Orientador: Fabio Ramoa Pires / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-08T12:19:16Z (GMT). No. of bitstreams: 1 Azevedo_RebecadeSouza_M.pdf: 4868074 bytes, checksum: 58d90f52fd964c01b78efa26a4a55ae8 (MD5) Previous issue date: 2007 / Resumo: O carcinoma mucoepidermóide (CME) é a neoplasia maligna de glândulas salivares mais comum, apresentando grande diversidade de tipos celulares e histogênese incerta e controversa. O objetivo deste trabalho foi avaliar a expressão imunohistoquímica de citoqueratinas (CKs) de epitélios simples (CKs 7, 8, 18 e 19) e de epitélios complexos (CKs 6, 13 e 14) e de um marcador de diferenciação mioepitelial (actina de músculo liso - AML) em CMEs de glândulas salivares maiores e menores nas diferentes gradações histológicas, na tentativa de estabelecer correlação entre a imunopositividade das células tumorais e o processo de diferenciação e histogênese. Foram selecionados 80 casos de CMEs de glândulas salivares do Departamento de Cirurgia de Cabeça e Pescoço e Otorrinolaringologia do Hospital do Câncer/A.C. Camargo, São Paulo, entre 1957 e 1997. Os locais mais acometidos foram parótida (47,5%) e palato (26,3%). Do total, 45% dos casos foram classificados como de alto grau, 44% de baixo grau, e somente 11% de grau intermediário de malignidade. Células escamosas estavam presentes em 98% dos casos, intermediárias em 71%, mucosas em 54%, claras em 30%, colunares em 29% e oncocíticas em 3%. O padrão de crescimento neoplásico mostrou proporção similar entre os arranjos sólido (89%) e cístico/ductal (81%). A expressão das CKs variou de acordo com o tipo celular: células escamosas apresentaram alta expressão de CKs 6, 7, 8, 14, 18 e 19; células intermediárias de CKs 6, 7 e 8; células mucosas somente de CK7; células claras de CKs 6, 7 e 8; e células colunares de CKs 6, 7, 8 e 18. A CK13 mostrou expressão reduzida em todos os tipos celulares. Diferenciação mioepitelial, embora infreqüente, foi mais observada nas células escamosas e intermediárias. Nas glândulas salivares normais adjacentes, ácinos serosos e mucosos apresentaram alta expressão imunohistoquímica de CK18; ductos intercalados de CKs 6, 7, 18 e 19; ductos estriados de CKs 6, 7, 8, 13, 18 e 19; células ductais excretoras de CKs 6, 7, 8, 18 e 19; células basais excretoras de CK14; e células mioepiteliais de AML e CK14. A grande variedade de tipos celulares associada à expressão imunohistoquímica de diferentes CKs e em menor proporção de AML, similar aos ductos excretores, reforça o conceito de origem do CME a partir de células indiferenciadas pluripotentes localizadas nos ductos excretores das glândulas salivares normais / Abstract: Mucoepidermoid carcinoma (MEC) is the most common malignat salivary gland tumor, composed of several different cell types, with unsettled and controversial histogenesis. The purpose of this study was to analyze the immunohistochemical expression of cytokeratins (CKs) of simple epithelia (7, 8, 18 and 19) and stratified epithelia (6, 13 and 14) and a myoepithelial marker (smooth muscle actin - SMA) â?¿in MECs from major and minor salivary glands in their different histological grading, in order to establish a correlation between tumor cells immunostain and MEC histogenesis and differentiation. Eighty cases of salivary gland MECs retrieved from the Department of Head and Neck Surgery and Otorhinolaryngology/A.C. Camargo Cancer Hospital, São Paulo, Brazil, from 1957 to 1997, were selected. The most common sites were parotid (47,5%) and palate (26,3%). From the total, 45% of the cases were classified as high grade, 44% as low grade, and only 11% as intermediate grade. Squamous cells were present in 98% of the cases, intermediate cells in 71%, mucous cells in 54%, clear cells in 30%, columnar cells in 29% and oncocytic cells in 3%. Tumor organization showed similar amount of solid nests (89%) and cystic structures or duct-like elements (81%). Cytokeratin expression was variable according to the cellular type: squamous cells presented high expression of CKs 6, 7, 8, 14, 18 and 19; intermediate cells of CKs 6, 7 and 8; mucous cells only of CK7; clear cells of CKs 6, 7 and 8; and columnar cells of CKs 6, 7, 8 and 18. CK13 was infrequently expressed in all cell types. Myoepithelial expression, albeit uncommon, was more frequently observed in squamous and intermediate cells. In normal salivary gland tissue found adjacent to the tumors, serous and mucous acini showed high immunohistochemical expression of CK18; intercalated ducts of CKs 6, 7, 18 and 19; striated ducts of CKs 6, 7, 8, 13, 18 and 19; ductal cells of excretory ducts of CKs 6, 7, 8, 18 and 19; basal cells of excretory ducts of CK14; and myoepithelial cells of SMA and CK14. The diversity of cellular types associated to the immunohistochemical expression of different CKs and, in less amount of SMA, similarly to excretory ducts reinforces the concept of MEC origin from pluripotential cells localized at the excretory ducts of normal salivary glands / Mestrado / Estomatologia / Mestre em Estomatopatologia

