Literatura académica sobre el tema "Melanoma, TDG"

ZusammenfassungVorgestellt wird ein bislang nicht beschriebener Fall eines malignen Melanoms im Gehirn eines Schafs. Ein wegen Ataxie euthanasiertes, erst 7 Monate altes, weibliches Schaf wurde pathologisch-anatomisch und histopathologisch untersucht. Sowohl das Gehirn als auch das Schädeldach waren von einem malignen Melanom infiltriert. Metastasen fanden sich in Leber und Nieren. Auch histomorphologisch zeigte das Melanom die Charakteristika einer malignen Neoplasie. Die kongenitale Ansammlung von Melanozyten in der Hirnhaut des Schafs (kongenitale Melanose) ist eine regelmäßig beobachtete Pigmentanomalie, die sich im vorliegenden Fall als Ausgangspunkt des Melanoms anbietet. Das geringe Alter des vorgestellten Tieres legt diesen Zusammenhang nahe. In Fällen von diagnostisch unklaren Erkrankungen sollte auch bei landwirtschaftlichen Nutztieren einschließlich des Schafs ein neoplastisches Geschehen differenzialdiagnostisch in Betracht gezogen werden.

ZusammenfassungEine 10-jährige Lamastute wurde mit einer chronisch wuchernden Masse des linken Auges vorgestellt. Das Tier zeigte einen linksseitigen Exophthalmus, die Nickhaut war gerötet. Die Hornhaut war von einer gelblich-rötlichen, undurchsichtigen Gewebsmasse bedeckt und wies ulzerative Veränderungen auf. Die tieferen Strukturen des Auges ließen sich nicht beurteilen. Das rechte Auge stellte sich unauffällig dar. Das linke Auge wurde unter Allgemeinanästhesie entfernt. Die histopathologische Untersuchung des Exstirpats ergab ein okuläres amelanotisches Melanom. Kornea, Sklera, Glaskörper und Linse waren nicht mehr zu identifizieren. Vierzehn Monate später wurde das Lama mit einer Umfangsvermehrung im Bereich der linken Orbita und Blindheit auf dem rechten Auge eingeliefert und aufgrund des schlechten Allgemeinzustands eingeschläfert. Bei der pathologisch-anatomischen und histopathologischen Untersuchung wurde ein Rezidiv des amelanotischen Melanoms mit Metastasierung in die regionären Lymphknoten unter Mitbeteiligung des Nervus opticus festgestellt, was die Blindheit des rechten Auges erklärte.

Objectives Cutaneous melanoma rates are steadily increasing. Up to 20% of patients diagnosed with AJCC Stage I/II melanomas will develop metastatic disease. To date there are no consistently reliable means to accurately identify truly high versus low-risk patient subpopulations. There is hence an urgent need for more accurate prediction of prognosis to determine appropriate clinical management. Validation of a novel prognostic test based on the immunohistochemical expression of two protein biomarkers in the epidermal microenvironment of primary melanomas was undertaken; loss of these biomarkers had previously been shown to be associated with a higher risk of recurrence or metastasis. A parallel qualitative study exploring secondary care health professional and patient views of the test was undertaken and this paper reports the perceived barriers and enablers to its implementation into the melanoma care pathway. Methods Qualitative methods were employed drawing upon the Theoretical Domains Framework (TDF) in the exploration and analysis. An inductive-deductive analysis was performed, with all data coded using a thematic then TDF framework. Findings 20 dermatologists, plastic surgeons, cancer nurse specialists, oncologists and histopathologists participated. Nine TDF domains were relevant to all health professional groups and the ‘Skills’ and ‘Beliefs about Capabilities’ domains were relevant only to histopathologists. ‘Optimism’ and ‘Beliefs about consequences’ were strong enablers particularly for clinicians. ‘Environmental context and resources’ (impact on pathology services) and ‘Knowledge’ (the need for robust evidence about the test reliability) were the main perceived barriers. 19 patients and one carer were interviewed. For the patients eight domains were relevant. (‘Knowledge’, ‘Emotions’, ‘Beliefs about consequences’, ‘Social Role and identity’, ‘Behavioural regulation’, ‘Memory, attention and decision processes’, ‘Reinforcement’ and ‘Skills’). The consequences of the implementation of the test were reassurance about future risk, changes to the follow-up pathway on which there were mixed views, and the need to ensure they maintained self-surveillance (Beliefs about consequences). The test was acceptable to all patient interviewees but the resultant changes to management would need to be supported by mechanisms for fast-track back into the clinic, further information on self-surveillance and clear management plans at the time the result is conveyed (Behavioural regulation). Conclusions Health professionals and patients perceived positive consequences—for patients and for health services—of adopting the test. However, its implementation would require exploration of the resource implications for pathology services, psychological support for patients with a high-risk test result and mechanisms to reassure and support patients should the test lead to reduced frequency or duration of follow-up. Exploring implementation at an early stage with health professionals presented challenges related to the provision of specific details of the test and its validation.

