoma and 3 cases of metastatic melanoma. The vast majority of nevi and melanomas examined in this study were positive for c-Kit, with minimal differences between benign and malignant lesions. C-Kit cytoplasmatic immunoreactivity in the intraepidermal proliferating nevus cells, was detected in benign pigmented lesions as well as in malignant melanoma, increasing with the age of patients (P=0.007) in both groups. The patient’s age at presentation appeared to be the variable able to cluster benign and malignant pigmented lesions. The percentage of c-Kit positive intraepidermal nevus cells was better associated with age despite other variables (P=0.014). The intensity and percentage of c-Kit positivity in the proliferating nevus cells in the dermis was significantly increased in malignant melanocytic lesions (P=0.015 and P=0.008) compared to benign lesions (compound melanocytic nevi, Spitz nevi, intradermal nevi, blue nevi). Immunostaning for c-Kit in metastatic melanomas was negative. Interestingly in two cases of melanoma occurring on a pre-existent nevus, the melanoma tumor cells showed strong cytoplasmatic and membranous positivity for c-kit, in contrast with the absence of any immunoreactivity in pre-existent intradermal nevus cells. C-Kit does not appear to be a strong immunohistochemical marker for distinguishing

  2. A colonization of basal cell carcinoma by malignant melanoma in situ resembling a malignant basomelanocytic tumor.

    PubMed

    Goeser, Megan; DiMaio, Dominick J

    2014-11-01

    We report a case of colonization of basal cell carcinoma (BCC) by malignant melanoma in situ (MIS) simulating a malignant basomelanocytic tumor. A biopsy of a pigmented lesion present on an 83-year-old man's scalp displayed intimate admixing of basaloid and melanocytic cells. This seemingly inseparable combination of BCC and neoplastic melanocytes has been referred to as a malignant basomelanocytic tumor. However, our case also displays an adjacent component of MIS, thus favoring colonization of BCC by MIS as the etiology. To our knowledge, this is the third case report of colonization of BCC by MIS resembling a malignant basomelanocytic tumor. PMID:24752214

  3. Immune-phenotypical markers for the differential diagnosis of melanocytic lesions

    PubMed Central

    Botti, Gerardo; Marra, Laura; Anniciello, Annamaria; Scognamiglio, Giosuè; Gigantino, Vincenzo; Cantile, Monica

    2015-01-01

    For specific subsets of melanocytic proliferations, there are morphologic limitations in the histological diagnosis, especially for borderline melanocytic tumors. In particular, Spitzoid proliferations can be difficult to diagnose. For these reasons, in the last years, clinic research has focusedattention on discovery of new diagnostic markers. Published gene expression and proteomic profiling data indicate new candidate molecules involved in melanoma pathogenesis, and useful in differential diagnosis of difficult melanocytic lesions. Recently, the diagnostic power of galectin-3 was demonstrated in series of melanocytic lesions, with a strong increasing of expression in malignant lesions compared with benign lesions. Similarly, the accumulation of Collagen XVII antibody was detected in vertical melanoma fronts and associated with invasive phenotype. Moreover, overexpression of cyclin D1 and p21 was detected in Spitz nevi compared with non-spitzoid melanomas; Ki-67 appears highly expressed in deep areas of non-spitzoid melanomas. In this review,werealizedan overviewofthe main molecular markersthat canbe a usefultoolfor the differential diagnosisofbenign, borderlineand malignant melanocytic lesions, related to their biological behavior, useful also for predicting the evolutionof the disease. PMID:26617684

  4. The melanocyte lineage in development and disease

    PubMed Central

    Mort, Richard L.; Jackson, Ian J.; Patton, E. Elizabeth

    2015-01-01

    Melanocyte development provides an excellent model for studying more complex developmental processes. Melanocytes have an apparently simple aetiology, differentiating from the neural crest and migrating through the developing embryo to specific locations within the skin and hair follicles, and to other sites in the body. The study of pigmentation mutations in the mouse provided the initial key to identifying the genes and proteins involved in melanocyte development. In addition, work on chicken has provided important embryological and molecular insights, whereas studies in zebrafish have allowed live imaging as well as genetic and transgenic approaches. This cross-species approach is powerful and, as we review here, has resulted in a detailed understanding of melanocyte development and differentiation, melanocyte stem cells and the role of the melanocyte lineage in diseases such as melanoma. PMID:25670789

  5. Sox proteins in melanocyte development and melanoma

    PubMed Central

    Harris, Melissa L.; Baxter, Laura L.; Loftus, Stacie K.; Pavan, William J.

    2010-01-01

    Over ten years has passed since the first Sox gene was implicated in melanocyte development. Since then, we have discovered that SOX5, SOX9, SOX10 and SOX18 all participate as transcription factors that affect key melanocytic genes in both regulatory and modulatory fashions. Both SOX9 and SOX10 play major roles in the establishment and normal function of the melanocyte; SOX10 has been shown to heavily influence melanocyte development and SOX9 has been implicated in melanogenesis in the adult. Despite these advances, the precise cellular and molecular details of how these SOX proteins are regulated and interact during all stages of the melanocyte life cycle remain unknown. Improper regulation of SOX9 or SOX10 is also associated with cancerous transformation, and thus understanding the normal function of SOX proteins in the melanocyte will be key to revealing how these proteins contribute to melanoma. PMID:20444197

  6. Automatic Classification of Specific Melanocytic Lesions Using Artificial Intelligence

    PubMed Central

    Jaworek-Korjakowska, Joanna; Kłeczek, Paweł

    2016-01-01

    Background. Given its propensity to metastasize, and lack of effective therapies for most patients with advanced disease, early detection of melanoma is a clinical imperative. Different computer-aided diagnosis (CAD) systems have been proposed to increase the specificity and sensitivity of melanoma detection. Although such computer programs are developed for different diagnostic algorithms, to the best of our knowledge, a system to classify different melanocytic lesions has not been proposed yet. Method. In this research we present a new approach to the classification of melanocytic lesions. This work is focused not only on categorization of skin lesions as benign or malignant but also on specifying the exact type of a skin lesion including melanoma, Clark nevus, Spitz/Reed nevus, and blue nevus. The proposed automatic algorithm contains the following steps: image enhancement, lesion segmentation, feature extraction, and selection as well as classification. Results. The algorithm has been tested on 300 dermoscopic images and achieved accuracy of 92% indicating that the proposed approach classified most of the melanocytic lesions correctly. Conclusions. A proposed system can not only help to precisely diagnose the type of the skin mole but also decrease the amount of biopsies and reduce the morbidity related to skin lesion excision. PMID:26885520

  7. UVB induces atypical melanocytic lesions and melanoma in human skin.

    PubMed Central

    Atillasoy, E. S.; Seykora, J. T.; Soballe, P. W.; Elenitsas, R.; Nesbit, M.; Elder, D. E.; Montone, K. T.; Sauter, E.; Herlyn, M.

    1998-01-01

    A direct causal relationship between ultraviolet (UV) light in the B range and melanoma development has not been demonstrated in humans; this study aims to establish causality. A total of 158 RAG-1 mice, grafted with human newborn foreskin, were separated into four groups and observed for a median of 10 months: 1) no treatment, 2) a single treatment with 7,12-dimethyl(a)benzanthracene (DMBA), 3) UVB irradiation at 500 J/m2 alone, three times weekly, and 4) a combination of DMBA and UVB. Twenty-three percent of 40 normal human skin grafts treated with UVB only and 38% of 48 grafts treated with the combination of DMBA and UVB developed solar lentigines within 5 to 10 months of treatment. Melanocytic hyperplasia was found in 73% of all UVB-treated xenografts. Histological melanocytic changes resembling lentigo and lentigo maligna were seen in several skin grafts treated with both DMBA and UVB. In one graft of an animal treated with a combination of DMBA and UVB, a human malignant melanoma, nodular type, developed. This experimental system demonstrates that chronic UVB irradiation with or without an initiating carcinogen can induce human melanocytic lesions, including melanoma. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:9588887

  8. Bilateral diffuse uveal melanocytic proliferation: a management dilemma

    PubMed Central

    Alrashidi, Salah; Aziz, Ayman A; Krema, Hatem

    2014-01-01

    A female patient suffered from gradual decline of vision for few months. She presented with bilateral multiple pigmented choroidal tumours, associated with overlying retinal changes. The clinical presentation suggested bilateral diffuse uveal melanocytic proliferation (BDUMP) syndrome, which is a paraneoplastic disease, although there was no evidence of any concurrent malignancy. The periodic systemic surveillance that was undertaken for the following 4 years failed to reveal any occult cancer. Nevertheless, there has been relentless progressive deterioration in vision as a consequence of BDUMP syndrome. The management of the declining vision in BDUMP syndrome is challenging and controversial. PMID:24855079

  9. Imaging pigment chemistry in melanocytic conjunctival lesions with pump-probe microscopy

    NASA Astrophysics Data System (ADS)

    Wilson, Jesse W.; Vajzovic, Lejla; Robles, Francisco E.; Cummings, Thomas J.; Mruthyunjaya, Prithvi; Warren, Warren S.

    2013-03-01

    We extend nonlinear pump-probe microscopy, recently demonstrated to image the microscopic distribution of eumelanin and pheomelanin in unstained skin biopsy sections, to the case of melanocytic conjunctival lesions. The microscopic distribution of pigmentation chemistry serves as a functional indicator of melanocyte activity. In these conjunctival specimens (benign nevi, primary acquired melanoses, and conjunctival melanoma), we have observed pump-probe spectroscopic signatures of eumelanin, pheomelanin, hemoglobin, and surgical ink, in addition to important structural features that differentiate benign from malignant lesions. We will also discuss prospects for an in vivo `optical biopsy' to provide additional information before having to perform invasive procedures.

  10. UVB-irradiated keratinocytes induce melanoma-associated ganglioside GD3 synthase gene in melanocytes via secretion of tumor necrosis factor α and interleukin 6

    SciTech Connect

    Miyata, Maiko; Ichihara, Masatoshi; Tajima, Orie; Sobue, Sayaka; Kambe, Mariko; Sugiura, Kazumitsu; Furukawa, Koichi; Furukawa, Keiko

    2014-03-07

    Highlights: • Melanocytes showed low ST8SIA1 and high B3GALT4 levels in contrast with melanomas. • Direct UVB irradiation of melanocytes did not induce ganglioside synthase genes. • Culture supernatants of UVB-irradiated keratinocytes induced ST8SIA1 in melanocytes. • TNFα and IL-6 secreted from keratinocytes enhanced ST8SIA1 expression in melanocytes. • Inflammatory cytokines induced melanoma-related ST8SIA1 in melanocytes. - Abstract: Although expression of gangliosides and their synthetic enzyme genes in malignant melanomas has been well studied, that in normal melanocytes has been scarcely analyzed. In particular, changes in expression levels of glycosyltransferase genes responsible for ganglioside synthesis during evolution of melanomas from melanocytes are very important to understand roles of gangliosides in melanomas. Here, expression of glycosyltransferase genes related to the ganglioside synthesis was analyzed using RNAs from cultured melanocytes and melanoma cell lines. Quantitative RT-PCR revealed that melanomas expressed high levels of mRNA of GD3 synthase and GM2/GD2 synthase genes and low levels of GM1/GD1b synthase genes compared with melanocytes. As a representative exogenous stimulation, effects of ultraviolet B (UVB) on the expression levels of 3 major ganglioside synthase genes in melanocytes were analyzed. Although direct UVB irradiation of melanocytes caused no marked changes, culture supernatants of UVB-irradiated keratinocytes (HaCaT cells) induced definite up-regulation of GD3 synthase and GM2/GD2 synthase genes. Detailed examination of the supernatants revealed that inflammatory cytokines such as TNFα and IL-6 enhanced GD3 synthase gene expression. These results suggest that inflammatory cytokines secreted from UVB-irradiated keratinocytes induced melanoma-associated ganglioside synthase genes, proposing roles of skin microenvironment in the promotion of melanoma-like ganglioside profiles in melanocytes.

  11. Diagnosis and staging of female genital tract melanocytic lesions using pump-probe microscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Robles, Francisco E.; Selim, Maria A.; Warren, Warren S.

    2016-02-01

    Melanoma of the vulva is the second most common type of malignancy afflicting that organ. This disease caries poor prognosis, and shows tendencies to recur locally and develop distant metastases through hematogenous dissemination. Further, there exists significant clinical overlap between early-stage melanomas and melanotic macules, benign lesions that are believed to develop in about 10% of the general female population. In this work we apply a novel nonlinear optical method, pump-probe microscopy, to quantitatively analyze female genitalia tract melanocytic lesions. Pump-probe microscopy provides chemical information of endogenous pigments by probing their electronic excited state dynamics, with subcellular resolution. Using unstained biopsy sections from 31 patients, we find significant differences between melanin type and structure in tissue regions with invasive melanoma, melanoma in-situ and non-malignant melanocytic proliferations (e.g., nevi, melanocytic macules). The molecular images of non-malignant lesion have a well-organized structure, with relatively homogenous pigment chemistry, most often consistent with that of eumelanin with large aggregate size or void of metals, such as iron. On the other hand, pigment type and structure observed in melanomas in-situ and invasive melanomas is typically much more heterogeneous, with larger contributions from pheomelanin, melanins with larger metal content, and/or melanins with smaller aggregate size. Of most significance, clear differences can be observed between melanocytic macules and vulvar melanoma in-situ, which, as discussed above, can be difficult to clinically distinguish. This initial study demonstrates pump-probe microscopy's potential as an adjuvant diagnostic tool by revealing systematic chemical and morphological differences in melanin pigmentation among invasive melanoma, melanoma in-situ and non-malignant melanocytic lesions.

  12. [Management of benign melanocytic lesions as a melanoma prevention. Systematic review].

    PubMed

    Linertová, Renata; Valcárcel-Nazco, Cristina; Lacalle-Remigio, Juan Ramón

    2016-08-19

    There is a growing concern and awareness of skin cancer. As a result, possibly unnecessary surgeries of melanocytic lesions are carried out as a prophylactic measure. We performed a systematic review of the medical literature to identify primary studies on the effectiveness and cost-effectiveness of surgery treatment of benign melanocytic lesions for melanoma prevention. We included 19 primary studies on surgical treatment of acquired melanocytic lesions and one economic evaluation. Indicators, such as number needed to treat and the malignancy ratio, depend on several factors such as specialty and experience of the physician, pressure from the patient or patient characteristics. Early diagnosis of melanoma is critical in preventing skin cancer. However, primary studies show through several indicators that there are factors that increase the proportion of lesions treated unnecessarily. Effectiveness can be improved by careful use of techniques to identify suspicious lesions and educational programs for physicians, especially in primary care. PMID:27026061

  13. Biological characteristics of mouse skin melanocytes.

    PubMed

    Shi, Zhanquan; Ji, Kaiyuan; Yang, Shanshan; Zhang, Junzhen; Yao, Jianbo; Dong, Changsheng; Fan, Ruiwen

    2016-04-01

    The objective of this research was to evaluate the optimal passage number according to the biological characteristics of mouse skin melanocytes from different passages. Skin punch biopsies harvested from the dorsal region of 2-day old mice were used to establish melanocyte cultures. The cells from passage 4, 7, 10 and 13 were collected and evaluated for their melanogenic activity. Histochemical staining for tyrosinase (TYR) activity and immunostaining for the melanocyte specific markers including S-100 antigen, TYR, tyrosinase related protein 1 (TYRP1), tyrosinase related protein 2 (TYRP2) and micropthalmia associated transcription factor (MITF) confirmed purity and melanogenic capacity of melanocytes from different passages, with better melanogenic activity of passage 10 and 13 cells being observed. Treatment of passage 13 melanocytes with α-melanocyte stimulating hormone (α-MSH) showed increased expression of MITF, TYR and TYRP2 mRNA. However, considering the TYR mRNA dramatically high expression which is the characteristics of melanoma cells, melanocytes from passage 10 was the optimal passage number for the further research. Our results demonstrate culture of pure populations of mouse melanocytes to at least 10 passages and illustrate the potential utility of passage 10 cells for studies of intrinsic and extrinsic regulation of genes controlling pigmentation and coat color in mouse. PMID:26905193

  14. Melanocytic naevi clustered on normal background skin.

    PubMed

    Torchia, D

    2015-04-01

    Several types of maculopapular melanocytic naevi can occur in a multiple form, and be arranged in a nonrandom fashion on the skin. The most frequently reported segmentally grouped naevi are lentigines. Two types of segmentally arranged lentigines probably exist. The first is associated with neurofibromatosis (NF)1 or NF1 signs, features scattered light-brown lesions and can be considered a type of mosaic NF1. By contrast, non-NF1 associated lesions are characterized by densely packed, dark lesions, and can be defined as 'non-NF1 checkerboard-arranged lentigines'. Blue naevi, Spitz naevi and common acquired melanocytic naevi can occur, clustered in an agminated (or cannonball) shape. However, if large enough, they always follow a checkerboard pattern. Hence, such mosaic conditions should be termed 'checkerboard-arranged blue naevi', 'checkerboard-arranged Spitz naevi' and 'checkerboard-arranged common acquired melanocytic naevi'. Segmentally arranged dysplastic melanocytic naevi probably represent a mosaic form of dysplastic naevus syndrome. Dysplastic melanocytic naevi confined to a cutaneous segment could be defined as 'isolated segmental dysplastic naevus syndrome', while segmentally arranged dysplastic melanocytic naevi co-occurring with widespread, nonsegmental dysplastic melanocytic naevi might configure a 'superimposed segmental dysplastic naevus syndrome'. Small congenital melanocytic naevi are always grouped along Blaschko lines. The only other instances following Blaschko lines are the so-called 'linear lentiginous naevus' and a unique case of multiple deep penetrating naevi. PMID:25703021

  15. Desmoplastic Melanocytic Nevus of Oral Mucosa.

    PubMed

    Damm, Douglas D; Fowler, Craig B; Schmidt, David P

    2016-09-01

    The desmoplastic melanocytic nevus is an uncommon variant that easily may be confused with a fibrohistiocytic neoplasm or a desmoplastic melanoma. It is believed that the following report describes the first known example of a desmoplastic melanocytic nevus arising in the oral mucosa. The histopathologic and immunohistochemical features that allow separation from other microscopically similar pathoses are stressed. PMID:26747459

  16. Melanocytic glaucoma in a cairn terrier.

    PubMed

    Hanselman, Beth A

    2002-04-01

    Melanocytic glaucoma, previously known as pigmentary glaucoma, is characterized by diffuse intraocular infiltration of heavily pigmented melanocytes. This unusual ocular disorder has been documented only in the cairn terrier and is considered familial. Treatment strategies are based on evidence that the condition is slowly progressive but not neoplastic. PMID:11963666

  17. Melanocytic glaucoma in a cairn terrier

    PubMed Central

    Hanselman, Beth A.

    2002-01-01

    Melanocytic glaucoma, previously known as pigmentary glaucoma, is characterized by diffuse intraocular infiltration of heavily pigmented melanocytes. This unusual ocular disorder has been documented only in the cairn terrier and is considered familial. Treatment strategies are based on evidence that the condition is slowly progressive but not neoplastic. PMID:11963666

  18. Maintenance of distinct melanocyte populations in the interfollicular epidermis.

    PubMed

    Glover, James D; Knolle, Stefan; Wells, Kirsty L; Liu, Dianbo; Jackson, Ian J; Mort, Richard L; Headon, Denis J

    2015-07-01

    Hair follicles and sweat glands are recognized as reservoirs of melanocyte stem cells (MSCs). Unlike differentiated melanocytes, undifferentiated MSCs do not produce melanin. They serve as a source of differentiated melanocytes for the hair follicle and contribute to the interfollicular epidermis upon wounding, exposure to ultraviolet irradiation or in remission from vitiligo, where repigmentation often spreads outwards from the hair follicles. It is unknown whether these observations reflect the normal homoeostatic mechanism of melanocyte renewal or whether unperturbed interfollicular epidermis can maintain a melanocyte population that is independent of the skin's appendages. Here, we show that mouse tail skin lacking appendages does maintain a stable melanocyte number, including a low frequency of amelanotic melanocytes, into adult life. Furthermore, we show that actively cycling differentiated melanocytes are present in postnatal skin, indicating that amelanotic melanocytes are not uniquely relied on for melanocyte homoeostasis. PMID:25847135

  19. S-100 protein in soft-tissue tumors derived from Schwann cells and melanocytes.

    PubMed Central

    Stefansson, K.; Wollmann, R.; Jerkovic, M.

    1982-01-01

    In soft tissues outside the central nervous system, S-100 protein is found normally only in Schwann cells. Using the peroxidase-antiperoxidase immunohistochemical method S-100 was also found in tumors derived from Schwann cells and melanocytes, including neurofibromas, neurilemomas, granular cell myoblastomas, cutaneous nevi, and malignant melanomas. S-100 was not detected in malignant Schwannomas, neuroblastomas, oat cell carcinomas, medullary carcinomas of the thyroid, paragangliomas, or meningiomas. S-100 was also absent from neoplasms of soft tissues not usually considered to arise from cells of neural crest origin. S-100 appears to be a useful marker for identifying neoplasms derived from Schwann cells and melanocytes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:6278936

  20. Epithelial, non-melanocytic and melanocytic proliferations of the ocular surface.

    PubMed

    Kheir, Wajiha J; Tetzlaff, Michael T; Pfeiffer, Margaret L; Mulay, Kaustubh; Ozgur, Omar; Morrell, Gail; Esmaeli, Bita

    2016-05-01

    Ocular surface tumors are commonly encountered by ophthalmologists and ophthalmic pathologists. These tumors have varied clinical manifestations. In this article, we discuss the most commonly encountered non-melanocytic and melanocytic ocular surface tumors, with emphasis on their common clinical features, morphologic patterns, and prognostic factors. PMID:27021909

  1. Melanocytic Nests Arising in Lichenoid Inflammation”: Reappraisal of the Terminology “Melanocytic Pseudonests”

    PubMed Central

    Chung, Hye Jin; Simkin, A. David; Bhawan, Jag

    2015-01-01

    Abstract: Pseudonests or pseudomelanocytic nests represent aggregates of cells and cell fragments, including keratinocytes, macrophages, lymphocytes, and occasional melanocytes. Pseudomelanocytic nests in the setting of lichenoid inflammation can mimic atypical melanocytic proliferations. Several reports documented nonspecific staining of pseudonests with melanoma antigen recognized by T cells-1/Melan-A, which can be detected in the cytoplasm of nonmelanocytic cells. In contrast, nuclear stains, such as MITF and SOX10, avoid this nonmelanocyte cytoplasmic staining. The authors have previously proposed the term melanocytic pseudonests to describe junctional nests with numerous (>2) true melanoma antigen recognized by T cells-1/Melan-A, SOX10, and MITF in a nonmelanocytic lesion with lichenoid inflammation (unilateral lichen planus pigmentosus/erythema dyschromicum perstans). In this study, the authors report another case of this phenomenon arising in a different lichenoid inflammatory dermatitis (lichen planus). The immunophenotype and number of clustered true melanocytes indicate that these dermoepidermal aggregates represent true melanocytic nests and not pseudonests of any type. Therefore, the authors propose the revised terminology of “melanocytic nests arising in lichenoid inflammation” to describe this novel pattern of benign melanocytic reorganization or proliferation in a subset of lichenoid dermatitides. Because this phenomenon can mimic atypical melanocytic proliferations, clinicopathologic correlation is essential for the correct diagnosis. PMID:26588340

  2. "Melanocytic Nests Arising in Lichenoid Inflammation": Reappraisal of the Terminology "Melanocytic Pseudonests".

    PubMed

    Chung, Hye Jin; Simkin, A David; Bhawan, Jag; Wolpowitz, Deon

    2015-12-01

    Pseudonests or pseudomelanocytic nests represent aggregates of cells and cell fragments, including keratinocytes, macrophages, lymphocytes, and occasional melanocytes. Pseudomelanocytic nests in the setting of lichenoid inflammation can mimic atypical melanocytic proliferations. Several reports documented nonspecific staining of pseudonests with melanoma antigen recognized by T cells-1/Melan-A, which can be detected in the cytoplasm of nonmelanocytic cells. In contrast, nuclear stains, such as MITF and SOX10, avoid this nonmelanocyte cytoplasmic staining. The authors have previously proposed the term melanocytic pseudonests to describe junctional nests with numerous (>2) true melanoma antigen recognized by T cells-1/Melan-A, SOX10, and MITF in a nonmelanocytic lesion with lichenoid inflammation (unilateral lichen planus pigmentosus/erythema dyschromicum perstans). In this study, the authors report another case of this phenomenon arising in a different lichenoid inflammatory dermatitis (lichen planus). The immunophenotype and number of clustered true melanocytes indicate that these dermoepidermal aggregates represent true melanocytic nests and not pseudonests of any type. Therefore, the authors propose the revised terminology of "melanocytic nests arising in lichenoid inflammation" to describe this novel pattern of benign melanocytic reorganization or proliferation in a subset of lichenoid dermatitides. Because this phenomenon can mimic atypical melanocytic proliferations, clinicopathologic correlation is essential for the correct diagnosis. PMID:26588340

  3. [Histological spectrum of malignant melanoma].

    PubMed

    Brenn, T

    2015-02-01

    The diagnosis of melanocytic tumors is one of the most problematic areas in dermatology and diagnostic pathology. Melanoma is a malignant melanocytic tumor and the risk for metastasis and associated mortality is mainly dependent on tumor thickness and depth of invasion. Early recognition and correct diagnosis is therefore important for successful and effective treatment. The correct diagnosis of melanoma is, however, challenging due to the wide morphological spectrum. Historically, the disease was subdivided into superficial spreading, nodular, lentigo maligna and acral lentiginous melanoma but many more subtypes have subsequently been added. Some of these melanoma variants also show differences relating to the genetic background, clinical presentation, prognosis and treatment and may be associated with a specific differential diagnosis. In this article four of these melanoma variants, desmoplastic melanoma, nevoid melanoma, malignant blue nevus and pigment synthesizing melanoma will be discussed in more detail. PMID:25589353

  4. Malignant Melanoma With Osteoclast-Like Differentiation.

    PubMed

    Wasserman, Jason K; Sekhon, Harmanjatinder S; Ayroud, Yasmine

    2015-09-01

    Osteoclast-like giant cells are frequently encountered in nonskeletal malignancies; however, the evidence to date suggests that they represent a tissue response to the lesion rather than neoplastic differentiation. We describe a case of metastatic melanoma demonstrating osteoclast-like differentiation in the lung. The lung nodule was diagnosed as a metastatic melanoma by histological features and confirmed by immunohistochemistry. Resection specimen showed numerous multinucleated giant cells exhibiting osteoclast-like morphology dispersed throughout the lesion. Both the neoplastic melanocytes and giant cells were reactive for HMB-45, Melan-A, and S100. In addition, the multinucleated neoplastic giant cells were also reactive for the monocyte/macrophage lineage markers CD68 and CD163, and alkaline phosphatase, an enzyme present in normal osteoclasts. The neoplastic melanocytes and the multinucleated neoplastic giant cells were also reactive for microphthalmia-associated transcription factor, a protein required for the development of both melanocytes and osteoclasts. Collectively, a co-expression of monocyte/macrophage markers along with melanocytic markers and alkaline phosphatase in the multinucleated neoplastic giant cells in metastatic melanoma suggest that malignant melanocytes are capable of differentiating into osteoclast-like cells and consequently aid invasion into various structures and eliciting the aggressive behavior. PMID:26113663

  5. UVB-irradiated keratinocytes induce melanoma-associated ganglioside GD3 synthase gene in melanocytes via secretion of tumor necrosis factor α and interleukin 6.

    PubMed

    Miyata, Maiko; Ichihara, Masatoshi; Tajima, Orie; Sobue, Sayaka; Kambe, Mariko; Sugiura, Kazumitsu; Furukawa, Koichi; Furukawa, Keiko

    2014-03-01

    Although expression of gangliosides and their synthetic enzyme genes in malignant melanomas has been well studied, that in normal melanocytes has been scarcely analyzed. In particular, changes in expression levels of glycosyltransferase genes responsible for ganglioside synthesis during evolution of melanomas from melanocytes are very important to understand roles of gangliosides in melanomas. Here, expression of glycosyltransferase genes related to the ganglioside synthesis was analyzed using RNAs from cultured melanocytes and melanoma cell lines. Quantitative RT-PCR revealed that melanomas expressed high levels of mRNA of GD3 synthase and GM2/GD2 synthase genes and low levels of GM1/GD1b synthase genes compared with melanocytes. As a representative exogenous stimulation, effects of ultraviolet B (UVB) on the expression levels of 3 major ganglioside synthase genes in melanocytes were analyzed. Although direct UVB irradiation of melanocytes caused no marked changes, culture supernatants of UVB-irradiated keratinocytes (HaCaT cells) induced definite up-regulation of GD3 synthase and GM2/GD2 synthase genes. Detailed examination of the supernatants revealed that inflammatory cytokines such as TNFα and IL-6 enhanced GD3 synthase gene expression. These results suggest that inflammatory cytokines secreted from UVB-irradiated keratinocytes induced melanoma-associated ganglioside synthase genes, proposing roles of skin microenvironment in the promotion of melanoma-like ganglioside profiles in melanocytes. PMID:24548412

  6. Selective cytotoxicity of 4-S-cysteaminylphenol on follicular melanocytes of the black mouse: rational basis for its application to melanoma chemotherapy

    SciTech Connect

    Ito, Y.; Jimbow, K.

    1987-06-15

    We have previously shown that 4-S-cysteaminylphenol (4-S-CAP) causes a significant inhibition of in vivo melanoma growth. To clarify the mechanism of the in vivo antimelanoma effect, this study evaluated the cellular and subcellular changes of follicular melanocytes after s.c. administration of 4-S-CAP on the lumbar areas of black and albino mice. 4-S-CAP produced a prompt, selective swelling and lysis of melanocytes, resulting eventually in the necrosis of melanocytes and the depigmentation of black hair follicles. None of the degenerative changes were seen in melanocytes and keratinocytes of control albino follicles. Comparison of melanocytes in black and albino follicles revealed that melanin synthesis is highly active in the melanocytes of black follicles while melanin and tyrosinase synthesis is not seen in the melanocytes of albino follicles. The findings indicate that the selective melanocytotoxicity of 4-S-CAP is manifested by lysis and necrosis of cells which are actively engaged in melanin synthesis. 4-S-CAP appears to provide a new modality for rational chemotherapy of malignant melanoma.

  7. Cytolytic antibodies to melanocytes in vitiligo.

    PubMed

    Cui, J; Arita, Y; Bystryn, J C

    1993-06-01

    Patients with vitiligo have been found to have circulating antibodies to pigment cells. To evaluate the functional activity of these antibodies, a highly sensitive europium release assay was used to compare complement-mediated cytolysis of human melanocytes by sera of 56 patients with vitiligo (20 with active disease, 25 with inactive disease, 11 with unidentified disease activity) and 47 control individuals. Significant melanocyte lysis was mediated by 32 (57%) of the patients with vitiligo but by only three (6%) of the control sera (p < 0.001), and by 17 (85%) of 20 patients with active vitiligo versus 11 (44%) of 25 patients with inactive disease (p < 0.025). Mean melanocyte lysis by vitiligo sera was 24% versus 6% by control sera (p < 0.0001). A subset of 12 vitiligo sera with high titers of cytolytic antibodies to melanocytes (34% mean cytolysis) reacted minimally (< 2% mean cytolysis) to a panel of control cells that included human and murine melanomas, human fibroblasts, lung carcinoma, and rhabdomyosarcoma. These findings indicate that antibodies present in patients with vitiligo have the functional ability to selectively kill melanocytes and are more common in active disease. These observations support, but do not prove, the hypothesis that vitiligo is an autoimmune disease and that anti-pigment cell antibodies have a role in inducing the disease. PMID:8496621

  8. Germline mutations in BAP1 predispose to melanocytic tumors

    PubMed Central

    Wiesner, Thomas; Obenauf, Anna C.; Murali, Rajmohan; Fried, Isabella; Griewank, Klaus G.; Ulz, Peter; Windpassinger, Christian; Wackernagel, Werner; Loy, Shea; Wolf, Ingrid; Viale, Agnes; Lash, Alex E.; Pirun, Mono; Socci, Nicholas D.; Rütten, Arno; Palmedo, Gabriele; Abramson, David; Offit, Kenneth; Ott, Arthur; Becker, Jürgen C.; Cerroni, Lorenzo; Kutzner, Heinz; Bastian, Boris C.; Speicher, Michael R.

    2012-01-01

    Common acquired melanocytic nevi are benign neoplasms that are composed of small uniform melanocytes and typically present as flat or slightly elevated, pigmented lesions on the skin. We describe two families with a new autosomal dominant syndrome characterized by multiple skin-colored, elevated melanocytic tumors. In contrast to common acquired nevi, the melanocytic neoplasms in affected family members ranged histopathologically from epithelioid nevi to atypical melanocytic proliferations that showed overlapping features with melanoma. Some affected patients developed uveal or cutaneous melanomas. Segregating with this phenotype, we found inactivating germline mutations of the BAP1 gene. The majority of melanocytic neoplasms lost the remaining wild-type allele of BAP1 by various somatic alterations. In addition, we found BAP1 mutations in a subset of sporadic melanocytic neoplasms showing histologic similarities to the familial tumors. These findings suggest that loss of BAP1 is associated with a clinically and morphologically distinct type of melanocytic neoplasm. PMID:21874003

  9. Appearance of New Vemurafenib-associated Melanocytic Nevi on Normal-appearing Skin

    PubMed Central

    Bedikian, Agop Y.; Kim, Kevin B.

