Avaliação da via do c-kit no adenoma pleomórfico e carcinoma adenoide cístico das glândulas salivares: estudo da expressão das proteínas da via, das mutações e da regulação pós-transcricional do gene kit / c-Kit signaling cascade in pleomorphic adenoma and adenoid cystic carcinoma of salivary glands: evaluation of cascade proteins, mutations and post-transcriptional regulation of gene Kit

Introdução: As neoplasias das glândulas salivares têm amplo espectro histológico resultante da múltipla diferenciação celular tumoral. O adenoma pleomórfico (AP) e o carcinoma adenoide cístico (CAC) são as mais comuns neoplasias benignas e malignas provenientes do ducto intercalado, respectivamente, além de serem compostas por estruturas luminais e células mioepiteliais. Em estudo realizado previamente pelo nosso grupo, detectamos que a proteína c-kit está envolvida nos processos da morfogênese das glândulas salivares e no adenoma pleomórfico. A proteína c-Kit tem papel importante no desenvolvimento de muitos processos embrionários, incluindo a gametogênese, melanogênese e hematopoiese, e também na biologia de tumores. Sua ativação induz diversas respostas intracelulares através de cascatas de sinalização de vias como PI3K/AKT e MAPK. Em tumores da glândula salivar ainda há poucos estudos sobre as alterações do gene KIT e das proteínas relacionadas a sua via de sinalização, assim como sua regulação pós-transcricional, realizada principalmente por meio dos microRNAs. O presente estudo avaliou, em APs e CACs (a) a localização das proteínas das vias PI3K/AKT/mTOR e MAPK por meio da técnica de imunoistoquímica; (b) a expressão dos microRNAs 221 e 222, relacionados ao gene KIT (c) a associação dos achados laboratoriais com variáveis clínicas, patológicas e sobrevida. Resultados: Nos casos de AP a proteína c-Kit foi identificada em formações luminais e em raras células isoladas no parênquima tumoral. Já nos CAC, observou-se positividade na membrana das células ductais. Para a via de PI3K/AKT/mTOR, no AP, a proteína PI3K beta mostrou-se parcialmente positiva no citoplasma das células próximas à capsula tumoral, e as proteínas AKT e mTOR fosforiladas, foram expressas especialmente nas células epiteliais e em poucas células mioepiteliais. Já no CAC, a proteína PI3K beta e AKT fosforilada mostraram-se negativas na maioria dos casos, e a proteína mTOR fosforilada foi expressa no citoplasma das células epiteliais e em algumas células mioepiteliais. Para a via MAPK, as proteínas RAS, MEK-1 fosforilada e ERK 1/2 foram negativas na maioria dos AP e CAC; B-Raf e MEK-2 fosforilada foram observadas nas células luminais dos AP. Nos CAC, estruturas luminais neoplásicas foram positivas para a proteína MEK-2 fosforilada; B-Raf foi positivo nas células luminais e mioepiteliais. Além disso, os pacientes que expressaram as proteínas mTOR e MEK-2 fosforilada apresentaram sobrevida câncer-específica significativamente aumentada (p=0,040 e p=0,005, respectivamente). Na análise do microRNAs, a expressão do miR-221 foi variável nas 13 amostras analisadas, tendo baixa expressão em 30,77% dos casos, expressão normal em 38,46 e expressão aumentada em 30,77% dos casos. Já nos APs o miR-221 foi detectado em 19 amostras, sendo 36,84% com baixa expressão, 52,63% com expressão normal e expressão aumentada foi vista em 10,53% dos casos. A expressão do miR-222 foi detectada em 14 CACs, sendo que a maioria dos casos (8 casos ­ 57,1%) a expressão do miR-222 foi semelhante ao observado nas amostras não neoplásicas. Nos APs, o miR-222 foi detectado em 22 amostras, sendo 31,8% com baixa expressão, 31,8% com expressão normal e 36,4% com expressão aumentada. Conclusão: Apesar de a proteína c-Kit ser expressa em ambas as neoplasias ­ AP e CAC, sua influência sobre as vias de sinalização MAPK e PI3K/AKT/mTOR ainda permanece por ser estabelecida. Ainda, os microRNAs 221 e 222 não mostram correlação consistente com a expressão de c-Kit nos tipos tumorais estudados.