Objective.Determine the frequency of occurrence of tyrosine kinase expression of the mutated ALK and TAG-72 gene among patients with primary melanoma of the skin, to identify their association with a number of histological parameters, and to assess the diagnostic value of the determination of ALK and TAG-72.Materials and methods.Paraffin blocks with surgical material from 40 patients with primary skin melanoma. For routine histological examination, the material was fixed with 10 % neutral formalin for 24 h, poured into paraffin, sections were prepared with a thickness of 4–5 μm, stained with hematoxylin and eosin. IHC study with monoclonal antibodies D57.3 to ALK was performed on an immunostender – Ventana, with antibodies B72.3 to TAG-72 – on Thermo Fischer. As a detection system used: Envision – for TAG-72 and Ventana – for ALK.Results.ALK mutation was detected in 7 (12 %), TAG-72 – 4 (10 %) cases. Evaluation of the correlation force between the presence of ALK and TAG-72 showed a direct average coupling strength (correlation coefficient was 0.31). A direct correlation of the mean force between the presence of TAG-72 oncoprotein, ALK mutation and ulceration in the patient was found – the correlation coefficient was 0.53 and 0.68, respectively. There was a statistically significant association between the presence of ALK and lymphoid infiltration, which in most cases (57 %) was pronounced (p <0.05).Conclusion.Comparing the positive sign of the expression of ALK – 17.5 % and TAG-72 – 10 %, and the positive of their simultaneous detection – 7.5 %, it can be concluded that further studies to determine their diagnostic value are promising. The presence of severe lymphoid infiltration in ALK-positive patients claims a diagnostic value in primary skin melanoma.

AbstractOne of Nick’s key early achievements at QIMR was to establish a twin study on melanoma risk factors. The Brisbane Twin Nevus Study (BTNS) had an initial focus on nevus (mole) count in adolescents but, reflecting Nick’s broad interests, expanded in scope enormously over the decades. In the skin cancer arena, BTNS was essential to genetic discoveries in melanoma, eye color and pigmentation. Later studies amassed data on thousands of phenotypes, ranging from molecular phenotypes such as gene expression to studies where gene mapping findings in adolescents turned out to have translational potential in late-onset diseases. Nick’s twin data have formed the basis for an enormous range of discoveries, with Nick and his colleagues continuing to capitalize on these data.

Melanoma is highly aggressive and is known to be efficient at resisting drug-induced apoptotic signals. Resection is currently the gold standard for melanoma management, but it only offers local control of the early stage of the disease. Metastatic melanoma is prone to recurrence, and has a poor prognosis and treatment response. Thus, the need for advanced theranostic alternatives is evident. Photodynamic therapy has been increasingly studied for melanoma treatment; however, it relies on passive drug accumulation, leading to off-target effects. Nanoparticles enhance drug biodistribution, uptake and intra-tumoural concentration and can be functionalised with monoclonal antibodies that offer selective biorecognition. Antibody–drug conjugates reduce passive drug accumulation and off-target effects. Nonetheless, one limitation of monoclonal antibodies and antibody–drug conjugates is their lack of versatility, given cancer’s heterogeneity. Monoclonal antibodies suffer several additional limitations that make recombinant antibody fragments more desirable. SNAP-tag is a modified version of the human DNA-repair enzyme, O6-alkylguanine-DNA alkyltransferase. It reacts in an autocatalytic and covalent manner with benzylguanine-modified substrates, providing a simple protein labelling system. SNAP-tag can be genetically fused with antibody fragments, creating fusion proteins that can be easily labelled with benzylguanine-modified payloads for site-directed delivery. This review aims to highlight the benefits and limitations of the abovementioned approaches and to outline how their combination could enhance photodynamic therapy for melanoma.

Abstract Suppressor cells of myeloid origin contribute to the immune imbalance observed in advanced melanoma. Toll-Like Receptor (TLR) signaling regulates myeloid differentiation and maturation. This study sought to determine the distribution of myeloid suppressor cell subsets in B16F10 melanoma-bearing mice, and modulate their immunosuppressive phenotype by employing a regimen of intracellular TLR agonist(s). Tolerogenic dendritic cells (tDC) and granulocytic myeloid-derived suppressor cells (gMDSC) are primarily observed in the periphery (spleen, PBMC, draining lymph node) of B16F10-bearing mice whereas M2 macrophages (M2) are noted to be intratumoral. Toll-Like Receptor-expression analysis by quantitative PCR showed TLR9 was ubiquitously expressed on tDC, gMDSC and M2, while TLR3 was restricted to tDC and M2. Myeloid conditioning regimens employing TLR3 and 9 agonists were tested in vitro on bone marrow-derived tDC (CD11c+, MHCII+, IL-10+) and M2 (F4/80+, CD206+, Arg1+). Combinations of TLR3+9 agonists or Type A+B TLR9 agonists decreased IL-10/Arg1 mRNA expression while triggered IL-12 expression. In vivo, subcutaneous injection of type A+B TLR9 agonists reduced circulating tDC and gMDSC prevalence by 67% and 82% respectively, intratumoral M2 dropped by 35%. In conclusion, we demonstrate combining type A+B TLR9 agonists promoted immune potency by reducing prevalence of peripheral tDC and gMDSC, as well as tumoral M2 in vivo, and triggering IL-12 production by tDC and M2 in vitro.

Starting from the experimental observations of Prof. Bellacosa, Prof. Giordano and Prof. Larue research groups, in the following study we have tried to elucidate the relationship between TDG (Thymine-DNA Glycosylase) and melanoma disease. Originally, we detected variable endogenous levels of TDG protein within the human melanoma cell lines banked in our labs and a correlation between TDG and tumorigenicity was tentatively established, since cell lines with low to undetectable levels of TDG are known to be tumorigenic in xenotransplant experiments. Moreover, TDG knock-out mouse embryos showed a dramatic phenotype that affects neural crest cells -that are precursors of melanocytes- (see Supplementary Material) therefore, according to those scientific evidences above mentioned, we initially hypothesized and eventually demonstrated, that modulation of TDG levels may significantly affect the biology of melanoma. Melanoma is an aggressive neoplasm with increasing incidence that is classified by the National Cancer Institute (NCI) as a recalcitrant cancer, i.e., a cancer with poor prognosis, lacking progress in diagnosis and treatment. In addition to conventional therapy, melanoma treatment is currently based on targeting the BRAF/MEK/ERK signaling pathway and immune checkpoints. As drug resistance remains a major obstacle to treatment success, advanced therapeutic approaches based on novel targets are still urgently needed. We reasoned that the base excision repair enzyme TDG could be such a target for its dual role in safeguarding the genome and the epigenome, by performing the last of the multiple steps in DNA demethylation. Here, we show that TDG knockdown in melanoma cell lines causes cell cycle arrest, senescence and death by mitotic alterations, and impairs xenograft tumor formation. Importantly, untransformed melanocytes are not affected by TDG knockdown, and adult mice with conditional knockout of Tdg are viable. Candidate TDG inhibitors, identified through a high-throughput fluorescence-based screen, reduced viability and clonogenic capacity of melanoma cell lines and increased cellular levels of 5-carboxylcytosine, the last intermediate in DNA demethylation, indicating successful on-target activity. These findings suggest that TDG may provide critical functions specific to cancer cells that make it a highly suitable anti-melanoma drug target. By potentially disrupting both DNA repair and the epigenetic state, targeting TDG may therefore represent a completely new approach to melanoma therapy.

