As mucinas e o NCAM (CD56) na colangiocarcinogênese intra-hepática / Mucins and NCAM (CD56) in intrahepatic cholangiocarcinogenesis

Introduction: Cholangiocarcinoma is the second most common malignant neoplasm of the hepatobiliary system. During cholangiocarcinogenesis phenotypic changes occur in the ductal epithelium, including the expression of mucins (MUC). However, the evaluating studies of the expression of mucins in the different stages of cholangiocarcinogenesis are scarce. CD56 has also contributed in differentiating benign ductal proliferation and cholangiocarcinoma; however, its expression has not been evaluated in dysplastic epithelium of the bile duct yet. Objective: To assess immunohistochemical profile of (MUC) 1, 2, 5, 6, and CD56 in cholangiocarcinoma, pre-neoplastic and reactive lesions in the epithelium of intrahepatic bile ducts. Material and methods: Immunohistochemical expression of MUC 1, 2, 5, 6, and CD56 were studied for 11 cases of cholangiocarcinoma and 83 intrahepatic bile ducts (67 reactive and 16 dysplastic). Variables were considered significant when p < 0.05. Results: The expression of MUC1 occurred in about 90% of the cholangiocarcinomas, contrasting with the low frequency of positive cases in reactive and dysplastic bile ducts (p < 0.001). However, there was no statistically significant difference in the expression of MUC5, MUC6 and CD56 between the reactive or dysplastic lesions and cholangiocarcinoma. The anti-MUC2 antibody was negative in all cases. Conclusions: MUC1 contributed for the differential diagnosis between cholangiocarcinoma and pre-neoplastic and reactive/regenerative lesions of intrahepatic bile ducts, and it should compose the antibodies panel aiming at improvement of these differential diagnoses. In contrast, MUC2, MUC5, MUC6 and CD56 were not promising in differentiating all the phases of cholangiocarcinogenesis...

Introdução: O colangiocarcinoma é a segunda neoplasia maligna mais comum do sistema hepatobiliar. Durante a colangiocarcinogênese podem ocorrer alterações fenotípicas do epitélio ductal, incluindo a expressão de mucinas. Entretanto, os estudos que avaliam a expressão das mucinas nas diferentes etapas da colangiocarcinogênese são escassos. O CD56, apesar de contribuir na diferenciação entre as proliferações ductais benignas e o colangiocarcinoma, ainda não teve a sua expressão avaliada no epitélio displásico dos ductos biliares. Objetivos: Analisar o perfil das mucinas (MUC) 1, 2, 5, 6 e do CD56 no colangiocarcinoma, nas lesões pré-neoplásicas e reacionais de ductos biliares intra-hepáticos. Material e métodos: A expressão imuno-histoquímica da MUC 1, 2, 5, 6 e do CD56 foram avaliadas em 11 colangiocarcinomas e 83 ductos biliares intra-hepáticos (67 reativos e 16 displásicos). As variáveis foram consideradas como significativas quando p < 0,05. Resultados: A expressão da MUC1 ocorreu em cerca de 90% dos colangiocarcinomas, contrastando com a baixa frequência de casos positivos nos ductos biliares reativos ou displásicos (p < 0,001). Não houve diferença estatisticamente significativa na expressão de MUC5, MUC6 e CD56 entre as lesões reativas, displásicas e o colangiocarcinoma. O anticorpo anti-MUC2 foi negativo em todos os casos. Conclusão: A MUC1 contribuiu no diagnóstico diferencial entre o colangiocarcinoma e as lesões pré-neoplásicas e reacionais/regenerativas dos ductos biliares intra-hepáticos, e deve compor o painel de anticorpos a ser empregado visando o aprimorando destes diagnósticos diferenciais. Contrariamente, a MUC2, MUC5, MUC6 e o CD56 não se mostraram promissoras na diferen...

Overexpression of Mucin 13 due to Promoter Methylation Promotes Aggressive Behavior in Ovarian Cancer Cells