    2013-01-01

    Background: Vemurafenib, a selective BRAF inhibitor that has antineoplastic activity in patients with unresectable or metastatic malignant melanoma whose tumor harbors a BRAF V600E mutation, has multiple drug-associated cutaneous adverse effects. Purpose: To provide a detailed and comprehensive review of reported changing or new pigmented lesions in oncology patients who have been treated with vemurafenib. Methods: The new appearance of melanocytic nevi on normal-appearing skin after initiating treatment with vemurafenib is described in two men with metastatic malignant melanoma whose tumors demonstrated a BRAF V600E mutation. Using the PubMed database, an extensive literature search was performed for the following topics: vermurafenib, nevus, nevi, melanoma, pigmented lesion, cutaneous, adverse effect, side effect. The results of the search were used to secure all reports of new or changing pigmented lesions after initiating treatment with vemurafenib. Results: Vemurafenib is associated with both changes in existing pigmented lesions (including involution, alteration of color and size, and progression to melanoma) and the onset of new melanocytic lesions—nevi (in 5 patients) and primary melanomas (in 2 patients). Visual examination, dermoscopic evaluation, and reflectance confocal microscopy have been used to document the changes in existing or new melanocytic lesions subsequent to initiating treatment with vermurafenib. Histopathology analysis has shown these lesions to usually be either dysplastic nevi or new primary melanomas. Conclusion: Vemurafenib-treated patients can develop new pigmented lesions (such as nevi) and/or morphological changes in their existing melanocytic lesions (such as involution, increase in size, or alternation of color). In addition, they can develop new primary malignant melanomas that either occur de novo on normal-appearing skin or develop in pre-existing melanocytic lesions. Therefore, total body skin examination should be

  10. Links between Schwann cells and melanocytes in development and disease.

    PubMed

    Van Raamsdonk, Catherine D; Deo, Mugdha

    2013-09-01

    Melanocytes are pigment-producing cells that reside in the skin, eyes, ears, heart, and central nervous system meninges of mammals. Schwann cells are glial cells, which closely associate with peripheral nerves, myelinating, and sheathing them. Melanocytes and Schwann cells both arise from the neural crest during development, and some melanocytes arise directly from Schwann cell precursors lining developing spinal nerves. In this review, we explore the connections between melanocytes and Schwann cells in development and transformation. PMID:23815504

  11. Primary Malignant Melanoma of Renal Pelvis with Extensive Clear Cell Change

    PubMed Central

    Liapis, George; Sarlanis, Helen; Poulaki, Elpida; Stravodimos, Konstandinos; Lazaris, Andreas C

    2016-01-01

    Our presentation illustrates a rare case of primary renal pelvis malignant melanoma in a 35-year-old man. The diagnosis of malignant melanoma was based on immunophenotype and the detection of intracellular melanin pigment. The renal origin was proven by the presence of scattered melanocytes within the urothelium of the pelvis. The tumor exhibited extensive clear cell change that closely mimics clear cell renal cell carcinoma. The patient’s clinical history did not disclose any signs of previous melanocytic skin or mucosa lesions. Differential diagnosis includes tumors capable of synthesizing melanin or expressing melanocytic markers. PMID:27226943

  12. Active Notch1 Confers a Transformed Phenotype to Primary Human Melanocytes

    PubMed Central

    Pinnix, Chelsea C.; Lee, John T.; Liu, Zhao-Jun; McDaid, Ronan; Balint, Klara; Beverly, Levi J.; Brafford, Patricia A.; Xiao, Min; Himes, Benjamin; Zabierowski, Susan E.; Yashiro-Ohtani, Yumi; Nathanson, Katherine L.; Bengston, Ana; Pollock, Pamela M.; Weeraratna, Ashani T.; Nickoloff, Brian J.; Pear, Warren S.; Capobianco, Anthony J.; Herlyn, Meenhard

    2009-01-01

    The importance of MAPK signaling in melanoma is underscored by the prevalence of activating mutations in N-Ras and B-Raf; yet, clinical development of inhibitors of this pathway has been largely ineffective, suggesting that alternative oncogenes may also promote melanoma. Notch is an interesting candidate that has only been correlated with melanoma development and progression; a thorough assessment of tumor-initiating effects of activated Notch on human melanocytes would clarify the mounting correlative evidence and perhaps identify a novel target for an otherwise untreatable disease. Analysis of a substantial panel of cell lines and patient lesions demonstrated that Notch activity is significantly higher in melanomas than their non-transformed counterparts. The use of a constitutively-active, truncated Notch transgene construct (NIC) was exploited to determine if Notch activation is a ‘driving’ event in melanocytic transformation or instead a ‘passenger’ event associated with melanoma progression. NIC-infected melanocytes displayed increased proliferative capacity and biological features more reminiscent of melanoma such as dysregulated cell adhesion and migration. Gene expression analyses supported these observations and aided in the identification of MCAM, an adhesion molecule associated with acquisition of the malignant phenotype, as a direct target of Notch transactivation. NIC-positive melanocytes grew at clonal density, proliferated in limiting media conditions, and also exhibited anchorage-independent growth suggesting that Notch, alone, is a transforming oncogene in human melanocytes, a phenomenon not previously described for any melanoma oncogene; this new information yields valuable insight into the basic epidemiology of melanoma and launches a realm of possibilities for drug intervention in this deadly disease. PMID:19549918

  13. THE MOLECULAR PATHOLOGY OF MELANOMA: AN INTEGRATED TAXONOMY OF MELANOCYTIC NEOPLASIA

    PubMed Central

    Bastian, Boris C.

    2016-01-01

    Melanomas are comprised of multiple biologically distinct categories, which differ in cell of origin, age of onset, clinical and histologic presentation, pattern of metastasis, ethnic distribution, causative role of UV radiation, predisposing germ line alterations, mutational processes, and patterns of somatic mutations. Neoplasms are initiated by gain of function mutations in one of several primary oncogenes, typically leading to benign melanocytic nevi with characteristic histologic features. The progression of nevi is restrained by multiple tumor suppressive mechanisms. Secondary genetic alterations override these barriers and promote intermediate or overtly malignant tumors along distinct progression trajectories. The current knowledge about pathogenesis, clinical, histological and genetic features of primary melanocytic neoplasms is reviewed and integrated into a taxonomic framework. PMID:24460190

  14. Generation of Human Melanocytes from Induced Pluripotent Stem Cells

    PubMed Central

    Okada, Yohei; Akamatsu, Wado; Kuwahara, Reiko; Ohyama, Manabu; Amagai, Masayuki; Matsuzaki, Yumi; Yamanaka, Shinya; Okano, Hideyuki; Kawakami, Yutaka

    2011-01-01

    Epidermal melanocytes play an important role in protecting the skin from UV rays, and their functional impairment results in pigment disorders. Additionally, melanomas are considered to arise from mutations that accumulate in melanocyte stem cells. The mechanisms underlying melanocyte differentiation and the defining characteristics of melanocyte stem cells in humans are, however, largely unknown. In the present study, we set out to generate melanocytes from human iPS cells in vitro, leading to a preliminary investigation of the mechanisms of human melanocyte differentiation. We generated iPS cell lines from human dermal fibroblasts using the Yamanaka factors (SOX2, OCT3/4, and KLF4, with or without c-MYC). These iPS cell lines were subsequently used to form embryoid bodies (EBs) and then differentiated into melanocytes via culture supplementation with Wnt3a, SCF, and ET-3. Seven weeks after inducing differentiation, pigmented cells expressing melanocyte markers such as MITF, tyrosinase, SILV, and TYRP1, were detected. Melanosomes were identified in these pigmented cells by electron microscopy, and global gene expression profiling of the pigmented cells showed a high similarity to that of human primary foreskin-derived melanocytes, suggesting the successful generation of melanocytes from iPS cells. This in vitro differentiation system should prove useful for understanding human melanocyte biology and revealing the mechanism of various pigment cell disorders, including melanoma. PMID:21249204

  15. Role of TRPM in melanocytes and melanoma

    PubMed Central

    Guo, Huazhang; Carlson, J. Andrew; Slominski, Andrzej

    2012-01-01

    Transient receptor potential (TRP) cation channel superfamily plays important roles in variety cellular processes including polymodal cellular sensing, cell adhesion, cell polarity, proliferation, differentiation, and apoptosis. One of its subfamilies are TRPM channels. mRNA expression of its founding member, TRPM1 (melastatin), correlates with terminal melanocytic differentiation and loss of its expression has been identified as an important diagnostic and prognostic marker for primary cutaneous melanoma. Because TRPM1 gene codes two transcripts: TRPM1 channel protein in its exons, and miR-211 in one of its introns, we propose a dual role for TRPM1 gene where the loss of TRPM1 channel protein is an excellent marker of melanoma aggressiveness, while the expression of miR-211 is linked to the tumor suppressor function of TRPM1. In addition, three other members of this subfamily, TRPM 2, 7 and 8 are implicated in regulation of melanocytic behavior. TRPM2 is capable of inducing melanoma apoptosis and necrosis. TRPM7 can be a protector and detoxifier in both melanocytes and melanoma cells. TRPM8 can mediate agonist-induced melanoma cell death. Therefore, we propose that TRPM1, TRPM2, TRPM7, and TRPM8 play crucial roles in melanocyte physiology and melanoma oncology, and are excellent diagnostic markers and theraputic targets. PMID:22897572

  16. Acquired unilateral melanocytic nevi in otherwise normal skin.

    PubMed

    Yu, Xijun; Nagai, Hiroshi; Nishigori, Chikako; Horikawa, Tatsuya

    2008-01-01

    We describe a case with numerous melanocytic nevi in otherwise normal skin. A 5-year-old girl presented with more than 100 small pigment lesions on her left arm, shoulder and upper back without underlying light brown macule. The pigment lesions were first found on her left forearm at 3 months old and gradually increased along with her growth. Skin biopsy from a pigmented lesion shows a pathological change in compound-type melanocytic nevus without any atypical changes. Speckled lentiginous nevus is known to have multiple melanocytic lesions on the underlying brown macule from birth. Partial unilateral lentiginosis is characterized by unilateral lentigines with histopathological changes in lentigo but not melanocytic proliferation in the dermis. Agminated melanocytic nevi tend to be clustered together in a circumscribed area, whereas in the present case melanocytic nevi were segmentally arranged but not agminated. We consider that this is an unusual type of mosaicism of melanocytic disorders. PMID:18401177

  17. High-definition optical coherence tomography of melanocytic skin lesions.

    PubMed

    Gambichler, Thilo; Plura, Iris; Schmid-Wendtner, Monika; Valavanis, Konstantinos; Kulichova, Daniela; Stücker, Markus; Pljakic, Azem; Berking, Carola; Maier, Tanja

    2015-08-01

    High-definition optical coherence tomography (HD-OCT) scanners have recently been developed. We assessed micromorphological HD-OCT correlates of benign naevi (BN) and malignant melanoma (MM). 28 BN and 20 MM were studied using HD-OCT and histology. Epidermal honeycomb/cobblestone pattern, regular junctional cell nests, and edged papillae are more often observed in BN, whereas fusion of rete ridges, pagetoid cells and junctional and/or dermal nests with atypical cells are more frequently seen in MM. A high overlap of HD-OCT features in BN and MM was observed and in 20% of MM we did not find evidence for malignancy in OCT images at all. Using HD-OCT it is possible to visualize architectural and cellular alterations of melanocytic skin lesions. The overlap of HD-OCT features seen in BN and MM and the absence of suspicious HD-OCT features in some MM represents an important limitation of HD-OCT affecting the sensitivity of HD-OCT in diagnosing MM. High-definition optical coherence tomography and the corresponding vertically sectioned histology of a compound naevus. PMID:25237005

  18. Melanocyte antigen triggers autoimmunity in human psoriasis

    PubMed Central

    Arakawa, Akiko; Siewert, Katherina; Stöhr, Julia; Besgen, Petra; Kim, Song-Min; Rühl, Geraldine; Nickel, Jens; Vollmer, Sigrid; Thomas, Peter; Krebs, Stefan; Pinkert, Stefan; Spannagl, Michael; Held, Kathrin; Kammerbauer, Claudia; Besch, Robert; Dornmair, Klaus

    2015-01-01

    Psoriasis vulgaris is a common T cell–mediated inflammatory skin disease with a suspected autoimmune pathogenesis. The human leukocyte antigen (HLA) class I allele, HLA-C*06:02, is the main psoriasis risk gene. Epidermal CD8+ T cells are essential for psoriasis development. Functional implications of HLA-C*06:02 and mechanisms of lesional T cell activation in psoriasis, however, remained elusive. Here we identify melanocytes as skin-specific target cells of an HLA-C*06:02–restricted psoriatic T cell response. We found that a Vα3S1/Vβ13S1 T cell receptor (TCR), which we had reconstituted from an epidermal CD8+ T cell clone of an HLA-C*06:02–positive psoriasis patient specifically recognizes HLA-C*06:02–positive melanocytes. Through peptide library screening, we identified ADAMTS-like protein 5 (ADAMTSL5) as an HLA-C*06:02–presented melanocytic autoantigen of the Vα3S1/Vβ13S1 TCR. Consistent with the Vα3S1/Vβ13S1-TCR reactivity, we observed numerous CD8+ T cells in psoriasis lesions attacking melanocytes, the only epidermal cells expressing ADAMTSL5. Furthermore, ADAMTSL5 stimulation induced the psoriasis signature cytokine, IL-17A, in CD8+ T cells from psoriasis patients only, supporting a role as psoriatic autoantigen. This unbiased analysis of a TCR obtained directly from tissue-infiltrating CD8+ T cells reveals that in psoriasis HLA-C*06:02 directs an autoimmune response against melanocytes through autoantigen presentation. We propose that HLA-C*06:02 may predispose to psoriasis via this newly identified autoimmune pathway. PMID:26621454

  19. Melanocyte antigen triggers autoimmunity in human psoriasis.

    PubMed

    Arakawa, Akiko; Siewert, Katherina; Stöhr, Julia; Besgen, Petra; Kim, Song-Min; Rühl, Geraldine; Nickel, Jens; Vollmer, Sigrid; Thomas, Peter; Krebs, Stefan; Pinkert, Stefan; Spannagl, Michael; Held, Kathrin; Kammerbauer, Claudia; Besch, Robert; Dornmair, Klaus; Prinz, Jörg C

    2015-12-14

    Psoriasis vulgaris is a common T cell-mediated inflammatory skin disease with a suspected autoimmune pathogenesis. The human leukocyte antigen (HLA) class I allele, HLA-C*06:02, is the main psoriasis risk gene. Epidermal CD8(+) T cells are essential for psoriasis development. Functional implications of HLA-C*06:02 and mechanisms of lesional T cell activation in psoriasis, however, remained elusive. Here we identify melanocytes as skin-specific target cells of an HLA-C*06:02-restricted psoriatic T cell response. We found that a Vα3S1/Vβ13S1 T cell receptor (TCR), which we had reconstituted from an epidermal CD8(+) T cell clone of an HLA-C*06:02-positive psoriasis patient specifically recognizes HLA-C*06:02-positive melanocytes. Through peptide library screening, we identified ADAMTS-like protein 5 (ADAMTSL5) as an HLA-C*06:02-presented melanocytic autoantigen of the Vα3S1/Vβ13S1 TCR. Consistent with the Vα3S1/Vβ13S1-TCR reactivity, we observed numerous CD8(+) T cells in psoriasis lesions attacking melanocytes, the only epidermal cells expressing ADAMTSL5. Furthermore, ADAMTSL5 stimulation induced the psoriasis signature cytokine, IL-17A, in CD8(+) T cells from psoriasis patients only, supporting a role as psoriatic autoantigen. This unbiased analysis of a TCR obtained directly from tissue-infiltrating CD8(+) T cells reveals that in psoriasis HLA-C*06:02 directs an autoimmune response against melanocytes through autoantigen presentation. We propose that HLA-C*06:02 may predispose to psoriasis via this newly identified autoimmune pathway. PMID:26621454

  20. Treatment of a giant congenital melanocytic nevus in the adult: review of the current management of giant congenital melanocytic nevus.

    PubMed

    Su, Jeannie J; Chang, Daniel K; Mailey, Brian; Gosman, Amanda

    2015-05-01

    Giant congenital melanocytic nevi (GCMNs) create cosmetic disfigurements and pose risk for malignant transformation. Adult GCMN cases are uncommon because most families opt for surgical treatment during childhood. We review the current literature on GCMN and present an interesting case of an adult with a GCMN encompassing the entire back with painful nodules exhibiting gross involvement of his back musculature, without pathologic evidence of malignancy. Surgical management was deferred in childhood because of parental desires to allow the patient to make his own decision, and treatment in adulthood was pursued on the basis of the significant impairment of the patient's quality of life and self-esteem due to the massive size and deforming nature of the nevus. The treatment strategy used for this young adult male patient involved a massive en bloc excision of the GCMN with partial resection of the latissimus dorsi, followed by a 5-week staged reconstructive process using dermal regenerative matrices and split-thickness skin grafting. Because of the shift in GCMN management from early surgical management to more conservative management, we may see an increase in adult cases of GCMN. Thus, it is critical to better understand the controversy surrounding early versus delayed management of GCMN. PMID:25664413

  1. Investigating associations of cyclooxygenase-2 expression with angiogenesis, proliferation, macrophage and T-lymphocyte infiltration in canine melanocytic tumours.

    PubMed

    Gregório, Hugo; Raposo, Teresa P; Queiroga, Felisbina L; Prada, Justina; Pires, Isabel

    2016-08-01

    Cyclooxygenase-2 (COX-2) is known to be involved in tumour progression and has been suggested as a therapeutic target in many human and animal malignancies. A number of different pathways subjacent to cancer hallmarks are considered to be involved in COX-2-mediated tumour progression, although these are still largely undefined. Our aim is to investigate associations between COX-2 expression and angiogenesis, proliferation and the inflammatory microenvironment in canine melanocytic tumours. Understanding the involvement of COX-2 with cancer hallmarks might enable us to adapt therapeutic strategies for canine melanomas, an aggressive and often lethal malignancy with value in comparative oncology. Immunohistochemical staining of COX-2, Ki-67 (proliferation index), vascular endothelial growth factor (VEGF), factor VIII (microvessel density), CD3 (lymphocytes) and MAC387 (macrophages) was performed in 51 melanocytic tumours (31 malignant melanomas, 20 melanocytomas). Statistical associations between COX-2 and the other parameters detected were analysed. In melanocytic tumours (n=51), both COX-2 labelling extension and intensity showed a statistically significant association with angiogenesis by factor VIII, VEGF, Ki-67, CD3+ T lymphocytes and MAC387. Within malignant melanomas, COX-2 expression has shown significant associations with microvessel density (factor VIII), lymphocyte and macrophage infiltration and, considering all melanocytic tumours, COX-2 was also associated with VEGF intensity and Ki-67 cell proliferation. Our results point to a role for COX-2 in angiogenesis and in the establishment of an inflammatory microenvironment, favourable to melanoma tumour progression. Further mechanistic studies are warranted to dissect molecular pathways in which COX-2 is involved. Present evidence suggests that COX-2 inhibitors might be useful as an adjuvant treatment to hinder canine melanoma progression. PMID:27105172

  2. Infrared A radiation promotes survival of human melanocytes carrying ultraviolet radiation-induced DNA damage.

    PubMed

    Kimeswenger, Susanne; Schwarz, Agatha; Födinger, Dagmar; Müller, Susanne; Pehamberger, Hubert; Schwarz, Thomas; Jantschitsch, Christian

    2016-06-01

    The link between solar radiation and melanoma is still elusive. Although infrared radiation (IR) accounts for over 50% of terrestrial solar energy, its influence on human skin is not well explored. There is increasing evidence that IR influences the expression patterns of several molecules independently of heat. A previous in vivo study revealed that pretreatment with IR might promote the development of UVR-induced non-epithelial skin cancer and possibly of melanoma in mice. To expand on this, the aim of the present study was to evaluate the impact of IR on UVR-induced apoptosis and DNA repair in normal human epidermal melanocytes. The balance between these two effects is a key factor of malignant transformation. Human melanocytes were exposed to physiologic doses of IR and UVR. Compared to cells irradiated with UVR only, simultaneous exposure to IR significantly reduced the apoptotic rate. However, IR did not influence the repair of UVR-induced DNA damage. IR partly reversed the pro-apoptotic effects of UVR via modification of the expression and activity of proteins mainly of the extrinsic apoptotic pathway. In conclusion, IR enhances the survival of melanocytes carrying UVR-induced DNA damage and thereby might contribute to melanomagenesis. PMID:26844814

  3. Mechanical properties of growing melanocytic nevi and the progression to melanoma

    NASA Astrophysics Data System (ADS)

    Taloni, Alessandro; Alemi, Alexander; Ciusani, Emilio; Sethna, James P.; Zapperi, Stefano; La Porta, Caterina A. M.; National Research Council Of Italy Team; Lassp, Department Of Physics, Cornell University Team; Istituto Neurologico Carlo Besta Collaboration; Department Of Biosciences, University Of Milano Team

    2015-03-01

    Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma in a way that is still unclear from the biochemical and genetic point of view. Diagnostic and prognostic tools are then mostly based on dermoscopic examination and morphological analysis of histological tissues. To investigate the role of mechanics and geometry in the morpholgical dynamics of melanocytic nevi, we present a computational model for cell proliferation in a layered non-linear elastic tissue. Our simulations show that the morphology of the nevus is correlated to the initial location of the proliferating cell starting the growth process and to the mechanical properties of the tissue. We also demonstrate that melanocytes are subject to compressive stresses that fluctuate widely in the nevus and depend on the growth stage. Numerical simulations of cells in the epidermis releasing matrix metalloproteinases display an accelerated invasion of the dermis by destroying the basal membrane. Moreover, we show experimentally that osmotic stress and collagen inhibit growth in primary melanoma cells while the effect is much weaker in metastatic cells.

  4. Pirin Inhibits Cellular Senescence in Melanocytic Cells

    PubMed Central

    Licciulli, Silvia; Luise, Chiara; Scafetta, Gaia; Capra, Maria; Giardina, Giuseppina; Nuciforo, Paolo; Bosari, Silvano; Viale, Giuseppe; Mazzarol, Giovanni; Tonelli, Chiara; Lanfrancone, Luisa; Alcalay, Myriam

    2011-01-01

    Cellular senescence has been widely recognized as a tumor suppressing mechanism that acts as a barrier to cancer development after oncogenic stimuli. A prominent in vivo model of the senescence barrier is represented by nevi, which are composed of melanocytes that, after an initial phase of proliferation induced by activated oncogenes (most commonly BRAF), are blocked in a state of cellular senescence. Transformation to melanoma occurs when genes involved in controlling senescence are mutated or silenced and cells reacquire the capacity to proliferate. Pirin (PIR) is a highly conserved nuclear protein that likely functions as a transcriptional regulator whose expression levels are altered in different types of tumors. We analyzed the expression pattern of PIR in adult human tissues and found that it is expressed in melanocytes and has a complex pattern of regulation in nevi and melanoma: it is rarely detected in mature nevi, but is expressed at high levels in a subset of melanomas. Loss of function and overexpression experiments in normal and transformed melanocytic cells revealed that PIR is involved in the negative control of cellular senescence and that its expression is necessary to overcome the senescence barrier. Our results suggest that PIR may have a relevant role in melanoma progression. PMID:21514450

  5. Autophagy as a melanocytic self-defense mechanism.

    PubMed

    Setaluri, Vijayasaradhi

    2015-05-01

    Defects in autophagy have implications for melanocyte survival and manifestations of skin pigmentary disorders. Zhang et al. (2015) show that mouse melanocytes lacking the autophagy protein Atg7 undergo premature senescence in vitro and accumulate products of oxidative damage, despite activation of the redox response. Interestingly, contrary to previous findings, the melanocyte-specific deficiency in autophagy did not cause major defects in melanosome biogenesis, nor did it produce visually striking changes in mouse coat color. PMID:25882462

  6. Melanocytes as instigators and victims of oxidative stress.

    PubMed

    Denat, Laurence; Kadekaro, Ana L; Marrot, Laurent; Leachman, Sancy A; Abdel-Malek, Zalfa A

    2014-06-01

    Epidermal melanocytes are particularly vulnerable to oxidative stress owing to the pro-oxidant state generated during melanin synthesis, and to the intrinsic antioxidant defenses that are compromised in pathologic conditions. Melanoma is thought to be oxidative stress driven, and melanocyte death in vitiligo is thought to be instigated by a highly pro-oxidant state in the epidermis. We review the current knowledge about melanin and the redox state of melanocytes, how paracrine factors help counteract oxidative stress, the role of oxidative stress in melanoma initiation and progression and in melanocyte death in vitiligo, and how this knowledge can be harnessed for melanoma and vitiligo treatment. PMID:24573173

  7. Growth of melanocytes in human epidermal cell cultures

    SciTech Connect

    Staiano-Coico, L.; Hefton, J.M.; Amadeo, C.; Pagan-Charry, I.; Madden, M.R.; Cardon-Cardo, C. )

    1990-08-01

    Epidermal cell cultures were grown in keratinocyte-conditioned medium for use as burn wound grafts; the melanocyte composition of the grafts was studied under a variety of conditions. Melanocytes were identified by immunohistochemistry based on a monoclonal antibody (MEL-5) that has previously been shown to react specifically with melanocytes. During the first 7 days of growth in primary culture, the total number of melanocytes in the epidermal cultures decreased to 10% of the number present in normal skin. Beginning on day 2 of culture, bipolar melanocytes were present at a mean cell density of 116 +/- 2/mm2; the keratinocyte to melanocyte ratio was preserved during further primary culture and through three subpassages. Moreover, exposure of cultures to mild UVB irradiation stimulated the melanocytes to proliferate, suggesting that the melanocytes growing in culture maintained their responsiveness to external stimuli. When the sheets of cultured cells were enzymatically detached from the plastic culture flasks before grafting, melanocytes remained in the basal layer of cells as part of the graft applied to the patient.

  8. Role of nitric oxide and cyclic GMP signaling in melanocyte response to hypergravity

    NASA Astrophysics Data System (ADS)

    Ivanova, Krassimira; Lambers, Britta; Tsiockas, Wasiliki; Block, Ingrid; Gerzer, Rupert

    , respond to hyper-g (up to 5xg for 24 h) with an increase in cGMP efflux and pigmentation in comparison to 1-g controls under conditions of reduced cGMP hydrolysis or accelerated cGMP synthesis (e.g., by NO but not natriuretic peptides). The elevated cGMP extrusion was related to a hyper-g-induced increase in the expression of the multidrug resistance proteins 4/5 as selective cGMP exporters as shown on mRNA and protein levels using real-time polymerase chain reaction and flow cytometric analysis. These results suggest that an environment modified by centrifugal acceleration represents a new factor for regulating cGMP levels in unstimulated and NO-stimulated human melanocytes that involves multidrug resistance proteins, which could be important for malignant transformation. Future studies on these aspects in real microgravity will be important for residents on the International Space Station and astronauts involved in long space flights.

  9. Rare Skin Adnexal and Melanocytic Tumors Arising in Ovarian Mature Cystic Teratomas: A Report of 3 Cases and Review of the Literature.

    PubMed

    Moulla, Alexandra A; Magdy, Nesreen; Francis, Nicholas; Taube, Janis; Ronnett, Brigitte M; El-Bahrawy, Mona

    2016-09-01

    Mature teratoma of the ovary is the most common primary ovarian tumor accounting for 15% (10%-20%) of all ovarian neoplasms. Skin and skin adnexal structures are the most common elements identified in mature teratomas. Benign and malignant skin tumors can arise in ovarian teratomas, the most common being epithelial tumors. Melanocytic and adnexal tumors developing in a teratoma are rare and can be easily overlooked. We report 3 cases and review melanocytic and skin adnexal tumors encountered in ovarian teratomas. PMID:26974995

  10. Rare emerging malignant skin tumours.

    PubMed

    Rongioletti, F; Ferreli, C; Pinna, A L; Atzori, L

    2015-08-01

    As clinical skills improve and innovative diagnostic techniques become available in the field of dermatology and dermatopathology, new types or additional variants of malignant skin tumors are described. This article reviews the current nomenclature, clinico-pathological features, differential diagnosis, prognostic and therapeutic implications of some new dermato(patho)logical rare emerging skin tumors, including epithelial tumors (squamous cell carcinoma with mucinous metaplasia), adnexal tumors (endocrine mucin-producing sweat gland carcinoma), soft tissue tumors of vascular differentiation (pseudolymphomatous cutaneous angiosarcoma, pseudomyogenic hemangioendothelioma), hematopoietic tumors (blastic plasmacytoid dendritic cell neoplasm) and mixed epithelial/melanocytic tumor (squamomelanocytic tumor). PMID:26086411

  11. Comparative cytogenetic characterization of primary canine melanocytic lesions using array CGH and fluorescence in situ hybridization.

    PubMed

    Poorman, Kelsey; Borst, Luke; Moroff, Scott; Roy, Siddharth; Labelle, Philippe; Motsinger-Reif, Alison; Breen, Matthew

    2015-06-01

    Melanocytic lesions originating from the oral mucosa or cutaneous epithelium are common in the general dog population, with up to 100,000 diagnoses each year in the USA. Oral melanoma is the most frequent canine neoplasm of the oral cavity, exhibiting a highly aggressive course. Cutaneous melanocytomas occur frequently, but rarely develop into a malignant form. Despite the differential prognosis, it has been assumed that subtypes of melanocytic lesions represent the same disease. To address the relative paucity of information about their genomic status, molecular cytogenetic analysis was performed on the three recognized subtypes of canine melanocytic lesions. Using array comparative genomic hybridization (aCGH) analysis, highly aberrant distinct copy number status across the tumor genome for both of the malignant melanoma subtypes was revealed. The most frequent aberrations included gain of dog chromosome (CFA) 13 and 17 and loss of CFA 22. Melanocytomas possessed fewer genome wide aberrations, yet showed a recurrent gain of CFA 20q15.3-17. A distinctive copy number profile, evident only in oral melanomas, displayed a sigmoidal pattern of copy number loss followed immediately by a gain, around CFA 30q14. Moreover, when assessed by fluorescence in situ hybridization (FISH), copy number aberrations of targeted genes, such as gain of c-MYC (80 % of cases) and loss of CDKN2A (68 % of cases), were observed. This study suggests that in concordance with what is known for human melanomas, canine melanomas of the oral mucosa and cutaneous epithelium are discrete and initiated by different molecular pathways. PMID:25511566

  12. Neurotized Congenital Melanocytic Nevus Resembling a Pigmented Neurofibroma

    PubMed Central

    Singh, Nidhi; Chandrashekar, Laxmisha; Kar, Rakhee; Sylvia, Mary Theresa; Thappa, Devinder Mohan

    2015-01-01

    Neurotized congenital melanocytic nevus and pigmented neurofibroma (PNF) are close mimics and pose a clinicopathological challenge. We present a case of pigmented hypertrichotic plaque over lumbosacral region and discuss the differential diagnosis and its clinical, histopathological and immunohistochemistry features which may aid in differentiation. We highlight the difficulties faced in differentiating neurotized congenital melanocytic nevus from pigmented neurofibroma. PMID:25657396

  13. Exosomes released by keratinocytes modulate melanocyte pigmentation

    PubMed Central

    Cicero, Alessandra Lo; Delevoye, Cédric; Gilles-Marsens, Floriane; Loew, Damarys; Dingli, Florent; Guéré, Christelle; André, Nathalie; Vié, Katell; van Niel, Guillaume; Raposo, Graça

    2015-01-01

    Cells secrete extracellular vesicles (EVs), exosomes and microvesicles, which transfer proteins, lipids and RNAs to regulate recipient cell functions. Skin pigmentation relies on a tight dialogue between keratinocytes and melanocytes in the epidermis. Here we report that exosomes secreted by keratinocytes enhance melanin synthesis by increasing both the expression and activity of melanosomal proteins. Furthermore, we show that the function of keratinocyte-derived exosomes is phototype-dependent and is modulated by ultraviolet B. In sum, this study uncovers an important physiological function for exosomes in human pigmentation and opens new avenues in our understanding of how pigmentation is regulated by intercellular communication in both healthy and diseased states. PMID:26103923

  14. Exosomes released by keratinocytes modulate melanocyte pigmentation.

    PubMed

    Lo Cicero, Alessandra; Delevoye, Cédric; Gilles-Marsens, Floriane; Loew, Damarys; Dingli, Florent; Guéré, Christelle; André, Nathalie; Vié, Katell; van Niel, Guillaume; Raposo, Graça

    2015-01-01

    Cells secrete extracellular vesicles (EVs), exosomes and microvesicles, which transfer proteins, lipids and RNAs to regulate recipient cell functions. Skin pigmentation relies on a tight dialogue between keratinocytes and melanocytes in the epidermis. Here we report that exosomes secreted by keratinocytes enhance melanin synthesis by increasing both the expression and activity of melanosomal proteins. Furthermore, we show that the function of keratinocyte-derived exosomes is phototype-dependent and is modulated by ultraviolet B. In sum, this study uncovers an important physiological function for exosomes in human pigmentation and opens new avenues in our understanding of how pigmentation is regulated by intercellular communication in both healthy and diseased states. PMID:26103923

  15. Meningeal Melanocytes in the Mouse: Distribution and Dependence on Mitf

    PubMed Central

    Gudjohnsen, Stefán A. H.; Atacho, Diahann A. M.; Gesbert, Franck; Raposo, Graca; Hurbain, Ilse; Larue, Lionel; Steingrimsson, Eirikur; Petersen, Petur Henry

    2015-01-01

    Summary: Melanocytes are pigment producing cells derived from the neural crest. They are primarily found in the skin and hair follicles, but can also be found in other tissues including the eye, ear and heart. Here, we describe the distribution of pigmented cells in C57BL/6J mouse meninges, the membranes that envelope the brain. These cells contain melanosomes of all four stages of development and they depend on Microphthalmia associated transcription factor (MITF), the master regulator of melanocyte development, suggesting that they are bona-fide melanocytes. The location of these pigmented cells is consistent with the location of meningeal melanomas in humans and animal models. Significance: Here, we document and define pigmented cells in the meninges of the mouse brain and confirm that they are melanocytes. This is important for understanding the role of this cell type and for understanding primary meningeal melanoma, a rare disease that likely arises from normal meningeal melanocytes. PMID:26635543

  16. A distinctive melanocytic lesion associated with melanoma-prone dysplastic naevus syndrome: the hybrid naevus.

    PubMed

    Schubert, C; Parwaresch, R; Rudolph, P

    2001-02-01

    Clinically and histologically, the concept of dysplastic nevi remains controversial. To elaborate more precise criteria for the nevi of patients with dysplastic naevus syndrome (DNS), we examined 58 nevi from seven DNS patients who developed one or several malignant melanomas. Clinical presentation and histomorphology were evaluated, and immunohistochemistry was performed using proliferation marker Ki-S5 and antibody DO-7 to the p53 protein. Sixty nevi from individuals without history of melanoma served as controls. Of the DNS nevi, 21 (36.2%) exhibited no morphological particularities. The remaining 37 nevi presented distinctive histological features consisting of a slight epidermal acanthosis, spitzoid vertically oriented nests of dyscohesive nevus cells, and single-standing atypical melanocytes in the basal cell layer of the epidermis. Immunohistochemical analysis revealed an average proliferation index of 2.5%, which significantly surpassed the mean growth fraction of conventional dysplastic nevi (<1%). No increase in p53 expression was observed. Characteristically, active proliferation was found in junctional single-standing melanocytes with or without nuclear atypia rather than in nest-shaped compounds. In conclusion, certain moles of patients with DNS possess distinctive features. The newly characterized criteria may provide a basis for the diagnosis of DNS and might help to identify patients at increased risk for malignant melanoma by examination of a single biopsy. PMID:11253119

  17. Non psammomatous melanocytic schwannoma presenting as a subcutaneous nodule: A rare presentation of a rare lesion

    PubMed Central

    Gulati, Harveen Kaur; Joshi, Avinash R.; Anand, Mani; Deshmukh, S. D.