The objective of this study was to retrospectively evaluate the prevalence of perineural invasion in cases of mucoepidermoid carcinoma (MEC). The study will determine if previously assessed perineural invasion by original pathology reports would be increased by re-review of the originally hematoxylin-eosin-(H &E) stained slides as well as review of slides reacted immunohistochemically with S100 to enhance visualization of nerves. The study will also assess whether perineural invasion or its absence in MEC is associated with clinical outcome. Thirty-one cases of major and minor salivary gland MEC were reviewed for perineural invasion and compared to the perineural invasion status stated on the original pathology report when available (13/31). All H & E-stained slides were reviewed as well as S100-reacted sections of each case’s tissue blocks that contained tumor. Patient demographics and clinical outcome were collected from electronic medical records. Perineural invasion was identified in 23% (3/13) of tumors in the original reports, 13% (4/31) of the authors' re-review of the same slides, and 29% (9/31) when cases were reacted with S100. A positive relationship was seen between the discovery of perineural invasion on H & E-stained slides and a greater number of foci of perineural invasion. Perineural invasion and larger-diameter nerve involvement was significantly associated with death at 5-year follow-up. In conclusion, immunohistochemical enhancement improves the accuracy, ease and speed of perineural invasion determination. Perineural invasion is a significant factor in the decreased survival outcome of cases of MEC. These findings support continued inclusion of the presence or absence of perineural invasion as a grading parameter in MEC.

O carcinoma mucoepidermoide (CME) é a neoplasia maligna de glândula salivar mais comum, e com maior frequência de metástase linfonodal. Alterações genéticas estão intimamente associadas à carcinogênese e, também, aos processos de metástase tumoral. Para o CME o tratamento de escolha mais aplicado hoje é a cirurgia seguida de radioterapia, pois a quimioterapia não tem mostrado muita eficiência para o tratamento destas neoplasias. Entre os quimioterápicos mais prescritos para o tratamento de cânceres encontra-se a cisplatina, à base de platina, que atua no DNA da célula, induzindo a apoptose. Pouco se sabe a respeito de seu mecanismo de ação sobre o CME, inclusive sobre os genes homeobox. Estes genes compreendem uma família grande e essencial de reguladores do desenvolvimento que são vitais para o crescimento e diferenciação celular, e a expressão anômala destes genes têm sido implicados na carcinogênese. Assim, este trabalho teve como objetivo avaliar a expressão dos genes homeobox em células derivadas de carcinoma mucoepidermoide tratadas com cisplatina. Os genes avaliados neste trabalho foram: PROX1, MEIS1, HOXB5, HOXB7 e HOXB9 por RT-qPCR. Previamente, as linhagens celulares derivadas de carcinoma mucoepidermoide UM-HMC1 UM-HMC2 e UM-HMC3A foram tratadas com a cisplatina por 24h e posteriormente submetidas aos ensaios de RT-qPCR. Adicionalmente, as amostras tratadas e sem tratamento foram analisadas pelo ensaio de formação de esferas e ensaio de ferida para verificar o efeito da cisplatina sobre propriedades relacionadas às células quimiorresistentes (putativas células tronco tumorais). Como resultados, entre os genes analisados foram expressos PROX1, MEIS1 e HOXB7. A UM-HMC3A apresentou maior expressão destes genes que as demais linhagens. Os genes HOXB5 e HOXB9 não foram expressos nas linhagens analisadas. A cisplatina reduziu a expressão de MEIS1 e aumentou a expressão de HOXB7, em todas as linhagens. O gene PROX1 apresentou expressão variável entre as linhagens, sendo expresso na UM-HMC1 apenas quando são tratadas com cisplatina e reduzido nas UM-HMC2 e UM-HMC3A tratadas. O número de esferas formadas não apresentou diferença significativa para UM-HMC1 e UM-HMC3A, o número de esferas aumentou na linhagem UM-HMC2 tratada com cisplatina. No ensaio de ferida, a cisplatina foi capaz de reduzir a migração celular em todas as linhagens quando comparadas com seus controles. Os resultados sugerem que o PROX1 e HOXB7 podem estar relacionados com carcinomas mucoepidermoides mais invasivos, enquanto que o MEIS1 pode estar relacionado à carcinogênese e autorrenovação tumoral. A cisplatina é capaz de afetar a expressão dos genes homeobox PROX1, MEIS1 e HOXB7, os quais foram encontrados nas linhagens de carcinoma mucoepidermoide analisados. A cisplatina não afeta as células formadoras de esferas, mas reduzir a migração das linhagens de carcinoma mucoepidermoide. / Mucoepidermoid carcinoma (MEC) is the most common malignant neoplasm of salivary gland and presents higher frequency of lymph node metastasis. Genetic alterations are closely associated with carcinogenesis and also with processes of tumor metastasis. For MEC the treatment of choice most applied today is surgery followed by radiotherapy, since chemotherapy has not shown much efficiency for the treatment of these neoplasms. Among the most commonly prescribed chemotherapic drugs for cancer treatment is platinum-based cisplatin, which acts on the cell\'s DNA, inducing apoptosis. There is