Melanoma is one of the most aggressive and inherently resistant cancers and the most dangerous skin cancer. While it accounts for fewer than 5% of skin cancer cases, 80% of skin cancer related deaths are attributed to melanoma. While resection remains the gold standard for melanoma treatment, surgery is only effective in providing local control of the disease if the cancer is detected in the early stages. Once melanoma enters the later stages, and particularly in the metastatic phase, recurrence is probable, and no adequate treatment exists. Previous work in this group has shown that photodynamic therapy (PDT) presents an opportunity to induce cell death in melanoma cells through the production of ROS and singlet oxygen at doses high enough to overwhelm the resistance mechanisms of the cancer. In this study, we investigated the use of recombinant SNAP-tag-based antibody fusion proteins as a means of delivering phototoxic molecules directly to cancer cells expressing the CSPG4 and PD-L1 cell surface receptors. SNAP-tag is an engineered version of the human DNA repair enzyme O6-alkylguanine-DNA alkyltransferase. It reacts autocatalytically and in a strictly 1:1 coupling chemistry with substrates that have been modified with benzylguanine (BG). Through genetic fusion of this self-labelling protein with a tumour targeting antibody, we developed a recombinant immunoconjugate able to carry BG-modified photosensitizers to selectively target and eliminate malignant melanoma cells. Conjugation of the SNAP-tag fusion protein with the fluorescent dye Alex Fluor 488 showed that anti-CSPG4-SNAP binds specifically to melanoma cells expressing the CSPG4 surface antigen. Binding was tested across a range of cell lines presenting melanoma in its radial and vertical growth phases, in the metastatic growth phase, in its chemoresistant form, and in both its pigmented and unpigmented forms. This binding data thus confirms CSPG4 as a suitable targeted for this treatment strategy. Conjugation of the fusion protein with the BGmodified photosensitizer IRDye 700DX (IR700) has produced no phototoxicity as of yet. In light of the convincing binding analysis, it is concluded that inefficient solubilization of the lyophilized product resulted in inadequate conjugation of BG-IR700 with SNAP-tag. Nonetheless, steps have been planned to resolve the problem in future ongoing work on this project, and we remain confident in the applicability of this technology. The results for the PD-L1 fusion protein were inconclusive. In summary, SNAP-tag technology offers a simple and efficient method for immunofluorescent detection of cancerous cells. These fusions proteins are versatile as they 1) can contain any antibody targeting a tumour-associated or tumour-specific antigen of choice and 2) can be endowed with a wide variety of substrates, as long as the latter contains the BG moiety.

O desenvolvimento de novas estratégias terapêuticas ao melanoma é de particular importância devido à sua baixa resposta aos tratamentos tradicionais. No presente trabalho, utilizamos modelo de melanoma murino experimental para estudarmos os efeitos da fosfoetanolamina (PEA) sintética sobre o desenvolvimento deste tumor. Nossos resultados demonstram que o fosfomonoéster apresentou efeito inibidor da proliferação de células da linhagem B16F10 in vitro, induzindo apoptose após estimulação por 24 a 72h. In vivo, o tratamento (via oral) de animais portadores de melanoma com diferentes doses de PEA (10, 20 e 40mg/Kg), durante 10 ou 20 dias consecutivos, resultou em volumes tumorais pelo menos 70% menores que o de animais controle e diferenças macroscópicas consideráveis. PEA induziu, de maneira dose-dependente, aumento da apoptose e diminuição da proliferação de células tumorais. O tratamento resultou em alterações hematológicas como aumento do número de plaquetas, eritrócitos e leucócitos. Dentre os leucócitos, observou-se uma maior proporção de linfócitos e monócitos após 10 e 20 dias de tratamento, respectivamente. Em adição, PEA induziu uma maior produção da citocina pró-inflamatória IL-6 e das citocinas anti-inflamatórias IL-10 e TGF- e menores níveis da citocina pró-inflamatória IFN-. Os níveis de IL-1, IL-12p70 e IL-17 não foram alterados com o tratamento. Nossos resultados demonstram um papel inibidor da PEA sobre a progressão do melanoma, contribuindo para um melhor entendimento de sua atividade anti-tumoral.
The low responsiveness of melanoma to traditional treatments together with its increasing incidence makes the development of new therapeutic strategies against this type of cancer extremely important. In this study, we used a murine melanoma model to evaluate the effects of synthetic phosphoethanolamine (PEA) on the development of this tumor. In vitro, PEA had an inhibitory effect on the proliferation of B16F10 cells, inducing apoptosis after 24 to 72h stimulation. In vivo, oral treatment of melanoma-bearing animals with different doses of PEA (10, 20 e 40mg/Kg) during 10 or 20 consecutive days resulted in reduced tumor volumes (at least 70% compared to the control) and in expressive macroscopic differences. PEA also induced a dose-dependent increase of apoptosis and decrease in tumor cell proliferation. The treatment also resulted in hematological changes, such as increased numbers of platelets, erythrocytes and leukocytes. Among leukocytes, we observed a higher proportion of lymphocytes and monocytes after 10 and 20 days of treatment, respectively. In addition, PEA induced higher levels of the pro-inflammatory cytokine IL-6 and of the anti-inflammatory cytokines IL-10 and TGF-, and it also induced a lower production of the pro-inflammatory cytokine IFN-. No differences were observed in the levels of IL-1, TNF-, IL-12p70 and IL-17 upon treatment. Our results demonstrate an inhibitory role of PEA in the development of melanoma, contributing to a better understanding of its antitumoral activity.