    2016-01-01

    Melanocytic schwannoma (MS) is an extremely rare soft tissue tumor accounting for less than 1% of all primitive nerve sheath tumors, with a predilection for spinal nerve involvement. To date, only 20 cases of cutaneous/subcutaneous MS have been described in literature. Here, we describe a case of MS presenting as a subcutaneous nodule in a 22-year-old male in right thigh. On examination, the nodule measured 2.5 × 2.0 × 1.5 cm with overlying skin showing a bluish hue and an ulcer. With a preoperative diagnosis of hemangioma, the patient was taken up for wide local excision and was diagnosed as a case of non psammomatous melanocytic schwannoma based on clinical, histological, and immunohistochemical studies. Immunohistochemistry revealed positivity with S-100, HMB-45, and Melan A with pericellular Laminin positivity. Carney's syndrome was ruled out. MS needs to be differentiated from other pigmented lesions like pigmented neurofibroma, Bednar tumor, cellular blue neavus, and especially malignant melanoma, which has an obvious ominous prognosis. Since MS can show unpredictable behavior especially in absence of overt malignant features, a long term follow up with or without radiotherapy is recommended. PMID:27366278

  18. A murine monoclonal antibody, MoAb HMSA-5, against a melanosomal component highly expressed in early stages, and common to normal and neoplastic melanocytes.

    PubMed Central

    Der, J. E.; Dixon, W. T.; Jimbow, K.; Horikoshi, T.

    1993-01-01

    The melanosome is a secretory organelle unique to the melanocyte and its neoplastic counterpart, malignant melanoma. The synthesis and assembly of these intracytoplasmic organelles is not yet fully understood. We have developed a murine monoclonal antibody (MoAb) against melanosomes isolated from human melanocytes (newborn foreskin) cultured in the presence of 12-O tetradecanoyl phorbol-13-acetate (TPA). This MoAb, designated HMSA-5 (Human Melanosome-Specific Antigen-5) (IgG1), recognised a cytoplasmic antigen in both normal human melanocytes and neoplastic cells, such as common and dysplastic melanocytic nevi, and malignant melanoma. None of the carcinoma or sarcoma specimens tested showed positive reactivity with MoAb HMSA-5. Under immunoelectron microscopy, immuno-gold deposition was seen on microvesicles associated with melanosomes, and a portion of the ER-Golgi complexes. Radioimmunoprecipitation analysis showed that the HMSA-5 reactive antigen was a glycoprotein of M(r) 69 to 73 kDa. A pulse-chase time course study showed that the amount of antigen detected by MoAb HMSA-5 decreased over a 24 h period without significant expression on the cell surface, or corresponding appearance of the antigen in the culture supernatant. This glycoprotein appears to play a role in the early stages of melanosomal development, and the HMSA-5 reactive epitope may be lost during subsequent maturation processes. Importantly, HMSA-5 can be identified in all forms of human melanocytes, hence it can be considered a new common melanocytic marker even on routine paraffin sections. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:7678981

  19. Melanocyte regeneration in vitiligo requires WNT beneath their wings

    PubMed Central

    Harris, John E.

    2015-01-01

    Melanocytes in patients with vitiligo possess intrinsic abnormalities that contribute to its pathogenesis. In this issue, Regazzetti, et al. report that CXCL10 expression reflects subtle inflammation in normal-appearing skin but not in stable depigmented lesions, supporting the hypothesis that melanocytes themselves initiate autoimmune inflammation prior to clinically evident disease. In addition, they find that oxidative stress in melanocytes impairs WNT signaling and that targeting this pathway induces melanoblast differentiation. Thus, activating the WNT pathway may serve as an adjunctive strategy to support repigmentation in patients with vitiligo. PMID:26569586

  20. Active melanogenesis in non-S phase melanocytes in B16 melanomas in vivo investigated by double-tracer microautoradiography with 18F-fluorodopa and 3H-thymidine.

    PubMed Central

    Kubota, R.; Yamada, S.; Ishiwata, K.; Kubota, K.; Ido, T.

    1992-01-01

    3,4-Dihydroxy-2-[18F]fluoro-L-phenylalanine (2-[18F]FDOPA) and [6-3H]thymidine ([3H]Thd) were simultaneously injected into mice transplanted with B16 melanomas of FM3A mammary carcinoma. Melanogenesis was differentiated from DNA synthesis in the mitotic cell cycle by monitoring grain distribution with double-tracer microautoradiography. The percentages of pigmented cells were inversely proportional to those of [3H]Thd-labelled cells, indicating that the greater the number of melanocytes, the smaller was the number of proliferating cells. The number of grains produced by 2-[18F]FDOPA in the [3H]Thd-unlabelled melanocytes was significantly higher (P < 0.001) than the numbers in the [3H]Thd-labelled melanocytes and in nonmelanocytes. The [3H]Thd-unlabelled non-melanocytes and FM3A cells showed the lowest accumulation of 2-[18F]DOPA, which may have resulted from the basic amino acid demand by malignant neoplasms via amino acid transport. The [3H]Thd-labelled cells, regardless of whether they were pigmented or not, had slightly more grains with 2-[18F]FDOPA than the [3H]Thd-unlabelled non-melanocytes (P < 0.05), which may have resulted from the enhanced amino acid requirement for proliferation. Melanogenesis appeared to be activated only in the non-S phase of the mitotic cycle in melanocytes. Images Figure 2 PMID:1419597

  1. Monitoring human melanocytic cell responses to piperine using multispectral imaging

    NASA Astrophysics Data System (ADS)

    Samatham, Ravikant; Phillips, Kevin G.; Sonka, Julia; Yelma, Aznegashe; Reddy, Neha; Vanka, Meenakshi; Thuillier, Philippe; Soumyanath, Amala; Jacques, Steven

    2011-03-01

    Vitiligo is a depigmentary disease characterized by melanocyte loss attributed most commonly to autoimmune mechanisms. Currently vitiligo has a high incidence (1% worldwide) but a poor set of treatment options. Piperine, a compound found in black pepper, is a potential treatment for the depigmentary skin disease vitiligo, due to its ability to stimulate mouse epidermal melanocyte proliferation in vitro and in vivo. The present study investigates the use of multispectral imaging and an image processing technique based on local contrast to quantify the stimulatory effects of piperine on human melanocyte proliferation in reconstructed epidermis. We demonstrate the ability of the imaging method to quantify increased pigmentation in response to piperine treatment. The quantization of melanocyte stimulation by the proposed imaging technique illustrates the potential use of this technology to quickly assess therapeutic responses of vitiligo tissue culture models to treatment non-invasively.

  2. Timeline and distribution of melanocyte precursors in the mouse heart.

    PubMed

    Brito, Flavia Carneiro; Kos, Lidia

    2008-08-01

    Apart from the well-studied melanocytes of the skin, eye and inner ear, another population has recently been described in the heart. In this study, we tracked cardiac melanoblasts using in situ hybridization with a dopachrome tautomerase (Dct) probe and Dct-LacZ transgenic mice. Large numbers of melanoblasts were found in the atrioventricular (AV) endocardial cushions at embryonic day (E) 14.5 and persisted in the AV valves into adulthood. The earliest time Dct-LacZ-positive cells were observed in the AV endocardial cushions was E12.5. Prior to that, between E10.5 and E11.5, small numbers of melanoblasts traveled between the post-otic area and third somite along the anterior and common cardinal veins and branchial arch arteries with other neural crest cells expressing CRABPI. Cardiac melanocytes were not found in the spotting mutants Ednrb s-l/s-l and Kit w-v/w-v, while large numbers were observed in transgenic mice that overexpress endothelin 3. These results indicate that cardiac melanocytes depend on the same signaling molecules known to be required for proper skin melanocyte development and may originate from the same precursor population. Cardiac melanocytes were not found in zebrafish or frog but were present in quail suggesting an association between cardiac melanocytes and four-chambered hearts. PMID:18444965

  3. Melanocyte Stem Cells as Potential Therapeutics in Skin Disorders

    PubMed Central

    Lee, Ju Hee; Fisher, David E.

    2015-01-01

    Introduction Melanocytes produce pigment granules that color both skin and hair. In the hair follicles melanocytes are derived from stem cells (MelSC) that are present in hair bulges or sub-bulge regions and function as melanocyte reservoirs. Quiescence, maintenance, activation, and proliferation of MelSC are controlled by specific activities in the microenvironment that can influence the differentiation and regeneration of melanocytes. Therefore, understanding MelSC and their niche may lead to use of MelSC in new treatments for various pigmentation disorders. Areas covered We describe here pathophysiological mechanisms by which melanocyte defects lead to skin pigmentation disorders such as vitiligo and hair graying. The development, migration, and proliferation of melanocytes and factors involved in the survival, maintenance, and regeneration of MelSC are reviewed with regard to the biological roles and potential therapeutic applications in skin pigmentation diseases. Expert Opinion MelSC biology and niche factors have been studied mainly in murine experimental models. Human MelSC markers or methods to isolate them are much less well understood. Identification, isolation and culturing of human MelSC would represent a major step toward new biological therapeutic options for patients with recalcitrant pigmentary disorders or hair graying. By modulating the niche factors for MelSC it may one day be possible to control skin pigmentary disorders and prevent or reverse hair graying. PMID:25104310

  4. Distinctive molecular responses to ultraviolet radiation between keratinocytes and melanocytes.

    PubMed

    Sun, Xiaoyun; Kim, Arianna; Nakatani, Masashi; Shen, Yao; Liu, Liang

    2016-09-01

    Solar ultraviolet radiation (UVR) is the major risk factor for skin carcinogenesis. To gain new insights into the molecular pathways mediating UVR effects in the skin, we performed comprehensive transcriptomic analyses to identify shared and distinctive molecular responses to UVR between human keratinocytes and melanocytes. Keratinocytes and melanocytes were irradiated with varying doses of UVB (10, 20 and 30 mJ/cm(2) ) then analysed by RNA-Seq at different time points post-UVB radiation (4, 24 and 72 h). Under basal conditions, keratinocytes and melanocytes expressed similar number of genes, although they each expressed a distinctive subset of genes pertaining to their specific cellular identity. Upon UVB radiation, keratinocytes displayed a clear pattern of time- and dose-dependent changes in gene expression that was different from melanocytes. The early UVB-responsive gene set (4 h post-UVR) differed significantly from delayed UVB-responsive gene sets (24 and 72 h). We also identified multiple novel UVB signature genes including PRSS23, SERPINH1, LCE3D and CNFN, which were conserved between melanocyte and keratinocyte lines from different individuals. Taken together, our findings elucidated both common and distinctive molecular features between melanocytes and keratinocytes and uncovered novel UVB signature genes that might be utilized to predict UVB photobiological effects on the skin. PMID:27119462

  5. Functionally distinct melanocyte populations revealed by reconstitution of hair follicles in mice.

    PubMed

    Aoki, Hitomi; Hara, Akira; Motohashi, Tsutomu; Osawa, Masatake; Kunisada, Takahiro

    2011-02-01

    Hair follicle reconstitution analysis was used to test the contribution of melanocytes or their precursors to regenerated hair follicles. In this study, we first confirmed the process of chimeric hair follicle regeneration by both hair keratinocytes and follicular melanocytes. Then, as first suggested from the differential growth requirements of epidermal skin melanocytes and non-cutaneous or dermal melanocytes, we confirmed the inability of the latter to be involved as follicular melanocytes to regenerate hair follicles during the hair reconstitution assay. This clear functional discrimination between non-cutaneous or dermal melanocytes and epidermal melanocytes suggests the presence of two different melanocyte cell lineages, a finding that might be important in the pathogenesis of melanocyte-related diseases and melanomas. PMID:21054816

  6. Papillary thyroid cancer in a young woman affected by giant congenital melanocytic nevus, ultrasound diagnosis.

    PubMed

    Manganaro, L; Onesti, M G; Sergi, M E; Vinci, V; Maruccia, M; Soda, G; Marini, M

    2011-01-01

    Data literatures report numerous association between giant congenital nevus and development alteration; only two cases describe its coexistence with thyroid disorders. However, we report the association of papillary thyroid cancer and giant congenital nevus. Papillary thyroid cancer is the most common differentiated thyroid cancer and has high prevalence in young women. In this paper we report: the case of a 18 years-old woman, affected by giant congenital melanocytic nevus on her back, who came to our observation because of one month of fever and increased volume of latero-cervical lymph nodes. Negative serologic tests allowed us to exclude lymphoma and mononucleosis. Because of the high risk (6%) that giant congenital melanocytic nevi could transform into malignant melanoma, we performed an ultrasound examination (US) of the cervical lymph nodes. The examination extended to the thyroid gland enabled us to visualize the same parenchyma alteration in both thyroid gland and lymph nodes. At last, fine-needle percoutaneus aspiration on thyroid lesion confirmed the presence of papillary carcinoma. In our case, thank to the optimal visualization of the parenchyma structure, US was diriment allowing a diagnosis of primitive thyroid lesion with an involvement of all lymph nodes in the neck. This findings legitimate the role of US as an accurate, noninvasive, radiation free and low-cost imaging technique in detecting differential diagnosis in the cervical lymphadenopathy, as well in preoperative staging thyroid carcinoma. PMID:22041799

  7. Expression of fibronectin, fibronectin isoforms and integrin receptors in melanocytic lesions.

    PubMed Central

    Natali, P. G.; Nicotra, M. R.; Di Filippo, F.; Bigotti, A.

    1995-01-01

    In vitro studies have demonstrated that fibronectin (FN) can deliver a mitogenic signal to quiescent human melanoma cells and that the alpha 5/beta 1-integrin receptor mediates this stimulus. In view of this finding we have analysed the in vivo expression of FN, and of ED-A and ED-B FN isoforms, in benign and malignant lesions of melanocyte origin. In the same specimens the expression of fibronectin integrin receptors was evaluated. The results demonstrate that, while detection of FN does not correlate with transformation and tumour progression, the expression of the two isoforms is associated with transformation and that only the ED-A variant is found in metastases. Integrin phenotyping disclosed that alpha 3/beta 1 expression is associated with tumour progression, alpha v/beta 3 is a marker of transformation, alpha 4 is rarely expressed and alpha 5 is expressed by about 50% and 30% of the primary and metastatic lesions respectively. Taken together, the results of this study demonstrate that transformation and tumour progression of the melanocyte lineage are associated with modulation of expression of FN isoforms and FN integrin receptors. Furthermore, the expression of alpha 5-integrin in a considerable percentage of primary and metastatic lesions indicates that FN may deliver a proliferative stimulus to melanoma cells in vivo. Images Figure 1 PMID:7779718

  8. Prehistological evaluation of benign and malignant pigmented skin lesions with optical computed tomography

    NASA Astrophysics Data System (ADS)

    Kokolakis, Athanasios; Zacharakis, Giannis; Krasagakis, Konstantin; Lasithiotakis, Konstantinos; Favicchio, Rosy; Spiliopoulos, George; Giannikaki, Elpida; Ripoll, Jorge; Tosca, Androniki

    2012-06-01

    Discrimination of benign and malignant melanocytic lesions is a major issue in clinical dermatology. Assessment of the thickness of melanoma is critical for prognosis and treatment selection. We aimed to evaluate a novel optical computed tomography (optical-CT) system as a tool for three-dimensional (3-D) imaging of melanocytic lesions and its ability to discriminate benign from malignant melanocytic lesions while simultaneously determining the thickness of invasive melanoma. Seventeen melanocytic lesions, one hemangioma, and normal skin were assessed immediately after their excision by optical-CT and subsequently underwent histopathological examination. Tomographic reconstructions were performed with a back-propagation algorithm calculating a 3-D map of the total attenuation coefficient (AC). There was a statistically significant difference between melanomas, dysplastic nevi, and non-dysplastic nevi, as indicated by Kruskal-Wallis test. Median AC values were higher for melanomas compared with dysplastic and non-dysplastic nevi. No statistically significant difference was observed when thickness values obtained by optical-CT were compared with histological thickness using a Wilcoxon sighed rank test. Our results suggest that optical-CT can be important for the immediate prehistological evaluation of biopsies, assisting the physician for a rapid assessment of malignancy and of the thickness of a melanocytic lesion.

  9. Proton pump inhibitors decrease melanogenesis in melanocytes

    PubMed Central

    BAEK, SEUNG-HWA; LEE, SANG-HAN

    2015-01-01

    Proton pump inhibitors (PPIs) are widely used as inhibitors of gastric juice secretion for treatment of gastroesophageal reflux disease. However, there are no previous studies of the effects on melanogenesis resulting from PPI treatments. Therefore, the aim of the present study was to investigate the effects of PPIs on melanogenesis in melan-a cells derived from immortalized mouse melanocytes. Tyrosinase activity and copper-chelating activity were measured spectrophotometrically. In addition, the melanin content and viability of melan-a cells treated with PPIs were assessed and the mRNA levels of melanogenesis-associated genes were measured by reverse transcription-polymerase chain reaction. Treatment with rabeprazole, but not the other PPIs tested, resulted in strong, dose-dependent inhibition of mushroom tyrosinase (TYR). By contrast, each of the PPIs tested exhibited copper-chelating activity. Treatment of melan-a cells with 100 µM concentrations of the PPIs resulted in significantly reduced melanin synthesis and reduced expression of several melanogenesis-associated genes, including TYR, TYR-related protein-1 (TRP-1) and TRP-2, and microphthalmia-associated transcription factor, but did not result in cytotoxic effects. These results suggest that PPIs inhibit melanin biosynthesis in melan-a cells via the downregulation of melanogenesis-associated genes. Furthermore, the findings indicate that PPIs in general could be utilized as skin-whitening agents and/or as biomaterial for treating hyperpigmentation disorders. PMID:26405553

  10. DNA microarrays and likelihood ratio bioinformatic methods: discovery of human melanocyte biomarkers.

    PubMed

    Dooley, Thomas P; Curto, Ernest V; Davis, Richard L; Grammatico, Paola; Robinson, Edward S; Wilborn, Teresa W

    2003-06-01

    In this article, some of the advantages and limitations of DNA microarray technologies for gene expression profiling are summarized. As a model experiment, DermArray DNA microarrays were utilized to identify potential biomarkers of cultured normal human melanocytes in two different experimental comparisons. In the first case, melanocyte RNA was compared with vastly dissimilar non-melanocytic RNA samples of normal skin keratinocytes and fibroblasts. In the second case, melanocyte RNA was compared with a primary cutaneous melanoma line (MS7) and a metastatic melanoma cell line (SKMel-28). The alternative approaches provide dramatically different lists of 'normal melanocyte' biomarkers. The most robust biomarkers were identified using principal component analysis bioinformatic methods related to likelihood ratios. Only three of 25 robust biomarkers in the melanocyte-proximal study (i.e. melanocytes vs. melanoma cells) were coincidentally identified in the melanocyte-distal study (i.e. melanocytes vs. non-melanocytic cells). Selected up-regulated biomarkers of melanocytes (i.e. TRP-1, melan-A/MART-1, silver/Pmel17, and nidogen-2) were validated by qRT-PCR. Some of the melanocytic biomarkers identified here may be useful in molecular diagnostics, as potential molecular targets for drug discovery, and for understanding the biochemistry of melanocytic cells. PMID:12753397

  11. Clinicopathological and prognostic relevance of Rap1-GAP expression in melanocytic tumors.

    PubMed

    Weiss, J; Biwer, B; Schliz, M; Jung, E G

    1997-09-01

    Rap1-GAP protein has been identified as an inactivator of Rap1 activity, a putative endogenous antagonist of Ras proteins. The Rap1-GA1 locus maps to 1p36.1-35, the region which may harbor a gene for familial melanoma. In the present immunohistochemical study we analyzed the clinicopathological and prognostic relevance of Rap1-GAP expression in 60 benign and 103 malignant melanocytic tumors. Cytoplasmic immunoreactivity was detected in the cells of 27/60 nevi (45%) and 59/103 melanomas (57%). In the latter group the frequency of Rap1-GAP expression increased (P < 0.05) with the thickness of primary tumors and was highest in metastatic lesions. Rap1-GAP protein was detected in 15/19 subsequently recurring primary melanomas (79%) but only in 32/67 tumors (47%) of patients who remained free of disease (P < 0.05) for at least 6 years. Five out of six recurring thin melanomas (< 2 mm) were found to be immunoreactive. Although being no indicator for malignant transformation of melanocytic lesions, Rap1-GAP overexpression may represent a useful marker for identifying thin high-risk melanomas. Cytoplasmic expression of Rap1-GAP has also been observed in the cells of skin appendages and in keratinocytes, particularly in suprabasal layers of the epidermis. Therefore, Rap1-GAP is likely to be associated with cellular growth and/or differentiation. However, the present study did not provide evidence that this gene, despite its chromosomal localization, represents an early melanoma gene. PMID:9373716

  12. TERT Promoter Mutations Are Predictive of Aggressive Clinical Behavior in Patients with Spitzoid Melanocytic Neoplasms

    PubMed Central

    Lee, Seungjae; Barnhill, Raymond L.; Dummer, Reinhard; Dalton, James; Wu, Jianrong; Pappo, Alberto; Bahrami, Armita

    2015-01-01

    Spitzoid neoplasms constitute a morphologically distinct category of melanocytic tumors, encompassing Spitz nevus (benign), atypical Spitz tumor (intermediate malignant potential), and spitzoid melanoma (fully malignant). Currently, no reliable histopathological criteria or molecular marker is known to distinguish borderline from overtly malignant neoplasms. Because TERT promoter (TERT-p) mutations are common in inherently aggressive cutaneous conventional melanoma, we sought to evaluate their prognostic significance in spitzoid neoplasms. We analyzed tumors labeled as atypical Spitz tumor or spitzoid melanoma from 56 patients with available follow-up data for the association of TERT-p mutations, biallelic CDKN2A deletion, biallelic PTEN deletion, kinase fusions, BRAF/NRAS mutations, nodal status, and histopathological parameters with risk of hematogenous metastasis. Four patients died of disseminated disease and 52 patients were alive and disease free without extranodal metastasis (median follow-up, 32.5 months). We found TERT-p mutations in samples from the 4 patients who developed hematogenous metastasis but in none of tumors from patients who had favorable outcomes. Presence of TERT-p mutations was the most significant predictor of haematogenous dissemination (P < 0.0001) among variables analyzed. We conclude that TERT-p mutations identify a clinically high-risk subset of patients with spitzoid tumors. Application of TERT-p mutational assays for risk stratification in the clinic requires large-scale validation. PMID:26061100

  13. Hesperetin induces melanin production in adult human epidermal melanocytes.

    PubMed

    Usach, Iris; Taléns-Visconti, Raquel; Magraner-Pardo, Lorena; Peris, José-Esteban

    2015-06-01

    One of the major sources of flavonoids for humans are citrus fruits, hesperidin being the predominant flavonoid. Hesperetin (HSP), the aglycon of hesperidin, has been reported to provide health benefits such as antioxidant, anti-inflammatory and anticarcinogenic effects. However, the effect of HSP on skin pigmentation is not clear. Some authors have found that HSP induces melanogenesis in murine B16-F10 melanoma cells, which, if extrapolated to in vivo conditions, might protect skin against photodamage. Since the effect of HSP on normal melanocytes could be different to that observed on melanoma cells, the described effect of HSP on murine melanoma cells has been compared to the effect obtained using normal human melanocytes. HSP concentrations of 25 and 50 µM induced melanin synthesis and tyrosinase activity in human melanocytes in a concentration-dependent manner. Compared to control melanocytes, 25 µM HSP increased melanin production and tyrosinase activity 1.4-fold (p < 0.01) and 1.1-fold (p < 0.01), respectively, and the corresponding increases in the case of 50 µM HSP were 1.9-fold (p < 0.001) and 1.3-fold (p < 0.001). Therefore, HSP could be considered a valuable photoprotective substance if its capacity to increase melanin production in human melanocyte cultures could be reproduced on human skin. PMID:25765751

  14. Lineage specific transcriptional regulation of DICER by MITF in melanocytes

    PubMed Central

    Levy, Carmit; Khaled, Mehdi; Robinson, Kathleen C.; Veguilla, Rosa A.; Chen, Po-Hao; Yokoyama, Satoru; Makino, Eiichi; Lu, Jun; Larue, Lionel; Beermann, Friedrich; Chin, Lynda; Bosenberg, Marcus; Song, Jun. S.; Fisher, David E.

    2010-01-01

    Summary DICER is a central regulator of microRNA maturation. However little is known about mechanisms regulating its expression in development or disease. While profiling miRNA expression in differentiating melanocytes, two populations were observed: some upregulated at the pre-miRNA stage, and others upregulated as “mature” miRNAs (with stable pre-miRNA levels). Conversion of pre-miRNAs to fully processed miRNAs appeared to be dependent upon stimulation of DICER expression—an event found to occur via direct transcriptional targeting of DICER by the melanocyte master transcriptional regulator MITF. MITF binds and activates a conserved regulatory element upstream of DICER’s transcriptional start site upon melanocyte differentiation. Targeted KO of DICER is lethal to melanocytes, at least partly via DICER-dependent processing of the pre-miRNA-17~92 cluster thus targeting BIM, a known pro-apoptotic regulator of melanocyte survival. These observations highlight a central mechanism underlying miRNA regulation which could exist for other cell types during development. PMID:20550935

  15. Characterization of two novel small molecules targeting melanocyte development in zebrafish embryogenesis.

    PubMed

    Chen, Lu; Ren, Xi; Liang, Fang; Li, Song; Zhong, Hanbing; Lin, Shuo

    2012-07-01

    Melanocytes are pigment cells that are closely associated with many skin disorders, such as vitiligo, piebaldism, Waardenburg syndrome, and the deadliest skin cancer, melanoma. Through studies of model organisms, the genetic regulatory network of melanocyte development during embryogenesis has been well established. This network also seems to be shared with adult melanocyte regeneration and melanoma formation. To identify chemical regulators of melanocyte development and homeostasis, we screened a small-molecule library of 6000 compounds using zebrafish embryos and identified five novel compounds that inhibited pigmentation. Here we report characterization of two compounds, 12G9 and 36E9, which disrupted melanocyte development. TUNEL assay indicated that these two compounds induced apoptosis of melanocytes. Furthermore, compound 12G9 specifically inhibited the viability of mammalian melanoma cells in vitro. These two compounds should be useful as chemical biology tools to study melanocytes and could serve as drug candidates against melanocyte-related diseases. PMID:22574862

  16. Wnt inhibitory factor (WIF)-1 promotes melanogenesis in normal human melanocytes.

    PubMed

    Park, Tae Jun; Kim, Misun; Kim, Hyeran; Park, Sun Yi; Park, Kyoung-Chan; Ortonne, Jean-Paul; Kang, Hee Young

    2014-01-01

    Wnt signaling plays a role in the differentiation as well as the development of melanocytes. Using a microarray analysis, hyperpigmentary skin of melasma expressed high levels of Wnt inhibitory factor-1 (WIF-1) compared with perilesional normal skin. In this study, the expression and functional roles of WIF-1 on melanocytes were investigated. WIF-1 was expressed both in the melanocytes of normal human skin and in cultured melanocytes. The upregulation of WIF-1 on cultured normal human melanocytes significantly induced expressions of MITF and tyrosinase, which were associated with increased melanin content and tyrosinase activity. Consistent with the stimulatory effect of WIF-1, WIF-1 siRNA reduced melanogenesis in the cells. Moreover, WIF-1 increases pigmentation in melanocytes co-cultured with WIF-1-overexpressed fibroblasts and of organ-cultured human skin. These findings suggest that melanocytes express WIF-1 constitutively in vivo and in vitro and that WIF-1 promotes melanogenesis in normal human melanocytes. PMID:24131586

  17. Multiple roles of NF1 in the melanocyte lineage.

    PubMed

    Larribère, Lionel; Utikal, Jochen

    2016-07-01

    NF1 is a tumour suppressor gene, germline mutations of which lead to neurofibromatosis type 1 syndrome. Patients develop benign tumours from several types of cells including neural crest-derived cells. NF1 somatic mutations also occur in 15% of sporadic melanoma, a cancer originating from melanocytes. Evidence now suggests the involvement of NF1 mutations in melanoma resistance to targeted therapies. Although NF1 is ubiquitously expressed, genetic links between NF1 and genes involved in melanocyte biology have been described, implying the lineage-specific mechanisms. In this review, we summarize and discuss the latest advances related to the roles of NF1 in melanocyte biology and in cutaneous melanoma. PMID:27155159

  18. Fibronectin-Containing Extracellular Vesicles Protect Melanocytes against Ultraviolet Radiation-Induced Cytotoxicity.

    PubMed

    Bin, Bum-Ho; Kim, Dae-Kyum; Kim, Nan-Hyung; Choi, Eun-Jeong; Bhin, Jinhyuk; Kim, Sung Tae; Gho, Yong Song; Lee, Ai-Young; Lee, Tae Ryong; Cho, Eun-Gyung

    2016-05-01

    Skin melanocytes are activated by exposure to UV radiation to secrete melanin-containing melanosomes to protect the skin from UV-induced damage. Despite the continuous renewal of the epidermis, the turnover rate of melanocytes is very slow, and they survive for long periods. However, the mechanisms underlying the survival of melanocytes exposed to UV radiation are not known. Here, we investigated the role of melanocyte-derived extracellular vesicles in melanocyte survival. Network analysis of the melanocyte extracellular vesicle proteome identified the extracellular matrix component fibronectin at a central node, and the release of fibronectin-containing extracellular vesicles was increased after exposure of melanocytes to UVB radiation. Using an anti-fibronectin neutralizing antibody and specific inhibitors of extracellular vesicle secretion, we demonstrated that extracellular vesicles enriched in fibronectin were involved in melanocyte survival after UVB radiation. Furthermore, we observed that in the hyperpigmented lesions of patients with melasma, the extracellular space around melanocytes contained more fibronectin compared with normal skin, suggesting that fibronectin is involved in maintaining melanocytes in pathological conditions. Collectively, our findings suggest that melanocytes secrete fibronectin-containing extracellular vesicles to increase their survival after UVB radiation. These data provide important insight into how constantly stimulated melanocytes can be maintained in pathological conditions such as melasma. PMID:26854492

  19. The melanocyte differentiation program predisposes to metastasis following neoplastic transformation.

    PubMed Central

    Gupta, Piyush B.; Kuperwasser, Charlotte; Brunet, Jean-Philippe; Ramaswamy, Sridhar; Kuo, Wen-Lin; Gray, Joe W.; Naber, Stephen P.; Weinberg, Robert A.

    2006-01-01

    The aggressive clinical behavior of melanoma has led to the hypothesis that the developmental origins of melanocytes in the neural crest might be relevant for their metastatic propensity. We demonstrate that primary human melanocytes, transformed using a specific set of introduced genes, form melanomas that frequently metastasize to multiple secondary sites, while human fibroblasts and epithelial cells transformed using an identical set of genes generate primary tumors that rarely do so. Importantly, these melanomas exhibit a metastasis spectrum similar to that observed in human patients. These observations indicate that part of the metastatic proclivity of melanoma is attributable to lineage-specific factors expressed in melanocytes and not in other cell types analyzed. Analysis of microarray data from human nevi reveals that Slug, a master regulator of neural crest cell specification and migration, correlates in its expression pattern with other genes that are important for neural crest cell migrations during development. Moreover, Slug is required for the metastasis of the transformed melanoma cells. These findings indicate that melanocyte-specific factors present prior to neoplastic transformation can play a pivotal role in governing melanoma's progression. PMID:16142232

  20. Genome-wide transcriptome analysis of human epidermal melanocytes

    PubMed Central

    Haltaufderhyde, Kirk D.; Oancea, Elena

    2015-01-01

    Because human epidermal melanocytes (HEMs) provide critical protection against skin cancer, sunburn, and photoaging, a genome-wide perspective of gene expression in these cells is vital to understanding human skin physiology. In this study we performed high throughput sequencing of HEMs to obtain a complete data set of transcript sizes, abundances, and splicing. As expected, we found that melanocyte specific genes that function in pigmentation were among the highest expressed genes. We analyzed receptor, ion channel and transcription factor gene families to get a better understanding of the cell signalling pathways used by melanocytes. We also performed a comparative transcriptomic analysis of lightly versus darkly pigmented HEMs and found 16 genes differentially expressed in the two pigmentation phenotypes; of those, only one putative melanosomal transporter (SLC45A2) has known function in pigmentation. In addition, we found 166 genes with splice isoforms expressed exclusively in one pigmentation phenotype, 17 of which are genes involved in signal transduction. Our melanocyte transcriptome study provides a comprehensive view and may help identify novel pigmentation genes and potential pharmacological targets. PMID:25451175

  1. Adipose-Derived Stem Cells Improve Efficacy of Melanocyte Transplantation in Animal Skin

    PubMed Central

    Lim, Won-Suk; Kim, Chang-Hyun; Kim, Ji-Young; Do, Byung-Rok; Kim, Eo Jin; Lee, Ai-Young

    2014-01-01

    Vitiligo is a pigmentary disorder induced by a loss of melanocytes. In addition to replacement of pure melanocytes, cocultures of melanocytes with keratinocytes have been used to improve the repigmentation outcome in vitiligo treatment. We previously identified by in vitro studies, that adipose-derived stem cells (ADSCs) could be a potential substitute for keratinocytes in cocultures with melanocytes. In this study, the efficacy of pigmentation including durability of grafted melanocytes and short-term safety was examined in the nude mouse and Sprague-Dawley rat after grafting of primary cultured human melanocytes, with or without different ratios of primary cultured human ADSCs. Simultaneous grafting of melanocytes and ADSCs, which were separately cultured and mixed on grafting at the ratios of 1:1, 1:2, or 1:3, showed better efficacy than that of pure melanocytes. Grafting of melanocytes cocultured with ADSCs resulted in a similar outcome as the grafting of cell mixtures. Skin pigmentation by melanocytes : ADSCs at the ratios of 1:1 and 1:2 was better than at 1:3. No significant difference was observed between the 1-week and 2-week durations in coculturing. Time-course microscopic examination showed that the grafted melanocytes remained a little longer than 6-week post-grafting. No inflammatory cell infiltration was observed in the grafted skin and no melanocytes were detectable in other organs. Collectively, grafting of melanocytes and ADSCs was equally safe and more effective than grafting of melanocytes alone. Despite the absence of significant differences in efficacy between the group of 1:1 and that of 1:2 ratio, 1:2 ratio for 1-week coculturing may be better for clinical use from the cost-benefit viewpoint. PMID:25143812

  2. Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi

    PubMed Central

    Margaryan, Naira V.; Gilgur, Alina; Seftor, Elisabeth A.; Purnell, Chad; Arva, Nicoleta C.; Gosain, Arun K.; Hendrix, Mary J. C.; Strizzi, Luigi

    2016-01-01

    Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro

  3. Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi.