no information in the literature regarding its action mechanism on MEC including homeobox genes. These genes comprise a large and essential family of developmental regulators that are vital for cell growth and differentiation and the anomalous expression of these genes have been implicated in carcinogenesis. Therefore, this work aimed to evaluate the expression of the homeobox genes in cells derived from mucoepidermoid carcinoma treated with cisplatin. The genes evaluated in this work were: PROX1, MEIS1, HOXB5, HOXB7 and HOXB9 by RT-qPCR. Previously, cell lines derived from mucoepidermoid carcinoma UM-HMC1 UM-HMC2 and UM-HMC3A were treated with cisplatin for 24h and subsequently subjected to the RT-qPCR assays. In addition, treated and untreated samples were analyzed by the sphere-forming assay and wound assay to verify the effect of cisplatin on chemo resistant cell-related (putative tumor stem cell) properties. As results, PROX1, MEIS1 and HOXB7 were expressed among the analyzed genes. UM-HMC3A showed higher expression of these genes than the other lineages. The HOXB5 and HOXB9 genes were not expressed in the analyzed lineages. Cisplatin reduced MEIS1 expression and increased HOXB7 expression in all lineages. The PROX1 gene showed variable expression between the lineages, being expressed in UM-HMC1 only when treated with cisplatin and reduced in treated UM-HMC2 and UM-HMC3A. The number of spheres formed did not show significant difference for UM-HMC1 and UM-HMC3A, the number of spheres increased in the cisplatin-treated UM-HMC2 lineage. In the wound assay, cisplatin was able to reduce cell migration in all lineages when compared to their controls. The results suggested that PROX1 and HOXB7 may be related to more invasive mucoepidermoid carcinoma, while MEIS1 be related to its carcinogenesis and selfrenew tumoral capacity. Cisplatin is capable to affect the expression of the homeobox genes PROX1, MEIS1 and HOXB7, which were found in the mucoepidermoid carcinoma cell lines analyzed. Cisplatin does not affect sphere formation of cells, but seems to reduce the migration of mucoepidermoid carcinoma lineages.

O carcinoma mucoepidermóide de pulmão, um tipo histológico que deriva das glândulas mucosas traqueobrônquicas, manifesta-se com sintomas obstrutivos e tende a comprometer a traqueia. Com finalidade curativa ou paliativa da doença, atualmente há uma forte tendência na oncologia em desenvolver estratégias terapêuticas que visam à administração de compostos com elevado potencial de otimizar o efeito do tratamento com a radiação ionizante, de modo a aumentar a morte de células tumorais e preservar íntegras as células dos tecidos sadios adjacentes. A intensa busca por tais estratégias evidenciou resultados promissores apresentados pelo composto denominado Resveratrol (3,4,5-trihidroxiestilbeno), tornando-o amplamente divulgado e alvo de intensas pesquisas. O principal objetivo do presente estudo foi determinar o efeito do resveratrol em cultura celular de carcinoma mucoepidermóide de pulmão exposta a diferentes doses de radiação ionizante. Para tal, os estudos de citotoxicidade utilizando o método de incorporação do vermelho neutro, e da determinação da dose letal 50 % (DL50) da radiação ionizante, foram realizados em cultura de células da linhagem NCI-H292 [H292] (ATCC® CRL-1848TM), CCIAL069. Com base nos resultados do IC50% (401,5 μM) e da DL50 (693 Gy) foram realizados o teste in vitro do micronúcleo e os ensaios para avaliar o efeito do resveratrol no ciclo celular, reparo da lesão no DNA e processo de lesão radioinduzida, necrose e apoptose celular. Os resultados evidenciaram que o resveratrol na concentração de 30 μM apresenta uma importante capacidade em promover danos às células NCI-H292 após 24 h da irradiação. / Mucoepidermoid lung carcinoma is a histological type that derives from the tracheobronchial mucous glands. It is manifested by trachea symptoms. Curative or palliative purpose for the disease, nowadays presents a strong oncology tendency to develop therapeutic strategies aimed at the administration of high potential compounds to improve the ionizing radiation treatments, so as to increase the radiation effects on tumor cells while minimizing these effects to surrounding normal tissues. The intensive search for such strategies showed promising results by the compound called Resveratrol, making it widely available and subject of many studies. The main of this study was to determine in vitro resveratrol effect in mucoepidermoid lung carcinoma cells NCI-H292 [H292] (ATCC® CRL-1848TM), CCIAL069, exposed to ionizing radiation doses. For this purpose, there were performed in vitro cytotoxicity studies by neutral red uptake assay, as well as the lethal dose 50 % (LD50) of ionizing radiation. On the basis of the IC50% (401.5 μM) and LD50 (693 Gy) results, there were performed in vitro micronucleus test and other tests in order to evaluate the cell cycle, repair and injury processes, cellular apoptosis and necrosis inductions. The results showed that resveratrol in 30 μM concentrations showed an important capability to injury NCI-H292 cells after 24 h of irradiation.