INTRODUÇÃO: O melanoma cutâneo constitui cerca de 3% de todos os tumores da pele. Atinge indivíduos jovens com média de idade de aparecimento entre 50 e 58 anos. Em torno de 20% dos doentes apresentarão doença avançada e morrerão antes de completar cinco anos de sobrevida. CASUÍSTICA E MÉTODOS: Neste estudo retrospectivo de 364 casos acompanhados de maio de 1993 a janeiro de 2006 descreveram-se as variáveis: sexo, idade, cor, localização da lesão primária, tipo de crescimento, espessura de Breslow, nível de Clark, presença de ulceração, estadiamento e suas correlações. RESULTADOS: Predominou o sexo feminino (58,8%) resultando em uma proporção de 1,4 mulheres para cada homem. A média das idades dos pacientes foi de 58,9 anos e a mediana de 61,0 anos. Pacientes não-brancos constituíram 13,7% da amostra. Para homens e mulheres o melanoma cutâneo localizou-se, predominantemente no tronco (24,3-38,0%) e pés (21,4-23,9%). O melanoma acrolentiginoso representou 22,3% de toda amostra. Os padrões melanoma expansivo superficial e melanoma nodular (p < 0,001) e lesões no tronco (52,8%) predominaram nos indivíduos brancos. O melanoma acrolentiginoso (64%) e a localização nos pés (68,2%)prevaleceram nos pacientes não-brancos. Observou-se minoria de casos com lesão primária in situ (14,6%- EC 0) e alto percentual de melanoma cutâneo espesso (39,7% > 4,0 mm). Presença de ulceração foi observada em 13,4% para tumores finos (= 1,0 mm). Homens apresentaram lesões mais espessas (p = 0,011) e ulceradas (p < 0,001) em relação às mulheres, assim como idosos em relação à não idosos (p = 0,021 para a espessura e p = 0,015 para ulceração). A sobrevida média para os pacientes com doença localizada foi de 97,8 meses e a taxa de sobrevida específica para melanoma cutâneo foi de 85,1% em três anos. CONCLUSÕES: Esta amostra constituiu-se de pacientes com tumores espessos e ulcerados denotando diagnóstico tardio do melanoma cutâneo e pior prognóstico. Caracterizou-se por apresentar predomínio de mulheres, de pacientes não-brancos, de lesões nas extremidades e de melanoma acrolentiginoso.
INTRODUCTION: Cutaneous melanoma represents around 3% of all skin tumors. Affecting young patients, with mean age between 50 and 58 years old. About 20% of the patients will have advanced disease and will die before five years of survival. CASUISTIC AND METHODS: In this retrospective study of 364 cases recorded from May 1993 to January 2006 at the Melanoma Unit of Santa Casa de São Paulo the following variables were described: sex, age, skin color, tumor site, growth pattern, tumor thickness, Clark level, ulceration, staging and their correlations. RESULTS: Female (58,8%) prevailed resulting in 1,4 women for each man. The mean age of the patients was 58,9 years old and the median, 61,0 years old. Non-white patients were 13,7% of the sample. The anatomic site of cutaneous melanoma on men and women prevailed at trunk (24,3 – 38,0%) and feet (21,4 – 23,9%). Acral entiginous melanoma represented 22,3% of the cohort. Superficial expansive melanoma and nodular melanoma patterns (p<0,001) and trunk lesions (52,8%) predominated on white patients. Acral lentiginous melanoma (64%) and feet anatomic site 68,2%) prevailed on non-white patients. In situ primary lesions were observed in few cases (14,6% - EC 0) and there was high percentage of thick cutaneous melanoma (39,7% > 4,0 mm). In thin tumors (=1,0 mm) were found 13,4% of ulceration. Thickener (p = 0,011) and ulcerated lesions (p < 0,001) were found more in male and in elderly patients (p = 0,021 for thickeness and p = 0,015 for ulceration). The mean survival of patients with local disease was 97,8 months and the three-year survival rate for cutaneous melanoma was 85,1%. CONCLUSIONS: The cohort consisted mostly of thick and ulcerated tumors, which meant late diagnosis and bad prognosis. Also distinguished by considerable prevalence of female, non-white patients, limb lesions and acral lentiginous melanoma.