    PubMed

    Margaryan, Naira V; Gilgur, Alina; Seftor, Elisabeth A; Purnell, Chad; Arva, Nicoleta C; Gosain, Arun K; Hendrix, Mary J C; Strizzi, Luigi

    2016-01-01

    Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro

  4. The "Umbrella Sign": A Useful Clue in the Diagnosis of Melanocytic Lesions in Sun Damaged Skin.

    PubMed

    Wood, Benjamin A; Harvey, Nathan T

    2016-07-01

    As ultraviolet radiation is an important aetiological agent in melanoma development, the presence of solar elastosis is an important factor in the assessment of any melanocytic lesion. However, melanocytic naevi are also seen in chronically sun damaged skin, particularly in regions with high levels of ultraviolet exposure and fair skinned populations. It has previously been noted that the relationship of a melanocytic proliferation to elastic fibers in the dermis can be of discriminatory value in the separation of melanoma from melanocytic naevus, in particular, it has been proposed that naevi act as a "sunscreen," which may result in a histological clue that the authors colloquially refer to in practice as "the umbrella sign." The aim of this study was to evaluate the patterns of solar elastosis within and beneath melanocytic proliferations developing in sun damaged skin and to determine the utility of the "umbrella sign" in diagnostic practice. We assessed 81 melanocytic proliferations in sun damaged skin for the presence of an umbrella sign, that was present in 49/53 melanocytic naevi (92%) compared with only 2/28 melanomas (7%, P < 0.05). In addition, entrapped elastotic fibers displaying distinct purple discolouration were identified in 16 melanocytic naevi. This finding was not identified in any of the melanomas. The umbrella sign appears to be a useful clue in the distinction of melanoma from melanocytic naevus in sun damaged skin, although as with all histological features in melanocytic pathology, it requires interpretation within a multifactorial assessment cognizant of potential diagnostic pitfalls. PMID:26909586

  5. Altered E-Cadherin Levels and Distribution in Melanocytes Precede Clinical Manifestations of Vitiligo.

    PubMed

    Wagner, Roselyne Y; Luciani, Flavie; Cario-André, Muriel; Rubod, Alain; Petit, Valérie; Benzekri, Laila; Ezzedine, Khaled; Lepreux, Sébastien; Steingrimsson, Eirikur; Taieb, A; Gauthier, Yvon; Larue, Lionel; Delmas, Véronique

    2015-07-01

    Vitiligo is the most common depigmenting disorder resulting from the loss of melanocytes from the basal epidermal layer. The pathogenesis of the disease is likely multifactorial and involves autoimmune causes, as well as oxidative and mechanical stress. It is important to identify early events in vitiligo to clarify pathogenesis, improve diagnosis, and inform therapy. Here, we show that E-cadherin (Ecad), which mediates the adhesion between melanocytes and keratinocytes in the epidermis, is absent from or discontinuously distributed across melanocyte membranes of vitiligo patients long before clinical lesions appear. This abnormality is associated with the detachment of the melanocytes from the basal to the suprabasal layers in the epidermis. Using human epidermal reconstructed skin and mouse models with normal or defective Ecad expression in melanocytes, we demonstrated that Ecad is required for melanocyte adhesiveness to the basal layer under oxidative and mechanical stress, establishing a link between silent/preclinical, cell-autonomous defects in vitiligo melanocytes and known environmental stressors accelerating disease expression. Our results implicate a primary predisposing skin defect affecting melanocyte adhesiveness that, under stress conditions, leads to disappearance of melanocytes and clinical vitiligo. Melanocyte adhesiveness is thus a potential target for therapy aiming at disease stabilization. PMID:25634357

  6. Thiostrepton is an Inducer of Oxidative and Proteotoxic Stress that Impairs Viability of Human Melanoma Cells but not Primary Melanocytes

    PubMed Central

    Qiao, Shuxi; Lamore, Sarah D.; Cabello, Christopher M.; Lesson, Jessica L.; Muñoz-Rodriguez, José L.; Wondrak, Georg T.

    2012-01-01

    Pharmacological induction of oxidative and proteotoxic stress has recently emerged as a promising strategy for chemotherapeutic intervention targeting cancer cells. Guided by a differential phenotypic drug screen for novel lead compounds that selectively induce melanoma cell apoptosis without compromising viability of primary human melanocytes, we have focused on the cyclic pyridinyl-polythiazolyl peptide-antimicrobial thiostrepton. Using comparative gene expression-array analysis, the early cellular stress response induced by thiostrepton was examined in human A375 metastatic melanoma cells and primary melanocytes. Thiostrepton displayed selective antimelanoma activity causing early induction of proteotoxic stress with massive upregulation of heat shock (HSPA6, HSPA1A, DNAJB4, HSPB1, HSPH1, HSPA1L, CRYAB, HSPA5, DNAJA1), oxidative stress (HMOX1, GSR, SOD1), and ER stress response (DDIT3) gene expression, confirmed by immunodetection (Hsp70, Hsp70B′, HO-1, phospho-eIF2α). Moreover, upregulation of p53, proapoptotic modulation of Bcl-2 family members (Bax, Noxa, Mcl-1, Bcl-2), and induction of apoptotic cell death were observed. Thiostrepton rapidly induced cellular oxidative stress followed by inactivation of chymotrypsin-like proteasomal activity and melanoma cell-directed accumulation of ubiquitinated proteins, not observed in melanocytes that were resistant to thiostrepton-induced apoptosis. Proteotoxic and apoptogenic effects were fully antagonized by antioxidant intervention. In RPMI 8226 multiple myeloma cells, known to be exquisitely sensitive to proteasome inhibition, early proteotoxic and apoptogenic effects of thiostrepton were confirmed by array analysis indicating pronounced upregulation of heat shock response gene expression. Our findings demonstrate that thiostrepton displays dual activity as a selective prooxidant and proteotoxic chemotherapeutic, suggesting feasibility of experimental intervention targeting metastatic melanoma and other

  7. Endothelin-1 increases melanin synthesis in an established sheep skin melanocyte culture.

    PubMed

    Pang, Yamiao; Geng, Jianjun; Qin, Yilong; Wang, Haidong; Fan, Ruiwen; Zhang, Ying; Li, Hongquan; Jiang, Shan; Dong, Changsheng

    2016-08-01

    The aims of the study were to establish a culture system for sheep skin melanocytes and uncover the effects of endothelin-1 on melanin synthesis in cultured melanocytes in order to provide an optimal cell system and a theoretical basis for studying the regulatory mechanism of coat color in sheep. In this study, skin punch biopsies were harvested from the dorsal region of 1-3-yr-old sheep, and skin melanocytes were then obtained by the two-step digestion using dispase II and trypsin/ethylene diamine tetraacetic acid (EDTA). The primary cultures of the melanocytes were established and characterized by dopa-staining, immunocytochemical localization of melanocyte markers, and RT-polymerase chain reaction (PCR) analysis of coat color genes. To determine the effect of endothelin-1 on proliferation and melanin synthesis of melanocytes, the cultured cells were treated with different doses of endothelin-1 (10(-7), 10(-8), 10(-9), 10(-10), and 0 mol/L), and the growth rate of melanocytes, production of melanin, expression of related genes, and location of related protein in cultured cells were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), ultraviolet spectrophotometry, qRT-PCR, and immunocytochemical localization, respectively. The results showed that the established melanocyte culture functions properly. Endothelin-1 treatment increased markedly the number of melanocytes and melanin content. In responding to this treatment, expressions of microphthalmia-associated transcription factor (MITF), melanocortin 1 receptor (MC1R), tyrosinase (TYR), and endothelin receptor B (EDNRB) in the melanocytes were significantly up regulated (P < 0.05). Immunocytochemical localization revealed that TYR was mainly localized in the cytoplasm. Positive staining of TYR in the melanocytes was significant. The findings demonstrated that the culture system of sheep skin melanocytes was established successfully in vitro, and endothelin-1 promotes the

  8. Mitochondria are more numerous and smaller in pink-eyed dilution melanoblasts and melanocytes than in wild-type melanocytes in the neonatal mouse epidermis.

    PubMed

    Hirobe, Tomohisa; Ishizuka, Kenji; Ogawa, Shigeru; Abe, Hiroyuki

    2008-11-01

    Abstract The mouse pink-eyed dilution (p) locus is known to control the melanin content in melanocytes. However, it was not known whether the p gene is involved in regulating the proliferation and differentation of melanocytes during development, especially the biogenesis of melanosomes and other organelles. Epidermal cell suspensions of neonatal dorsal skin derived from mice wild type for the p locus (black, C57BL/10JHir-P/P) and their congenic mutant phenotype (pink-eyed dilution, C57BL/10JHir-p/p) were cultured in serum-free melanocyte-proliferation medium (MDMD). The supplement of additional L-tyrosine (Tyr) into the MDMD stimulated the differentiation of p/p melanoblasts into melanocytes. Electron microscopy revealed that in p/p melanoblasts and melanocytes treated with L-Tyr, the number of stage II and III melanosomes dramatically increased. Moreover, p/p melanoblasts possessed smaller but more numerous mitochondria than P/P melanocytes. The treatment of p/p melanoblasts and melanocytes with L-Tyr decreased the number of mitochondria. The supplement of 2, 4-dinitrophenol (DNP), an inhibitor of mitochondrial function, into the MDMD stimulated both the proliferation and differentiation of p/p melanoblasts. Simultaneous treatment of DNP and L-Tyr dramatically stimulated the differetiation of p/p melanocytes. These results suggest that L-Tyr and some unknown factors related to mitochondrial function may influence the differentiation of melanoblasts in the epidermis of p/p mice. PMID:19267617

  9. Angiotropic metastatic malignant melanoma in a canine mammary gland

    PubMed Central

    Yang, Hai Jie; Lee, Eun-Mi; Kim, Ah-Young; Lee, Eun-Joo; Hong, IL-Hwa; Huh, Sung-Oh

    2011-01-01

    An eleven-year-old spayed female Yorkshire Terrier presented with a sublumbar mass and upon ultrasonographic examination, was revealed to have a mammary gland tumor. Black to reddish colored masses, located in the visceral peritoneum of the sublumbar region was observed on laparotomy with masectomy of the right side. In the laparotomy, we observed reddish masses multifocally located in the serosal membrane of the large intestine. Histopathologic examination of the intestinal and abdominal mass showed highly invasiveness into the muscle and metastasis of melanocytic tumor cells through the blood vessels. The mammary glands showed abnormal hyperplasia of melanocytes, destruction of the normal glands by tumor cells and infiltration of some lymphocytes in the pool of melanocytic cells. We have identified a malignant melanoma containing an angiotumoral complex in which tumor cells occupied a pericytic location along the microvessels with intravasation determined by immunohistochemistry for S100 protein and protein kinase C-α. Histologic findings in this dog lead to a diagnosis of an angiotropic metastatic malignant melanoma. PMID:22232646

  10. Asymmetry and irregularity border as discrimination factor between melanocytic lesions

    NASA Astrophysics Data System (ADS)

    Sbrissa, David; Pratavieira, Sebastião.; Salvio, Ana Gabriela; Kurachi, Cristina; Bagnato, Vanderlei Salvadori; Costa, Luciano Da Fontoura; Travieso, Gonzalo

    2015-06-01

    Image processing tools have been widely used in systems supporting medical diagnosis. The use of mobile devices for the diagnosis of melanoma can assist doctors and improve their diagnosis of a melanocytic lesion. This study proposes a method of image analysis for melanoma discrimination from other types of melanocytic lesions, such as regular and atypical nevi. The process is based on extracting features related with asymmetry and border irregularity. It were collected 104 images, from medical database of two years. The images were obtained with standard digital cameras without lighting and scale control. Metrics relating to the characteristics of shape, asymmetry and curvature of the contour were extracted from segmented images. Linear Discriminant Analysis was performed for dimensionality reduction and data visualization. Segmentation results showed good efficiency in the process, with approximately 88:5% accuracy. Validation results presents sensibility and specificity 85% and 70% for melanoma detection, respectively.

  11. Spontaneous Involution of Congenital Melanocytic Nevus With Halo Phenomenon

    PubMed Central

    Lee, Noo Ri; Chung, Hee-Chul; Hong, Hannah; Lee, Jin Wook

    2015-01-01

    Abstract: Congenital melanocytic nevus (CMN) is a neural crest-derived hamartoma, which appear at or soon after birth. CMN has a dynamic course and may show variable changes over time, including spontaneous involution. Spontaneous involution of CMN is a rare phenomenon and is often reported in association with halo phenomenon or vitiligo. The mechanism of halo phenomenon is yet to be investigated but is suggested to be a destruction of melanocytes by immune responses of cytotoxic T cells or IgM autoantibodies. Here, the authors report an interesting case of spontaneously regressed medium-sized CMN with halo phenomenon and without vitiligo, which provides evidence that cytotoxic T cells account for the halo formation and pigmentary regression of CMN. PMID:26588343

  12. Ultraviolet radiation directly induces pigment production by cultured human melanocytes

    SciTech Connect

    Friedmann, P.S.; Gilchrest, B.A.

    1987-10-01

    In humans the major stimulus for cutaneous pigmentation is ultraviolet radiation (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after the last exposure. There was a dose-related increase in melanin content per cell and uptake of /sup 14/C-DOPA, accompanied by growth inhibition. Cells from donors of different racial origin gave proportionately similar increases in melanin, although there were approximately tenfold differences in basal values. Light and electron microscopy revealed UVR-stimulated increases in dendricity as well as melanosome number and degree of melanization, analogous to the well-recognized melanocyte changes following sun exposure of intact skin. Similar responses were seen with Cloudman S91 melanoma cells, although this murine cell line required lower UVR dosages and fewer exposures for maximal stimulation. These data establish that UVR is capable of directly stimulating melanogenesis. Because cyclic AMP elevation has been associated in some settings with increased pigment production by cultured melanocytes, preliminary experiments were conducted to see if the effects of UVR were mediated by cAMP. Both alpha-MSH and isobutylmethylxanthine (IBMX), as positive controls, caused a fourfold increase in cAMP level in human melanocytes and/or S91 cells, but following a dose of UVR sufficient to stimulate pigment production there was no change in cAMP level up to 4 hours after exposure. Thus, it appears that the UVR-induced melanogenesis is mediated by cAMP-independent mechanisms.

  13. Epidermal nevi with aberrant epidermal structure in keratinocytes and melanocytes.

    PubMed

    Oiso, Naoki; Sugawara, Koji; Yonamine, Ayano; Tsuruta, Daisuke; Kawada, Akira

    2015-04-01

    Epidermal nevi are congenital cutaneous hamartomas caused by embryonic somatic mutations. Ultrastructural features of adult epidermal nevi have rarely been investigated. Herein, we report a case involving a Japanese adult who had epidermal nevi with right congenital blindness and a right accessory nipple. The histopathologic and ultrastructural studies showed divergent abnormal epidermal structures in both melanocytes and keratinocytes. Our case indicates the need to further investigate histopathologic, ultrastructural, and genetic associations in adult epidermal nevi. PMID:25657059

  14. Cellular origin and developmental mechanisms during the formation of skin melanocytes

    SciTech Connect

    Ernfors, Patrik

    2010-05-01

    Melanocytes are derived from the neural crest (NC), which are transient multipotent cells arising by delamination from the developing dorsal neural tube. During recent years, signaling systems and molecular mechanisms of melanocyte development have been studied in detail, but the exact diversification of the NC into melanocytes and how they migrate, expand and disperse in the skin have not been fully understood. The recent finding that Schwann cell precursors (SCPs) of the growing nerve represents a stem cell niche from which various cell types, including Schwann cells, endoneural fibroblasts and melanocytes arise has exposed new knowledge on the cellular basis for melanocyte development. This opens for the identification of new factors and reinterpretation of old data on cell fate instructive, proliferative, survival and cell homing factors participating in melanocyte development.

  15. A blueprint for staging of murine melanocytic lesions based on the Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) model.

    PubMed

    Wurm, Elisabeth M T; Lin, Lynlee L; Ferguson, Blake; Lambie, Duncan; Prow, Tarl W; Walker, Graeme J; Soyer, H Peter

    2012-09-01

    It has been shown that gene mutations which drive the development of malignant melanoma (MM) in humans also lead to emergence of MM when engineered mice. However, little attention has been paid to the clinical and histopathological features of melanocytic lesions and their natural history in a given mouse model. This knowledge is crucial to enable us to understand how engineered mutations influence the initiation and evolution of melanocytic lesions, and/or for the use of mice as a preclinical model to test specific treatments. We recently reported the development of melanocytic proliferations along the spectrum of naevi to MM in a Cdk4 ( R24C/R24C ) ::Tyr- NRAS ( Q ) ( 61K ) mouse model. In this study, we followed the development of lesions over time using digital photography and dermoscopy with the aim to correlate the clinical and histopathological features of lesions developing in this model. We identified two types of lesions. The first are slow-growing dermal MMs that emanate from dermal naevi. The second did not emanate from naevi, grew rapidly, and appeared to be solely confined to the subcutaneous fat. We present a simple staging system for the MMs that progress from naevi, based on depth of extension into the dermis and subcutis. This represents a blueprint for documentation and follow-up of MMs in the live animal, which is critical for the proper use of murine melanoma models. PMID:22742762

  16. UVA Phototransduction Drives Early Melanin Synthesis in Human Melanocytes

    PubMed Central

    Wicks, Nadine L.; Chan, Jason W.; Najera, Julia A.; Ciriello, Jonathan M.; Oancea, Elena

    2013-01-01

    Summary Exposure of human skin to solar ultraviolet radiation (UVR), a powerful carcinogen [1] comprising ~95% UVA and ~5% UVB at the Earth’s surface, promotes melanin synthesis in epidermal melanocytes [2, 3], which protects skin from DNA damage [4, 5]. UVB causes DNA lesions [6] that lead to transcriptional activation of melanin-producing enzymes, resulting in delayed skin pigmentation within days [7]. In contrast, UVA causes primarily oxidative damage [8] and leads to immediate pigment darkening (IPD) within minutes, via an unknown mechanism [9, 10]. No receptor protein directly mediating phototransduction in skin has been identified. Here we demonstrate that exposure of primary human epidermal melanocytes (HEMs) to UVA causes calcium mobilization and early melanin synthesis. Calcium responses were abolished by treatment with G protein or PLC inhibitors, or by depletion of intracellular calcium stores. We show that the visual photopigment rhodopsin [11] is expressed in HEMs and contributes to UVR phototransduction. Upon UVR exposure, significant melanin production was measured within one hour; cellular melanin continued to increase in a retinal- and calcium-dependent manner up to five-fold after 24 hours. Our findings identify a novel UVA-sensitive signaling pathway in melanocytes that leads to calcium mobilization and melanin synthesis, and may underlie the mechanism of IPD in human skin. PMID:22055294

  17. EFFECT OF PARACETAMOL ON MELANIZATION PROCESS IN HUMAN EPIDERMAL MELANOCYTES.

    PubMed

    Wrześniok, Dorota; Oprzondek, Martyna; Hechmann, Anna; Beberok, Artur; Otreba, Michał; Buszman, Ewa

    2016-01-01

    Paracetamol (acetaminophen) is commonly used as a drug of choice for treatment of pain and fever. Unlike non-steroidal anti-inflammatory drugs (NSAIDs) it does not cause gastrointestinal damage or untoward cardiorenal effects, however cutaneous adverse effects have been reported. It is known that paracetamol binds to melanin biopolymers, but the relation between the affinity of this drug to melanin and its toxicity is not documented. The aim of this work was to examine the impact of paracetamol on melanogenesis in cultured human normal epidermal melanocytes (HEMn-DP). The effect of paracetamol on cell viability was determined by WST-1 assay, melanin content and tyrosinase activity were measured spectrophotometrically. It has been demonstrated that paracetamol induced concentration-dependent loss in melanocytes viability. The value of EC50 was found to be - 20.0 mM. The analyzed drug inhibited melanin biosynthesis in a concentration-dependent manner by decreasing the melanin content as well as the tyrosinase activity. The demonstrated inhibitory effect of paracetamol on melanization process in normal epidermal melanocytes in vitro may explain the potential role of melanin biopolymer in the mechanisms of undesirable side effects of this drug in vivo, as a result of its accumulation in pigmented tissues. PMID:27476283

  18. Diagnostic utility of 5-hydroxymethylcytosine immunohistochemistry in melanocytic proliferations

    PubMed Central

    Rodić, Nemanja; Zampella, John; Sharma, Reema; Burns, Kathleen H.; Taube, Janis M.

    2015-01-01

    Decreased hydroxymethylated cytosine (5-hydroxymethycytosine, 5-hmC) is reported to correlate with melanocyte dysplasia. The purpose of this study was to assess the diagnostic utility of this observation. 5-hmC immunohistochemistry was performed on tissue microarrays containing 171-melanocytic lesions from two different institutions. An immunohistochemical staining score representing the percentage and intensity of nuclear staining was assigned. The performance characteristics of 5-hmC immunohistochemistry for discriminating between a nevus and melanoma were determined. Additional cases of melanoma arising in a nevus (n = 8), nodal nevi (n = 5) and melanoma micrometastases to a lymph node (n = 6) were also assessed. Pronounced 5-hmC loss was observed in melanomas when compared with nevi (mean ± standard deviation = 6.71 ± 11.78 and 55.19 ± 23.66, respectively, p < 0.0001). While the mean immunohistochemical staining score values for melanocytic nevi and melanoma were distinct, there was considerable variability in immunohistochemical staining score within a single diagnostic category. The sensitivity and specificity of this assay for nevus vs. melanoma is 92.74 and 97.78%, respectively. Distinct biphasic staining patterns were observed in cases of melanoma arising in association with a nevus. Relative changes of 5-hmC expression within a single lesion may be more informative than absolute values when using 5-hmC as a diagnostic adjunct. PMID:26239102

  19. Malignant mesothelioma

    PubMed Central

    Moore, Alastair J; Parker, Robert J; Wiggins, John

    2008-01-01

    Malignant mesothelioma is a fatal asbestos-associated malignancy originating from the lining cells (mesothelium) of the pleural and peritoneal cavities, as well as the pericardium and the tunica vaginalis. The exact prevalence is unknown but it is estimated that mesotheliomas represent less than 1% of all cancers. Its incidence is increasing, with an expected peak in the next 10–20 years. Pleural malignant mesothelioma is the most common form of mesothelioma. Typical presenting features are those of chest pain and dyspnoea. Breathlessness due to a pleural effusion without chest pain is reported in about 30% of patients. A chest wall mass, weight loss, sweating, abdominal pain and ascites (due to peritoneal involvement) are less common presentations. Mesothelioma is directly attributable to occupational asbestos exposure with a history of exposure in over 90% of cases. There is also evidence that mesothelioma may result from both para-occupational exposure and non-occupational "environmental" exposure. Idiopathic or spontaneous mesothelioma can also occur in the absence of any exposure to asbestos, with a spontaneous rate in humans of around one per million. A combination of accurate exposure history, along with examination radiology and pathology are essential to make the diagnosis. Distinguishing malignant from benign pleural disease can be challenging. The most helpful CT findings suggesting malignant pleural disease are 1) a circumferential pleural rind, 2) nodular pleural thickening, 3) pleural thickening of > 1 cm and 4) mediastinal pleural involvement. Involvement of a multidisciplinary team is recommended to ensure prompt and appropriate management, using a framework of radiotherapy, chemotherapy, surgery and symptom palliation with end of life care. Compensation issues must also be considered. Life expectancy in malignant mesothelioma is poor, with a median survival of about one year following diagnosis. PMID:19099560

  20. Video-Assisted Thoracoscopic Surgery Lobectomy for Pulmonary Malignant Melanoma Metastasis

    PubMed Central

    Samancilar, Ozgur; Kaya, Seyda Ors; Akcay, Onur; Akcam, Tevfik Ilker; Ceylan, Kenan Can; Yener, Ali Galip

    2015-01-01

    Malign melanoma (MM) develops as a result of malign transformation of the melanocytes and constitutes 2–4% of all skin cancers, while being the most common cause of mortality among all skin cancers. In addition to other organs, distant organ metastases also include lung metastasis. A metastasectomy is an acceptable treatment option in cases of malign melanoma with isolated lung metastasis. The current report presents a case with isolated lung metastasis that underwent a right upper VATS (video-assisted thoracoscopic surgery) lobectomy due to tumour localization. PMID:26644775

  1. Differential PAX3 functions in normal skin melanocytes and melanoma cells

    SciTech Connect

    Medic, Sandra; Rizos, Helen; Ziman, Mel

    2011-08-12

    Highlights: {yields} PAX3 retains embryonic roles in adult melanocytes and melanoma cells. {yields} Promotes 'stem' cell-like phenotype via NES and SOX9 in both cells types. {yields} Regulates melanoma and melanocyte migration through MCAM and CSPG4. {yields} PAX3 regulates melanoma but not melanocyte proliferation via TPD52. {yields} Regulates melanoma cell (but not melanocyte) survival via BCL2L1 and PTEN. -- Abstract: The PAX3 transcription factor is the key regulator of melanocyte development during embryogenesis and is also frequently found in melanoma cells. While PAX3 is known to regulate melanocyte differentiation, survival, proliferation and migration during development, it is not clear if its function is maintained in adult melanocytes and melanoma cells. To clarify this we have assessed which genes are targeted by PAX3 in these cells. We show here that similar to its roles in development, PAX3 regulates complex differentiation networks in both melanoma cells and melanocytes, in order to maintain cells as 'stem' cell-like (via NES and SOX9). We show also that mediators of migration (MCAM and CSPG4) are common to both cell types but more so in melanoma cells. By contrast, PAX3-mediated regulation of melanoma cell proliferation (through TPD52) and survival (via BCL2L1 and PTEN) differs from that in melanocytes. These results suggest that by controlling cell proliferation, survival and migration as well as maintaining a less differentiated 'stem' cell like phenotype, PAX3 may contribute to melanoma development and progression.

  2. Effects of diethylstilbestrol on the proliferation and tyrosinase activity of cultured human melanocytes

    PubMed Central

    TANG, JIANBING; LI, QIN; CHENG, BIAO; HUANG, CHONG; CHEN, KUI

    2015-01-01

    The aim of the present study was to observe the effects of different exogenous estrogen diethylstilbestrol (DES) concentrations on the human melanocyte proliferation and tyrosinase activity. Skin specimens were obtained following blepharoplasty, and the melanocytes were primary cultured and passaged to the third generation. The melanocytes were seeded in 96-well plates, each well had 5×103 cells. The medium was changed after 24 h, and contained 10−4-10−8 M DES. After the melanocytes were incubated, the proliferation and tyrosinase activity were detected by the MTT assay and L-DOPA reaction. DES (10−8-10−6 M) enhanced the proliferation of cultured melanocytes. The intensity was positively correlated with the concentration of drug. DES, >10−5 M, inhibited the melanocytes proliferation or even produced the toxicity effect. Following the addition of 10−6 M DES to the medium, the tyrosinase activity of melanocytes was significantly increased, with P<0.05. In conclusion, a certain concentration of DES promoted the proliferation of melanocytes, enhanced the activity of tyrosinase and promoted pigment synthesis of melanocytes, with the optimal concentration of 10−6 M. PMID:26171155

  3. The trk family of receptors mediates nerve growth factor and neurotrophin-3 effects in melanocytes.

    PubMed Central

    Yaar, M; Eller, M S; DiBenedetto, P; Reenstra, W R; Zhai, S; McQuaid, T; Archambault, M; Gilchrest, B A

    1994-01-01

    We have recently shown that (a) human melanocytes express the p75 nerve growth factor (NGF) receptor in vitro; (b) that melanocyte dendricity and migration, among other behaviors, are regulated at least in part by NGF; and (c) that cultured human epidermal keratinocytes produce NGF. We now report that melanocyte stimulation with phorbol 12-tetra decanoate 13-acetate (TPA), previously reported to induce p75 NGF receptor, also induces trk in melanocytes, and TPA effect is further potentiated by the presence of keratinocytes in culture. Moreover, trk in melanocytes becomes phosphorylated within minutes after NGF stimulation. As well, cultures of dermal fibroblasts express neurotrophin-3 (NT-3) mRNA; NT-3 mRNA levels in cultured fibroblasts are modulated by mitogenic stimulation, UV irradiation, and exposure to melanocyte-conditioned medium. Moreover, melanocytes constitutively express low levels of trk-C, and its expression is downregulated after TPA stimulation. NT-3 supplementation to cultured melanocytes maintained in Medium 199 alone prevents cell death. These combined data suggest that melanocyte behavior in human skin may be influenced by neurotrophic factors, possibly of keratinocyte and fibroblast origin, which act through high affinity receptors. Images PMID:7929831

  4. Acral, Superficial Spreading Melanoma Arising on Melanocytic Nevus in a Pregnant Woman: A Case Report with Review.

    PubMed

    Gupta, Sunil Kumar; Kumar, Ajay; Gupta, Vivek; Thakur, Alpna

    2015-01-01

    We are reporting a case of superficial spreading melanoma (SSM) on left palm of a 37-year-old pregnant housewife. She had a small acquired melanocytic nevus on her left palm since childhood, which changed its consistency and color in the last 4 months. Dermoscopy of the lesion indicated malignant changes. The lesion was managed surgically using split-thickness skin graft. The histopathology report was suggestive of SSM with positive HMB-45 cells. SSM is very rare on the acral site, and it is very difficult to differentiate it from acral lentiginous melanoma. The rarity of the site (acral nonchronic sun damage) with evolution during pregnancy and importance of management approach are reasons for publishing this case. PMID:26677279

  5. Ultraviolet B, melanin and mitochondrial DNA: Photo-damage in human epidermal keratinocytes and melanocytes modulated by alpha-melanocyte-stimulating hormone

    PubMed Central

    Böhm, Markus; Hill, Helene Z.

    2016-01-01

    Alpha-melanocyte-stimulating hormone (alpha-MSH) increases melanogenesis and protects from UV-induced DNA damage. However, its effect on mitochondrial DNA (mtDNA) damage is unknown. We have addressed this issue in a pilot study using human epidermal keratinocytes and melanocytes incubated with alpha-MSH and irradiated with UVB. Real-time touchdown PCR was used to quantify total and deleted mtDNA. The deletion detected encompassed the common deletion but was more sensitive to detection. There were 4.4 times more mtDNA copies in keratinocytes than in melanocytes. Irradiation alone did not affect copy numbers. Alpha-MSH slightly increased copy numbers in both cell types in the absence of UVB and caused a similar small decrease in copy number with dose in both cell types. Deleted copies were nearly twice as frequent in keratinocytes as in melanocytes. Alpha-MSH reduced the frequency of deleted copies by half in keratinocytes but not in melanocytes. UVB dose dependently led to an increase in the deleted copy number in alpha-MSH-treated melanocytes. UVB irradiation had little effect on deleted copy number in alpha-MSH-treated keratinocytes. In summary, alpha-MSH enhances mtDNA damage in melanocytes presumably by increased melanogenesis, while α-MSH is protective in keratinocytes, the more so in the absence of irradiation. PMID:27303631

  6. New melanogenesis and photobiological processes in activation and proliferation of precursor melanocytes after UV-exposure: ultrastructural differentiation of precursor melanocytes from Langerhans cells

    SciTech Connect

    Jimbow, K.; Uesugi, T.

    1982-02-01

    Photobiological processes involving new melanogenesis after exposure to ultraviolet (UV) light were experimentally studied in C57 black adult mice by histochemistry, cytochemistry, and autoradiography. The trunk and the plantar region of the foot, where no functioning melanocytes were present before exposure, were exposed to UV-A for 14 consecutive days. Both regions revealed a basically similar pattern for new melanogenesis which involved an activation of precursor melanocytes. Essentially all of ''indeterminate'' cells appeared to be precursor melanocytes, the fine structure of which could be differentiated even from poorly developed Langerhans cells. New melanogenesis was manifested by 4 stages of cellular and subcellular reactions of these cells as indicated by histochemistry of dihydroxyphenylalanine (dopa) and autoradiography of thymidine incorporation: (a) an initial lag in the activation of precursor melanocytes with development of Golgi cisternae and rough endoplasmic reticulum followed by formation of unmelanized melanosomes (day 0 to 2); (b) synthesis of active tyrosinase accumulated in Golgi cisternae and vesicles with subsequent formation of melanized melanosomes in these cells (day 3 to 5); (c) mitotic proliferation of many of these activated cells, followed by an exponential increase of new melanocytes (day 6 to 7); and (d) melanosome transfer with differentiation of 10 nm filaments and arborization of dendrites, but without any significant change in the melanocyte population (day 8 to 14). The melanosome transfer was, however, not obvious until after 7 days of exposure. The size of newly synthesized melanosomes was similar to that of tail skin where native melanocytes were present before exposure.

  7. Ultraviolet B, melanin and mitochondrial DNA: Photo-damage in human epidermal keratinocytes and melanocytes modulated by alpha-melanocyte-stimulating hormone.

    PubMed

    Böhm, Markus; Hill, Helene Z

    2016-01-01

    Alpha-melanocyte-stimulating hormone (alpha-MSH) increases melanogenesis and protects from UV-induced DNA damage. However, its effect on mitochondrial DNA (mtDNA) damage is unknown. We have addressed this issue in a pilot study using human epidermal keratinocytes and melanocytes incubated with alpha-MSH and irradiated with UVB. Real-time touchdown PCR was used to quantify total and deleted mtDNA. The deletion detected encompassed the common deletion but was more sensitive to detection. There were 4.4 times more mtDNA copies in keratinocytes than in melanocytes. Irradiation alone did not affect copy numbers. Alpha-MSH slightly increased copy numbers in both cell types in the absence of UVB and caused a similar small decrease in copy number with dose in both cell types. Deleted copies were nearly twice as frequent in keratinocytes as in melanocytes. Alpha-MSH reduced the frequency of deleted copies by half in keratinocytes but not in melanocytes. UVB dose dependently led to an increase in the deleted copy number in alpha-MSH-treated melanocytes. UVB irradiation had little effect on deleted copy number in alpha-MSH-treated keratinocytes. In summary, alpha-MSH enhances mtDNA damage in melanocytes presumably by increased melanogenesis, while α-MSH is protective in keratinocytes, the more so in the absence of irradiation. PMID:27303631

  8. Hematologic malignancies

    SciTech Connect

    Hoogstraten, B.