O carcinoma mucoepidermóide de pulmão, um tipo histológico que deriva das glândulas mucosas traqueobrônquicas, manifesta-se com sintomas obstrutivos e tende a comprometer a traqueia. Com finalidade curativa ou paliativa da doença, atualmente há uma forte tendência na oncologia em desenvolver estratégias terapêuticas que visam à administração de compostos com elevado potencial de otimizar o efeito do tratamento com a radiação ionizante, de modo a aumentar a morte de células tumorais e preservar íntegras as células dos tecidos sadios adjacentes. A intensa busca por tais estratégias evidenciou resultados promissores apresentados pelo composto denominado Resveratrol (3,4,5-trihidroxiestilbeno), tornando-o amplamente divulgado e alvo de intensas pesquisas. O principal objetivo do presente estudo foi determinar o efeito do resveratrol em cultura celular de carcinoma mucoepidermóide de pulmão exposta a diferentes doses de radiação ionizante. Para tal, os estudos de citotoxicidade utilizando o método de incorporação do vermelho neutro, e da determinação da dose letal 50 % (DL50) da radiação ionizante, foram realizados em cultura de células da linhagem NCI-H292 [H292] (ATCC® CRL-1848TM), CCIAL069. Com base nos resultados do IC50% (401,5 μM) e da DL50 (693 Gy) foram realizados o teste in vitro do micronúcleo e os ensaios para avaliar o efeito do resveratrol no ciclo celular, reparo da lesão no DNA e processo de lesão radioinduzida, necrose e apoptose celular. Os resultados evidenciaram que o resveratrol na concentração de 30 μM apresenta uma importante capacidade em promover danos às células NCI-H292 após 24 h da irradiação. / Mucoepidermoid lung carcinoma is a histological type that derives from the tracheobronchial mucous glands. It is manifested by trachea symptoms. Curative or palliative purpose for the disease, nowadays presents a strong oncology tendency to develop therapeutic strategies aimed at the administration of high potential compounds to improve the ionizing radiation treatments, so as to increase the radiation effects on tumor cells while minimizing these effects to surrounding normal tissues. The intensive search for such strategies showed promising results by the compound called Resveratrol, making it widely available and subject of many studies. The main of this study was to determine in vitro resveratrol effect in mucoepidermoid lung carcinoma cells NCI-H292 [H292] (ATCC® CRL-1848TM), CCIAL069, exposed to ionizing radiation doses. For this purpose, there were performed in vitro cytotoxicity studies by neutral red uptake assay, as well as the lethal dose 50 % (LD50) of ionizing radiation. On the basis of the IC50% (401.5 μM) and LD50 (693 Gy) results, there were performed in vitro micronucleus test and other tests in order to evaluate the cell cycle, repair and injury processes, cellular apoptosis and necrosis inductions. The results showed that resveratrol in 30 μM concentrations showed an important capability to injury NCI-H292 cells after 24 h of irradiation.