Introduction: Salivary gland tumors present broad histological spectrum resulting from multiple tumor cell differentiation. Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) are the commonest benign and malignant salivary gland neoplasms originated from the intercalated duct region, respectively, and are composed by luminal structures and myoepithelial cells. In a previous study we detected that protein c-kit is involved in the process of salivary gland morphogenesis and PA. c-Kit protein is important during embryogenesis, including gametogenesis, melanogeneis and hematopoiesis as well as in tumorigenesis. Its activation induces various intracellular responses through pathways such as MAPK and PI3K/AKT/mTOR signaling cascades. In salivary gland neoplasms, only a few reports have shown that alterations in KIT gene are present and proteins related to its signaling pathway as well as its post-transcriptional regulation. This study has aimed at evaluating in PA and ACC: (a) the proteins location of PI3K/AKT/mTOR and MAPK pathways using immunohistochemistry (IHC); (b) expression of miR-221 and miR-222, related to KIT gene; and (c) the association of these findings with clinical, pathological and survival data of patients. Results: In PA c-kit was positive in isolated luminal cells; in ACC, neoplastic luminal structures were positive for c-Kit. In PA, PI3K beta protein was shown to be partially positive in the cytoplasm of cells near the tumor capsule and phosphor AKT and phospho mTOR, are specifically expressed in epithelial cells and in a few myoepithelial. In ACC, PI3K and phosphor AKT protein showed to be negative in most of cases. Phospho mTOR protein was expressed in the cytoplasm of epithelial cells and some myoepithelial cells. In MAPK pathway, Ras, ERK1/2 and phosphor MEK-1 proteins were negative in most PAs and CACs; B-Raf and phospho MEK-2 were detected in luminal cells of PA. In ACC neoplastic luminal structures were positive for phospho MEK-2; B-Raf was also positive in myoepithelial and epithelial cells. In addition, cases with expressed phospho-mTOR and phosphor MEK-2 proteins were significantly associated with higher cancer-specific survival (p = 0.040 and p = 0.005, respectively). Moreover, expression of miR-221 was detected in 13 CAC samples and 19 PA samples. In CAC, expression of miR-221 was downregulated in 30,77% of the samples, upregulated in 30,77% samples, and normal in 38,46% samples. In PA, miR-221 expression was downregulated in 36,84% samples, upregulated in 10,53% samples, and normal in 52,63% samples. Expression of miR-222 was detected in 14 CAC samples and 22 PA samples. In the majority of CAC samples, the expression of miR-222 was similar to that observed in non-neoplastic samples. In PA samples, expression of miR-222 was downregulated in 31,8% samples, upregulated in 36,4% samples, and normal in 31,8% samples. Conclusion: Although c-Kit expression is detected in PA and ACC, its influence on the MAPK e PI3K/AKT/mTOR signaling cascades remains to be established. miR-221 e -222 did not show a robust correlation with c-Kit expression in the tumors studied.

Expression of Autophagy and Reactive Oxygen Species-Related Proteins in Lacrimal Gland Adenoid Cystic Carcinoma

PURPOSE: To investigate the difference of expression of autophagy and reactive oxygen species (ROS) related proteins in adenoid cystic carcinoma (ACC) of lacrimal gland in comparison with ACC of salivary gland. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded tissue samples from patients pathologically diagnosed as lacrimal gland ACC (n=11) and salivary gland ACC (n=64) were used. Immunochemistry was used to measure expression of autophagy related proteins [beclin-1, light chain (LC) 3A, LC3B, p62, and BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3)] and ROS related proteins [catalase, thioredoxinreductase, glutathione S-transferasepi (GSTpi), thioredoxin interacting protein, and manganese superoxide dismutase (MnSOD)]. The prognostic factors related to disease-free and overall survival (OS) in lacrimal gland ACC by log-rank tests, were determined. RESULTS: GSTpi in stromal cells was more highly expressed in lacrimal gland ACC (p=0.006), however, MnSOD in epithelial cells was expressed more in salivary gland ACC (p=0.046). LC3B positivity and BNIP3 positivity in epithelial component were associated with shorter disease-free survival (both p=0.002), and LC3A positivity in stromal component was the factor related to shorter OS (p=0.005). CONCLUSION: This is the first study to demonstrate the expression of autophagy and ROS related proteins in lacrimal gland ACC in comparison with the salivary gland ACC, which would provide a basis for further study of autophagy and ROS mechanism as novel therapeutic targets in lacrimal gland ACC.