    1986-01-01

    The principle aim of this book is to give practical guidelines to the modern treatment of the six important hematologic malignancies. Topics considered include the treatment of the chronic leukemias; acute leukemia in adults; the myeloproliferative disorders: polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis/agnogenic myeloid metaplasia; Hodgkin's Disease; non-Hodgkin's lymphoma; and Multiple Myeloma.

  9. Narrow Band Ultraviolet B Treatment for Human Vitiligo Is Associated with Proliferation, Migration, and Differentiation of Melanocyte Precursors.

    PubMed

    Goldstein, Nathaniel B; Koster, Maranke I; Hoaglin, Laura G; Spoelstra, Nicole S; Kechris, Katerina J; Robinson, Steven E; Robinson, William A; Roop, Dennis R; Norris, David A; Birlea, Stanca A

    2015-08-01

    In vitiligo, the autoimmune destruction of epidermal melanocytes produces white spots that can be repigmented by melanocyte precursors from the hair follicles, following stimulation with UV light. We examined by immunofluorescence the distribution of melanocyte markers (C-KIT, DCT, PAX3, and TYR) coupled with markers of proliferation (KI-67) and migration (MCAM) in precursors and mature melanocytes from the hair follicle and the epidermis of untreated and narrow band UVB (NBUVB)-treated human vitiligo skin. NBUVB was associated with a significant increase in the number of melanocytes in the infundibulum and with restoration of the normal melanocyte population in the epidermis, which was lacking in the untreated vitiligo. We identified several precursor populations (melanocyte stem cells, melanoblasts, and other immature phenotypes), and progressively differentiating melanocytes, some with putative migratory and/or proliferative abilities. The primary melanocyte germ was present in the untreated and treated hair follicle bulge, whereas a possible secondary melanocyte germ composed of C-KIT+ melanocytes was found in the infundibulum and interfollicular epidermis of UV-treated vitiligo. This is an exceptional model for studying the mobilization of melanocyte stem cells in human skin. Improved understanding of this process is essential for designing better treatments for vitiligo, ultimately based on melanocyte stem cell activation and mobilization. PMID:25822579

  10. Narrow Band Ultraviolet B Treatment for Human Vitiligo Is Associated with Proliferation, Migration, and Differentiation of Melanocyte Precursors

    PubMed Central

    Goldstein, Nathaniel B.; Koster, Maranke I.; Hoaglin, Laura G.; Spoelstra, Nicole S.; Kechris, Katerina J.; Robinson, Steven E.; Robinson, William A.; Roop, Dennis R.; Norris, David A.; Birlea, Stanca A.

    2015-01-01

    In vitiligo, the autoimmune destruction of epidermal melanocytes produces white spots that can be repigmented by melanocyte precursors from the hair follicles, following stimulation with UV light. We examined by immunofluorescence the distribution of melanocyte markers (C-KIT, DCT, PAX3, and TYR) coupled with markers of proliferation (KI-67) and migration (MCAM) in precursors and mature melanocytes from the hair follicle and the epidermis of untreated and narrow band UVB (NBUVB)-treated human vitiligo skin. NBUVB was associated with a significant increase in the number of melanocytes in the infundibulum and with restoration of the normal melanocyte population in the epidermis, which was lacking in the untreated vitiligo. We identified several precursor populations (melanocyte stem cells, melanoblasts, and other immature phenotypes), and progressively differentiating melanocytes, some with putative migratory and/or proliferative abilities. The primary melanocyte germ was present in the untreated and treated hair follicle bulge, whereas a possible secondary melanocyte germ composed of C-KIT+ melanocytes was found in the infundibulum and interfollicular epidermis of UV-treated vitiligo. This is an exceptional model for studying the mobilization of melanocyte stem cells in human skin. Improved understanding of this process is essential for designing better treatments for vitiligo, ultimately based on melanocyte stem cell activation and mobilization. PMID:25822579

  11. Applying a Dermal Regenerative Template in Management of Congenital Melanocytic Nevi of the Hand

    PubMed Central

    Yuen, James C.; Tait, Mark A.

    2015-01-01

    Summary: Congenital melanocytic nevus of the hand in the pediatric population is an uncommon diagnosis. These lesions have malignant potential and can cause psychosocial effects from cosmetic deformity. Early surgical intervention is recommended in these cases. The literature suggests that full-thickness skin grafting is to be performed in the hand to maintain functionality and avoid contracture and scarring. This creates a large donor-site defect and increased risk of graft loss due to slow revascularization from graft thickness. In addition, for large defects, the full-thickness skin graft donor site would require a split-thickness graft. However, split-thickness skin grafting is avoided in the hand due to increased scarring and contracture and decreased range of motion despite decreased donor-site morbidity and better revascularization. We describe a novel reconstructive technique that uses a dermal regenerative template (Integra) with split-thickness grafting. Having performed in 2 pediatric patients, we demonstrate that aesthetic and functional outcomes are equivalent to full-thickness grafting while creating a superficial donor site and allowing for improved revascularization from decreased graft thickness. PMID:26495228

  12. Bilateral Diffuse Uveal Melanocytic Proliferation Presenting as a Giant Unilateral Choroidal Nevus: A Case Report

    PubMed Central

    Menezes, Carlos; Carvalho, Rui; Neves-Martins, Joana; Teixeira, Carla

    2015-01-01

    Background/Aims The aim of our study was to report a case of bilateral diffuse uveal melanocytic proliferation (BDUMP) with a markedly asymmetric presentation and fundoscopic response to palliative chemotherapy. Case Report We report a 67-year-old Caucasian man who presented with vision loss in his right eye. The best-corrected visual acuities were 2/10 in the right eye and 10/10 in the left eye, and biomicroscopy revealed bilateral mild cataracts. Fundoscopy of the right eye showed a macular flat and pigmented lesion extending beyond the posterior pole with areas of giraffe-type pigmentation and an overlying exudative retinal detachment. Nothing remarkable was detected in the left eye apart from a small round hypopigmented area of retinal pigment epithelium atrophy in the papillomacular bundle. BDUMP was diagnosed, and the workup for systemic malignancy revealed a pulmonary adenocarcinoma. After chemotherapy, not only did the right eye's visual acuity improve and the serous detachment resolve, but also the pigmentation decreased. Conclusion BDUMP presentation can be markedly asymmetric and resemble a giant unilateral choroidal nevus. Response to chemotherapy was unique not only for the usual retinal detachment resolution, but also because of an evident regression of pigmentation. PMID:27171585

  13. Malignant Melanoma and Melanocortin 1 Receptor

    PubMed Central

    Slastnikova, T. A.; Durymanov, M. O.; Sobolev, A. S.

    2014-01-01

    The conventional chemotherapeutic treatment of malignant melanoma still remains poorly efficient in most cases. Thus the use of specific features of these tumors for development of new therapeutic modalities is highly needed. Melanocortin receptor-1 (MC1R) overexpression on the cell surface of the vast majority of human melanomas, making MC1R a valuable marker of these tumors, is one of these features. Naturally, MC1R plays a key role in skin protection against damaging ultraviolet radiation by regulating eumelanin production. MC1R activation is involved in regulation of melanocyte cell division. This article reviews the peculiarities of regulation and expression of MC1R, melanocytes, and melanoma cells, along with the possible connection of MC1R with signaling pathways regulating proliferation of tumor cells. MC1R is a cell surface endocytic receptor, thus considered perspective for diagnostics and targeted drug delivery. A number of new therapeutic approaches that utilize MC1R, including endoradiotherapy with Auger electron and α- and β-particle emitters, photodynamic therapy, and gene therapy are now being developed. PMID:24460937

  14. Ocular surface foreign bodies: novel findings mimicking ocular malignant melanoma

    PubMed Central

    Maudgil, A; Wagner, B E; Rundle, P; Rennie, I G; Mudhar, H S

    2014-01-01

    Purpose Malignant melanoma of the eye is an uncommon condition that is important to recognise. We describe three cases in which ocular foreign bodies have masqueraded as ocular malignant melanoma. Methods Interventional case reports. Results Case 1 describes diathermy-induced carbon particle implantation, during plaque therapy for the treatment of uveal melanoma, mimicking recurrence with extra-scleral invasion. Case 2 shows a foreign body called ‘mullite' mimicking conjunctival melanoma. Case 3 demonstrates a conjunctival foreign body called ‘illite' that mimicked a limbal melanocytic lesion, clinically thought to be either melanocytoma or melanoma. Conclusion This report highlights the importance of careful history taking, examination, and appropriate biopsy in cases of suspected malignant melanoma, to prevent unnecessary and potentially radical treatment. PMID:25104745

  15. Malignant melanoma of the oral cavity: Report of two cases.

    PubMed

    Munde, Anita; Juvekar, Monica Vivek; Karle, Ravindra R; Wankhede, Pranali

    2014-04-01

    Primary malignant melanoma is a rare and aggressive neoplasm that originates from the proliferation of melanocytes. Although, it comprises 1.3% of all cancers, malignant melanoma of the oral cavity accounts for only 0.2-8% of all reported melanomas and occurs approximately 4 times more frequently in the oral mucosa of the upper jaw, usually on the palate or alveolar gingivae. Most of the mucosal melanomas are usually asymptomatic in early stages, and presents as pigmented patch or a mass delaying the diagnosis until symptoms of swelling, ulceration, bleeding, or loosening of teeth are noted. The prognosis is extremely poor, especially in advanced stages. Therefore, any pigmented lesion of undetermined origin should always be biopsied. We herewith report of two cases of oral malignant melanoma in a 60 and 75-year-old female. PMID:24963252

  16. Malignant melanoma of the oral cavity: Report of two cases

    PubMed Central

    Munde, Anita; Juvekar, Monica Vivek; Karle, Ravindra R.; Wankhede, Pranali

    2014-01-01

    Primary malignant melanoma is a rare and aggressive neoplasm that originates from the proliferation of melanocytes. Although, it comprises 1.3% of all cancers, malignant melanoma of the oral cavity accounts for only 0.2-8% of all reported melanomas and occurs approximately 4 times more frequently in the oral mucosa of the upper jaw, usually on the palate or alveolar gingivae. Most of the mucosal melanomas are usually asymptomatic in early stages, and presents as pigmented patch or a mass delaying the diagnosis until symptoms of swelling, ulceration, bleeding, or loosening of teeth are noted. The prognosis is extremely poor, especially in advanced stages. Therefore, any pigmented lesion of undetermined origin should always be biopsied. We herewith report of two cases of oral malignant melanoma in a 60 and 75-year-old female. PMID:24963252

  17. Coexpression of SOX10/CD271 (p75NTR) and β-Galactosidase in Large to Giant Congenital Melanocytic Nevi of Pediatric Patients

    PubMed Central

    Barysch, Marjam J.; Levesque, Mitchell P.; Cheng, Phil; Karpova, Maria B.; Mihic-Probst, Daniela; Civenni, Gianluca; Shakhova, Olga; Sommer, Lukas; Biedermann, Thomas; Schiestl, Clemens; Dummer, Reinhard

    2014-01-01

    Background Congenital melanocytic nevi (CMNs) are melanocytic neoplasms that can transform into melanoma. However, this development is impeded in the majority of cases and mostly affects patients with large or giant CMNs. Methods To elucidate mechanisms that keep CMNs from malignant transformation, CMN tissue biopsies were investigated for p-ERK and senescence markers by immunohistochemistry and for SOX10/CD271 (p75NTR) by immunofluorescence. CMN cells were cultivated, and MTT assays were performed for evaluating cell viability. Mutation status for NRAS and BRAF was performed by real-time PCR. Results 13 CMNs (from patients aged 0.5-11.8 years, mean: 2.7) showed immunoreactivity for SOX10/CD271 (p75NTR) in 34.2%. p-ERK was immunoreactive in 80% (4/5); β-galactosidase was significantly stronger expressed in CMNs compared to melanocytic nevi of patients over 70 years (p = 0.0085). The 5 CMN cultures were immunoreactive for SOX10/CD271 (p75NTR) in 36.7%. By silencing SOX10 by siRNA in 2 CMN cell cultures, cell viability decreased significantly. NRASQ61K mutation was found in 91.7% (11/12) and BRAFV600E in 6.3% of all analyzable CMNs (1/16). Conclusions Oncogene-induced senescence might prevent malignant transformation through activation of the mitogen-activated protein kinase pathway. SOX10 is necessary for the viability of human CMN cell cultures and may be responsible for clinical changes during aging. PMID:27047921

  18. Chromatin-Remodelling Complex NURF Is Essential for Differentiation of Adult Melanocyte Stem Cells.

    PubMed

    Koludrovic, Dana; Laurette, Patrick; Strub, Thomas; Keime, Céline; Le Coz, Madeleine; Coassolo, Sebastien; Mengus, Gabrielle; Larue, Lionel; Davidson, Irwin

    2015-10-01

    MIcrophthalmia-associated Transcription Factor (MITF) regulates melanocyte and melanoma physiology. We show that MITF associates the NURF chromatin-remodelling factor in melanoma cells. ShRNA-mediated silencing of the NURF subunit BPTF revealed its essential role in several melanoma cell lines and in untransformed melanocytes in vitro. Comparative RNA-seq shows that MITF and BPTF co-regulate overlapping gene expression programs in cell lines in vitro. Somatic and specific inactivation of Bptf in developing murine melanoblasts in vivo shows that Bptf regulates their proliferation, migration and morphology. Once born, Bptf-mutant mice display premature greying where the second post-natal coat is white. This second coat is normally pigmented by differentiated melanocytes derived from the adult melanocyte stem cell (MSC) population that is stimulated to proliferate and differentiate at anagen. An MSC population is established and maintained throughout the life of the Bptf-mutant mice, but these MSCs are abnormal and at anagen, give rise to reduced numbers of transient amplifying cells (TACs) that do not express melanocyte markers and fail to differentiate into mature melanin producing melanocytes. MSCs display a transcriptionally repressed chromatin state and Bptf is essential for reactivation of the melanocyte gene expression program at anagen, the subsequent normal proliferation of TACs and their differentiation into mature melanocytes. PMID:26440048

  19. Chromatin-Remodelling Complex NURF Is Essential for Differentiation of Adult Melanocyte Stem Cells

    PubMed Central

    Koludrovic, Dana; Laurette, Patrick; Strub, Thomas; Keime, Céline; Le Coz, Madeleine; Coassolo, Sebastien; Mengus, Gabrielle; Larue, Lionel; Davidson, Irwin

    2015-01-01

    MIcrophthalmia-associated Transcription Factor (MITF) regulates melanocyte and melanoma physiology. We show that MITF associates the NURF chromatin-remodelling factor in melanoma cells. ShRNA-mediated silencing of the NURF subunit BPTF revealed its essential role in several melanoma cell lines and in untransformed melanocytes in vitro. Comparative RNA-seq shows that MITF and BPTF co-regulate overlapping gene expression programs in cell lines in vitro. Somatic and specific inactivation of Bptf in developing murine melanoblasts in vivo shows that Bptf regulates their proliferation, migration and morphology. Once born, Bptf-mutant mice display premature greying where the second post-natal coat is white. This second coat is normally pigmented by differentiated melanocytes derived from the adult melanocyte stem cell (MSC) population that is stimulated to proliferate and differentiate at anagen. An MSC population is established and maintained throughout the life of the Bptf-mutant mice, but these MSCs are abnormal and at anagen, give rise to reduced numbers of transient amplifying cells (TACs) that do not express melanocyte markers and fail to differentiate into mature melanin producing melanocytes. MSCs display a transcriptionally repressed chromatin state and Bptf is essential for reactivation of the melanocyte gene expression program at anagen, the subsequent normal proliferation of TACs and their differentiation into mature melanocytes. PMID:26440048

  20. Ocular findings in a case of periorbital giant congenital melanocytic nevus

    PubMed Central

    Raina, Usha K.; Seth, Anisha; Gupta, Anika; Batta, Supriya

    2014-01-01

    Giant congenital melanocytic nevus (GCMN) is a large melanocytic nevus that rarely occurs in the periorbital region. Various systemic, as well as ophthalmic associations, have been reported with GCMN. However, there is only one case report describing ophthalmic findings in periorbital GCMN. We describe the ocular findings in a case of periorbital GCMN. PMID:25378884

  1. Size Functions for the Morphological Analysis of Melanocytic Lesions

    PubMed Central

    Ferri, Massimo; Stanganelli, Ignazio

    2010-01-01

    Size Functions and Support Vector Machines are used to implement a new automatic classifier of melanocytic lesions. This is mainly based on a qualitative assessment of asymmetry, performed by halving images by several lines through the center of mass, and comparing the two halves in terms of color, mass distribution, and boundary. The program is used, at clinical level, with two thresholds, so that comparison of the two outputs produces a report of low-middle-high risk. Experimental results on 977 images, with cross-validation, are reported. PMID:20300598

  2. The most common mistakes on dermatoscopy of melanocytic lesions

    PubMed Central

    Kamińska-Winciorek, Grażyna

    2015-01-01

    Dermatoscopy is a method of in vivo evaluation of the structures within the epidermis and dermis. Currently, it may be the most precise pre-surgical method of diagnosing melanocytic lesions. Diagnostic errors may result in unnecessary removal of benign lesions or what is even worse, they can cause early and very early melanomas to be overlooked. Errors in assessment of dermatoscopy can be divided into those arising from failure to maintain proper test procedures (procedural and technical errors) and knowledge based mistakes related to the lack of sufficient familiarity and experience in dermatoscopy. The article discusses the most common mistakes made by beginner or inexperienced dermatoscopists. PMID:25821425

  3. Nicotinamide enhances repair of ultraviolet radiation-induced DNA damage in primary melanocytes.

    PubMed

    Thompson, Benjamin C; Surjana, Devita; Halliday, Gary M; Damian, Diona L

    2014-07-01

    Cutaneous melanoma is a significant cause of morbidity and mortality. Nicotinamide is a safe, widely available vitamin that reduces the immune suppressive effects of UV, enhances DNA repair in keratinocytes and has shown promise in the chemoprevention of non-melanoma skin cancer. Here, we report the effect of nicotinamide on DNA damage and repair in primary human melanocytes. Nicotinamide significantly enhanced the repair of oxidative DNA damage (8-oxo-7,8-dihydro-2'-deoxyguanosine) and cyclobutane pyrimidine dimers induced by UV exposure. It also enhanced the repair of 8-oxo-7,8-dihydro-2'-deoxyguanosine induced by the culture conditions in unirradiated melanocytes. A significant increase in the percentage of melanocytes undergoing unscheduled but not scheduled DNA synthesis was observed, confirming that nicotinamide enhances DNA repair in human melanocytes. In summary, nicotinamide, by enhancing DNA repair in melanocytes, is a potential agent for the chemoprevention of cutaneous melanoma. PMID:24798949

  4. S100B as a potential biomarker for the detection of cytotoxicity of melanocytes.

    PubMed

    Cheong, Kyung Ah; Noh, Minsoo; Kim, Chang-Hyun; Lee, Ai-Young

    2014-03-01

    Skin irritation is one of the most common adverse reactions in hydroquinone (HQ) and retinoic acid (RA). Although melanocytes have rarely been considered to be involved in skin irritation, RA and particularly HQ could induce melanocyte toxicity, resulting in depigmentation. We chose S100B as a candidate gene for melanocytotoxicity from a genome-wide transcriptional profiling analysis after applying irritant doses of HQ, RA and sodium lauryl sulphate (SLS) to cultures of keratinocytes and/or melanocytes. In this study, the role of S100B on melanocyte viability and cytotoxicity was examined. S100B was detected in melanocytes, but not in keratinocytes or fibroblasts. Melanocytes after treatment with increasing concentrations of HQ, RA, SLS and urushiol showed significant increases in intracellular and extracellular S100B expression with reduced viable cell number and increased release of lactate dehydrogenase. No RAGE expression and no significant function of CD166/ALCAM in melanocyte survival and cytotoxicity favoured the role of intracellular S100B in chemically irritated melanocytes. S100B knock-down increased apoptosis through inhibition of PI3K/AKT, NF-κB and ERK activation, suggesting the increased intracellular S100B expression by chemical irritation as a compensatory reaction to reduce cytotoxicity. The numerical decrease in S100B/c-kit-double-positive melanocytes was also examined in human skin epidermis irritated by HQ or RA with stronger staining intensities of S100B. Collectively, the decrease in viable cell number by reduced intracellular S100B levels in vitro and by chemical irritation in vivo suggests that S100B could be a potential biomarker for melanocytes cytotoxicity. PMID:24451020

  5. Melanoma Therapy with Rhenium-Cyclized Alpha Melanocyte Stimulating Hormone Peptide Analogs

    SciTech Connect

    Thomas P Quinn

    2005-11-22

    Malignant melanoma is the 6th most commonly diagnosed cancer with increasing incidence in the United States. It is estimated that 54,200 cases of malignant melanoma will be newly diagnosed and 7,600 cases of death will occur in the United States in the year 2003 (1). At the present time, more than 1.3% of Americans will develop malignant melanoma during their lifetime (2). The average survival for patients with metastatic melanoma is about 6-9 months (3). Moreover, metastatic melanoma deposits are resistant to conventional chemotherapy and external beam radiation therapy (3). Systematic chemotherapy is the primary therapeutic approach to treat patients with metastatic melanoma. Dacarbazine is the only single chemotherapy agent approved by FDA for metastatic melanoma treatment (5). However, the response rate to Dacarbazine is only approximately 20% (6). Therefore, there is a great need to develop novel treatment approaches for metastatic melanoma. The global goal of this research program is the rational design, characterization and validation of melanoma imaging and therapeutic radiopharmaceuticals. Significant progress has been made in the design and characterization of metal-cyclized radiolabeled alpha-melanocyte stimulating hormone peptides. Therapy studies with {sup 188}Re-CCMSH demonstrated the therapeutic efficacy of the receptor-targeted treatment in murine and human melanoma bearing mice (previous progress report). Dosimetry calculations, based on biodistribution data, indicated that a significant dose was delivered to the tumor. However, {sup 188}Re is a very energetic beta-particle emitter. The longer-range beta-particles theoretically would be better for larger tumors. In the treatment of melanoma, the larger primary tumor is usually surgically removed leaving metastatic disease as the focus of targeted radiotherapy. Isotopes with lower beta-energies and/or shorter particle lengths should be better suited for targeting metastases. The {sup 177}Lu

  6. Endothelin-1 is a transcriptional target of p53 in epidermal keratinocytes and regulates UV induced melanocyte homeostasis

    PubMed Central

    Hyter, Stephen; Coleman, Daniel J.; Ganguli-Indra, Gitali; Merrill, Gary F.; Ma, Steven; Yanagisawa, Masashi; Indra, Arup K.

    2013-01-01

    Summary Keratinocytes contribute to melanocyte activity by influencing their microenvironment, in part, through secretion of paracrine factors. Here we discovered that p53 directly regulates Edn1 expression in epidermal keratinocytes and controls UV-induced melanocyte homeostasis. Selective ablation of EDN1 in murine epidermis (EDN1ep−/−) does not alter melanocyte homeostasis in newborn skin but decreases dermal melanocytes in adult skin. Results showed that keratinocytic EDN1 in a non-cell autonomous manner controls melanocyte proliferation, migration, DNA damage and apoptosis after UVB irradiation. Expression of other keratinocyte derived paracrine factors did not compensate for the loss of EDN1. Topical treatment with EDN1 receptor (EDNRB) antagonist BQ788 abrogated UV induced melanocyte activation and recapitulated the phenotype seen in EDN1ep−/− mice. Altogether, present studies establish an essential role of EDN1 in epidermal keratinocytes to mediate UV induced melanocyte homeostasis in vivo. PMID:23279852

  7. YY1 regulates melanocyte development and function by cooperating with MITF.

    PubMed

    Li, Juying; Song, Jun S; Bell, Robert J A; Tran, Thanh-Nga T; Haq, Rizwan; Liu, Huifei; Love, Kevin T; Langer, Robert; Anderson, Daniel G; Larue, Lionel; Fisher, David E

    2012-01-01

    Studies of coat color mutants have greatly contributed to the discovery of genes that regulate melanocyte development and function. Here, we generated Yy1 conditional knockout mice in the melanocyte-lineage and observed profound melanocyte deficiency and premature gray hair, similar to the loss of melanocytes in human piebaldism and Waardenburg syndrome. Although YY1 is a ubiquitous transcription factor, YY1 interacts with M-MITF, the Waardenburg Syndrome IIA gene and a master transcriptional regulator of melanocytes. YY1 cooperates with M-MITF in regulating the expression of piebaldism gene KIT and multiple additional pigmentation genes. Moreover, ChIP-seq identified genome-wide YY1 targets in the melanocyte lineage. These studies mechanistically link genes implicated in human conditions of melanocyte deficiency and reveal how a ubiquitous factor (YY1) gains lineage-specific functions by co-regulating gene expression with a lineage-restricted factor (M-MITF)-a general mechanism which may confer tissue-specific gene expression in multiple lineages. PMID:22570637

  8. RICTOR involvement in the PI3K/AKT pathway regulation in melanocytes and melanoma

    PubMed Central

    Laugier, Florence; Finet-Benyair, Adeline; André, Jocelyne; Rachakonda, P. Sivaramakrishna; Kumar, Rajiv; Bensussan, Armand; Dumaz, Nicolas

    2015-01-01

    Several studies have highlighted the importance of the PI3K pathway in melanocytes and its frequent over-activation in melanoma. However, little is known about regulation of the PI3K pathway in melanocytic cells. We showed that normal human melanocytes are less sensitive to selective PI3K or mTOR inhibitors than to dual PI3K/mTOR inhibitors. The resistance to PI3K inhibitor was due to a rapid AKT reactivation limiting the inhibitor effect on proliferation. Reactivation of AKT was linked to a feedback mechanism involving the mTORC2 complex and in particular its scaffold protein RICTOR. RICTOR overexpression in melanocytes disrupted the negative feedback, activated the AKT pathway and stimulated clonogenicity highlighting the importance of this feedback to restrict melanocyte proliferation. We found that the RICTOR locus is frequently amplified and overexpressed in melanoma and that RICTOR over-expression in NRAS-transformed melanocytes stimulates their clonogenicity, demonstrating that RICTOR amplification can cooperate with NRAS mutation to stimulate melanoma proliferation. These results show that RICTOR plays a central role in PI3K pathway negative feedback in melanocytes and that its deregulation could be involved in melanoma development. PMID:26356562

  9. Human melanocytes mitigate keratinocyte-dependent contraction in an in vitro collagen contraction assay.

    PubMed

    Rakar, Jonathan; Krammer, Markus P; Kratz, Gunnar

    2015-08-01

    Scarring is an extensive problem in burn care, and treatment can be especially complicated in cases of hypertrophic scarring. Contraction is an important factor in scarring but the contribution of different cell types remains unclear. We have investigated the contractile behavior of keratinocytes, melanocytes and fibroblasts by using an in vitro collagen gel assay aimed at identifying a modulating role of melanocytes in keratinocyte-mediated contraction. Cells were seeded on a collagen type I gel substrate and the change in gel dimensions were measured over time. Hematoxylin & Eosin-staining and immunohistochemistry against pan-cytokeratin and microphthalmia-associated transcription factor showed that melanocytes integrated between keratinocytes and remained there throughout the experiments. Keratinocyte- and fibroblast-seeded gels contracted significantly over time, whereas melanocyte-seeded gels did not. Co-culture assays showed that melanocytes mitigate the keratinocyte-dependent contraction (significantly slower and 18-32% less). Fibroblasts augmented the contraction in most assays (approximately 6% more). Non-contact co-cultures showed some influence on the keratinocyte-dependent contraction. Results show that mechanisms attributable to melanocytes, but not fibroblasts, can mitigate keratinocyte contractile behavior. Contact-dependent mechanisms are stronger modulators than non-contact dependent mechanisms, but both modes carry significance to the contraction modulation of keratinocytes. Further investigations are required to determine the mechanisms involved and to determine the utility of melanocytes beyond hypopigmentation in improved clinical regimes of burn wounds and wound healing. PMID:25466959

  10. Race Does Not Predict Melanocyte Heterogeneous Responses to Dermal Fibroblast-Derived Mediators

    PubMed Central

    Sirimahachaiyakul, Pornthep; Sood, Ravi F.; Muffley, Lara A.; Seaton, Max; Lin, Cheng-Ta; Qiao, Liang; Armaly, Jeffrey S.; Hocking, Anne M.; Gibran, Nicole S.

    2015-01-01

    Introduction Abnormal pigmentation following cutaneous injury causes significant patient distress and represents a barrier to recovery. Wound depth and patient characteristics influence scar pigmentation. However, we know little about the pathophysiology leading to hyperpigmentation in healed shallow wounds and hypopigmentation in deep dermal wound scars. We sought to determine whether dermal fibroblast signaling influences melanocyte responses. Methods and Materials Epidermal melanocytes from three Caucasians and three African-Americans were genotyped for single nucleotide polymorphisms (SNPs) across the entire genome. Melanocyte genetic profiles were determined using principal component analysis. We assessed melanocyte phenotype and gene expression in response to dermal fibroblast-conditioned medium and determined potential mesenchymal mediators by proteome profiling the fibroblast-conditioned medium. Results Six melanocyte samples demonstrated significant variability in phenotype and gene expression at baseline and in response to fibroblast-conditioned medium. Genetic profiling for SNPs in receptors for 13 identified soluble fibroblast-secreted mediators demonstrated considerable heterogeneity, potentially explaining the variable melanocyte responses to fibroblast-conditioned medium. Discussion Our data suggest that melanocytes respond to dermal fibroblast-derived mediators independent of keratinocytes and raise the possibility that mesenchymal-epidermal interactions influence skin pigmentation during cutaneous scarring. PMID:26418010

  11. In ovo gene manipulation of melanocytes and their adjacent keratinocytes during skin pigmentation of chicken embryos.

    PubMed

    Murai, Hidetaka; Tadokoro, Ryosuke; Sakai, Ken-Ichiro; Takahashi, Yoshiko

    2015-04-01

    During skin pigmentation in avians and mammalians, melanin is synthesized in the melanocytes, and subsequently transferred to adjacently located keratinocytes, leading to a wide coverage of the body surface by melanin-containing cells. The behavior of melanocytes is influenced by keratinocytes shown mostly by in vitro studies. However, it has poorly been investigated how such intercellular cross-talk is regulated in vivo because of a lack of suitable experimental models. Using chicken embryos, we developed a method that enables in vivo gene manipulations of melanocytes and keratinocytes, where these cells are separately labeled by different genes. Two types of gene transfer techniques were combined: one was a retrovirus-mediated gene infection into the skin/keratinocytes, and the other was the in ovo DNA electroporation into neural crest cells, the origin of melanocytes. Since the Replication-Competent Avian sarcoma-leukosis virus long terminal repeat with Splice acceptor (RCAS) infection was available only for the White leghorn strain showing little pigmentation, melanocytes prepared from the Hypeco nera (pigmented) were back-transplanted into embryos of White leghorn. Prior to the transplantation, enhanced green fluorescent protein (EGFP)(+) Neo(r+) -electroporated melanocytes from Hypeco nera were selectively grown in G418-supplemented medium. In the skin of recipient White leghorn embryos infected with RCAS-mOrange, mOrange(+) keratinocytes and transplanted EGFP(+) melanocytes were frequently juxtaposed each other. High-resolution confocal microscopy also revealed that transplanted melanocytes exhibited normal behaviors regarding distribution patterns of melanocytes, dendrite morphology, and melanosome transfer. The method described in this study will serve as a useful tool to understand the mechanisms underlying intercellular regulations during skin pigmentation in vivo. PMID:25739909

  12. Microphthalmia-associated transcription factor as the molecular target of cadmium toxicity in human melanocytes

    SciTech Connect

    Chantarawong, Wipa; Takeda, Kazuhisa; Sangartit, Weerapon; Yoshizawa, Miki; Pradermwong, Kantimanee; Shibahara, Shigeki

    2014-11-28

    Highlights: • In human melanocytes, cadmium decreases the expression of MITF-M and tyrosinase and their mRNAs. • In human melanoma cells, cadmium decreases the expression of MITF-M protein and tyrosinase mRNA. • Expression of MITF-H is less sensitive to cadmium toxicity in melanocyte-linage cells. • Cadmium does not decrease the expression of MITF-H in retinal pigment epithelial cells. • MITF-M is the molecular target of cadmium toxicity in melanocytes. - Abstract: Dietary intake of cadmium is inevitable, causing age-related increase in cadmium accumulation in many organs, including hair, choroid and retinal pigment epithelium (RPE). Cadmium has been implicated in the pathogenesis of hearing loss and macular degeneration. The functions of cochlea and retina are maintained by melanocytes and RPE, respectively, and the differentiation of these pigment cells is regulated by microphthalmia-associated transcription factor (MITF). In the present study, we explored the potential toxicity of cadmium in the cochlea and retina by using cultured human melanocytes and human RPE cell lines. MITF consists of multiple isoforms, including melanocyte-specific MITF-M and widely expressed MITF-H. Levels of MITF-M protein and its mRNA in human epidermal melanocytes and HMV-II melanoma cells were decreased significantly by cadmium. In parallel with the MITF reduction, mRNA levels of tyrosinase, the key enzyme of melanin biosynthesis that is regulated by MITF-M, were also decreased. In RPE cells, however, the levels of total MITF protein, constituting mainly MITF-H, were not decreased by cadmium. We thus identify MITF-M as the molecular target of cadmium toxicity in melanocytes, thereby accounting for the increased risk of disability from melanocyte malfunction, such as hearing and vision loss among people with elevated cadmium exposure.