Orientador : Marcio Ajudarte Lopes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-06T00:25:09Z (GMT). No. of bitstreams: 1 Ito_FabioAugusto_D.pdf: 9945598 bytes, checksum: 5d7825a97ef3dd77141a70dd22e719c3 (MD5) Previous issue date: 2006 / Resumo: Além de incomuns, os tumores de glândulas salivares despertam interesses por apresentarem uma grande diversidade histológica, morfológica e de comportamento biológico. Nas últimas décadas vários estudos têm mostrado que tais diversidades estão relacionadas ao acúmulo de alterações genéticas. As investigações de tais alterações são importantes para entender os mecanismos de oncogênese, avaliar o comportamento biológico e conseqüentemente aperfeiçoar terapêuticas favorecendo o prognóstico. O objetivo deste estudo foi analisar as características histopatológicas e imunohistoquímicas dos quatro tumores de glândulas salivares mais freqüentes: adenoma pleomórfico, carcinoma mucoepidermóide, tumor de Warthin e carcinoma adenóide cístico. Para isso foi realizada análise histológica do componente epitelial e mesenquimal dos adenomas pleomórficos, classificação histológica dos tumores de Warthin, carcinomas mucoepidermóides e carcinomas adenóide cístico e estudo imunohistoquímico para Ki-67, EGF, EGFR, ErbB-2, FAS, receptor de andrógeno, receptor de estrógeno e receptor de progesterona. Dos 189 casos de adenoma pleomórfico selecionados para o estudo histopatológico, 99 (52,4%) foram classificados como estroma-rico, 69 (36,5%) como celular e 21 (11,1%) como clássico. Dos 30 casos de tumor de Warthin, 17 casos (56,7%) foram classificados como típicos, 10 (33,3%) como estroma pobre e 3 (10%) como estroma-rico. Dos 30 casos de carcinoma mucoepidermóide, 15 casos (50%) foram classificados histologicamente como de baixo grau, 3 (10%) como grau intermediário e 12 (40%) como de alto grau. Dos 30 casos de carcinoma adenóide cístico, 15 casos (50%) foram classificados como cribriforme, 8 (26,7%) como tubular e 7 (23,3%) como sólido. Ki-67, EGFR e ErbB-2 foram mais freqüentemente encontrados em carcinomas mucoepidermóides, principalmente em tumores de alto grau de malignidade. EGF e FAZ foram encontrados mais freqüentemente em adenomas pleomórficos e carcinomas mucoepidermóides. Todos os casos estudados foram negativos para receptor de estrógeno e receptor de progesterona. Receptor de andrógeno foi positivo em apenas 2 casos de adenoma pleomórfico, 2 de carcinoma mucoepidermóide e 2 de carcinoma adenóide cístico. Concluindo, EGFR, ErbB-2 e FAS parecem desempenhar papel na tumorigênese de tumores de glândulas salivares, especialmente em carcinomas mucoepidermóides, e devem ser mais extensivamente estudados; receptor de estrógeno e receptor de progesterona não desempenham papel na tumorigênese de adenomas pleomórficos, tumores de Warthin, carcinomas mucoepidermóides e carcinomas adenóide cístico; e apesar de poucos casos positivos em tumores de glândulas salivares, receptor de andrógeno deve ser melhor estudado e considerado como potencial alvo em tratamentos com drogas anti-andrógenos / Abstract: Beyond uncommon, salivary gland tumors are interesting because their great diversity of histological, morphological and biological behavior. In the last decades some studies have shown that such diversities are related to the accumulation of genetic alterations. The investigation of such alterations are important to understand the mechanisms of oncogenesis, to evaluate the biological behavior and consequently to improve therapeutics favoring the prognosis. The aim of this study was to analyze the histopathological and immunohistochemical characteristics of the four more frequent salivary gland tumors: pleomorphic adenoma, mucoepidermóide carcinoma, Warthin¿s tumor and adenoid cystic carcinoma. For this, it was realized the histological analysis of the epithelial and mesenchymal components of pleomorphic adenomas, histological classification of Warthin¿s tumors, mucoepidermoid carcinomas and adenoid cystic carcinoma and immunohistochemical study for Ki-67, EGF, EGFR, ErbB-2, FAS, androgen receptor, estrogen receptor and progesterone receptor. Of the 189 cases of pleomorphic adenoma selected for the histopathological study, 99 (52.4%) were classified as stroma-rich, 69 (36.5%) as cellular and 21 (11.1%) as classic. Of the 30 cases of Warthin¿s tumor, 17 cases (56.7%) were classified as typical, 10 (33.3%) as stroma-poor and 3 (10%) as stroma-rich. Of the 30 cases of