Catecholamine effects on human melanoma cells evoked by α1-adrenoceptors

The biological effects of catecholamines in mammalian pigment cells are poorly understood. Our previous results showed the presence of α1-adrenoceptors in SK-Mel 23 human melanoma cells. The aims of this work were to (1) characterize catecholamine effects on proliferation, tyrosinase activity and expression, (2) identify the α1- adrenoceptor subtypes, and (3) verify whether chronic norepinephrine (NE) treatment modified the types and/or pharmacological characteristics of adrenoceptors present in SK-Mel 23 human melanoma cells. Cells treated with the aradrenergic agonist, phenylephrine (PHE, 10-5 or 10-4 M), for 24-72 h, exhibited decreased cell proliferation and enhanced tyrosinase activity, but unaltered tyrosinase expression as compared with the control. The proliferation and tyrosinase activity responses were inhibited by the α1-adrenergic antagonist prazosin, suggesting they were evoked by α1-adrenoceptors. The presence of actinomycin D, a transcription inhibitor, did not diminish PHE-induced effects. RT-PCR assays, followed by cloning and sequencing, demonstrated the presence of α1A- and α1B-adrenoceptor subtypes. NE-treated cells (24 or 72 h) were used in competition assays, and showed no significant change in the competition curves of α1-adrenoceptors as compared with control curves. Other adrenoceptor subtypes were not identified in these cells, and NE pretreatment did not induce their expression. In conclusion, the activation of SK-Mel 23 human melanoma α1- radrenoceptors elicit biological effects, such as proliferation decrease and tyrosinase activity increase. Desensitization or expression of other adrenoceptor subtypes after chronic NE treatment were not observed.

Melanoma de coróide: Relato de caso insuspeito

The choroidal melanoma is the most frequent intraocular tumor in elderly, occurring mainly in the 60th. This paper shows a misdiagnosis tumor affecting a female aging 36 years-old, misdiagnosed and initially treated as a toxoplasmic uveitis. The tumor had orbit and neck metastasis. The authors call attention to the necessity of early diagnosis to improve the outcome.

Inhibition of eukaryotic translation initiation factor 5A (eIF5A) hypusination impairs melanoma growth

The eukaryotic translation initiation factor 5A (eIF5A) undergoes a specific post-translational modification called hypusination. This modification is required for the functionality of this protein. The compound N1-guanyl-1,7-diaminoheptane (GC7) is a potent and selective inhibitor of deoxyhypusine synthase, which catalyses the first step of eIF5A hypusination process. In the present study, the effects of GC7 on cell death were investigated using two cell lines: melan-a murine melanocytes and Tm5 marine melanoma. In vitro treatment with GC7 increased by 3-fold the number of cells presenting DNA fragmentation in Tm5 cells. Exposure to GC7 also decreased viability to both cell lines. This study also describes, for the first time, the in vivo antitumour effect of GC7, as indicated by impaired melanoma growth in C57BL/6 mice. Copyright © 2006 John Wiley & Sons, Ltd.

A biópsia de linfonodo sentinela não deve ser recomendada para pacientes portadores de melanoma espesso

Objective: To ascertain whether there is any relationship between the state of the sentinel lymph node histopathology, recurrence and mortality from thick melanoma in patients undergoing SLNB over a long follow-up. Methods: Eighty-six patients with thick melanoma undergoing SLNB were selected from a prospective database. Lymphoscintigraphy, lymphatic mapping and intraoperative gamma probe detection were performed in all patients. The sentinel lymph node (SLN) was analyzed by HE and immunohistochemistry. Complete lymphadenectomy was indicated for patients with positive sentinel node. The histopathological SLN status was related to the rate of recurrence and mortality from melanoma. Results: One hundred and sixty-six SLNs were taken from the 86 patients. Ages ranged from 18 to 73 years. There were 47 women and 39 men. Micrometastases were found in 44 patients. Forty-two patients underwent complete lymphadenectomy. Seven other patients had positive lymph node. Among the 44 patients with positive sentinel node, there were 20 recurrences and 15 deaths. There were 18 recurrences and 12 deaths in the group with negative SLN. The Breslow thickness was not correlated with the histopathological SLN status. The histopathological SLN status did not affect the rates of recurrence and mortality (Fisher test, p = 1.00). The median follow-up was 69 months. Conclusion: Considering the lack of evidence of benefit, SLNB should not be indicated for patients with thick melanoma outside of clinical studies.

Tonsilar metastases of melanoma in an older person

We presented a rare case of metastasis of melanoma in palatine tonsils alerting healthcare professionals to this diagnose in black oral lesions. © The Author 2013. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.