  13. Malignant thymoma.

    PubMed

    Wang, L S; Huang, M H; Lin, T S; Huang, B S; Chien, K Y

    1992-07-15

    Sixty-one patients underwent operations for malignant thymomas between 1961 and 1989. Twenty-three patients had associated myasthenia gravis (MG), an incidence of 37.7%. Upon being admitted to the hospital, the patients' most common symptoms included chest pain, MG, cough, and dyspnea. Only 7 of 61 (11.5%) patients had no symptom. Tumor staging of 58 patients with invasive thymomas was performed according to Masaoka classification. The patients were classified as follows: Stage II disease, 5; Stage III, 41; Stage IVa, 8; and Stage IVb, 4. In addition, thymic carcinoma was present in three patients. The series had a resection rate of 55.7%. The incidence of operative complications was 16.3%. Only one patient died of myocardial infarction; the incidence of operative mortality was 1.6%. The patients with MG had a higher rate of resection (69.6%) and a higher incidence of complete thymectomy (14 of 23 patients; 60.9%). Mixed lymphoepithelial tumors and epithelial cell predominant tumors were the most frequent histologic patterns (45.9% and 34.4%, respectively). Fifty-two patients had postoperative radiation therapy, and 10 patients had chemotherapy. The overall cumulative survival rates in the series were 59% and 34% at 5 and 10 years, respectively. The results demonstrated that the factors affecting the prognosis may include resectability, postoperative irradiation or chemotherapy, MG, and tumor staging. The influence of histologic variation on survival rates could not be clearly defined in the series. Surgical resection, particularly complete thymectomy, followed by irradiation is the primary option of therapeutic management for malignant thymoma. PMID:1617594

  14. RO4929097, Temozolomide, and Radiation Therapy in Treating Patients With Newly Diagnosed Malignant Glioma

    ClinicalTrials.gov

    2015-09-28

    Acoustic Schwannoma; Adult Anaplastic (Malignant) Meningioma; Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Brain Stem Glioma; Adult Choroid Plexus Neoplasm; Adult Craniopharyngioma; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Medulloblastoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Papillary Meningioma; Adult Pilocytic Astrocytoma; Adult Pineal Gland Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Primary Melanocytic Lesion of Meninges; Adult Subependymal Giant Cell Astrocytoma; Adult Subependymoma; Adult Supratentorial Primitive Neuroectodermal Tumor; Malignant Adult Intracranial Hemangiopericytoma

  15. Treatment of congenital melanocytic naevi with CO2 laser.

    PubMed

    Horner, Ben M; El-Muttardi, Naguib S; Mayou, Bryan J

    2005-09-01

    This study assesses the effectiveness of CO2 laser in treating congenital melanocytic naevi (CMN). A retrospective review of 12 patients with CMN treated with CO2 laser was carried out. In all cases, there was minimal visible naevus after treatment. Six patients developed hypertrophic scarring; this was significantly more likely following CO2 laser treatment on the anterior torso, flanks, or arms than on the back or buttocks (P = 0.01, 1-tailed Fisher exact test). We conclude that CO2 laser is an effective treatment for reducing visible pigmentation of CMN. However, it can cause hypertrophic scarring, which has not been reported before. This risk can be reduced by limited use in areas of the body where the dermis is thinner or there is a known risk of hypertrophic scarring. In addition, the cautious use of paint mode and prophylactic use of pressure or silicon dressings may also reduce the risk of hypertrophic scarring. PMID:16106167

  16. Laser treatment of congenital melanocytic nevi: a review of the literature.

    PubMed

    Bray, Fleta N; Shah, Vidhi; Nouri, Keyvan

    2016-01-01

    Congenital melanocytic nevi (CMN) are nevi that are present from birth and occur in approximately 1 % of newborns. CMN may be cosmetically disfiguring and are at risk for malignant transformation. For these two reasons, CMN are frequently treated. A variety of treatment modalities have been utilized with variable efficacy, including excision, dermabrasion, curettage, chemical peels, radiation therapy, cryotherapy, electrosurgery, and lasers. The current treatment of choice for CMN is surgical excision. However, some CMN occur in cosmetically sensitive areas, where a surgical scar is less acceptable, or in inoperable locations. For these reasons, there has been increasing interest in the potential for laser treatment of CMN. The lasers that have been studied to date for the treatment of CMN include pigment-specific lasers, including ruby (694 nm), alexandrite (755 nm), and Nd:yttrium aluminum garnet (YAG) (1064 nm), as well as ablative laser treatment with CO2 laser (10,600 nm) and Er:YAG (2940 nm). To date, ruby lasers have been studied most extensively in the treatment of CMN. Ruby laser has been shown to improve the cosmetic appearance of some CMN and may be cautiously considered for lesions located in cosmetically sensitive areas that are less amenable to surgical excision. For very large CMN, ruby laser has been tried as an alternative to extensive surgical and grafting procedures. Dual treatment with Q-switched ruby laser and normal mode ruby laser may provide the best outcomes; however, multiple treatment sessions should be anticipated. The practicality and expense of multiple treatments should be discussed with the patient prior to initiating treatment. Importantly, because of the persistence of dermal nevus cells, lifelong follow-up is required for all laser-treated CMN, even those with excellent cosmetic effect. PMID:26563957

  17. "Virtual microscopy" and the internet as telepathology consultation tools: diagnostic accuracy in evaluating melanocytic skin lesions.

    PubMed

    Okada, D H; Binder, S W; Felten, C L; Strauss, J S; Marchevsky, A M

    1999-12-01

    The Internet offers a widely available, inexpensive tool for telepathology consultations. It allows the transfer of image and text files through electronic mail (e-mail) or file transfer protocols (FTP), using a variety of microcomputer platforms. We studied the use of the Internet and "virtual microscopy" tools for the diagnosis of 35 skin biopsies, including a variety of benign and malignant melanocytic lesions. Digitized images from these lesions were obtained at 40x and 100x optical magnification, using a high resolution digital camera (Microlumina, Leaf Systems, Southborough, MA), a light microscope with a phototube adapter and a microcomputer with a Pentium 166 MHz microprocessor. Two to four images of each case were arranged on a "canvas" to represent the majority or an entire biopsy level, using Photoshop software (Adobe Systems Inc., San Jose, CA). The images were compressed using Joint Photographers Expert Group (JPEG) format. The images were then viewed on a computer video monitor in a manner that closely resembles light microscopy, including scrolling by using the "hand tool" of Photoshop and changing magnification digitally up to 4 times without visible image degradation. The image files, ranging in size from 700 kilobytes to 2.1 megabytes (average 1.6 megabytes) were attached to e-mail messages that contained clinical information, using standard Multipurpose Internet Mail Extension (MIME) protocols and sent through the Internet, for interpretation by a dermatopathologist. The consultant could open the images from the e-mail message, using Microsoft Outlook Express (Microsoft Corp., Redmond, WA) and Photoshop software, scroll them, change magnification and render a diagnosis in a manner that closely simulates light microscopy. One hundred percent concordance was obtained between the telepathology and traditional hematoxylin and eosin slide diagnoses. The Internet and relatively inexpensive "virtual microscopy" tools offer a novel technology for

  18. Malignant hyperpyrexia

    PubMed Central

    Isaacs, Hyam; Barlow, M. B.

    1973-01-01

    The history, clinical presentation, and management of malignant hyperpyrexia are presented. The aetiology seems to be associated with some inherited abnormality which affects the movement and binding of calcium ions in the sarcoplasmic reticulum, sarcoplasm, and mitochondria. Whether this is a primary muscular defect or secondary to some trophic neural influence is yet to be established. The subjects carrying the abnormal trait show evidence of a myopathy which is subclinical in most instances and revealed only by estimation of serum CPK or biopsy. In some families where the myopathy is clinically obvious there may be, in addition, a variety of musculoskeletal abnormalities. A plea is made for routine monitoring of temperature during anaesthesia and for procainamide or procaine to be readily available in all operating theatres. A history of anaesthetic deaths in a family calls for special care, and, if the serum CPK is elevated, suxamethonium and halothane are to be avoided. Families with orthopaedic and muscular abnormalities are at increased risk and should have estimation of serum CPK before surgery. As a bonus of this study it is suggested that serum CPK estimations be used to screen pigs for selective breeding and so eliminate the disease, which causes soft exudative pork. Images PMID:4708457

  19. EdnrB Governs Regenerative Response of Melanocyte Stem Cells by Crosstalk with Wnt Signaling.

    PubMed

    Takeo, Makoto; Lee, Wendy; Rabbani, Piul; Sun, Qi; Hu, Hai; Lim, Chae Ho; Manga, Prashiela; Ito, Mayumi

    2016-05-10

    Delineating the crosstalk between distinct signaling pathways is key to understanding the diverse and dynamic responses of adult stem cells during tissue regeneration. Here, we demonstrate that the Edn/EdnrB signaling pathway can interact with other signaling pathways to elicit distinct stem cell functions during tissue regeneration. EdnrB signaling promotes proliferation and differentiation of melanocyte stem cells (McSCs), dramatically enhancing the regeneration of hair and epidermal melanocytes. This effect is dependent upon active Wnt signaling that is initiated by Wnt ligand secretion from the hair follicle epithelial niche. Further, this Wnt-dependent EdnrB signaling can rescue the defects in melanocyte regeneration caused by Mc1R loss. This suggests that targeting Edn/EdnrB signaling in McSCs can be a therapeutic approach to promote photoprotective-melanocyte regeneration, which may be useful for those with increased risk of skin cancers due to Mc1R variants. PMID:27134165

  20. Direct conversion of mouse and human fibroblasts to functional melanocytes by defined factors.

    PubMed

    Yang, Ruifeng; Zheng, Ying; Li, Ling; Liu, Shujing; Burrows, Michelle; Wei, Zhi; Nace, Arben; Herlyn, Meenhard; Cui, Rutao; Guo, Wei; Cotsarelis, George; Xu, Xiaowei

    2014-01-01

    Direct reprogramming provides a fundamentally new approach for the generation of patient-specific cells. Here, by screening a pool of candidate transcription factors, we identify that a combination of the three factors, MITF, SOX10 and PAX3, directly converts mouse and human fibroblasts to functional melanocytes. Induced melanocytes (iMels) activate melanocyte-specific networks, express components of pigment production and delivery system and produce melanosomes. Human iMels properly integrate into the dermal-epidermal junction and produce and deliver melanin pigment to surrounding keratinocytes in a 3D organotypic skin reconstruct. Human iMels generate pigmented epidermis and hair follicles in skin reconstitution assays in vivo. The generation of iMels has important implications for studies of melanocyte lineage commitment, pigmentation disorders and cell replacement therapies. PMID:25510211

  1. NF1 loss induces senescence during human melanocyte differentiation in an iPSC-based model.

    PubMed

    Larribere, Lionel; Wu, Huizi; Novak, Daniel; Galach, Marta; Bernhardt, Mathias; Orouji, Elias; Weina, Kasia; Knappe, Nathalie; Sachpekidis, Christos; Umansky, Ludmila; Beckhove, Philipp; Umansky, Viktor; De Schepper, Sofie; Kaufmann, Dieter; Ballotti, Robert; Bertolotto, Corine; Utikal, Jochen

    2015-07-01

    Neurofibromatosis type 1 (NF1) is a frequent genetic disease leading to the development of Schwann cell-derived neurofibromas or melanocytic lesions called café-au-lait macules (CALMs). The molecular mechanisms involved in CALMs formation remain largely unknown. In this report, we show for the first time pathophysiological mechanisms of abnormal melanocyte differentiation in a human NF1(+/-) -induced pluripotent stem cell (iPSC)-based model. We demonstrate that NF1 patient-derived fibroblasts can be successfully reprogrammed in NF1(+/-) iPSCs with active RAS signaling and that NF1 loss induces senescence during melanocyte differentiation as well as in patient's-derived CALMs, revealing a new role for NF1 in the melanocyte lineage. PMID:25824590

  2. Direct conversion of mouse and human fibroblasts to functional melanocytes by defined factors

    PubMed Central

    Yang, Ruifeng; Zheng, Ying; Li, Ling; Liu, Shujing; Burrows, Michelle; Wei, Zhi; Nace, Arben; Herlyn, Meenhard; Cui, Rutao; Guo, Wei; Cotsarelis, George; Xu, Xiaowei

    2015-01-01

    Direct reprogramming provides a fundamentally new approach for the generation of patient-specific cells. Here, by screening a pool of candidate transcription factors, we identify that a combination of three factors, MITF, SOX10 and PAX3, directly converts mouse and human fibroblasts to functional melanocytes. Induced melanocytes (iMels) activate melanocyte-specific networks, express components of pigment production and delivery system, and produce melanosomes. Human iMels properly integrate into the dermal-epidermal junction, and produce and deliver melanin pigment to surrounding keratinocytes in a 3D organotypic skin reconstruct. Human iMels generate pigmented epidermis and hair follicles in skin reconstitution assays in vivo. The generation of iMels has important implications for studies of melanocyte lineage commitment, pigmentation disorders and cell replacement therapies. PMID:25510211

  3. Cutaneous malignant melanoma in a Haller's round ray Urobatis halleri.

    PubMed

    Nau, Melissa R; Gardiner, David W; Nilson, Erika; Schmitt, Todd L; Nollens, Hendrik H; St Leger, Judy

    2016-08-01

    Multiple black raised nodular masses were noted on the dorsal surface of an adult male Haller's round ray Urobatis halleri. Biopsy of 2 masses was performed, and histopathology revealed proliferative sheets of melanocytes exhibiting mild anisocytosis and anisokaryosis, supporting a diagnosis of malignant melanoma. Approximately 2 mo following the biopsy procedure, the round ray became acutely anorexic and was found dead in its enclosure. A full necropsy was performed, and tissues were submitted for histopathology. The black raised nodular masses again exhibited histologic features of a melanoma. In addition to the nodular masses present, multiple flat areas of increased pigmentation were also present throughout the course of the case and were not suggestive of neoplasia histologically. The transformation of benign to malignant neoplasia has been well described in other species and may have played a role in the development of multiple tumors in this case. PMID:27503921

  4. NFIB is a governor of epithelial–melanocyte stem cell behaviour in a shared niche

    PubMed Central

    Chang, Chiung-Ying; Pasolli, H. Amalia; Giannopoulou, Eugenia G.; Guasch, Géraldine; Gronostajski, Richard M.; Elemento, Olivier; Fuchs, Elaine

    2013-01-01

    Adult stem cells reside in specialized niches where they receive environmental cues to maintain tissue homeostasis. In mammals, the stem cell niche within hair follicles is home to epithelial hair follicle stem cells and melanocyte stem cells, which sustain cyclical bouts of hair regeneration and pigmentation1–4. To generate pigmented hairs, synchrony is achieved such that upon initiation of a new hair cycle, stem cells of each type activate lineage commitment2,5. Dissecting the inter-stem-cell crosstalk governing this intricate coordination has been difficult, because mutations affecting one lineage often affect the other. Here we identify transcription factor NFIB as an unanticipated coordinator of stem cell behaviour. Hair follicle stem-cell-specific conditional targeting of Nfib in mice uncouples stem cell synchrony. Remarkably, this happens not by perturbing hair cycle and follicle architecture, but rather by promoting melanocyte stem cell proliferation and differentiation. The early production of melanin is restricted to melanocyte stem cells at the niche base. Melanocyte stem cells more distant from the dermal papilla are unscathed, thereby preventing hair greying typical of melanocyte stem cell differentiation mutants. Furthermore, we pinpoint KIT-ligand as a dermal papilla signal promoting melanocyte stem cell differentiation. Additionally, through chromatin-immunoprecipitation with high-throughput-sequencing and transcriptional profiling, we identify endothelin 2 (Edn2) as an NFIB target aberrantly activated in NFIB-deficient hair follicle stem cells. Ectopically induced Edn2 recapitulates NFIB-deficient phenotypes in wild-type mice. Conversely, endothelin receptor antagonists and/or KIT blocking antibodies prevent precocious melanocyte stem cell differentiation in the NFIB-deficient niche. Our findings reveal how melanocyte and hair follicle stem cell behaviours maintain reliance upon cooperative factors within the niche, and how this can be uncoupled

  5. NFIB is a governor of epithelial-melanocyte stem cell behaviour in a shared niche.

    PubMed

    Chang, Chiung-Ying; Pasolli, H Amalia; Giannopoulou, Eugenia G; Guasch, Géraldine; Gronostajski, Richard M; Elemento, Olivier; Fuchs, Elaine

    2013-03-01

    Adult stem cells reside in specialized niches where they receive environmental cues to maintain tissue homeostasis. In mammals, the stem cell niche within hair follicles is home to epithelial hair follicle stem cells and melanocyte stem cells, which sustain cyclical bouts of hair regeneration and pigmentation. To generate pigmented hairs, synchrony is achieved such that upon initiation of a new hair cycle, stem cells of each type activate lineage commitment. Dissecting the inter-stem-cell crosstalk governing this intricate coordination has been difficult, because mutations affecting one lineage often affect the other. Here we identify transcription factor NFIB as an unanticipated coordinator of stem cell behaviour. Hair follicle stem-cell-specific conditional targeting of Nfib in mice uncouples stem cell synchrony. Remarkably, this happens not by perturbing hair cycle and follicle architecture, but rather by promoting melanocyte stem cell proliferation and differentiation. The early production of melanin is restricted to melanocyte stem cells at the niche base. Melanocyte stem cells more distant from the dermal papilla are unscathed, thereby preventing hair greying typical of melanocyte stem cell differentiation mutants. Furthermore, we pinpoint KIT-ligand as a dermal papilla signal promoting melanocyte stem cell differentiation. Additionally, through chromatin-immunoprecipitation with high-throughput-sequencing and transcriptional profiling, we identify endothelin 2 (Edn2) as an NFIB target aberrantly activated in NFIB-deficient hair follicle stem cells. Ectopically induced Edn2 recapitulates NFIB-deficient phenotypes in wild-type mice. Conversely, endothelin receptor antagonists and/or KIT blocking antibodies prevent precocious melanocyte stem cell differentiation in the NFIB-deficient niche. Our findings reveal how melanocyte and hair follicle stem cell behaviours maintain reliance upon cooperative factors within the niche, and how this can be uncoupled in

  6. Sensitivity of mouse Skh:HR-2 to ultraviolet radiation: melanocyte inactivation

    SciTech Connect

    Warren, R.; Gardner, P.A.; Reed, J.C.

    1987-03-01

    The hairless mouse, Skh:HR-2, was exposed to doses of ultraviolet (UV) radiation known to induce skin pigmentation. Three parameters associated with perturbations in skin pigmentation were monitored following UV exposure. These include spectroscopy (skin darkness), histology (melanocyte density), and biochemistry (melanin). Within 90 min of UV exposure, the skin became lighter. This was associated with a reduction of quantifiable melanin and the inactivation of epidermal melanocytes.

  7. Cooperative response of keratinocytes and melanocytes to UV radiation during PUVA therapy

    NASA Astrophysics Data System (ADS)

    Stolnitz, Mikhail M.; Baskakov, Pavel V.; Peshkova, Anna Y.

    1999-03-01

    The mathematical model of processes in UV-irradiated furocoumarin-sensitized epidermis is presented taking into account the mutual influence of keratinocytes and melanocytes populations. The model describes epidermis as a hierarchical structure on tissue (keratinocytes-melanocytes cooperation, melanin screen formation), cellular (proliferation and differentiation, transitions between subpopulations), subcellular (cell movement on mitotic cycle, generation, maturing and migration of melanosomes), and molecular (melanin synthesis, processes of DNA damage and repair, molecular signal transduction) levels.

  8. Complete regression of a melanocytic nevus after epilation with diode laser therapy

    PubMed Central

    Boleira, Manuela; de Almeida Balassiano, Laila Klotz; Jeunon3, Thiago

    2015-01-01

    The use of lasers and intense pulsed light (IPL) technology has become an established practice in dermatology and aesthetic medicine. The use of laser therapy and IPL in the treatment of pigmented melanocytic lesions is a controversial issue. We report clinical, dermoscopic and histological changes of a completely regressed pigmented melanocytic nevus after hair removal treatment with the LightSheer™ Diode Laser (Lumenis Ltd, Yokneam, Israel). PMID:26114064

  9. Image enhancement of optical images for binary system of melanocytes and keratinocytes

    NASA Astrophysics Data System (ADS)

    Takanezawa, S.; Baba, A.; Sako, Y.; Ozaki, Y.; Date, A.; Toyama, K.; Morita, S.

    2013-05-01

    Automatic determination of the cell shapes of large numbers of melanocytes based on optical images of human skin models have been largely unsuccessful (the complexities introduced by dendrites and the melanin pigmentation over the keratinocytes to give unclear outlines). Here, we present an image enhancement procedure for enhancing the contrast of images with removing the non-uniformity of background. The brightness is normalized also for the non-uniform population density of melanocytes.

  10. Prostaglandin E{sub 2} regulates melanocyte dendrite formation through activation of PKC{zeta}

    SciTech Connect

    Scott, Glynis Fricke, Alex; Fender, Anne; McClelland, Lindy; Jacobs, Stacey

    2007-11-01

    Prostaglandins are lipid signaling intermediates released by keratinocytes in response to ultraviolet irradiation (UVR) in the skin. The main prostaglandin released following UVR is PGE{sub 2}, a ligand for 4 related G-protein-coupled receptors (EP{sub 1}, EP{sub 2}, EP{sub 3} and EP{sub 4}). Our previous work established that PGE{sub 2} stimulates melanocyte dendrite formation through activation of the EP{sub 1} and EP{sub 3} receptors. The purpose of the present report is to define the signaling intermediates involved in EP{sub 1}- and EP{sub 3}-dependent dendrite formation in human melanocytes. We recently showed that activation of the atypical PKC{zeta} isoform stimulates melanocyte dendricity in response to treatment with lysophosphatidylcholine. We therefore examined the potential contribution of PKC{zeta} activation on EP{sub 1}- and EP{sub 3}-dependent dendrite formation in melanocytes. Stimulation of the EP{sub 1} and EP{sub 3} receptors by selective agonists activated PKC{zeta}, and inhibition of PKC{zeta} activation abrogated EP{sub 1}- and EP{sub 3}-receptor-mediated melanocyte dendricity. Because of the importance of Rho-GTP binding proteins in the regulation of melanocyte dendricity, we also examined the effect of EP{sub 1} and EP{sub 3} receptor activation on Rac and Rho activity. Neither Rac nor Rho was activated upon treatment with EP{sub 1,3}-receptor agonists. We show that melanocytes express only the EP{sub 3A1} isoform, but not the EP{sub 3B} receptor isoform, previously associated with Rho activation, consistent with a lack of Rho stimulation by EP{sub 3} agonists. Our data suggest that PKC{zeta} activation plays a predominant role in regulation of PGE{sub 2}-dependent melanocyte dendricity.

  11. Nitric oxide enhances the sensitivity of alpaca melanocytes to respond to {alpha}-melanocyte-stimulating hormone by up-regulating melanocortin-1 receptor

    SciTech Connect

    Dong, Yanjun; Cao, Jing; Wang, Haidong; Zhang, Jie; Zhu, Zhiwei; Bai, Rui; Hao, HuanQing; He, Xiaoyan; Fan, Ruiwen; Dong, Changsheng

    2010-06-11

    Nitric oxide (NO) and {alpha}-melanocyte-stimulating hormone ({alpha}-MSH) have been correlated with the synthesis of melanin. The NO-dependent signaling of cellular response to activate the hypothalamopituitary proopiomelanocortin system, thereby enhances the hypophysial secretion of {alpha}-MSH to stimulate {alpha}-MSH-receptor responsive cells. In this study we investigated whether an NO-induced pathway can enhance the ability of the melanocyte to respond to {alpha}-MSH on melanogenesis in alpaca skin melanocytes in vitro. It is important for us to know how to enhance the coat color of alpaca. We set up three groups for experiments using the third passage number of alpaca melanocytes: the control cultures were allowed a total of 5 days growth; the UV group cultures like the control group but the melanocytes were then irradiated everyday (once) with 312 mJ/cm{sup 2} of UVB; the UV + L-NAME group is the same as group UV but has the addition of 300 {mu}M L-NAME (every 6 h). To determine the inhibited effect of NO produce, NO produces were measured. To determine the effect of the NO to the key protein and gene of {alpha}-MSH pathway on melanogenesis, the key gene and protein of the {alpha}-MSH pathway were measured by quantitative real-time PCR and Western immunoblotting. The results provide exciting new evidence that NO can enhance {alpha}-MSH pathway in alpaca skin melanocytes by elevated MC1R. And we suggest that the NO pathway may more rapidly cause the synthesis of melanin in alpaca skin under UV, which at that time elevates the expression of MC1R and stimulates the keratinocytes to secrete {alpha}-MSH to enhance the {alpha}-MSH pathway on melanogenesis. This process will be of considerable interest in future studies.

  12. Analysis of the effects of hydroquinone and arbutin on the differentiation of melanocytes.

    PubMed

    Inoue, Yu; Hasegawa, Seiji; Yamada, Takaaki; Date, Yasushi; Mizutani, Hiroshi; Nakata, Satoru; Matsunaga, Kayoko; Akamatsu, Hirohiko

    2013-01-01

    Hydroquinone (HQ) is a chemical compound that inhibits the functions of melanocytes and has long been known for its skin-whitening effect. According to previous studies, the Tyrosinase (Tyr) activity inhibitory effect and melanocyte-specific cell toxicity are known depigmenting mechanisms; however, details of the underlying mechanisms are unknown. Arbutin (Arb) is also known for its Tyr activity inhibitory effect and is commonly used as a skin-whitening agent. However, the detailed depigmenting mechanism of Arb is also not yet fully understood. Few studies have attempted to elucidate the effects of HQ and Arb on undifferentiated melanocytes. In this study, we examined the effects of HQ and Arb throughout each stage of differentiation of melanocytes using a mouse embryonic stem cell (ESC) culture system to induce melanocytes. The results showed that HQ in particular downregulated the early stage of differentiation, in which neural crest cells were generated, and the late stage of differentiation, in which melanogenesis became active. On the other hand, Arb had no effect on the differentiation of melanocytes, and only suppressed melanogenesis by specifically suppressing elevations in Tyr expression in the late stage of differentiation. PMID:24189417

  13. Oncogenic mutations in melanomas and benign melanocytic nevi of the female genital tract

    PubMed Central

    Tseng, Diane; Kim, Julie; Warrick, Andrea; Nelson, Dylan; Pukay, Marina; Beadling, Carol; Heinrich, Michael; Selim, Maria Angelica; Corless, Christopher L.; Nelson, Kelly

    2015-01-01

    Background The genetic heterogeneity of melanomas and melanocytic nevi of the female genital tract is poorly understood. Objective We aim to characterize the frequency of mutations of the following genes: BRAF, NRAS, KIT, GNA11, and GNAQ in female genital tract melanomas. We also characterize the frequency of BRAF mutations in female genital tract melanomas compared with melanocytic nevi. Methods Mutational screening was performed on the following female genital tract melanocytic neoplasms: 25 melanomas, 7 benign melanocytic nevi, and 4 atypical melanocytic nevi. Results Of the 25 female genital tract melanoma specimens queried, KIT mutations were detected in 4 (16.0%), NRAS mutations in 4 (16.0%), and BRAF mutations in 2 (8.0%) samples. Two of the tumors with KIT mutations harbored double mutations in the same exon. No GNAQ or GNA11 mutations were identified among 11 melanomas screened. BRAF V600E mutations were detected in 7 of 7 benign melanocytic genital nevi (100%) and 3 of 4 atypical genital nevi (75%). Limitations Our study is limited by the small sample size of this rare subset of melanomas. Conclusion KIT, NRAS, and BRAF mutations are found in a subset of female genital tract melanomas. Screening for oncogenic mutations is important for developing and applying clinical therapies for melanomas of the female genital tract. PMID:24842760

  14. Understanding Melanocyte Stem Cells for Disease Modeling and Regenerative Medicine Applications

    PubMed Central

    Mull, Amber N.; Zolekar, Ashwini; Wang, Yu-Chieh

    2015-01-01

    Melanocytes in the skin play an indispensable role in the pigmentation of skin and its appendages. It is well known that the embryonic origin of melanocytes is neural crest cells. In adult skin, functional melanocytes are continuously repopulated by the differentiation of melanocyte stem cells (McSCs) residing in the epidermis of the skin. Many preceding studies have led to significant discoveries regarding the cellular and molecular characteristics of this unique stem cell population. The alteration of McSCs has been also implicated in several skin abnormalities and disease conditions. To date, our knowledge of McSCs largely comes from studying the stem cell niche of mouse hair follicles. Suggested by several anatomical differences between mouse and human skin, there could be distinct features associated with mouse and human McSCs as well as their niches in the skin. Recent advances in human pluripotent stem cell (hPSC) research have provided us with useful tools to potentially acquire a substantial amount of human McSCs and functional melanocytes for research and regenerative medicine applications. This review highlights recent studies and progress involved in understanding the development of cutaneous melanocytes and the regulation of McSCs. PMID:26703580

  15. Microphthalmia-associated transcription factor as the molecular target of cadmium toxicity in human melanocytes.

    PubMed

    Chantarawong, Wipa; Takeda, Kazuhisa; Sangartit, Weerapon; Yoshizawa, Miki; Pradermwong, Kantimanee; Shibahara, Shigeki

    2014-11-28

    Dietary intake of cadmium is inevitable, causing age-related increase in cadmium accumulation in many organs, including hair, choroid and retinal pigment epithelium (RPE). Cadmium has been implicated in the pathogenesis of hearing loss and macular degeneration. The functions of cochlea and retina are maintained by melanocytes and RPE, respectively, and the differentiation of these pigment cells is regulated by microphthalmia-associated transcription factor (MITF). In the present study, we explored the potential toxicity of cadmium in the cochlea and retina by using cultured human melanocytes and human RPE cell lines. MITF consists of multiple isoforms, including melanocyte-specific MITF-M and widely expressed MITF-H. Levels of MITF-M protein and its mRNA in human epidermal melanocytes and HMV-II melanoma cells were decreased significantly by cadmium. In parallel with the MITF reduction, mRNA levels of tyrosinase, the key enzyme of melanin biosynthesis that is regulated by MITF-M, were also decreased. In RPE cells, however, the levels of total MITF protein, constituting mainly MITF-H, were not decreased by cadmium. We thus identify MITF-M as the molecular target of cadmium toxicity in melanocytes, thereby accounting for the increased risk of disability from melanocyte malfunction, such as hearing and vision loss among people with elevated cadmium exposure. PMID:25449283

  16. Alpha-melanocyte stimulating hormone inhibits monocytes adhesion to vascular endothelium.

    PubMed

    Yang, Yang; Zhang, Weihua; Meng, Lin; Yu, Haitao; Lu, Na; Fu, Gang; Zheng, Yang

    2015-11-01

    Inflammation and its subsequent endothelial dysfunction have been reported to play a pivotal role in the initiation and progression of chronic vascular diseases. Inhibiting the attachment of monocytes to endothelium is a potential therapeutic strategy for vascular diseases treatment. α-Melanocyte stimulating hormone is generated from a precursor hormone called proopiomelanocortin by post-translational processing. However, whether α-melanocyte stimulating hormone plays a role in regulating endothelial inflammation is still unknown. In this study, the effects of α-melanocyte stimulating hormone on endothelial inflammation in human umbilical vein endothelial cell lines were investigated. And the result indicated that α-melanocyte stimulating hormone inhibits the expression of endothelial adhesion molecules, including vascular adhesion molecule-1 and E-selectin, thereby attenuating the adhesion of THP-1 cells to the surface of endothelial cells. Mechanistically, α-melanocyte stimulating hormone was found to inhibit NF-κB transcriptional activity. Finally, we found that the effect of α-melanocyte stimulating hormone on endothelial inflammation is dependent on its receptor melanocortin receptor 1. PMID:25898835

  17. Recombinant Adeno-Associated Virus Serotype 6 Efficiently Transduces Primary Human Melanocytes

    PubMed Central

    Verdon, Daniel; Chen, Jennifer; Taylor, John A.; Dunbar, P. Rod

    2013-01-01

    The study of melanocyte biology is important to understand their role in health and disease. However, current methods of gene transfer into melanocytes are limited by safety or efficacy. Recombinant adeno-associated virus (rAAV) has been extensively investigated as a gene therapy vector, is safe and is associated with persistent transgene expression without genome integration. There are twelve serotypes and many capsid variants of rAAV. However, a comparative study to determine which rAAV is most efficient at transducing primary human melanocytes has not been conducted. We therefore sought to determine the optimum rAAV variant for use in the in vitro transduction of primary human melanocytes, which could also be informative to future in vivo studies. We have screened eight variants of rAAV for their ability to transduce primary human melanocytes and identified rAAV6 as the optimal serotype, transducing 7–78% of cells. No increase in transduction was seen with rAAV6 tyrosine capsid mutants. The number of cells expressing the transgene peaked at 6–12 days post-infection, and transduced cells were still detectable at day 28. Therefore rAAV6 should be considered as a non-integrating vector for the transduction of primary human melanocytes. PMID:23646140

  18. Effect of nicotine on melanogenesis and antioxidant status in HEMn-LP melanocytes

    SciTech Connect

    Delijewski, Marcin; Beberok, Artur; Otręba, Michał; Wrześniok, Dorota; Rok, Jakub; Buszman, Ewa

    2014-10-15

    Nicotine is a natural ingredient of tobacco plants and is responsible for the addictive properties of tobacco. Nowadays nicotine is also commonly used as a form of smoking cessation therapy. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn affect biochemical processes in human cells producing melanin. The aim of this study was to examine the effect of nicotine on melanogenesis and antioxidant status in cultured normal human melanocytes HEMn-LP. Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC{sub 50} was determined to be 7.43 mM. Nicotine inhibited a melanization process in human light pigmented melanocytes and caused alterations of antioxidant defense system. Significant changes in cellular antioxidant enzymes: superoxide dismutase and catalase activities and in hydrogen peroxide content were stated. The obtained results may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long term exposition to nicotine. - Graphical abstract: Nicotine inhibits melanogenesis and induces oxidative stress in HEMn-LP melanocytes. - Highlights: • Nicotine induces concentration-dependent loss in melanocytes viability. • Nicotine in non-cytotoxic concentrations inhibits melanogenesis. • Nicotine in higher concentrations induces oxidative stress.