Os tumores de origem melanocítica representam as mais frequentes neoplasias intra-oculares diagnosticadas nos cães. O presente trabalho teve por objetivo realizar estudo retrospectivo das neoplasias melanocíticas da úvea do cão analisando suas características morfológicas e epidemiológicas. Foi estudado um total de 29 casos; destas, 51,7 % foram diagnosticadas como melanocitoma, enquanto que 48,3 % como melanoma. As raças mais acometidas foram SRD (sem raça definida), Cocker Spaniel Inglês e Labrador Retriver, porém não houve predominância racial significativa. A faixa etária foi de 6 a 15 anos, com média de 10,3 anos. Os tumores acometeram igualmente machos e fêmeas. A úvea anterior foi a localização mais comum, representando 96,5 % de todos os tumores, enquanto a úvea posterior representou 3,5 %, sendo o último, um melanoma. Em 5 casos, o tumor ocupava todo espaço intra-ocular, sendo todos melanomas. Os melanocitomas apresentaram predominância de células grandes, redondas ou poliédricas, densamente pigmentadas e núcleo pequeno. Os melanomas apresentaram 2 padrões celulares distintos. Dos 14 melanomas, 8 (57,2 %) eram compostos por células epitelióides, 2 (14,3 %) por células fusiformes, e 4 (28,5%) apresentaram padrão misto. Em 7 melanomas observou-se áreas de melanocitoma, sugerindo transformação maligna.
Melanocytic tumors are the most common intraocular neoplasia in dogs. The aim of the present work was to perform a retrospective study of the canine uveal melanocytic neoplasias analyzing the morphologic and epidemiologic features. It was 29 cases in total; 51,7 % was diagnosed as melanocitoma, while 48,3 % was diagnosed as melanoma. The most common breed was mixed breed dogs, English Cocker Spaniel and Labrador, but there was no significant racial predominance. The age range was 6 to 15 years old, with mean of 10,3 years old. The tumors affected equally males and females. The anterior uvea was the most common site, representing 95,5 % of all tumors and the posterior uvea represented 3,5 %, the latter, was a melanoma. In five cases (17,2%), the tumor occupied the entire intraocular space, all of them melanomas. The melanocitomas presented predominance of round or poliedric, plump cells, densely pigmented with small nucleus. The melanomas presented two distinct patterns. Of the 14 melanomas, eight (57,2 %) was composed of epithelioid cells, two (14,3 %) of spindle cells, and four (28,5 %) presented mixed pattern. There were 7 melanomas that presented melanocitoma areas, suggesting malignant transformation.

Os melanomas possuem diferentes comportamentos entre as espécies, sendo de grande importância a caracterização do mecanismo molecular que influencia tal diversidade comportamental. Objetivou-se neste estudo avaliar as características moleculares das neoplasias melanocíticas uveais em cães, a fim de compreender as diferenças entre o melanoma uveal humano e o canino. Foram utilizados 64 olhos de 64 cães com diagnóstico de neoplasia intraocular primária de origem melanocítica. Com base nos critérios histopatológicos estabelecidos foram diagnosticados 37 melanocitomas e 27 melanomas. Não houve predominância sexual e cães sem raça definida, Labrador Retriever e Cocker Spaniel Inglês foram os mais acometidos. Foram analisadas características morfológicas, taxa de mitose, grau de pigmentação, presença de extensão extraocular, localização, infiltrado inflamatório, loop vascular e necrose. Foi realizada análise imunoistoquímica avaliando os marcadores Melan-A, HMB-45, Ki-67 e COX-2. O Melan-A mostrou ser mais sensível, sendo expresso em 53,1% dos casos, enquanto o HMB-45 foi positivo em apenas 31,2% dos casos. O Melan-A e o HMB-45 foram menos frequentes nos melanocitomas comparado com os melanomas. Em 23 casos, nenhum dos dois marcadores reagiu. Os resultados do marcador de proliferação Ki-67 revelaram maior positividade entre os melanomas, com média do índice Ki-67 de 37,8%, enquanto a média dos melanocitomas foi de 15%. Não houve diferença estatística da marcação do Ki-67 com os tipos celulares dentre os melanomas. A COX-2 reagiu positivamente na maioria dos casos e não foi observada diferença estatística entre melanocitomas e melanomas. Dentre os melanomas não houve diferença estatística entre os tipos celulares para a marcação da COX-2. Os achados aqui discutidos revelam interessantes diferenças e similaridades entre as neoplasias melanocíticas uveais no homem e no cão
Melanomas have different behavior between species and is of great importance to characterize the molecular mechanism influencing this behavioral diversity. The objective of this study was to evaluate the molecular characteristics of uveal melanocytic neoplasias in dogs, in order to understand the differences between uveal melanoma in humans and dogs. Sixty-four eyes of 64 dogs diagnosed with primary intraocular neoplasia of melanocytic origin were studied. Based on the established histopathological criteria 37 melanocytomas and 27 melanomas were diagnosed. There was no sexual predominance and mixed breed dogs, Labrador Retriever and English Cocker Spaniel were the most affected. Morphological features, mitotic rate, degree of pigmentation, presence of extraocular extension, location, inflammatory infiltrate, vascular loop and necrosis were analyzed. Immunohistochemical analysis was performed to evaluate markers such as Melan-A, HMB-45, Ki-67 and COX-2. The Melan-A was more sensitive and expressed in 53.1% of cases, while the HMB-45 was positive in only 31.2%. The Melan-A, and HMB-45 were less frequent in melanocytomas compared to melanomas. In 23 cases, neither markers reacted. The results of the Ki-67 showed higher positivity among melanomas, mean Ki-67 index of 37.8%, while melanocytomas showed mean of 15%. There was no statistical difference in the Ki-67 labeling among melanoma's cell types. COX-2 reacted positively in most cases and found no statistically significant difference between melanocytomas and melanomas. Among the melanomas, there was no statistical difference between the cell types for COX-2. The findings discussed here reveal interesting differences and similarities between the uveal melanocytic neoplasms in humans and dogs