Técnicas de imagem para triagem de melanoma

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Fatores de crescimento e citocinas envolvidos na angiogênese de melanoma em animais selecionados pela intensidade da resposta inflamatória aguda

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento de melanoma em animais selecionados pela intensidade de resposta inflamatória aguda (Airmax/Airmin): caracterização das células Natural Killer, NKT, Treg e perfil de citocinas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da própolis sobre a produção de citocinas por camundongos submetidos a estresse crônico e desafiados com melanoma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antiproliferative effect of Pterogyne nitens on melanoma cells

As part of our program of bioprospecting for novel antitumor drug prototypes, twenty extracts and fractions obtained from Pterogyne nitens Tul. (Fabaceae, Caesalpinioideae) were screened for antiproliferative activity against B16F10 murine melanoma cells, by the MTT colorimetric assay. The strongest activity was found in EtOAc fractions from the flowers (IC50 = 0.35 µg/mL), fruits (IC50 = 0.34 µg/mL), leaves (IC50 = 0.33 µg/mL) and stems (IC50 = 0.29 µg/mL). Analysis by TLC and HPLC-DAD showed the presence of guanidine alkaloids, flavones and flavonols in the bioactive samples. Additionally, a phytochemical study of the EtOAc fraction of the stems afforded quercetin (1) and isoquercitrin (2), two flavonols with antiproliferative activity previously described in the literature. On the basis of these results, it can be concluded that P. nitens inhibits the growth of melanoma cells in vitro. Further investigations will be needed to assess the usefulness of the samples under study for the treatment of neoplasms and to characterize other bioactive compounds. Keywords: antiproliferative; Pterogyne nitens; Caesalpinioideae; melanoma; flavonoids; Fabaceae.

Estudo do perfil epidemiológico do melanoma cutâneo na cidade de Jaú-SP através do registro de base populacional

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Metastatic melanoma of the tongue: a case report with immunohistochemical profile

BackgroundMelanoma of the skin is characterised by a high metastatic potential, but reports of metastasis to the tongue are rare. We report a case of skin melanoma with metastasis to the lymph nodes, tongue and brain.ObjectivesThis report highlights the clinical and histological features of oral metastatic melanoma.Case reportA 72-year-old man was seen with a nodule on the tongue. The differential diagnosis included salivary gland tumour, lymphoma and metastatic melanoma. His medical history revealed treatment for melanoma in the periumbilical region and micrometastases in the inguinal lymph nodes. An incisional biopsy was obtained and histological analysis showed the presence of a solid, epithelioid malignant tumour of monotonous appearance infiltrating the skeletal musculature. Immunohistochemistry showed reactivity of neoplastic cells to anti-HMB45, anti-melan A and anti-S100 antibodies and negativity for anti-PAN cytokeratin, confirming the diagnosis of metastatic melanoma.ConclusionThe present findings highlight the importance of a complete medical evaluation of the patient by anamnesis to identify possible oral repercussions of primary diseases in other organs and/or systems.

Pyrostegia venusta heptane extract containing saturated aliphatic hydrocarbons induces apoptosis on B16F10-Nex2 melanoma cells and displays antitumor activity in vivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antitumor Activity of Kielmeyera Coriacea Leaf Constituents in Experimental Melanoma, Tested in Vitro and in Vivo in Syngeneic Mice

Purpose: The antitumor activity of Kielmeyera coriacea (Clusiaceae), a medicinal plant used in the treatment of parasitic, as well as fungal and bacterial infections by the Brazilian Cerrado population, was investigated. Methods: A chloroform extract (CE) of K. coriacea was tested in the murine melanoma cell line (B16F10-Nex2) and a panel of human tumor cell lines. Tumor cell migration was determined by the wound-healing assay and the in vivo antitumor activity of CE was investigated in a melanoma cell metastatic model. 1H NMR and GC/MS were used to determine CE chemical composition. Results: We found that CE exhibited strong cytotoxic activity against murine melanoma cells and a panel of human tumor cell lines in vitro. CE also inhibited growth of B16F10- Nex2 cells at sub lethal concentrations, inducing cell cycle arrest at S phase, and inhibition of tumor cell migration. Most importantly, administration of CE significantly reduced the number of melanoma metastatic nodules in vivo. Chemical analysis of CE indicated the presence of the long chain fatty compounds, 1-eicosanol, 1-docosanol, and 2-nonadecanone as main constituents. Conclusion: These results indicate that K. coriacea is a promising medicinal plant in cancer therapy exhibiting antitumor activity both in vitro and in vivo against different tumor cell lines.

Epitheliotropic cutaneous T-cell lymphoma associated with melanoma in a dog: case report

Several types of tumors affect dogs' skin. Simultaneously occurring neoplasms with different histological patterns might be rarely present in the same animal. This paper describes the occurrence of epitheliotropic cutaneous T-cell lymphoma and melanoma in a dog. The animal had nodular lesions in the abdominal region and serpiginous plaques on the dorsal region of the trunk. Cytology evidenced malignant fusiform cells from the abdominal lesions as well as few round cells from the dorsal. The histopathological examination of the abdominal lesions showed dermis with polygonal to spindle-shaped neoplastic cells. The lesion of the dorsal region evidenced neoplastic round cells with generally distinct cell borders and a moderate amount of eosinophilic cytoplasm. Abdominal lesions were positive for Melan A. Dorsal and forelimb lesions were positive for CD3. This study reports the occurrence of epitheliotropic cutaneous T-cell lymphoma and malignant melanoma in a crossbred Boxer dog and discusses the importance of performing immunohistochemical profile to confirm the phenotype of the tumor.