Expression of beclin 1 in primary salivary adenoid cystic carcinoma and its relation to Bcl-2 and p53 and prognosis

Beclin 1 plays a critical role in autophagy and functions as a haploinsufficient tumor suppressor. The expression and prognostic significance of beclin 1 in head and neck adenoid cystic carcinoma (ACC) are largely unexplored. Therefore, we investigated the expression of beclin 1, Bcl-2, and p53 in head and neck ACC tissue. Tissue samples from 35 cases (15 females, 20 males) of head and neck ACC were utilized for immunohistochemistry. Beclin 1 expression was observed in 32 cases (91.4%) and considered to be high in 15 cases (42.9%) and low in 20 cases (57.1%). Beclin 1 expression was significantly correlated with a histological growth pattern (P=0.046) and histological grade (P=0.037). Beclin 1 expression was inversely correlated with Bcl-2 expression (P=0.013) and significantly associated with overall survival (P=0.006). Bcl-2 and p53 expression were observed in 21 cases (60.0%) and 16 cases (45.7%). Bcl-2 expression was significantly correlated with perineural invasion (P=0.041) and not associated with overall survival (P=0.053). p53 expression was directly correlated with beclin 1 expression (P=0.044). Our results indicated that beclin 1 may be a novel, promising prognostic factor for clinical outcome in head and neck ACC patients and may play a part in the development of head and neck ACC by interacting with Bcl-2 and p53.

Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90 percent of lactadherin but only about 75 and 70 percent of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

Immunohistochemical expression of vimentin, calponin and HHF-35 in salivary gland tumors

Myoepithelial cells present a complex immunophenotype, with the expression of proteins varying according to the stage of normal or neoplastic differentiation of the cell. In order to evaluate the immunohistochemical markers expressed by these cells, a panel of antibodies composed of vimentin, calponin and HHF-35 was applied to 28 salivary gland tumors. The results demonstrated a higher percent sensitivity of vimentin and calponin compared to HHF-35. However, calponin and HHF-35 presented a focal labeling pattern in contrast with the diffuse distribution of vimentin. The cells predominantly stained by all tested antibodies included nonluminal cells in duct-like and tubular structures, such as those seen in pleomorphic adenomas and adenoid cystic carcinomas, as well as cells in the cords and nests of polymorphous low-grade adenocarcinomas and peripheral cells of sheets and nests of myoepitheliomas. In conclusion, the combination of calponin and vimentin is suggested for the identification of myoepithelial cells in salivary gland tumors.

As células mioepiteliais apresentam um imunofenótipo complexo, variando a expressão de suas proteínas na dependência do seu estágio de diferenciação normal ou neoplásico. Com o objetivo de avaliar comparativamente marcadores imuno-histoquímicos para estas células, um painel de anticorpos composto pela vimentina, calponina e HHF-35 foi aplicado em 28 tumores de glândulas salivares. Os resultados demonstraram que a vimentina e a calponina foram percentualmente mais sensíveis que o HHF-35; entretanto, a calponina e o HHF-35 apresentaram padrão de distribuição focal diferentemente da distribuição difusa da vimentina. As células predominantemente marcadas, por todos os anticorpos utilizados, foram as não luminais presentes nas estruturas ductiformes e tubulares, vistas no adenoma pleomórfico e no carcinoma adenóide cístico, bem como as células dos cordões e ninhos dos adenocarcinomas polimorfo de baixo grau e periferia de lençóis e ninhos dos mioepiteliomas. Em conclusão, sugere-se que se faça associação da calponina com vimentina para identificação de células mioepiteliais em neoplasias de glândula salivar.