O melanoma é composto por células malignas e também por um estroma de sustentação que inclui fibroblastos, células imunológicas, endoteliais, matriz extracelular, dentre outros fatores. Assim, os tumores não são entidades independentes, eles interagem ativamente com o microambiente adjacente de forma bidirecional através de sinais moleculares que modulam o fenótipo maligno. Um dos sinais bioquímicos para desenvolvimento desse fenótipo se dá pelo catabolismo de Trp pela via das quinureninas, que gera compostos com diversas atividades biológicas, que no tumor estão envolvidas com tolerância e imunoescape e, logo, com prognóstico ruim para os pacientes. Até o presente momento apenas o consumo de Trp e a formação de um único metabólito, a quinurenina (KYN), tem sido associada a malignidade dos melanomas. A fim de ampliar e elucidar os mecanismos bioquímicos do metabolismo desse aminoácido em melanomas, estudamos mais de quinze compostos de todas as rotas catabólicas de Trp em células da pele, células imunológicas, linhagens tumorais e amostras clínicas de melanoma. De forma inédita pudemos observar que as células da pele tem maior habilidade de sintetizar KYN quando comparadas às linhagens tumorais, demonstrando que o catabolismo de Trp peritumoral pode ser responsável pelos fenômenos de imunotolerância e escape. Além disso, o metabolismo de Trp pode estar envolvido nos mecanismos de homeostasia da pele, já que especificamente essas células produzem compostos com atividade biológica nesse órgão. As células imunológicas possuem um perfil metabólico completamente diferente umas das outras: monócitos, macrófagos e dendríticas possuem maior ativação da via KYN enquanto linfócitos e neutrófilos possuem maior indução da rota que gera serotonina e melatonina. Mesmo nos diferentes fenótipos de macrófagos, M1 e M2a, foram observadas marcações especificas de metabolismo, que podem estar relacionadas às atividades anti- ou pró-tumoral dessas células no microambiente. Em amostras clínicas, apesar da principal diferença entre nevos e melanomas ser a concentração de KYN, diversas outras alterações no metabolismo de tiptofano foram observadas, o que mostra a complexa magnitude deste metabolismo na fisiopatologia da pele
Melanoma is composed of malignant cells and also by a stromal support that includes fibroblasts, immune cells, endothelial cells, extracellular matrix, among other factors. Thus, tumors are not separate entities; they actively interact with the surrounding microenvironment bi-directionally through molecular signals that modulate the malignant phenotype. One of biochemical signals for the development of this phenotype occurs by Trp catabolism through kynurenine pathway, that generates compounds with diverse biological activities, which in tumors are involved with tolerance and imunoescape and therefore with poor prognosis for patients. To date only the consumption of Trp and formation of a single metabolite, kynurenine (KYN), has been associated with malignant melanomas. In order to enlarge and clarify the biochemical mechanisms of this amino acid metabolism in melanomas, we have studied more than fifteen compounds of all catabolic routes of Trp in skin cells, immune cells, tumor cell lines and clinical samples of melanoma. In an unique way we could observe that the skin cells has superior ability to synthesize KYN when compared to tumor cell lines, demonstrating that the peritumoral catabolism of Trp may be responsible for the phenomena of immune tolerance and escape. Furthermore, the Trp metabolism may be involved in skin homeostasis mechanisms, since these cells produce specific compounds with biological activity in this organ. The immune cells have a completely different metabolic profile among them: monocytes, macrophages and dendritic cells have greater KYN pathway activation, and lymphocytes and neutrophils possess greater induction of the route that generates serotonin and melatonin. Even in different macrophages phenotypes, M1 and M2a, we observed specific metabolic marks, which may be related to the anti- or pro-tumoral activity of these cells in the tumor microenvironment. In clinical samples, although the main difference between nevi and melanomas is the concentration of KYN, a range of other changes in Trp metabolism were observed, which shows the complex magnitude of this metabolism in the skin pathophysiology

Os objetivos deste trabalho foram os de avaliar a eficácia da cimetidina como única forma de tratamento para reduzir o tamanho de melanomas localizados em região ventral de cauda e períneo em equinos tordilhos, determinar a eficácia da droga no controle do aparecimento de novas formações nas mesmas regiões e avaliar a duração do tratamento com cimetidina após a sua suspensão com relação à manutenção da redução de tamanho e do aparecimento de novas formações. Para o desenvolvimento do trabalho foram utilizados 32 equinos tordilhos, sem restrições de raça ou sexo, com idade entre sete e 30 anos, com melanomas em região de cauda e períneo de até 5,0 cm de diâmetro e sem histórico anterior de tratamento com cimetidina ou procedimento cirúrgico para esta finalidade. Os animais foram divididos em dois grupos: 21 animais no grupo tratamento que receberam 18 mg/kg de cimetidina por via oral, BID durante noventa dias e 11 animais no grupo controle, que não receberam nenhuma medicação ou placebo. Os equinos foram avaliados quinzenalmente durante o período de tratamento e monitorados mensalmente durante 150 dias após o término da administração da droga. A cimetidina, na dose de 18 mg/kg VO BID, apresenta ação sobre os melanomas em equinos tordilhos, mas sua ação mostrou-se bastante variável e individual, além de não apresentar efetividade na manutenção da redução do volume após o término do tratamento.
The purpose of this study was to evaluate the efficacy of cimetidine as treatment for melanoma present in the perineal area and ventral tail of Grey horses. Reduction in tumor volume and the capability of the drug to control the appearance of new nodules were evaluated. Thirty two grey horses with ages ranging between sete and 30 years and no predilection of breed or gender were used in this study. All the animals selected had no attempted treatment prior to this study. The animals were divided in two groups: the treatment group, consisting of 21 horses and the control group consisting of 11 animals. Cimetidine was administered at a dosage of 18 mg/kg orally twice a day for a total of ninety days. During the lenght of treatment, the group was evaluated every two weeks, and all the animals were monitored once a month for another 150 days after the end of therapy. The efficacy of the treatment with cimetidine was observed in 11 animals of the treatment group which showed size reduction of the masses during the drug administration period followed by a slight increase and stabilization at lower volumes than the initial measures. In addition, the animals that responded to the treatment presented a very variable and individual response.