PURPOSE: Recent discoveries suggest that aberrant DNA methylation provides cancer cells with advanced metastatic properties. However, the precise regulatory mechanisms controlling metastasis genes and their role in metastatic transformation are largely unknown. To address epigenetically-regulated gene products involved in ovarian cancer metastasis, we examined the mechanisms regulating mucin 13 (MUC13) expression and its influence on aggressive behaviors of ovarian malignancies. MATERIALS AND METHODS: We injected SK-OV-3 ovarian cancer cells peritoneally into nude mice to mimic human ovarian tumor metastasis. Overexpression of MUC13 mRNA was detected in metastatic implants from the xenografts by expression microarray analysis and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The DNA methylation status within the MUC13 promoter region was determined using bisulfite sequencing PCR and quantitative methylation-specific PCR. We evaluated the effects of exogenous MUC13 on cell invasion and migration using in vitro transwell assays. RESULTS: MUC13 mRNA expression was up-regulated, and methylation of specific CpG sites within the promoter was reduced in the metastatic implants relative to those in wild-type SK-OV-3 cells. Addition of a DNA methyltransferase inhibitor to SK-OV-3 cells induced MUC13 expression, thereby implying epigenetic regulation of MUC13 by promoter methylation. MUC13 overexpression increased migration and invasiveness, compared to control cells, suggesting aberrant up-regulation of MUC13 is strongly associated with progression of aggressive behaviors in ovarian cancer. CONCLUSION: We provide novel evidence for epigenetic regulation of MUC13 in ovarian cancer. We suggest that the DNA methylation status within the MUC13 promoter region may be a potential biomarker of aggressive behavior in ovarian cancer.

Expressão de CDX2 e mucinas (MUC1, MUC2, MUC5AC e MUC6) em esôfago de Barrett antes e após fundoplicatura de Nissen / Expression of CDX2 and mucins (MUC1, MUC2, MUC5AC and MUC6) in Barrett's esophagus before and after Nissen fundoplication

INTRODUÇÃO: O esôfago de Barrett (EB) corresponde à substituição do epitélio escamoso por um do tipo intestinal, em resposta ao refluxo crônico nos pacientes com doença do refluxo gastroesofágico (DRGE). É um importante precursor do adenocarcinoma esofágico. A fundoplicatura de Nissen (FN) é uma cirurgia antirrefluxo que visa a reduzir a agressão à mucosa esofágica. Alterações no padrão de expressão imuno-histoquímica de mucinas e de CDX2 no EB antes e depois da FN podem ser úteis na identificação de um padrão de expressão desses marcadores e, eventualmente, na identificação de casos com risco de evolução para malignidade. OBJETIVOS: Avaliar e comparar a imunoexpressão de CDX2 e mucinas no EB de pacientes com DRGE submetidos à FN antes e após a cirurgia. MATERIAIS E MÉTODOS: Estudo retrospectivo de 25 pacientes com diagnóstico de DRGE e EB submetidos à FN, acompanhados por, pelo menos, três anos. Foram feitos análise histológica e estudo imuno-histoquímico das biópsias endoscópicas antes e após a cirurgia, comparando-se a inflamação e a imunoexpressão de MUC1, MUC2, MUC5AC, MUC6 e CDX2. Estimou-se a porcentagem de células com expressão para os marcadores estudados na mucosa de Barrett: 0%-25%, 25%-75% e 75%-100% das células positivas. Foram utilizados os testes de McNemar e Stuart-William e adotou-se o nível de 5% de significância estatística. RESULTADOS E CONCLUSÃO: Não houve diferenças significativas quanto a presença ou intensidade de inflamação, nem da imunoexpressão de mucinas e CDX2 no EB antes e após a FN. O tratamento cirúrgico não influenciou a mudança da expressão dessas glicoproteínas no EB.

INTRODUCTION: Barrett´s esophagus (BE) is characterized by the exchange of esophageal squamous epithelium for intestinal type in response to chronic reflux in patients with gastroesophageal reflux disease (GERD).It is an important precursor of esophageal adenocarcinoma. Nissen fundoplication (NF) is an antireflux surgery which aims to reduce esophageal mucosa inflammation. Changes in the immunohistochemical expression patterns of mucins (MUC1, MUC2, MUC5AC and MUC6) and CDX2 in BE before and after NF may be useful to identify the expression patterns of these markers and, possibly, to detect cases with risks of malignancy. OBJECTIVES: To investigate and compare mucin and CDX2 immunoexpression in BE patients with GERD before and after NF. MATERIAL AND METHODS: This retrospective study comprised 25 patients with GERD and BE who had been submitted to NF. The patients had a 3-year minimum follow up. Histological and immunohistochemical analyses of endoscopic biopsies were performed before and after the surgery, comparing inflammation and MUC1, MUC2, MUC5AC, MUC6 and CDX2 immunoexpression. The percentage of Barrett mucosa cells with expression to the studied markers was estimated at 0%-25%, 25%-75% and 75%-100%. McNemar and Stuart-William tests were used and the significance level of <0.05 was applied. RESULTS AND CONCLUSION: Concerning the presence or the intensity of inflammation and mucin and CDX2 expression in BE, there were no significant differences before and after NF. The surgical procedure did not promote any changes in the expression of these glycoproteins in BE.