mucoepidermoid carcinoma, 15 cases (50%) were classified as low grade, 3 (10%) as intermediate grade and 12 (40%) as high grade. Of the 30 cases of adenoid cystic carcinoma, 15 cases (50%) were classified as cribriform, 8 (26.7%) as tubular and 7 (23.3%) as solid. Ki-67, EGFR and ErbB-2 were more frequently found in mucoepidermoid carcinomas, particularly in high grade tumors. EGF and FAS were more frequently found in pleomorphic adenomas and mucoepidermoid carcinomas. All studied cases were negative for estrogen receptor and progesterone receptor. Androgen receptor was positive in only 2 cases of pleomorphic adenoma, 2 of mucoepidermoid carcinoma and 2 of adenoid cystic carcinoma. In conclusion, EGFR, ErbB-2 and FAS seem to play a role in the tumorigenesis of salivary gland tumors, especially in MEC, and they should be more extensively studied; estrogen receptor and progesterone receptor do not play a role in the tumorigenesis of pleomorphic adenomas, Warthin¿s tumors, mucoepidermoid carcinomas and adenoid cystic carcinomas; and regardless of few positive cases in salivary gland tumors, androgen receptor should be better studied and considered as potential targets for treatment with anti-androgens drugs / Doutorado / Patologia / Doutor em Estomatopatologia

Mucoepidermoid carcinom (MEC) är en malign mucin-producerande tumör som förekommer i både stora och små spottkörtlar. Syftet med denna studie var att undersöka histologiskt uttryck av muciner (MUC1, MUC4, MUC5AC, MUC5B, MUC6) i MEC för att eventuellt hitta en korrelation mellan kvalitativt mucinuttryck och tumörgrad. Tolv låg- och fem höggradiga MEC och nio normala spottkörtlar intill tumörvävnad undersöktes med hjälp av immunohistokemi där proverna utvärderades med avseende på färgningsmönster och positivitet i specifika celltyper. Normala spottkörtelceller uttryckte främst cytoplasmatiskt mucin MUC5B. MUC1 och MUC4 uttrycktes i normala spottkörtelgångsceller i ungefär hälften av proverna medan MUC5AC uttryck var sällsynt i normala spottkörtlar. MEC:ar uttryckte MUC1, MUC4, MUC5AC och MUC5B. Den apikala delen av membranet i de bägarceller som omger cystiska hålrum visade den starkaste färgningen för MUC1 och MUC4. Uttryck av MUC4 i bägarceller minskade med ökad histologisk grad. Bägarcellers uttryck av MUC5B:s i låggradig MEC var mindre intensivt än uttrycket av MUC5AC i samma celler. Högre uttryck av MUC5B jämfört med MUC5AC noterades i höggradiga tumörer. Sammanfattningsvis uttrycker MEC olika mängd av muciner än normala spottkörtlar. MUC5AC:s uttryck i MEC verkar vara en metaplastisk funktion och MUC4 tycks relatera till tumörens differentieringsgrad. Förhållandet mellan MUC5AC och MUC5B uttryck skulle kunna vara ett användbart verktyg vid diagnostisering och prognosutvärdering av MEC. / Mucoepidermoid carcinomas (MECs) are malignant epithelial mucin-producing tumours encountered in both major and minor salivary glands. The aim of this study was to investigate the histological characteristics of the expression of mucins (MUC1, MUC4, MUC5AC, MUC5B, MUC6) in MECs in search for a possible correlation between qualitative mucin expression and tumour grade. Twelve low-grade, five high-grade MECs and nine normal salivary glands adjacent to tumour tissue were investigated for these mucins by immunohistochemistry. The samples were evaluated with respect to staining pattern and positivity of specific cell types. Normal acinar cells mainly expressed the cytoplasmic mucin MUC5B. MUC1 and MUC4 were expressed in normal ductal cells in approximately half of the samples whereas MUC5AC expression was rare in normal salivary glands. MECs expressed MUC1, MUC4, MUC5AC and MUC5B. The apical membrane of mucous cells lining the cystic cavities showed the strongest staining for MUC1 and MUC4. The expression of MUC4 in mucous cells decreased with increasing histological grade. Expression of salivary mucin MUC5B in mucous cells in low-grade MECs was less intense compared to the expression of MUC5AC in the same cells. In high-grade tumours, a higher expression of MUC5B compared to MUC5AC was noted. In conclusion, MECs express different mucin quantity compared to normal salivary glands. MUC5AC expression in salivary tumour tissue seems to be a metaplastic feature and MUC4 appears to be related to tumour differentiation grade. The relationship between MUC5AC and MUC5B expression could be a useful tool in the diagnosis and estimation of prognosis of MECs.