Melanoma is a pigmented tumor that originates from the melanocytes; pigmented cells present throughout the body, including skin and iris. The cutaneous form is the most common type, and it represents about 5% of the skin tumors diagnosed in Brazil. Although it does not have a high incidence, it represents about 80% to 85% of all skin tumor deaths. The second most frequent type of melanoma is ocular. It represents 5% of all melanoma cases and is a potentially lethal disease, especially when it causes metastasis. The main therapeutic approach for melanomas, in general, is surgery, with resection of the cutaneous lesion or enucleation in the case of ocular melanoma. Other techniques such as adjuvant immunotherapy, palliative chemotherapy, and radiotherapy are also used. However, they have low efficacy and several side effects. Photodynamic therapy is a therapeutic modality based on the interaction of light at specific wavelength and photosensitizer, in the presence of molecular oxygen, leading the cell to death. As melanoma is a pigmented cancer, it usually does not respond well to photodynamic therapy due to the high absorption of light on the surface of the tumor, making volumetric eradication impossible. This project investigated optical strategies for the diagnosis and treatment of melanoma. For the diagnosis, it was evaluated the fluorescence lifetime technique to differentiate melanoma and normal skin. A sensitivity of 99.4%, specificity of 97.4% and accuracy of 98.4% were achieved using linear discrimination analysis. For the cutaneous melanoma treatment, PDT combined to optical clearing agents (OCAs) was investigated. Vascular and cell-target photosensitizers were evaluated combined or not to OCAs. OCA improved PDT response in all pigmented tumors treated, but the best results were achieved when a dual-photosensitizer treatment combined to OCA was performed. The treatment of conjunctival melanoma was conducted using 2-photon excitation photodynamic therapy. The advantage of this technique is the use of infrared light, in a wavelength that melanin has a low absorption, improving the light penetration into the tumor. The tumor histology shows that apoptosis was induced only at the treatment site, with no damage to the surrounding tissue. Additionally, a single TPE-PDT session could treat the entire tumor.
O melanoma é um tumor pigmentado que surge dos melanócitos, células pigmentadas presentes em todo o corpo, incluindo a pele e a íris. A forma cutânea é a mais comum e representa cerca de 5% dos tumores cutâneos diagnosticados no Brasil. Embora não tenha uma alta incidência, representa cerca de 80% a 85% de todas as mortes por tumor de pele. O segundo tipo de melanoma mais frequente é o ocular. Representa 5% de todos os casos de melanoma e é uma doença potencialmente letal, especialmente em casos de metástase. A principal abordagem terapêutica para melanomas, em geral, é a cirurgia, com ressecção da lesão cutânea ou enucleação no caso do melanoma ocular. Outras técnicas, como imunoterapia adjuvante, quimioterapia paliativa e radioterapia também são usadas, porém, apresentam baixa eficiência e muitos efeitos colaterais. A terapia fotodinâmica é uma modalidade terapêutica baseada na interação da luz em um comprimento de onda específico e um fotossensibilizador, na presença de oxigênio molecular, levando a célula à morte. Como o melanoma é um câncer pigmentado, geralmente não responde bem à terapia fotodinâmica devido à alta absorção de luz na superfície do tumor, impossibilitando a erradicação volumétrica. Este projeto investigou estratégias ópticas para o diagnóstico e tratamento do melanoma. Para o diagnóstico, foi avaliada a técnica de tempo de vida de fluorescência para distinguir melanoma de pele normal. Utilizando análise de discriminação linear, obteve-se uma sensibilidade de 99,4%, especificidade de 97,4% e precisão de 98,4%. Para o tratamento de melanoma cutâneo, a PDT combinada com clareadores ópticos (OCAs) foi investigada. Um fotossensibilizador que tem como alvo vaso sanguíneo e um fotossensibilizador de alvo celular foram avaliados combinados ou não com OCAs. OCAs são soluções hiperosmóticas que desidratam o tecido, diminuindo o espalhamento da luz e melhorando a penetração de luz em profundidade. OCA melhorou a resposta de PDT em todos os tumores melanóticos tratados, mas os melhores resultados foram obtidos quando a PDT foi realizada com a combinação dos fotossensibilizadores e clareador óptico em uma única sessão. O tratamento do melanoma conjuntival foi realizado utilizando a terapia fotodinâmica por excitação de 2 fótons (TPE-PDT). A vantagem desta técnica é o uso de luz na região do infravermelho, em um comprimento de onda que melanina tem baixa absorção, melhorando a penetração de luz no tumor. A histologia do tumor mostrou que a apoptose foi induzida apenas no local do tratamento, sem danos no tecido adjacente. Além disso, uma única sessão de TPE-PDT foi capaz de tratar todo o tumor.