Immunohistochemical evaluation of p27 (kip1) in pleomorphic adenomas and adenoid cystic carcinomas of the minor salivary glands.

BACKGROUND: p27(kip1), a universal cyclin-dependent kinase inhibitor, is a useful marker for predicting clinical aggressiveness with various human tumors. In this study, p27 expression was investigated in pleomorphic adenomas (PAs) and adenoid cystic carcinomas (ACCs) of minor salivary glands to evaluate its utility for differentiation purposes. At the same time, the correlation between p27 and ACC grading was evaluated. MATERIALS AND METHODS: Clinicopathological features of 22 patients (11 ACCs, 11 PAs), including age, sex and size of tumor were obtained from medical records. Immunohistochemical staining with p27(kip1) was performed for each specimen and p27 labelling indices were determined with a computer-assisted image-analyzing system (CAS 200). Pearson's correlation coefficient, Spearman's correlation coefficient, Students t-test, Kruskal-Wallis test and ANOVA were applied for statistical analyses using SPSS 11.5. RESULTS: p27 LIs for all PAs were above 25% whereas for ACCs they were under 25% (except one case). p27 expression (LI and intensity) was significantly lower in ACCs than PAs. The correlation between p27 expression and ACC grading was not significant. CONCLUSION: Overall, these findings suggest that reduced expression of p27 might be correlated with the development of ACC and could be an indicator of malignant behavior.

Análise quantitativa das AgNORs no carcinoma adenóide cístico intra-oral através da técnica de dupla marcação PCNA/AgNOR / PCNA/AgNOR double staining technique in adenoid cystic carcinoma

A análise quantitativa das AgNORs e imunomarcação para o PCNA têm sido empregadas de forma independente na avaliação da proliferação celular de vários tumores, e, em muitos casos, têm mostrado correlação positiva. Entretanto poucos trabalhos têm avaliado, em um mesmo corte histológico, a relação entre PCNA e AgNOR. O objetivo deste trabalho foi otimizar a técnica de dupla marcação com a finalidade de se estudar simultaneamente a correlação entre PCNA e AgNOR no carcinoma adenóide cístico (CAC) de glândulas salivares menores. Foram selecionados 16 casos de CAC classificados de acordo com o subtipo histológico. A análise quantitativa das AgNORs foi feita por meio de análise de imagens. As AgNORs foram contadas em cem núcleos PCNA positivos e em cem núcleos PCNA negativos. O número médio de AgNOR nos núcleos PCNA positivos foi 2,14 ñ 0,77, e, nos núcleos PCNA negativos, 1,97 ñ 0,79, entretanto esta diferença não se mostrou estatisticamente significante (p = 0,2537). Nosso trabalho não mostrou correlação entre o número de AgNOR e a imunomarcação para o PCNA em CAC quando estes marcadores foram demonstrados sinultaneamente através da dupla marcação. Quanto à técnica, o uso do microondas melhorou a coloração da AgNOR, permitindo uma redução no tempo de incubação com a solução de prata e uma melhor individualização das AgNORs, o que facilitou os procedimentos de contagem

Adenomyoepithelioma of the breast: its diagnostic problems and histogenesis

We report three cases of adenomyoepithelioma of the breast that occurred in middle aged women. The tumor is characterized by a balanced proliferation of epithelial tubules and surrounding myoepithelial cells that are spindle shaped or have clear cytoplasms. The first case mimicked tubular adenoma in the initial biopsy. However, on excision it turned out to be an adenomyoepithelioma of the tubular. The other two cases were lobulated types and had fibroadenomatous areas. The morphologic appearance of this tumor varies, making it misleading to other benign or even malignant lesions. The tumor has a potential for local recurrence, therefore, wide excision is recommended for proper diagnosis and treatment.