Carcinoma mucoepidermóide (CME) é o tumor maligno de glândulas salivares mais comum, representando cerca de 30% dos tumores malignos. O tratamento do CME é a ressecção cirúrgica com eventual radioterapia. Assim, o tratamento do CME pode levar a varias complicações estéticas e funcionais. A quimioterapia tem sido utilizadas apenas em casos recorrentes ou com metástases à distancia. Vários relatos na literatura tem mostrado que o tratamento com drogas isoladas ou combinadas possuem uma resposta insatisfatória e de curta duração em grande parte devido a aquisição de resistência a quimioterapia. Recentemente, a quimiorresistência tem sido relacionada com a presença de Células-Tronco Tumorais (CTT). Essa resistência tem sido associada ao fato de que as essa células são quiescentes e possuem altos níveis de proteínas associadas ao reparo do DNA e baixos níveis das proteínas que levam a apoptose. Recentemente mostrou-se que a resistência a quimioterapia tem sido relacionada com modificações de histonas, uma vez que as células quimiorresistentes possuem núcleo pequeno e baixos níveis de acetilação de histonas, adicionalmente as células sensíveis são relacionadas com núcleo aumentado. O objetivo desse estudo foi avaliar os efeitos do tratamento com IHDAC e cisplatina sobre a população de CTT de CME. Inicialmente analisamos os níveis de acetilação do histona através da expressão imuno-histoquímica de acetil histona H3 em casos de CME, sendo encontrado altos níveis de acetilação de histona principalmente nas células epiteliais do ducto excretor. Adicionalmente, demonstramos que o tratamento com SAHA (inibidor de histona deacetilase) impacta diretamente a população de CTT, de uma maneira mais eficiente do que a cisplatina ou da combinação de SAHA e cisplatina. É interessante que o tratamento com cisplatina resultou no acúmulo de uma subpopulação especifica de CTT em um processo que inclui o aumento na expressão da via de sinalização do mTOR. Estes achados sugerem que o uso de IHDAC constitui uma forma eficiente de tratamento de CME através da depleção da população de CTT , porém mais estudos são necessários para validar estes achados para uso clinico. / Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumor compromising about 30% of all salivary malignances. Managing MEC patients remain challenging especially due to the heterogeneous response of tumor cells to available therapy. For this reason clinical outcome remains unpredictable. Current treatment of MEC encompasses surgical resection with eventual adjuvant radiotherapy, which frequently leads to functional and aesthetic complications. The use of chemotherapy is often reserved for recurrent and metastatic tumors. Administration of single-agent or combination therapy has showed activity, however overall response rates are unsatisfactory and of short duration. Emerging evidences suggest that the modest response of tumor cells to therapy resulting in high recurrence rates and poor survival, are associated with the presence of cancer stem cells (CSC). Quiescence of CSC is achieved by the reduced levels of transcription in a process that requires tight folding of DNA driven by core histone proteins. Changes in DNA folding are responsible for different cellular phenotypes mediated by a cell type-specific chromatin organization. Of interest, we also found that acetylation of HNSCC tumor histones driven by histone deacetylase (HDAC) inhibitors abrogate tumor resistance to chemotherapy. We investigate the effects of HDACi and cisplatin in the population of CSCs of MEC. Initially, we found that MEC tumors are composed by a heterogeneous population of squamous-like and mucous-like cells presenting distinct acetylation levels of histone 3 (Lys9). Tumor cells where treated with cisplatin and SAHA, a Food and Drug Administration (FDA) approved histone deacetylase inhibitor. Surprisingly, we found that administration of SAHA resulted in complete depletion of MEC CSCs. In facts, SAHA alone surpassed the inhibitory therapeutic effects of cisplatin and the combined therapy using SAHA and cisplatin over the population of CSCs. We also found that administration of cisplatin to MEC tumor cells result in unexpected accumulation of a sub population of CSC (paraclones), suggesting a correlation between the administration of intercalating agents such as cisplatin to the development of resistance of MEC cells to chemotherapy.