Este trabalho teve por objetivo avaliar os efeitos do hipotireoidismo experimental induzido mediante utilização da droga propiltiouracil ou por tireoidectomia actínica, utilizando-se Iodo131, sobre o crescimento tumoral local e potencial metastático do melanoma murino, cepa B16F10 em camundongos C57BL6. O trabalho constituiu-se de dois experimentos distintos: 1. Influência do hipotireoidismo sobre o crescimento local e sobrevida, mediante indução do hipotireoidismo com propiltiouracil (PTU) a 0,05% na água de bebida e inoculação de células B16F10 por via subcutânea. 2. Influência do hipotireoidismo sobre o potencial metastático, onde os animais foram submetidos aos seguintes tratamentos: água (CTRL_M); indução do hipotireoidismo com propiltiouracil a 0,05% na água de bebida (PTU_M); indução do hipotireoidismo com iodo131 (I131_M) e do hipertireoidismo com L-tiroxina a 0,00005% na água de bebida (T4_M) e posterior inoculação de células B16F10, por via intravenosa. No experimento 1, os parâmetros avaliados consistiram na medida do volume tumoral e taxa de sobrevida. Os volumes tumorais variaram de 1,8 mm³ a 10.673,1 mm³. Na média diária dos volumes tumorais, o menor valor foi de 1,6 mm³ enquanto o maior volume obtido foi de 8140,9 mm³. A análise estatística das médias dos volumes, mediante teste de T não pareado, não indicou diferença significativa entre os grupos CTRL_L (controle) e PTU_L (tratado), com p = 0,795 para o teste de T e p = 0,5759 para o teste de F, para um intervalo de confiança de 95%. A média da sobrevida foi de 22 dias para o grupo CTRL_L e 21 dias para o grupo PTU_L. A analise estatística dos dados de sobrevida seguiu o Teste de Mantel-Haensze, não havendo diferença significativa na evolução da sobrevida entre os grupos, com p = 0,752 para um intervalo de confiança de 95%. No experimento 2, o parâmetro avaliado consistiu no número de nódulos metastáticos mediante contagem dos nódulos na superfície dos pulmões dos animais, após eutanásia. A distribuição de nódulos tumorais pulmonares apresentou média de 32 nódulos para o grupo CTRL_M; 91 nódulos para o grupo PTU_M; 23 nódulos para o grupo T4_M e 77 nódulos para o grupo I131_M. Houve diferença estatisticamente significativa (p < 0,01) entre os grupos CTRL_M versus PTU_M e I131_M e entre os grupos T4_M versus PTU_M e I131_M. Não houve diferença significativa (p > 0,05) entre os grupos CTRL_M versus T4_M e entre os grupos PTU_M versus I131_M. Os estudos estatísticos foram realizados mediante Teste de Analise de Variância simples (ANOVA) e aplicação de pós-teste de Dunnett, de múltipla comparação. Concluiu-se que o hipotireoidismo não interferiu no crescimento local da cepa B16F10 do melanoma murino em camundongos C57BL6 e significativamente alterou o comportamento metastático da referida cepa nesta linhagem isogênica, favorecendo a formação de nódulos metastáticos nos animais em que este estado patológico foi induzido, quer pela utilização de droga antitireoidiana PTU, quer pela tireoidectomia actínica com I131, no entanto, a administração de L-tiroxina não acarretou o efeito contrário
The aim of this study was to evaluate the effects of hypothyroidism induced by propylthiouracil or by actinic thyroidectomy, using I131, on focal and methastatic tumor growth of murine melanoma, B16F10, in mice C57BL6. The study was consisted of two different assays: 1. the influence of hypothyroidism on the focal growth and survival rate, by hypothyroidism induction with propylthiouracil (PTU) 0.05% in drinking water and subcutaneous inoculation of B16F10 and 2. the influence of hypothyroidism on the methastatic potential, were the animals underwent the followed treatments: drinking water (CTRL_L), hypothyroidism induction by propylthiouracil on 0.05% in drinking water (PTU_M group), hypothyroidism induction by I131 (I131_M group) and hypothyroidism induction by L-tiroxine on 0.00005% in drinking water (T4_M group). B16F10 cells were intravenously inoculated in all groups. On the first assay, the tumor volume was measured and the survival rate was evaluated. The tumor volumes ranged from 1.8 mm³ to 10673.1 mm³. Regarding the daily mean of tumor volumes, the lowest volume was 1.6 mm³ while the highest one was 8140.9 mm³. A statistical analysis of the tumor volumes was performed using unpaired T test and it showed no significant difference between group CTRL_L (control) and group PTU_L (treated one) (with p=0.795 on T test and p= 0.5759 on F test, using a confidence interval of 95%). The survival rate mean was 22 days on group CTRL_L and 21 days on group PTU_L. The Mantel-Haenszel (logrank) test was used for statistical analysis of these data, and there was no significant difference on the survival rate between groups CTRL_L and PTU_L (with p=0.752 and confidence interval of 95%). On the second assay, the number of methastatic nodules on the lung surface after euthanasia was evaluated. Regarding the lung nodules distribution, 32 nodules were found on group CTRL_M, 91 nodules were found on group CTRL_M, 23 on group T4_M and 77 on group I131_M. There was a statistically significant difference (p<0.01) between groups CTRL_M and PTU_M / I131_M and between groups T4_M and PTU_M / I131_M. No significant difference was observed (p>0.05) between groups CTRL_M and T4_M and between groups PTU_M and I131_M. ANOVA test was used for statistical analysis, followed by multiple comparison Dunnett?s post test. It was concluded that hypothyroidism did not have any influence on the focal growth of the murine melanoma B16F10 in mice C57BL6 and significantly did alter the methastatic behavior of that clone in this isogenic lineage, enhancing the methastatic nodules formation in the animals who were induced to this pathological condition, either by PTU or by actinic thyroidectomy, using I131; however, the administration of L-tiroxine did not show the opposite effect

Melanoma is the most deadly form of cancer which is easily curable if detected at the earlier stage. The main objective of this paper is to classify the Melanoma and Non-melanoma using dermoscopy images from the Med Node Dataset. The images are enhanced by bottomhat filter, and then segmentation is done by two methods 1. Morphological Operations, 2. Otsu Thresholding. The features extracted from the segmented lesions are ABCD features, Statistical features and is given to the classifier. The classification is done by Machine Learning Algorithms (FFNN, SVM, KNN). The performance is analysed by the sensitivity, specificity, accuracy, Positive predictive value, negative predictive value and manually by Total Dermatoscopy Score (TDS) for 9 different classification cases. The best among the cases is 96.7% accuracy is for FFNN algorithm.