  19. Melanocytic Hyperplasia in the Epidermis Overlying Trichoblastomas in 100 Randomly Selected Cases.

    PubMed

    Al Omoush, Tahseen M M; Michal, Michael; Konstantinova, Anastasia M; Michal, Michal; Kutzner, Heinz; Kazakov, Dmitry V

    2016-04-01

    One hundred cases of trichoblastomas (large nodular, small nodular, cribriform, lymphadenoma, and columnar) were randomly selected and studied for the presence of melanocytic hyperplasia in the epidermis overlying the tumors, which was defined as foci of increased melanocytes in the basal layer of the epidermis (more than 1 per 4 basal keratinocytes). Focal melanocytic hyperplasia was detected in a total of 22 cases of trichoblastoma (22%), and this phenomenon was most frequently seen in columnar trichoblastoma (7 cases), followed by large nodular trichoblastoma (5 cases). The mechanism of epidermal melanocytic hyperplasia overlying trichoblastoma is unclear. Ultraviolet may be a contributing factor, as focal melanocytic hyperplasia was also detected in one-third of cases in the epidermis overlying uninvolved skin, usually associated with solar elastosis. This is further corroborated by the occurrence of the lesions predominantly on the face. Melanocytic hyperplasia overlying trichoblastoma appears to have no impact on the clinical appearance of the lesion and is recognized only microscopically. In an adequate biopsy specimen containing at least part of trichoblastoma, it should not cause any diagnostic problems. PMID:26885602

  20. Primary Malignant Melanoma of Maxilla: Report of a Case with Discussion

    PubMed Central

    Rani, G. Shirisha; Kumar, T. Vinay; Begum, Md Rezwana; Priya Srinivasan, Anu

    2014-01-01

    Primary oral malignant melanoma, very rare neoplasm of melanocytic origin, usually presents as a bluish black to tan-brown colored lesion Which is accounting for 0.2 to 8% of all melanomas, 1.6% of all head and neck malignancies, and 0.5% of all oral neoplasia. In general, the prognosis of oral melanoma is poor and worse than that of cutaneous melanoma. Here a case of oral malignant melanoma is presented, which was undetected during the first visit to a dental clinic. When a simple oral surgical treatment was carried out in that region, it resulted in the appearance of a massive pigmented lesion which was histopathologically diagnosed as malignant melanoma. This paper is presented to reemphasize the fact that any pigmented lesion in the oral cavity should be viewed with suspicion and proper investigation (biopsy) should be carried out to rule out any untoward experiences later. PMID:25642350

  1. Collision Tumour of Squamous Cell Carcinoma and Malignant Melanoma in the Oral Cavity of a Dog.

    PubMed

    Rodríguez, F; Castro, P; Ramírez, G A

    2016-05-01

    A 7-year-old, male cocker spaniel was presented with a gingival proliferative lesion in the rostral maxilla and enlargement of the regional lymph node. Morphological and immunohistochemical analysis revealed a collision tumour composed of two malignant populations, epithelial and melanocytic, with metastasis of the neoplastic melanocytes to the regional lymph node. The epithelial component consisted of trabeculae and islands of well-differentiated squamous epithelium immunoreactive to cytokeratins. The melanocytic component had a varying degree of pigmentation of polygonal and spindle-shaped cells, growing in nests or densely packed aggregates and immunolabelled with S100, melanoma-associated antigen (melan A), neuron-specific enolase and vimentin antibodies. Protein markers involved in tumorigenesis or cell proliferation (i.e. COX-2, p53, c-kit and Ki67), were overexpressed by the neoplastic cells. To the authors' knowledge, this is the first description of an oral collision tumour involving malignant melanoma and squamous cell carcinoma in the dog. PMID:27147111

  2. Malignant melanoma--a genetic overview.

    PubMed

    Bloethner, S; Scherer, D; Drechsel, M; Hemminki, K; Kumar, R

    2009-11-01

    Malignant melanoma, a potentially lethal skin neoplasm, is characterized by a complex and heterogeneous etiology. Both incidences and deaths associated with melanoma are increasing in Caucasian populations. While exposure to ultraviolet radiation through sun-exposure is the major risk factor; the host factors including skin type and number of moles are critical in predisposition. The CDKN2A is a high penetrance melanoma susceptibility gene as carriers of the mutations are predisposed to the disease within familial settings. The gene is also somatically altered to varying degrees in sporadic melanoma. The CDK4 gene due to occurrence of activation mutations in a few families worldwide represents another melanoma susceptibility locus. The variants within the melanocortin receptor 1 (MC1R) gene, which encodes a melanocyte specific surface receptor with a key role in pigmentation, are associated with high risk phenotypes and increased risk of melanoma. Melanoma tumors are characterized by activation of the RAS-RAF-MEK-ERK pathway through either autocrine growth factor stimulation or oncogenic mutations in the B-RAF or N-RAS genes. Somatic mutations in the B-RAF gene are complemented by those in the N-RAS gene and represent the major genetic alterations. The mutations in the B-RAF gene in melanoma due to occurrence in melanocytic nevi represent early events that additionally require loss of cell cycle inhibitors like CDKN2A for melanoma progression and development. The sequence of events points to the cooperative collaboration between different genetic pathways in tumor development that can be and are being used as targets for developing specific therapeutic agents. PMID:20096196

  3. Functional melanocytes are readily reprogrammable from multilineage-differentiating stress-enduring (muse) cells, distinct stem cells in human fibroblasts.

    PubMed

    Tsuchiyama, Kenichiro; Wakao, Shohei; Kuroda, Yasumasa; Ogura, Fumitaka; Nojima, Makoto; Sawaya, Natsue; Yamasaki, Kenshi; Aiba, Setsuya; Dezawa, Mari

    2013-10-01

    The induction of melanocytes from easily accessible stem cells has attracted attention for the treatment of melanocyte dysfunctions. We found that multilineage-differentiating stress-enduring (Muse) cells, a distinct stem cell type among human dermal fibroblasts, can be readily reprogrammed into functional melanocytes, whereas the remainder of the fibroblasts do not contribute to melanocyte differentiation. Muse cells can be isolated as cells positive for stage-specific embryonic antigen-3, a marker for undifferentiated human embryonic stem cells, and differentiate into cells representative of all three germ layers from a single cell, while also being nontumorigenic. The use of certain combinations of factors induces Muse cells to express melanocyte markers such as tyrosinase and microphthalmia-associated transcription factor and to show positivity for the 3,4-dihydroxy-L-phenylalanine reaction. When Muse cell-derived melanocytes were incorporated into three-dimensional (3D) cultured skin models, they localized themselves in the basal layer of the epidermis and produced melanin in the same manner as authentic melanocytes. They also maintained their melanin production even after the 3D cultured skin was transplanted to immunodeficient mice. This technique may be applicable to the efficient production of melanocytes from accessible human fibroblasts by using Muse cells, thereby contributing to autologous transplantation for melanocyte dysfunctions, such as vitiligo. PMID:23563197

  4. Pigmented median raphe cyst of the penis with consideration of the possible mechanism of melanocytic colonization: A case report.

    PubMed

    Ishida, Mitsuaki; Iwai, Muneo; Yoshida, Keiko; Kagotani, Akiko; Okabe, Hidetoshi

    2014-02-01

    Median raphe cyst is a rare lesion located on the median raphe. The cyst wall is lined by cuboidal to columnar cells, transitional (urothelial) cells, stratified squamous cells or a mixture of these. The normal urethral mucosa and the median raphe cyst usually lack melanocytes and/or melanin pigment. However, albeit extremely rare, the presence of melanin pigment and/or melanocytes in median raphe cyst, namely pigmented median raphe cyst, has been previously reported. The current case report presents the sixth case of pigmented median raphe cyst and discusses the possible mechanism of melanocytic colonization in this tumor. A 48-year-old male presented with a nodule on the ventral surface of the penis. Histopathological study revealed that the cyst wall was covered by uniform bland cuboidal to urothelial cells. The peculiar observation was the presence of dendritic melanocytes among the epithelial cells. Therefore, a diagnosis of pigmented median raphe cyst was determined. Immunohistochemically, stem cell factor and endothelin-1 were not expressed in the epithelial cells of the cyst wall. It is well-known that melanocytes are rarely found in various non-melanocytic tumors, a phenomenon termed 'colonization'. The mechanism by which melanocytes appear in median raphe cyst remains unclear. The present report is the first to demonstrate that melanocytic proliferation and differentiation factors, such as stem cell factor and endothelin-1, are not involved in the pigmentation of median raphe cyst. In addition, aberrant melanocytic migration may contribute to the development of this type of lesion. PMID:24396444

  5. Amelanotic malignant melanoma of the uterine cervix diagnosed by cervical smear.

    PubMed

    Arık, Deniz; Öge, Tufan; Kabukçuoğlu, Sare; Yalçın, Ömer Tarık; Özalp, Sinan

    2016-06-01

    The melanocytic cells of the cervical epithelium are capable of forming the complete spectrum of melanocytic lesions, from benign lentigines to melanoma. Primary malignant melanoma of the uterine cervix is a rare neoplasm with aggressive behavior. The absence of melanin pigment can lead to misdiagnosis as carcinomas, sarcomas, or lymphoma. Immunohistochemical studies should be used for confirmation. In order to consent the cervix as a primary site, exclusion of any other probable primary sites of melanoma is needed. Here, we present a 61-year-old female patient with postmenopausal vaginal bleeding. After cervical smear, diagnosis was confirmed by cervical punch biopsy. Diagn. Cytopathol. 2016;44:535-537. © 2016 Wiley Periodicals, Inc. PMID:26991516

  6. A multimodal assessment of melanin and melanocyte activity in abnormally pigmented hypertrophic scar.

    PubMed

    Travis, Taryn E; Ghassemi, Pejhman; Ramella-Roman, Jessica C; Prindeze, Nicholas J; Paul, Dereck W; Moffatt, Lauren T; Jordan, Marion H; Shupp, Jeffrey W

    2015-01-01

    Using a validated swine model of human scar formation, hyperpigmented and hypopigmented scar samples were examined for their histological and optical properties to help elucidate the mechanisms and characteristics of dyspigmentation. Full-thickness wounds were created on the flanks of red Duroc pigs and allowed to heal. Biopsies from areas of hyperpigmentation, hypopigmentation, and uninjured tissue were fixed and embedded for histological examination using Azure B and primary antibodies to S100B, HMB45, and α-melanocyte-stimulating hormone (α-MSH). Spatial frequency domain imaging (SFDI) was then used to examine the optical properties of scars. Hyperpigmentation was first noticeable in healing wounds around weeks 2 to 3, gradually becoming darker. There was no significant difference in S100B staining for the presence of melanocytes between hyperpigmented and hypopigmented scar samples. Azure B staining of melanin was significantly greater in histological sections from hyperpigmented areas than in sections from both uninjured skin and hypopigmented scar (P < .0001). There was significantly greater staining for α-MSH in hyperpigmented samples compared with hypopigmented samples (P = .0121), and HMB45 staining was positive for melanocytes in hyperpigmented scar. SFDI at a wavelength of 632 nm resulted in an absorption coefficient map correlating with visibly hyperpigmented areas of scars. In a red Duroc model of hypertrophic scar formation, melanocyte number is similar in hyperpigmented and hypopigmented tissues. Hyperpigmented tissues, however, show a greater amount of melanin and α-MSH, along with immunohistochemical evidence of stimulated melanocytes. These observations encourage further investigation of melanocyte stimulation and the inflammatory environment within a wound that may influence melanocyte activity. Additionally, SFDI can be used to identify areas of melanin content in mature, pigmented scars, which may lead to its usefulness in wounds at earlier

  7. Dedifferentiation of human epidermal melanocytes into melanoblasts in vitro.

    PubMed

    Zhao, Zhiguo; Jin, Cheng; Ding, Keyun; Ge, Xiaopeng; Dai, Lllan

    2012-07-01

    Melanoblasts (MB) are also called melanocyte (MC) precursor cells. In recent years, people have successfully cultivated human and mouse MB. Previous studies have shown that EDN3 induces cultivated bird MC to re-differentiate into double potential progenitor cells of MB. However, no study has reported whether in vitro cultivated human MC can be dedifferentiated. Our research on MC that were purified and cultivated in vitro found that adding 10 nm endothelin 1 (EDN1) (ET-1) to the MC medium without phorbol 12-myristate 13-acetate (PMA) induced a few MC to dedifferentiate and become a new type of cell. This new cell type was separated, purified, cloned and identified using multiple approaches. The results show that 88.7%, 8.69% and 2.5% of this new cell type were cells in the G(0) -G(1) , G(2) -M and S stages, respectively. The new cell type did not exhibit an apparent apoptotic peak, and its apoptotic rate was 0.09%. Stage I melanosomes were observed in the cytoplasm and were negative for the DOPA reaction. The cell surface antigen expression was positive for tyrosinase-related protein 2, negative or positive for c-kit and negative for S-100 and HMB45, showing that these cells were dedifferentiated MB of MC. Our findings provided evidence for atavism of mature human MC under certain conditions. PMID:22540983

  8. Genetic construction, expression, and melanoma-selective cytotoxicity of a diphtheria toxin-related alpha-melanocyte-stimulating hormone fusion protein.

    PubMed Central

    Murphy, J R; Bishai, W; Borowski, M; Miyanohara, A; Boyd, J; Nagle, S

    1986-01-01

    The structural gene for diphtheria toxin, tox, has been modified at its Sph I site by the introduction of an oligonucleotide linker encoding a unique Pst I restriction endonuclease site and a synthetic oligonucleotide encoding alpha-melanocyte-stimulating hormone (alpha-MSH). The resulting fusion gene directs the expression of a diphtheria toxin-related alpha-MSH hybrid protein in which the diphtheria toxin receptor-binding domain has been replaced with alpha-MSH sequences. The chimeric toxin has been partially purified from periplasmic extracts of recombinant Escherichia coli K-12 and has been found to be selectively toxic for alpha-MSH receptor-positive human malignant melanoma NEL-M1 cells in vitro. Images PMID:3095831

  9. Sox10 – A marker for not only Schwannian and melanocytic neoplasms but also myoepithelial cell tumors of soft tissue. A systematic analysis of 5134 tumors

    PubMed Central

    Miettinen, Markku; McCue, Peter A.; Sarlomo-Rikala, Maarit; Biernat, Wojciech; Czapiewski, Piotr; Kopczynski, Janusz; Thompson, Lester D.; Lasota, Jerzy; Wang, Zengfeng; Fetsch, John F.

    2015-01-01

    Sox10 transcription factor is expressed in Schwannian and melanocytic lineages and is important in their development and can be used as a marker for corresponding tumors. Additionally, it has been reported in subsets of myoepithelial/basal cell epithelial neoplasms, but its expression remains incompletely characterized. In this study, we examined Sox10 express-ion in 5134 human neoplasms spanning a wide spectrum of neuroectodermal, mesenchymal, lymphoid, and epithelial tumors. A new rabbit monoclonal antibody (clone EP268) and Leica Bond Max automation were used on multitumor block libraries containing 30–70 cases per slide. Sox10 was consistently expressed in benign Schwann cell tumors of soft tissue and the GI-tract and metastatic melanoma, and was variably present in malignant peripheral nerve sheath tumors. In contrast, Sox10 was absent in many potential mimics of nerve sheath tumors such as cellular neurothekeoma, meningioma, gastrointestinal stromal tumors, PEComa, and a variety of fibroblastic-myofibroblastic tumors. Sox10 was virtually absent in mesenchymal tumors but occasionally seen in alveolar rhabdomyosarcoma. In epithelial tumors of soft tissue, Sox10 was expressed only in myoepitheliomas, although often absent in malignant variants. Carcinomas, other than basal cell type breast cancers, were only rarely positive but included rare squamous carcinomas of head and neck and pulmonary small cell carcinomas. Furthermore, Sox10 was often focally expressed in embryonal carcinoma reflecting a primitive Sox10-positive phenotype or neuroectodermal differentiation. Expression of Sox10 in entrapped non-neoplastic Schwann cells or melanocytes in various neoplasms has to be considered in diagnosing Sox10-positive tumors. The Sox10 antibody belongs in a modern immunohistochemical panel for the diagnosis of soft tissue and epithelial tumors. PMID:25724000

  10. Oxidative stress-induced overexpression of miR-25: the mechanism underlying the degeneration of melanocytes in vitiligo.

    PubMed

    Shi, Q; Zhang, W; Guo, S; Jian, Z; Li, S; Li, K; Ge, R; Dai, W; Wang, G; Gao, T; Li, C

    2016-03-01

    Oxidative stress has a critical role in the pathogenesis of vitiligo. However, the specific molecular mechanism involved in oxidative stress-induced melanocyte death is not well characterized. Given the powerful role of microRNAs (miRNAs) in the regulation of cell survival as well as the fact that the generation of miRNAs can be affected by oxidative stress, we hypothesized that miRNAs may participate in vitiligo pathogenesis by modulating the expression of vital genes in melanocytes. In the present study, we initially found that miR-25 was increased in both serum and lesion samples from vitiligo patients, and its serum level was correlated with the activity of vitiligo. Moreover, restoration of miR-25 promoted the H2O2-induced melanocyte destruction and led to the dysfunction of melanocytes. Further experiments proved that MITF, a master regulator in melanocyte survival and function, accounted for the miR-25-caused damaging impact on melanocytes. Notably, other than the direct role on melanocytes, we observed that miR-25 inhibited the production and secretion of SCF and bFGF from keratinocytes, thus impairing their paracrine protective effect on the survival of melanocytes under oxidative stress. At last, we verified that oxidative stress could induce the overexpression of miR-25 in both melanocytes and keratinocytes possibly by demethylating the promoter region of miR-25. Taken together, our study demonstrates that oxidative stress-induced overexpression of miR-25 in vitiligo has a crucial role in promoting the degeneration of melanocytes by not only suppressing MITF in melanocytes but also impairing the paracrine protective effect of keratinocytes. Therefore, it is worthy to investigate the possibility of miR-25 as a potential drug target for anti-oxidative therapy in vitiligo. PMID:26315342

  11. Epidemiology of Melanocytic Naevi in Children from Lleida, Catalonia, Spain: Protective Role of Sunscreen in the Development of Acquired Moles.

    PubMed

    Moreno, Sara; Soria, Xavier; Martínez, Montserrat; Martí, Rosa M; Casanova, Josep M

    2016-04-12

    The worldwide incidence of malignant melanoma is increasing. The number of pigmented naevi and amount of solar exposure are important risk factors. The aim of this study was to characterize a paediatric population (from Lleida, Catalonia, Spain) in terms of phenotype, sun behaviour and naevi prevalence. Data on the numbers and distributions of acquired naevi in 369 children, aged 4, 8 and 14 years, were collected and correlated with age, sex, skin phototype and environmental factors (annual/lifetime intermittent and chronic sun exposure, sunburns and sunscreen use). The density of naevi increased with age. Boys had more naevi on the trunk and girls had more naevi on the legs. Children with light skin phototype had more naevi. A higher level of accumulated sun exposure correlated with a higher number of naevi in children with non-adequate sunscreen use. In conclusion, several risk factors associated with naevi density and distribution were found, as previously reported by others. Multivariate analysis confirmed a protective role of sunscreen in the development of acquired melanocytic naevi. PMID:26551264

  12. Heme oxygenase-1 expression protects melanocytes from stress-induced cell death: implications for vitiligo

    PubMed Central

    Elassiuty, Yasser E.; Klarquist, Jared; Speiser, Jodi; Yousef, Randa M.; EL Refaee, Abdelaziz A.; Hunter, Nahla S.; Shaker, Olfat G.; Gundeti, Mohan; Nieuweboer-Krobotova, Ludmila; Le Poole, I. Caroline

    2013-01-01

    To study protection of melanocytes from stress-induced cell death by heme oxygenases during depigmentation and repigmentation in vitiligo, expression of isoforms 1 and 2 was studied in cultured control and patient melanocytes and normal skin explants exposed to UV or bleaching agent 4-TBP. Similarly, expression of heme oxygenases was followed in skin from vitiligo patients before and after PUVA treatment. Single and double immunostainings were used in combination with light and confocal microscopic analysis and Western blotting. Melanocyte expression of heme oxygenase 1 is upregulated, whereas heme oxygenase 2 is reduced in response to UV and 4-TBP. Upregulation of inducible heme oxygenase 1 was also observed in UV-treated explant cultures, in skin of successfully PUVA-treated patients and in melanocytes cultured from vitiligo non-lesional skin. Heme oxygenase encoding genes were subsequently cloned to study consequences of either gene product on cell viability, demonstrating that HO-1 but not HO-2 overexpression offers protection from stress-induced cell death in MTT assays. HO-1 expression by melanocytes may contribute to beneficial effects of UV treatment for vitiligo patients. PMID:21426408

  13. Lineage-specific transcriptional regulation of DICER by MITF in melanocytes.

    PubMed

    Levy, Carmit; Khaled, Mehdi; Robinson, Kathleen C; Veguilla, Rosa A; Chen, Po-Hao; Yokoyama, Satoru; Makino, Eiichi; Lu, Jun; Larue, Lionel; Beermann, Friedrich; Chin, Lynda; Bosenberg, Marcus; Song, Jun S; Fisher, David E

    2010-06-11

    DICER is a central regulator of microRNA maturation. However, little is known about mechanisms regulating its expression in development or disease. While profiling miRNA expression in differentiating melanocytes, two populations were observed: some upregulated at the pre-miRNA stage, and others upregulated as mature miRNAs (with stable pre-miRNA levels). Conversion of pre-miRNAs to fully processed miRNAs appeared to be dependent upon stimulation of DICER expression--an event found to occur via direct transcriptional targeting of DICER by the melanocyte master transcriptional regulator MITF. MITF binds and activates a conserved regulatory element upstream of DICER's transcriptional start site upon melanocyte differentiation. Targeted KO of DICER is lethal to melanocytes, at least partly via DICER-dependent processing of the pre-miRNA-17 approximately 92 cluster thus targeting BIM, a known proapoptotic regulator of melanocyte survival. These observations highlight a central mechanism underlying lineage-specific miRNA regulation which could exist for other cell types during development. PMID:20550935

  14. Ex vivo reconstruction of the epidermis with melanocytes and the influence of UVB.

    PubMed

    Bessou, S; Surlève-Bazeille, J E; Sorbier, E; Taïeb, A

    1995-10-01

    To study pigmentation, we have reconstructed an epidermis ex vivo with keratinocytes and melanocytes. Keratinocytes and melanocytes were grown first in primary cocultures and separately in secondary cultures, then seeded on a dead deepidermized dermis (Pruniéras type) at a 1:20 melanocyte/keratinocyte ratio. Reconstructed epidermis were grown in a special medium enriched with calcium and fetal bovine serum lifted for 15 days at the air-liquid interface. Using histology, immunohistochemistry and electron microscopy we have shown an excellent level of differentiation of the reconstructed epidermis and a physiologic distribution of dendritic melanocytes in the basal layer capable of melanosome transfer to keratinocytes. UVB irradiation 0.15 J/cm2 x 5 consecutive days increased melanocyte numbers and stimulated pigmentation as evidenced macroscopically and microscopically and at the biochemical level. Following UVB irradiation melanosome transfer was markedly increased and isolated or clumps of melanosomes were seen in the basal layers as well as in the stratum corneum. This model allows the study of the physiology of pigmentation ex vivo. PMID:8789198

  15. Functional Characterization of the Odorant Receptor 51E2 in Human Melanocytes.

    PubMed

    Gelis, Lian; Jovancevic, Nikolina; Veitinger, Sophie; Mandal, Bhubaneswar; Arndt, Hans-Dieter; Neuhaus, Eva M; Hatt, Hanns

    2016-08-19

    Olfactory receptors, which belong to the family of G-protein-coupled receptors, are found to be ectopically expressed in non-sensory tissues mediating a variety of cellular functions. In this study we detected the olfactory receptor OR51E2 at the transcript and the protein level in human epidermal melanocytes. Stimulation of primary melanocytes with the OR51E2 ligand β-ionone significantly inhibited melanocyte proliferation. Our results further showed that β-ionone stimulates melanogenesis and dendritogenesis. Using RNA silencing and receptor antagonists, we demonstrated that OR51E2 activation elevated cytosolic Ca(2+) and cAMP, which could mediate the observed increase in melanin synthesis. Co-immunocytochemical stainings using a specific OR51E2 antibody revealed subcellular localization of the receptor in early endosomes associated with EEA-1 (early endosome antigen 1). Plasma membrane preparations showed that OR51E2 protein is present at the melanocyte cell surface. Our findings thus suggest that activation of olfactory receptor signaling by external compounds can influence melanocyte homeostasis. PMID:27226631

  16. Testosterone and UVL-B stimulation of epidermal melanocytes in rat scrotal skin.

    PubMed

    Glimcher, M D; Wilson, M J; Szabo, G

    1979-01-01

    The effects of UVL-B and/or testosterone replacemnt therapy are compared in normal and castrated rats in order to determine whether testosterone is required for UVL-B (290-315 nm) stimulation of melanogenesis in the testosterone-dependent epidermal melanocyte system of the scrotal skin of black Long Evans rats. Testosterone is not a prerequisite for UVL-B stimulation of melanocytes as in both castrates and normal animals the melanocytes respond to UVL-B by increases in size, length and number of dendrites (dendriticness), and tyrosinase activity (intensity of Dopa reaction). Addition of testosterone to castrates does enhance the effects of UVL-B. However, UVL-B with or without testosterone cannot maintain normal melanogenesis in rats irradiated immediately after castration nor can it restore normal melanogenesis following long term castration. Bth the amount of UVL nergy/exposure and the number of exposures are important variables in stimulation of the epidermal melanocytes. Administration of a dose of UVL-B to castrates in a single exposure is ineffective, while the same overall dose spread over several exposures increases the size and dendriticness of melanocytes. Testosterone and UVL-B act synergistically in affecting melanogenesis although neither singly nor in combination are they able to fully restore normal melanogenesis. PMID:760595

  17. Extracellular vesicles are transferred from melanocytes to keratinocytes after UVA irradiation

    PubMed Central

    Wäster, Petra; Eriksson, Ida; Vainikka, Linda; Rosdahl, Inger; Öllinger, Karin

    2016-01-01

    Ultraviolet (UV) irradiation induces skin pigmentation, which relies on the intercellular crosstalk of melanin between melanocytes to keratinocytes. However, studying the separate effects of UVA and UVB irradiation reveals differences in cellular response. Herein, we show an immediate shedding of extracellular vesicles (EVs) from the plasma membrane when exposing human melanocytes to UVA, but not UVB. The EV-shedding is preceded by UVA-induced plasma membrane damage, which is rapidly repaired by Ca2+-dependent lysosomal exocytosis. Using co-cultures of melanocytes and keratinocytes, we show that EVs are preferably endocytosed by keratinocytes. Importantly, EV-formation is prevented by the inhibition of exocytosis and increased lysosomal pH but is not affected by actin and microtubule inhibitors. Melanosome transfer from melanocytes to keratinocytes is equally stimulated by UVA and UVB and depends on a functional cytoskeleton. In conclusion, we show a novel cell response after UVA irradiation, resulting in transfer of lysosome-derived EVs from melanocytes to keratinocytes. PMID:27293048

  18. Hyperoside protects human primary melanocytes against H2O2-induced oxidative damage

    PubMed Central

    YANG, BIN; YANG, QIN; YANG, XIN; YAN, HONG-BO; LU, QI-PING

    2016-01-01

    Cuscutae semen has been shown to have beneficial effects in the treatment of vitiligo, recorded in the Chinese Pharmacopoeia, whereas the effects of its constituent compounds remains to be elucidated. Using a tetrazolium bromide assay, the present study found that hyperoside (0.5–200 µg/ml) significantly increased the viability of human melanocytes in a time- and dose-dependent manner. The present study used a cell model of hydrogen peroxide (H2O2)-induced oxidative damage to examine the effect of hyperoside on human primary melanocytes. The results demonstrated that hyperoside pretreatment for 2 h decreased cell apoptosis from 54.03±9.11 to 17.46±3.10% in the H2O2-injured melanocytes. The levels of oxidative stress in the mitochondrial membrane potential of the melanocytes increased following hyperoside pretreatment. The mRNA and protein levels of B-cell lymphoma-2/Bcl-2-associated X protein and caspase 3 were regulated by hyperoside, and phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase signaling were also mediated by hyperoside. In conclusion, the results of the present study demonstrated that hyperoside protected the human primary melanocytes against oxidative damage. PMID:27082158

  19. Extracellular vesicles are transferred from melanocytes to keratinocytes after UVA irradiation.

    PubMed

    Wäster, Petra; Eriksson, Ida; Vainikka, Linda; Rosdahl, Inger; Öllinger, Karin

    2016-01-01

    Ultraviolet (UV) irradiation induces skin pigmentation, which relies on the intercellular crosstalk of melanin between melanocytes to keratinocytes. However, studying the separate effects of UVA and UVB irradiation reveals differences in cellular response. Herein, we show an immediate shedding of extracellular vesicles (EVs) from the plasma membrane when exposing human melanocytes to UVA, but not UVB. The EV-shedding is preceded by UVA-induced plasma membrane damage, which is rapidly repaired by Ca(2+)-dependent lysosomal exocytosis. Using co-cultures of melanocytes and keratinocytes, we show that EVs are preferably endocytosed by keratinocytes. Importantly, EV-formation is prevented by the inhibition of exocytosis and increased lysosomal pH but is not affected by actin and microtubule inhibitors. Melanosome transfer from melanocytes to keratinocytes is equally stimulated by UVA and UVB and depends on a functional cytoskeleton. In conclusion, we show a novel cell response after UVA irradiation, resulting in transfer of lysosome-derived EVs from melanocytes to keratinocytes. PMID:27293048

  20. Melanocytes and keratinocytes have distinct and shared responses to ultraviolet radiation and arsenic.

    PubMed

    Cooper, K L; Yager, J W; Hudson, L G

    2014-01-30

    The rise of melanoma incidence in the United States is a growing public health concern. A limited number of epidemiology studies suggest an association between arsenic levels and melanoma risk. Arsenic acts as a co-carcinogen with ultraviolet radiation (UVR) for the development of squamous cell carcinoma and proposed mechanisms include generation of oxidative stress by arsenic and UVR and inhibition of UVR-induced DNA repair by arsenic. In this study, we investigate similarities and differences in response to arsenic and UVR in keratinocytes and melanocytes. Normal melanocytes are markedly more resistant to UVR-induced cytotoxicity than normal keratinocytes, but both cell types are equally sensitive to arsenite. Melanocytes were more resistant to arsenite and UVR stimulation of superoxide production than keratinocytes, but the concentration of arsenite necessary to inhibit the activity of the DNA repair protein poly(ADP-ribose)polymerase and enhance retention of UVR-induced DNA damage was essentially equivalent in both cell types. These findings suggest that although melanocytes are less sensitive than keratinocytes to initial UVR-mediated DNA damage, both of these important target cells in the skin share a mechanism related to arsenic inhibition of DNA repair. These findings suggest that concurrent chronic arsenic exposure could promote retention of unrepaired DNA damage in melanocytes and act as a co-carcinogen in melanoma. PMID:24270004

  1. Malignant teratoma (image)

    MedlinePlus

    A malignant teratoma is a type of cancer consisting of cysts that contain one or more of the three primary embryonic germ layers: ectoderm, mesoderm, and endoderm. Because malignant teratomas have usually spread by the time of diagnosis, ...

  2. Organ culture of mammalian skin and the effects of ultraviolet light and testosterone on melanocyte morphology and function.

    PubMed

    Glimcher, M E; Garcia, R I; Szabó, G

    1978-05-01

    Scrotal skin of black Long-Evans rats and human thigh skin were maintained in vitro as organ cultures for as long as 14 days, and examined histologically using the combined skin splitting and Dopa techniques. Selected rat skin cultures received testosterone in the culture medium and/or were irradiated with ultraviolet light (290-320 nm UVL). With increased time in culture, scrotal melanocytes round up and there is an increase in epidermal pigmentation. Human skin behaves similarly; after eight days in vitro human melanocytes also become rounded, but remain strongly Dopa-positive. Addition of exogenous testosterone to cultured rat skin maintains dendritic morphology of melanocytes, but cell body size is still reduced. UVL irradiation stimulates melanocytes in rat skin cultures, maintaining their dendritic morphology and increasing epidermal and dermal pigmentation. Cultured skin receiving both UVL and testosterone illustrates a synergistic effect. Electron microscopic examination of cultured rat skin shows the presence of large melanosome complexes in keratinocytes, much larger than those found in vivo. Melanocytes appear to be active as they contain an extensive Golgi zone, rough endoplasmic reticulum, and melanosomes in various stages of formation. Dermis contained many dermal melanocytes and macrophages laden with melanosomes, correlating with the increased visible dermal pigmentation in vitro. This UVL stimulation of melanocytes in our skin organ cultures contrasts with the lack of melanogenic stimulation found in melanoma cell cultures. Our findings suggest that the intact epidermal melanin unit may be necessary for UVL stimulation of melanocytes. PMID:641488

  3. A deep penetrating facial congenital melanocytic tumor with bone involvement and ipsilateral eye blindness.

    PubMed

    Bergman, Reuven; Ben-Arush, Miriam W; Bar-Shalom, Rachel; Gilboa, Michael; Simon, Einav; Hershkovitz, Dov; Sabo, Edmond; Maly, Alexander; Gerami, Pedram; Goldsher, Dorith

    2015-01-01

    Bone involvement has been described in tumors with melanocytic differentiation such as melanotic neuroectodermal tumor of infancy, and very rarely in cellular blue nevi and neurocristic cutaneous hamartoma. We present an unusual case of facial congenital melanocytic tumor that involved the underlying bones and maxillary sinus and led to unilateral blindness. A newborn with a large red bluish patch with peripheral brown and black macules overlying marked swelling on the left side of his face was presented. The tumor was shown by magnetic resonance imaging, scintigraphy, and histopathology to invade the underlying bones and maxillary sinus and to compress the left eyeball resulting in blindness. Histopathology, immunohistochemistry, morphometric computerized microscopy, molecular genetic mutation analysis, and fluorescent in situ hybridization studies were more congruent with a melanocytic nevus. An 8.5-year follow-up was uneventful, with spontaneous partial shrinkage of the tumor. PMID:25222197

  4. Topology of feather melanocyte progenitor niche allows complex pigment patterns to emerge.

    PubMed

    Lin, S J; Foley, J; Jiang, T X; Yeh, C Y; Wu, P; Foley, A; Yen, C M; Huang, Y C; Cheng, H C; Chen, C F; Reeder, B; Jee, S H; Widelitz, R B; Chuong, C M

    2013-06-21

    Color patterns of bird plumage affect animal behavior and speciation. Diverse patterns are present in different species and within the individual. Here, we study the cellular and molecular basis of feather pigment pattern formation. Melanocyte progenitors are distributed as a horizontal ring in the proximal follicle, sending melanocytes vertically up into the epithelial cylinder, which gradually emerges as feathers grow. Different pigment patterns form by modulating the presence, arrangement, or differentiation of melanocytes. A layer of peripheral pulp further regulates pigmentation via patterned agouti expression. Lifetime feather cyclic regeneration resets pigment patterns for physiological needs. Thus, the evolution of stem cell niche topology allows complex pigment patterning through combinatorial co-option of simple regulatory mechanisms. PMID:23618762

  5. Pediatric Salivary Gland Malignancies.

    PubMed

    Ord, Robert A; Carlson, Eric R

    2016-02-01

    Pediatric malignant salivary gland tumors are extremely rare. The percentage of malignant tumors is higher than that seen in adults, although the outcomes in terms of survival are better in pediatric patients. The mainstay of treatment is surgical excision with negative margins. This article reviews current concepts in demographics, etiology, management, and outcomes of malignant salivary tumors in children. PMID:26614703

  6. Dual origin of melanocytes defined by Sox1 expression and their region-specific distribution in mammalian skin.

    PubMed

    Yoshimura, Naoko; Motohashi, Tsutomu; Aoki, Hitomi; Tezuka, Ken-ichi; Watanabe, Natsuki; Wakaoka, Takanori; Era, Takumi; Kunisada, Takahiro

    2013-02-01

    Melanocytes are pigment-producing cells generated from neural crest cells (NCCs) that delaminate from the dorsal neural tube. The widely accepted premise that NCCs migrating along the dorsolateral pathway are the main source of melanocytes in the skin was recently challenged by the finding that Schwann cell precursors are the major cellular source of melanocytes in the skin. Still, in a wide variety of vertebrate embryos, melanocytes are exclusively derived from NCCs. In this study, we show that a NCC population that is not derived from Sox1(+) dorsal neuroepithelial cells but are derived from Sox1(-) cells differentiate into a significant population of melanocytes in the skin of mice. Later, these Sox1(-) cells clearly segregate from cells that originated from Sox1(+) dorsal neuroepithelial cell-derived NCCs. The possible derivation of Sox1(-) cells from epidermal cells also strengthens their non-neuroepithelial origin. PMID:23347447

  7. A Case of Melanoacanthoma: Immunohistochemical Staining Using VECTOR® NovaRED™ to Distinguish Melanocytes from the Cutaneous Pigment

    PubMed Central

    Choi, Jae Eun; Bae, Eui Jong; Kim, Ae Ree; Son, Sang Wook; Song, Hae Jun

    2008-01-01

    Melanoacanthoma is a rare benign mixed tumor of both keratinocytes and melanocytes. Although some authors said that it is a rare variant of seborrheic keratosis, it has clinical and histological features distinct from seborrheic keratosis. It has large dendritic melanin-laden melanocytes throughout all levels of epidermis showing a disruption of melanin transfer from the melanocytes to neighboring keratinocytes. However, it is difficult to distinguish melanocytes clearly from cutaneous pigment in immunohistochemical stain with usually used brown chromogen. We used chromogen with brick-red indicator product (VECTOR® NovaRED™) in S-100 and melan-A immunohistochemical staining to distinguish melanocytes from melanin laden keratinocytes. We suggest that the immunohistochemical staining using this novel chromogen may be useful in the diagnosis of melanoacanthoma.