Carcinoma mucoepidermóide (CME) é o tumor maligno de glândulas salivares mais comum, representando cerca de 30% dos tumores malignos. O tratamento do CME é a ressecção cirúrgica com eventual radioterapia. Assim, o tratamento do CME pode levar a varias complicações estéticas e funcionais. A quimioterapia tem sido utilizadas apenas em casos recorrentes ou com metástases à distancia. Vários relatos na literatura tem mostrado que o tratamento com drogas isoladas ou combinadas possuem uma resposta insatisfatória e de curta duração em grande parte devido a aquisição de resistência a quimioterapia. Recentemente, a quimiorresistência tem sido relacionada com a presença de Células-Tronco Tumorais (CTT). Essa resistência tem sido associada ao fato de que as essa células são quiescentes e possuem altos níveis de proteínas associadas ao reparo do DNA e baixos níveis das proteínas que levam a apoptose. Recentemente mostrou-se que a resistência a quimioterapia tem sido relacionada com modificações de histonas, uma vez que as células quimiorresistentes possuem núcleo pequeno e baixos níveis de acetilação de histonas, adicionalmente as células sensíveis são relacionadas com núcleo aumentado. O objetivo desse estudo foi avaliar os efeitos do tratamento com IHDAC e cisplatina sobre a população de CTT de CME. Inicialmente analisamos os níveis de acetilação do histona através da expressão imuno-histoquímica de acetil histona H3 em casos de CME, sendo encontrado altos níveis de acetilação de histona principalmente nas células epiteliais do ducto excretor. Adicionalmente, demonstramos que o tratamento com SAHA (inibidor de histona deacetilase) impacta diretamente a população de CTT, de uma maneira mais eficiente do que a cisplatina ou da combinação de SAHA e cisplatina. É interessante que o tratamento com cisplatina resultou no acúmulo de uma subpopulação especifica de CTT em um processo que inclui o aumento na expressão da via de sinalização do mTOR. Estes achados sugerem que o uso de IHDAC constitui uma forma eficiente de tratamento de CME através da depleção da população de CTT , porém mais estudos são necessários para validar estes achados para uso clinico. / Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumor compromising about 30% of all salivary malignances. Managing MEC patients remain challenging especially due to the heterogeneous response of tumor cells to available therapy. For this reason clinical outcome remains unpredictable. Current treatment of MEC encompasses surgical resection with eventual adjuvant radiotherapy, which frequently leads to functional and aesthetic complications. The use of chemotherapy is often reserved for recurrent and metastatic tumors. Administration of single-agent or combination therapy has showed activity, however overall response rates are unsatisfactory and of short duration. Emerging evidences suggest that the modest response of tumor cells to therapy resulting in high recurrence rates and poor survival, are associated with the presence of cancer stem cells (CSC). Quiescence of CSC is achieved by the reduced levels of transcription in a process that requires tight folding of DNA driven by core histone proteins. Changes in DNA folding are responsible for different cellular phenotypes mediated by a cell type-specific chromatin organization. Of interest, we also found that acetylation of HNSCC tumor histones driven by histone deacetylase (HDAC) inhibitors abrogate tumor resistance to chemotherapy. We investigate the effects of HDACi and cisplatin in the population of CSCs of MEC. Initially, we found that MEC tumors are composed by a heterogeneous population of squamous-like and mucous-like cells presenting distinct acetylation levels of histone 3 (Lys9). Tumor cells where treated with cisplatin and SAHA, a Food and Drug Administration (FDA) approved histone deacetylase inhibitor. Surprisingly, we found that administration of SAHA resulted in complete depletion of MEC CSCs. In facts, SAHA alone surpassed the inhibitory therapeutic effects of cisplatin and the combined therapy using SAHA and cisplatin over the population of CSCs. We also found that administration of cisplatin to MEC tumor cells result in unexpected accumulation of a sub population of CSC (paraclones), suggesting a correlation between the administration of intercalating agents such as cisplatin to the development of resistance of MEC cells to chemotherapy.

We hypothesized that lymph node involvement in minor salivary gland cancers is associated with clinical and pathological factors commonly available to the clinician after a typical initial workup. Our aim was to identify these factors using a dataset that allowed us to compile the largest series of minor salivary gland cancers in the published literature. Using this dataset we also aimed to characterize the distribution of histological types by primary site, identify the predictors of the use of external beam radiation therapy and neck dissection, and examine the effect of lymph node involvement on survival. Using the SEER database, we identified 2667 minor salivary gland cancers with known lymph node status from 1988 to 2004. Univariate and multivariate analyses were conducted to identify factors associated with the use of neck dissection, the use of external beam radiation therapy, and the presence of cervical lymph node metastases. Kaplan Meier survival curves were constructed to examine the effect of lymph node involvement on survival. 426 (16.0%) patients had neck nodal involvement. Factors associated with neck nodal involvement on univariate analysis included increasing age, male gender, increasing tumor size, high tumor grade, T3-T4 stage, adenocarcinoma or mucoepidermoid carcinomas, and pharyngeal site of primary malignancy. On multivariate analysis, four statistically significant factors were identified, which included male gender, T3-T4 stage, pharyngeal site of primary malignancy, and high-grade adenocarcinoma or high-grade mucoepidermoid carcinomas. The proportions (and 95% confidence intervals) of patients with lymph node involvement for those with 0, 1, 2, 3 and 4 of these prognostic factors were 0.02 (0.01-0.03), 0.09 (0.07-0.11), 0.17 (0.14-0.21), 0.41 (0.33-0.49), and 0.70 (0.54-0.85) respectively. Grade was a significant predictor of metastasis for adenocarcinoma and mucoepidermoid carcinoma but not for adenoid cystic carcinoma. Overall survival was significantly worse at 5, 10, and 15 years for patients with lymph node involvement on presentation. A prognostic index using the four clinicopathological factors listed above can effectively differentiate patients into risk groups of nodal metastasis. The precision of this index is subject to the limitations of SEER data and it should be validated in further clinical studies.