  8. A Comparison Between Phorbol 12 Myristate 13 Acetate and Phorbol 12, 13 Dibutyrate in Human Melanocyte Culture

    PubMed Central

    Padma, Divya

    2016-01-01

    Introduction Melanocyte culture is an integral part of the studies of skin biology and cosmetic applications. After the introduction of selective medium for the culture of human melanocyte using Phorbol 12-myristate13-acetate (PMA) in 1982, a lot of methods of culturing were tried but till date PMA is a preferred mitogen because of its cost effectiveness compared to growth factors. We have tried to preliminarily evaluate the efficacy of another phorbol ester, Phorbol 12, 13-dibutyrate (PDBu) in melanocyte culture because of its less hydrophobic nature compared to PMA. This property minimizes the trace amount of mitogen in cell culture after washing off and hence does not interfere in other biological assays. Aim To evaluate the differences in the melanocyte survival rate, morphology and mitotic index when grown in media supplemented with PMA and PDBu. Materials and Methods Foreskins were collected from children undergoing circumcision. Epidermal cells were isolated from foreskin and cultured using PMA and PDBu. Melanocytes in culture were monitored for the better establishment and documented. In proliferative assay, melanocytes were treated with PMA and PDBu for 24, 48 and 72 hours and proliferation was measured using 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay method. Results When cultured, melanocytes acquired proliferative status and bipolar morphology quicker in PDBu medium than in PMA medium. Keratinocytes survived as contamination in PMA medium whereas PDBu medium had minimal keratinocytes. MTT assay showed that PDBu has higher proliferative induction capacity than PMA. In even lower concentration of PDBu in medium, melanocytes survived till 72 hours without significant cell loss in compared to PMA medium. Conclusion PDBu can be a valuable replacement for PMA in human melanocyte culture. Higher proliferation induction, unfavourable to keratinocyte survival and less hydrophobicity make PDBu a promising alternative for quicker

  9. Segmental neurofibromatosis and malignancy.

    PubMed

    Dang, Julie D; Cohen, Philip R

    2010-01-01

    Segmental neurofibromatosis is an uncommon variant of neurofibromatosis type I characterized by neurofibromas and/or café-au-lait macules localized to one sector of the body. Although patients with neurofibromatosis type I have an associated increased risk of certain malignancies, malignancy has only occasionally been reported in patients with segmental neurofibromatosis. The published reports of patients with segmental neurofibromatosis who developed malignancy were reviewed and the characteristics of these patients and their cancers were summarized. Ten individuals (6 women and 4 men) with segmental neurofibromatosis and malignancy have been reported. The malignancies include malignant peripheral nerve sheath tumor (3), malignant melanoma (2), breast cancer (1), colon cancer (1), gastric cancer (1), lung cancer (1), and Hodgkin lymphoma (1). The most common malignancies in patients with segmental neurofibromatosis are derived from neural crest cells: malignant peripheral nerve sheath tumor and malignant melanoma. The incidence of malignancy in patients with segmental neurofibromatosis may approach that of patients with neurofibromatosis type I. PMID:21137621

  10. Expression of microphthalmia transcription factor, S100 protein, and HMB-45 in malignant melanoma and pigmented nevi

    PubMed Central

    Xia, Jianxin; Wang, Yanlong; Li, Fuqiu; Wang, Jinfeng; Mu, Yan; Mei, Xianglin; Li, Xue; Zhu, Wenjing; Jin, Xianhua; Yu, Kai

    2016-01-01

    Malignant melanoma (MM) is a type of malignant tumor, which originates from neural crest melanocytes. MM progresses rapidly and results in a high mortality rate. The present study aims to investigate the expression of microphthalmia transcription factor (MITF), the S100 protein, and HMB-45 in MM and pigmented nevi. A total of 32 MM samples (including three skin metastasis, three lymph node metastasis and two spindle cell MM samples), two Spitz nevus samples, four pigmented nevus samples and two blue nevus samples were collected. The expression levels of S100 protein, HMB-45, and MITF were observed via immunostaining. The S100 protein exhibited high positive rates in MM and pigment disorders (96.7 and 100%, respectively), but with low specificity. The S100 protein was also expressed in fibroblasts, myoepithelial cells, histocytes and Langerhans cells in normal skin samples. HMB-45 had high specificity. Its positive expression was only confined to MM cells and junctional nevus cells. Furthermore, HMB-45 was not expressed in melanocytes in the normal tissue samples around the tumor or in the benign intradermal nevus cells. MITF exhibited high specificity and high sensitivity. It was expressed in the nuclei of melanocytes, MM cells and nevus cells. It was observed to be strongly expressed in metastatic MM and spindle cell MMs. Thus, MITF may present as a specific immunomarker for the diagnosis and differential diagnosis of MM. PMID:27602212

  11. Apparent absence of a benign precursor lesion: Implications for the pathogenesis of malignant melanoma

    SciTech Connect

    Ross, P.M. )

    1989-09-01

    This review relates concepts derived from the study of chemically induced skin cancer in animal models to the pathogenesis of malignant melanoma in humans. Most chemically induced experimental cancers in animals, including melanomas in rodents, arise within a benign precursor lesion. The initiation-promotion-progression sequence is a central concept in animal models for carcinogenesis. Many human melanomas appear to arise from epidermal melanocytes, with no associated precursor lesion. This article considers why there is no apparent precursor in many human melanomas and the consequences of this absence. Melanocyte physiology and factors that govern escape from defenses such as DNA repair, local tissue environment, and immunity presumably influence melanocyte conversion to melanoma. These factors may determine the absence of a precursor lesion in primary melanomas. In addition, it is possible that some human melanomas arise by cellular mechanisms different from those causing cancer in rodent models. Both molecular and prospective clinical studies will be required to explain this apparent paradox in the pathogenesis of melanoma. A similar approach may help to explain the origin of basal cell carcinoma and perhaps other human cancers that appear to arise directly from normal cells. From a clinical point of view, the absence of an identifiable, benign precursor lesion requires even greater emphasis on melanoma prevention. Research on mechanisms of ultraviolet carcinogenesis indicates that appropriate postexposure treatments may be useful in preventing long-term consequences of sunburn, including melanoma. 69 references.

  12. Dermoscopy of benign and malignant neoplasms in the pediatric population.

    PubMed

    Haliasos, Helen C; Zalaudek, Iris; Malvehy, Josep; Lanschuetzer, Christoph; Hinter, Helmut; Hofmann-Wellenhof, Rainer; Braun, Ralph; Marghoob, Ashfaq A

    2010-12-01

    Dermoscopy is a noninvasive technique that enables visualization of subsurface colors and structures within the skin that are imperceptible to the naked eye. The dermatoscope allows the physician to examine both the macroscopic and microscopic primary morphology of skin lesions, identify subtle clinical clues, confirm naked-eye clinical diagnoses, and monitor treatment progress while posing little threat to the young patient. Dermoscopic findings have been formulated into diagnostic criteria that assist experienced clinicians in differentiating benign and malignant neoplasms. In this review, clinical morphology of melanocytic nevi and melanoma in the pediatric population is examined and the relevant dermoscopic findings and histopathologic correlates that aid in the diagnosis and management of these lesions are described. PMID:21277535

  13. Seminal vesicle metastasis of cutaneous malignant melanoma: An unusual and challenging presentation.

    PubMed

    Foahom Kamwa, Alain D; Mateus, Christine; Thanigasalam, Ruban; Boulay-Coletta, Isabelle; Duchatelle, Véronique; Triller, Marie; Robert, Caroline; Baumert, Hervé

    2015-01-01

    Malignant melanoma is a tumour, which usually involves skin melanocytes. Involvement of the male genitourinary (GU) system by melanoma is an uncommon and challenging diagnosis. We report the first case of seminal vesicle metastasis from a primary cutaneous melanoma in a 58-year-old man, with hemospermia as the only clinical sign. This case highlights the role of multiparametric magnetic resonance imaging, as a more sensitive assessment to early detect metastatic melanoma in the GU system. The patient underwent a robot-assisted laparoscopic bilateral seminal vesiculectomy, which had good functional and oncological results and is still in complete remission at the 1-year follow-up. PMID:26085885

  14. Seminal vesicle metastasis of cutaneous malignant melanoma: An unusual and challenging presentation

    PubMed Central

    Foahom Kamwa, Alain D.; Mateus, Christine; Thanigasalam, Ruban; Boulay-Coletta, Isabelle; Duchatelle, Véronique; Triller, Marie; Robert, Caroline; Baumert, Hervé

    2015-01-01

    Malignant melanoma is a tumour, which usually involves skin melanocytes. Involvement of the male genitourinary (GU) system by melanoma is an uncommon and challenging diagnosis. We report the first case of seminal vesicle metastasis from a primary cutaneous melanoma in a 58-year-old man, with hemospermia as the only clinical sign. This case highlights the role of multiparametric magnetic resonance imaging, as a more sensitive assessment to early detect metastatic melanoma in the GU system. The patient underwent a robot-assisted laparoscopic bilateral seminal vesiculectomy, which had good functional and oncological results and is still in complete remission at the 1-year follow-up. PMID:26085885

  15. FGF2 regulates melanocytes viability through the STAT3-transactivated PAX3 transcription

    PubMed Central

    Dong, L; Li, Y; Cao, J; Liu, F; Pier, E; Chen, J; Xu, Z; Chen, C; Wang, R-a; Cui, R

    2012-01-01

    PAX3 (paired box 3) is known to have an important role in melanocyte development through modulation of microphthalmia-associated transcription factor transcription. Here we found that PAX3 transcriptional activity could be regulated through FGF2 (basic fibroblast growth factor)-STAT3 (signal transducer and activator of transcription 3) signaling in the pigment cells. To study its function in vivo, we have generated a transgenic mouse model expressing PAX3 driven by tyrosinase promoter in a tissue-specific fashion. These animals exhibit hyperpigmentation in the epidermis, evident in the skin color of their ears and tails. We showed that the darker skin color results from both increased melanocyte numbers and melanin synthesis. Together, our study delineated a novel pathway in the melanocyte lineage, linking FGF2-STAT3 signaling to increased PAX3 transcription. Moreover, our results suggest that this pathway might contribute to the regulation of melanocyte numbers and melanin levels, and thereby provide an alternative strategy to induce pigmentation. PMID:21997191

  16. Loss of tumorigenic potential upon transdifferentiation from keratinocytic into melanocytic lineage.

    PubMed

    Fehrenbach, Sabrina; Novak, Daniel; Bernhardt, Mathias; Larribere, Lionel; Boukamp, Petra; Umansky, Viktor; Utikal, Jochen

    2016-01-01

    Lineage-specific transcription factors determine the cell fate during development. Direct conversion of several cell types into other lineages has been achieved by the overexpression of specific transcription factors. Even cancer cells have been demonstrated to be amenable to transdifferentiation. Here, we identified a distinct set of transcription factors, which are sufficient to transform cells of the keratinocytic lineage to melanocyte-like cells. Melanocyte marker expression was induced and melanosome formation was observed in non-tumorigenic keratinocytes (HaCaT) and tumorigenic squamous cell carcinoma (MET-4) cells. Moreover, reduced proliferation, cell metabolism, invasion and migration were measured in vitro in transdifferentiated MT-MET-4 cells. A loss of tumorigenic potential of squamous cell carcinoma cells could be due to the upregulation of the melanocyte differentiation associated gene IL-24. Our data show that cells from the keratinocytic lineage can be transdifferented into the melanocytic lineage and provide a proof of principle for a potential new therapeutic strategy. PMID:27387763

  17. ENHANCED BLEACHING TREATMENT: OPPORTUNITIES FOR IMMUNE-ASSISTED MELANOCYTE SUICIDE IN VITILIGO

    PubMed Central

    Webb, Kirsten C.; Eby, Jonathan M.; Hariharan, Vidhya; Hernandez, Claudia; Luiten, Rosalie M.; Le Poole, I. Caroline

    2014-01-01

    Depigmentation in vitiligo occurs by progressive loss of melanocytes from the basal layer of the skin, and can be psychologically devastating to patients. T cell-mediated autoimmunity explains the progressive nature of this disease. Rather than being confronted with periods of rapid depigmentation and bouts of repigmentation, patients with long-standing, treatment-resistant vitiligo can undergo depigmentation treatment. The objective is to remove residual pigmentation in order to achieve a cosmetically acceptable result- that of skin with a uniform appearance. In the USA, only the use of mono-benzyl ether of hydroquinone (MBEH) is approved for this purpose. However, satisfactory results can take time to appear, and there is a risk of repigmentation. MBEH induces necrotic melanocyte death followed by a cytotoxic T cell response to remaining, distant melanocytes. As cytotoxic T cell responses are instrumental to depigmentation, we propose that combining MBEH with immune adjuvant therapies will accelerate immune-mediated melanocyte destruction to achieve faster, more definitive depigmentation than with MBEH alone. Since Toll-like Receptor (TLR) agonists-imiquimod, CpG, and Heat Shock Protein 70 (HSP 70)-all support powerful Th1 responses, we propose that using MBEH in combination with these agents can achieve superior depigmentation results for vitiligo patients. PMID:24840876

  18. The human melanocyte as a particular target for UVA radiation and an endpoint for photoprotection assessment.

    PubMed

    Marrot, L; Belaidi, J P; Meunier, J R; Perez, P; Agapakis-Causse, C

    1999-06-01

    The induction of DNA breaks by UVA (320-400 nm) in the nucleus of normal human melanocytes in culture was investigated using single cell gel electrophoresis, also called the comet assay. Endogenous pigment and/or melanin-related molecules were found to enhance DNA breakage: comets were more intense in melanocytes than in fibroblasts, in cells with high melanin content or after stimulation of melanogenesis by supplying tyrosine in the culture medium. After UVA doses where strong comets were observed, neither cytotoxicity nor stimulation of tyrosinase activity were detected. However, the accumulation of p53 protein suggested that cells reacted to genotoxic stress under these experimental conditions. The same approach was used to compare two sunscreens with identical sun protection factors but different UVA protection factors. The results presented in this paper suggest that human melanocytes may be used as a target cell to evidence broadspectrum photoprotection. Moreover, these data appear to be helpful in getting a better understanding of the role of sunlight in the initiating steps of melanocyte transformation. PMID:10378007

  19. Postnatal lineage mapping of follicular melanocytes with the Tyr::CreER(T) (2) transgene.

    PubMed

    Harris, Melissa L; Pavan, William J

    2013-03-01

    One of the main advantages of using inducible and conditional transgenes to study pigment cell biology is that they allow for genetic manipulation within melanocytes after roles in general neural crest or melanoblast development have been fulfilled. Specifically, we focus here on the ability of the Tyr::CreER(T) (2) transgenic line to alter genes within follicular melanocytes postnatally. Using the Gt(ROSA)26Sor(tm1sor) reporter allele, we present in detail the expression and activity of Tyr::CreER(T) (2) when induced during hair morphogenesis and adult hair cycling. We find that despite similarities in expression pattern to endogenous TYR, Tyr::CreER(T) (2) is effective at targeting both undifferentiated and differentiated melanocytes within the hair follicle. We also find that Tyr::CreER(T) (2) provides the highest levels of recombination when induced during the early phases of hair growth. In conclusion, the descriptions provided here will guide future analyses of gene function within the melanocyte system of the hair follicle when using this Tyr::CreER(T) (2) transgene. PMID:23176440

  20. NRAS mutation is the sole recurrent somatic mutation in large congenital melanocytic nevi.

    PubMed

    Charbel, Christelle; Fontaine, Romain H; Malouf, Gabriel G; Picard, Arnaud; Kadlub, Natacha; El-Murr, Nizar; How-Kit, Alexandre; Su, Xiaoping; Coulomb-L'Hermine, Aurore; Tost, Jorg; Mourah, Samia; Aractingi, Selim; Guégan, Sarah

    2014-04-01

    Congenital melanocytic nevus (CMN) is a particular melanocytic in utero proliferation characterized by an increased risk of melanoma transformation during infancy or adulthood. NRAS and BRAF mutations have consistently been reported in CMN samples, but until recently results have been contradictory. We therefore studied a series of large and giant CMNs and compared them with small and medium CMNs using Sanger sequencing, pyrosequencing, high-resolution melting analysis, and mutation enrichment by an enhanced version of ice-COLD-PCR. Large-giant CMNs displayed NRAS mutations in 94.7% of cases (18/19). At that point, the role of additional mutations in CMN pathogenesis had to be investigated. We therefore performed exome sequencing on five specimens of large-giant nevi. The results showed that NRAS mutation was the sole recurrent somatic event found in such melanocytic proliferations. The genetic profile of small-medium CMNs was significantly different, with 70% of cases bearing NRAS mutations and 30% showing BRAF mutations. These findings strongly suggest that NRAS mutations are sufficient to drive melanocytic benign proliferations in utero. PMID:24129063

  1. Gamma-melanocyte-stimulating hormone-like immunoreactivity in blood cells of human eosinophilic patients.

    PubMed

    Johansson, O; Virtanen, M; Hilliges, M; Hansson, L O

    1991-01-01

    The immunohistochemical localization of the peptide gamma-melanocyte-stimulating hormone (gamma-MSH) within human polymorphonuclear leucocytes of blood from eosinophilic patients is described. The gamma-MSH immunoreactivity was observed only in neutrophilic granulocytes leaving all other cell types immuno-negative. PMID:1805488

  2. Loss of tumorigenic potential upon transdifferentiation from keratinocytic into melanocytic lineage

    PubMed Central

    Fehrenbach, Sabrina; Novak, Daniel; Bernhardt, Mathias; Larribere, Lionel; Boukamp, Petra; Umansky, Viktor; Utikal, Jochen

    2016-01-01

    Lineage-specific transcription factors determine the cell fate during development. Direct conversion of several cell types into other lineages has been achieved by the overexpression of specific transcription factors. Even cancer cells have been demonstrated to be amenable to transdifferentiation. Here, we identified a distinct set of transcription factors, which are sufficient to transform cells of the keratinocytic lineage to melanocyte-like cells. Melanocyte marker expression was induced and melanosome formation was observed in non-tumorigenic keratinocytes (HaCaT) and tumorigenic squamous cell carcinoma (MET-4) cells. Moreover, reduced proliferation, cell metabolism, invasion and migration were measured in vitro in transdifferentiated MT-MET-4 cells. A loss of tumorigenic potential of squamous cell carcinoma cells could be due to the upregulation of the melanocyte differentiation associated gene IL-24. Our data show that cells from the keratinocytic lineage can be transdifferented into the melanocytic lineage and provide a proof of principle for a potential new therapeutic strategy. PMID:27387763

  3. Development of a three-dimensional surface imaging system for melanocytic skin lesion evaluation

    NASA Astrophysics Data System (ADS)

    Tosca, Androniki; Kokolakis, Athanasios; Lasithiotakis, Konstantinos; Zacharopoulos, Athanasios; Zabulis, Xenophon; Marnelakis, Ioannis; Ripoll, Jorge; Stephanidis, Constantine

    2013-01-01

    Even though surface morphology is always taken into account when assessing clinically pigmented skin lesions, it is not captured by most modern imaging systems using digital imaging. Our aim is to develop a novel three-dimensional (3D) imaging technique to record detailed information of the surface anatomy of melanocytic lesions that will enable improved classification through digital imaging. The apparatus consists of three high-resolution cameras, a light source, and accompanying software. Volume measurements of specific phantoms using volumetric tubes render slightly lower values than those obtained by our 3D imaging system (mean%±SD, 3.8%±0.98, P<0.05). To examine the reproducibility of the method, sequential imaging of melanocytic lesions is carried out. The mean%±SD differences of area, major axis length, volume, and maximum height are 2.1%±1.1, 0.9%±0.8, 3.8%±2.9, and 2.5%±3.5, respectively. Thirty melanocytic lesions are assessed, including common and dysplastic nevi and melanomas. There is a significant difference between nevi and melanomas in terms of variance in height and boundary asymmetry (P<0.001). Moreover, dysplastic nevi have significantly higher variances in pigment density values than common nevi (P<0.001). Preliminary data suggest that our instrument has great potential in the evaluation of the melanocytic lesions. However, these findings should be confirmed in larger-scale studies.

  4. The immunology and inflammatory responses of human melanocytes in infectious diseases.

    PubMed

    Gasque, Philippe; Jaffar-Bandjee, Marie Christine

    2015-10-01

    Melanin is a canonical and major defense molecule in invertebrates but its role in mammalian immunity remains unexplored. In contrast, several recent studies have highlighted the emerging innate immune activities of human melanin-producing cells which can sense and respond to bacterial and viral infections. Indeed, the skin is a major portal of entry for pathogens such as arboviruses (Chikungunya, Dengue) and bacteria (mycobacterium leprae, Leptospira spirochetes). Melanocytes of the epidermis could contribute to the phagocytosis of these invading pathogens and to present antigens to competent immune cells. Melanocytes are known to produce key cytokines such as IL-1β, IL6 and TNF-α as well as chemokines. These molecules will subsequently alert macrophages, neutrophils, fibroblasts and keratinocytes through unique crosstalk mechanisms. The infection and the inflammatory responses will control melanocyte's immune and metabolic functions and could contribute to skin manifestations (rash, hyper or de-pigmentation, epidermolysis and psoriasis-like lesions). This review will address the potential role of melanocytes in immunity, inflammation and infection of the skin in health and diseases. PMID:26092350

  5. CRH stimulation of corticosteroids production in melanocytes is mediated by ACTH.

    PubMed

    Slominski, Andrzej; Zbytek, Blazej; Szczesniewski, Andrzej; Semak, Igor; Kaminski, Jan; Sweatman, Trevor; Wortsman, Jacobo

    2005-04-01

    The response to systemic stress is organized along the hypothalamic-pituitary-adrenal axis (HPA), whereas the response to a peripheral stress (solar radiation) is mediated by epidermal melanocytes (cells of neural crest origin) responsible for the pigmentary reaction. Melanocytes express proopiomelanocortin (POMC), corticotropin-releasing hormone (CRH), and CRH receptor-1 (CRH-R1) and can produce corticosterone. In the present study, incubation of normal epidermal melanocytes with CRH was found to trigger a functional cascade structured hierarchically and arranged along the same algorithm as in the HPA axis: CRH activation of CRH-R1 stimulated cAMP accumulation and increased POMC gene expression and production of ACTH. CRH and ACTH also enhanced production of cortisol and corticosterone, and cortisol production was also stimulated by progesterone. The chemical identity of the cortisol was confirmed by liquid chromatography-mass spectrometry (LC/MS2) with [corrected] mass spectrometry-mass spectrometry analyses. POMC gene silencing abolished the stimulatory effect of CRH on corticosteroid synthesis, indicating that this is indirect and mediated via production of ACTH. Thus the melanocyte response to CRH is highly organized along the same functional hierarchy as the HPA axis. This pattern demonstrates the fractal nature of the response to stress with similar activation sequence at the single-cell and whole body levels. PMID:15572653

  6. Effects of PGF{sub 2{alpha}} on human melanocytes and regulation of the FP receptor by ultraviolet radiation

    SciTech Connect

    Scott, Glynis . E-mail: Glynis_Scott@urmc.rochester.edu; Jacobs, Stacey; Leopardi, Sonya; Anthony, Frank A.; Learn, Doug; Malaviya, Rama; Pentland, Alice

    2005-04-01

    Prostaglandins are potent lipid hormones that activate multiple signaling pathways resulting in regulation of cellular growth, differentiation, and apoptosis. In the skin, prostaglandins are rapidly released by keratinocytes following ultraviolet radiation and are chronically present in inflammatory skin lesions. We have shown previously that melanocytes, which provide photoprotection to keratinocytes through the production of melanin, express several receptors for prostaglandins, including the PGE{sub 2} receptors EP{sub 1} and EP{sub 3} and the PGF{sub 2{alpha}} receptor FP, and that PGF{sub 2{alpha}} stimulates melanocyte dendricity. We now show that PGF{sub 2{alpha}} stimulates the activity and expression of tyrosinase, the rate-limiting enzyme in melanin synthesis. Analysis of FP receptor regulation showed that the FP receptor is regulated by ultraviolet radiation in melanocytes in vitro and in human skin in vivo. We also show that ultraviolet irradiation stimulates production of PGF{sub 2{alpha}} by melanocytes. These results show that PGF{sub 2{alpha}} binding to the FP receptor activates signals that stimulate a differentiated phenotype (dendricity and pigmentation) in melanocytes. The regulation of the FP receptor and the stimulation of production of PGF{sub 2{alpha}} in melanocytes in response to ultraviolet radiation suggest that PGF{sub 2{alpha}} could act as an autocrine factor for melanocyte differentiation.

  7. Inhibitory effect of Korean Red Ginseng on melanocyte proliferation and its possible implication in GM-CSF mediated signaling

    PubMed Central

    Oh, Chang Taek; Park, Jong Il; Jung, Yi Ra; Joo, Yeon Ah; Shin, Dong Ha; Cho, Hyoung Joo; Ahn, Soo Mi; Lim, Young-Ho; Park, Chae Kyu; Hwang, Jae Sung

    2013-01-01

    Korean Red Ginseng (KRG) has been reported to exert anticancer, anti-oxidant, and anti-inflammatory effects. However, there has been no report on the effect of KRG on skin pigmentation. In this study, we investigated the inhibitory effect of KRG on melanocyte proliferation. KRG extract (KRGE) at different concentrations had no effect on melanin synthesis in melan-A melanocytes. Saponin of KRG (SKRG) inhibited melanin content to 80% of the control at 100 ppm. Keratinocyte-derived factors induced by UV-irradiation were reported to stimulate melanogenesis, differentiation, proliferation, and dendrite formation. In this study, treatment of melan-A melanocytes with conditioned media from UV-irradiated SP-1 keratinocytes increased melanocyte proliferation. When UV-irradiated SP-1 keratinocytes were treated with KRGE or SKRG, the increase of melanocyte proliferation by the conditioned media was blocked. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was produced and released from UV-irradiated keratinocytes. This factor has been reported to be involved in regulating the proliferation and differentiation of epidermal melanocytes. In this study, GM-CSF was significantly increased in SP-1 keratinocytes by UVB irradiation (30 mJ/cm2), and the proliferation of melan-A melanocytes increased significantly by GM-CSF treatment. In addition, the proliferative effect of keratinocyte-conditioned media on melan-A melanocytes was blocked by anti-GM-CSF treatment. KRGE or SKRG treatment decreased the expression of GM-CSF in SP-1 keratinocytes induced by UVB irradiation. These results demonstrate that UV irradiation induced GM-CSF expression in keratinocytes and KRGE or SKRG inhibited its expression. Therefore, KRG could be a good candidate for regulating UV-induced melanocyte proliferation. PMID:24235857

  8. Melanocyte expression of Survivin promotes development and metastasis of UV-induced melanoma in HGF-transgenic mice

    PubMed Central

    Thomas, Joshua; Liu, Tong; Cotter, Murray A.; Florell, Scott R.; Robinette, Kyle; Hanks, Adrianne N.; Grossman, Douglas

    2008-01-01

    We previously found the apoptosis inhibitor Survivin to be expressed in melanocytic nevi and melanoma, but not in normal melanocytes. To investigate the role of Survivin in melanoma development and progression, we examined the consequences of forced Survivin expression in melanocytes in vivo. Transgenic (Tg) mouse lines (Dct-Survivin) were generated with melanocyte-specific expression of Survivin, and melanocytes grown from Dct-Survivin mice expressed Survivin. Dct-Survivin melanocytes exhibited decreased susceptibility to UV-induced apoptosis but no difference in proliferative capacity compared to melanocytes derived from non-Tg littermates. Induction of nevi in Dct-Survivin and non-Tg mice by topical application of DMBA did not reveal significant differences in lesion onset (median 10 wks) or density (4 lesions/mouse after 15 wks). Dct-Survivin mice were bred with melanoma-prone MH19/HGF-B6 Tg mice and all progeny expressing either individual, neither, or both (Survivin/HGF) transgenes were UV-treated as neonates and then monitored for 43 wks. Melanocytes in neonatal Survivin+/HGF+ mouse skin were less susceptible to UV-induced apoptosis than those from Survivin−/HGF+ mice. Onset of melanocytic tumors was earlier (median 18 vs. 24 wks, p = .01, log-rank test) and overall tumor density was greater (7.7 vs. 5.2 tumors/mouse, p = .04) in Survivin+/HGF+ compared to Survivin−/HGF+ mice. Strikingly, melanomas arising in Survivin+/HGF+ mice demonstrated a greater tendency for lymph node (35% vs. 0%, p = .04) and lung (53% vs. 22%) metastasis, and lower rates of spontaneous apoptosis, than those in Survivin−/HGF+ mice. These studies demonstrate a role for Survivin in promoting both early and late events of UV-induced melanoma development in vivo. PMID:17545596

  9. Pigmented median raphe cyst of the penis with consideration of the possible mechanism of melanocytic colonization: A case report

    PubMed Central

    ISHIDA, MITSUAKI; IWAI, MUNEO; YOSHIDA, KEIKO; KAGOTANI, AKIKO; OKABE, HIDETOSHI

    2014-01-01

    Median raphe cyst is a rare lesion located on the median raphe. The cyst wall is lined by cuboidal to columnar cells, transitional (urothelial) cells, stratified squamous cells or a mixture of these. The normal urethral mucosa and the median raphe cyst usually lack melanocytes and/or melanin pigment. However, albeit extremely rare, the presence of melanin pigment and/or melanocytes in median raphe cyst, namely pigmented median raphe cyst, has been previously reported. The current case report presents the sixth case of pigmented median raphe cyst and discusses the possible mechanism of melanocytic colonization in this tumor. A 48-year-old male presented with a nodule on the ventral surface of the penis. Histopathological study revealed that the cyst wall was covered by uniform bland cuboidal to urothelial cells. The peculiar observation was the presence of dendritic melanocytes among the epithelial cells. Therefore, a diagnosis of pigmented median raphe cyst was determined. Immunohistochemically, stem cell factor and endothelin-1 were not expressed in the epithelial cells of the cyst wall. It is well-known that melanocytes are rarely found in various non-melanocytic tumors, a phenomenon termed ‘colonization’. The mechanism by which melanocytes appear in median raphe cyst remains unclear. The present report is the first to demonstrate that melanocytic proliferation and differentiation factors, such as stem cell factor and endothelin-1, are not involved in the pigmentation of median raphe cyst. In addition, aberrant melanocytic migration may contribute to the development of this type of lesion. PMID:24396444

  10. Smyth chicken melanocyte autoantibodies: cross-species recognition, in vivo binding, and plasma membrane reactivity of the antiserum.

    PubMed

    Searle, E A; Austin, L M; Boissy, Y L; Zhao, H; Nordlund, J J; Boissy, R E

    1993-06-01

    Smyth line (SL) chickens, which develop a depigmenting disorder similar to human vitiligo, produce circulating anti-melanocyte antibodies (Austin, L.M. et al., (1992) The detection of melanocyte autoantibodies in the Smyth chicken model for vitiligo. Clin. Immunol. Immunopathol., 64:112-120). In order to characterize these autoantibodies, we studied the reactivity of cultured chicken, mouse, and human melanocytes, as well as frozen sections of chicken feather follicles and embryonic eyes, against SL serum, employing indirect immunofluorescence. Light Brown Leghorn (LBL) serum was used as a negative control. Chicken (SL and LBL), mouse, and human melanocytes exhibited greater fluorescence with SL serum than with LBL serum (up to a 1:60,000 dilution). The fluorescent pattern was predominant along the perimeter of the cells, suggesting plasma membrane staining. Fluorescence-activated flow cytometry analysis and immunocytochemical localization at the ultrastructural level using intact chicken cells supported this hypothesis. Melanocytes were readily stained in cryosections of regenerating feather follicles and embryonic eyes incubated with SL, but not LBL, serum. In addition, amelanotic melanocytes in albino chicken feathers reacted with SL serum. SL serum also preferentially stained cells emigrating from cultured avian neural tubes and within the dermis of the proliferative germ of regenerating feather follicles suggesting that melanoblasts express the antigens. We conclude that Smyth line serum contains melanocyte autoantibodies that cross-react with mouse and human melanocytes, are able to bind to pigment cells within tissues, and recognize antigens expressed in the cytoplasm and on the surface of melanocytes and melanoblasts. PMID:8234200