Identifying a risk profile for thyroid cancer

The large use of simple and effective diagnostic tools has significantly contributed to the increase in diagnosis of thyroid cancer over the past years. However, there is compelling evidence that most micropapillary carcinomas have an indolent behavior and may never evolve into clinical cancers. Therefore, there is an urgent need for new tools able to predict which thyroid cancers will remain silent, and which thyroid cancers will present an aggressive behavior. There are a number of well-established clinical predictors of malignancy and recent studies have suggested that some of the patientÆs laboratory data and image methods may be useful. Molecular markers have also been increasingly tested and some of them appear to be very promising, such as BRAF, a few GST genes and p53 polymorphisms. In addition, modern tools, such as immunocytochemical markers, and the measure of the fractal nature of chromatin organization may increase the specificity of the pathological diagnosis of malignancy and help ascertain the prognosis. Guidelines designed to select nodules for further evaluation, as well as new methods aimed at distinguishing carcinomas of higher aggressiveness among the usually indolent thyroid tumors are an utmost necessity.

O uso cada vez mais freqüente de métodos diagnósticos simples e efetivos tem contribuído significativamente para um aumento no diagnóstico de câncer da tiróide nos últimos anos. Entretanto, existem importantes evidências de que muitos dos microcarcinomas papilíferos têm um comportamento indolente e podem nunca evoluir para cânceres clínicos. Existe, portanto, uma necessidade urgente de desenvolver novas ferramentas capazes de predizer quais os tumores tiroidianos que permanecerão silenciosos e quais desenvolverão comportamento agressivo. Há uma série de marcadores clínicos de evolução bem estabelecidos e alguns estudos recentes sugerem que dados laboratoriais e métodos de imagem podem ser úteis. Marcadores moleculares também vêm sendo ativamente investigados e alguns, como BRAF, os genes GST e polimorfismos de p53, parecem promissores. Além disso, marcadores imunocitoquímicos e a medida da natureza fractal da cromatina podem aumentar a especificidade do diagnóstico anatomopatológico e ajudar a predizer o prognóstico. Existe uma necessidade imperiosa de elaborarmos diretrizes destinadas a selecionar os nódulos que merecem prosseguimento em sua avaliação, assim como novos métodos capazes de identificar lesões mais agressivas entre os geralmente indolentes tumores tiroidianos.

A mucin like gene different from the previously reported members of the mucin like gene families is transcribed in Trypanosoma cruzi but not in Trypanosoma rangeli

Trypanosoma cruzi expresses mucin like glycoproteins encoded by a complex multigene family. In this work, we report the transcription in T. cruzi but not in T. rangeli of a mucin type gene automatically annotated by the T. cruzi genome project. The gene showed no nucleotide similarities with the previously reported T. cruzi mucin like genes, although the computational analysis of the deduced protein showed that it has the characteristic features of mucins: a signal peptide sequence, O-glycosylation sites, and glycosylphosphatidylinositol (GPI) anchor sequence. The presence in this gene of N- terminal and C- terminal coding sequences common to other annotated mucin like genes suggests the existence of a new mucin like gene family.

Expression of Mucin Genes in the Human Testis and Its Relationship to Spermatogenesis

In this study we investigate the expression pattern of mucin genes in the human testis and evaluate the relationship between the expression of mucin genes and impaired spermatogenesis in the human testis. Thirty human testis tissues were collected from patients undergoing diagnostic testicular biopsy to investigate the cause of infertility. One part of the tissue underwent histological observation, and the other part of the tissue was subjected to semiquantitative RT-PCR of mucin genes, that is, mucin1, 2, 3, 4, and 9. The relative amount of mucin mRNAs was calculated by densitometry using glyceraldehydes-3-phosphate dehydrogenase (GAPDH) as an internal control. The samples were histologically diagnosed as either obstructive azoospermia with normal spermatogenesis (n = 13) or non-obstructive azoospermia with impaired spermatogenesis (n = 17). In the human testis with normal spermatogenesis, mRNA expression of mucin1, 9, 13 and GAPDH were found, but RT-PCR products of mucin 2, 3 and 4 were not detected. In the testis with impaired spermatogenesis, however, RT-PCR product of mucin1 was not found. There was no difference in the other mucin mRNA expression patterns between the testis with either normal or impaired spermatogenesis. To our knowledge, this study is the first that has detected the mRNA of mucin9 and 13 in human testis. This study also shows that mucin1 expression might be closely related to spermatogenesis. Our findings should be substantiated by more direct evidence, such as mucin protein expression and localization.

Effects of glucocorticoid on IL-13-induced Muc5ac expression in airways of mice / 华中科技大学学报（医学）（英德文版）

To study the effects of glucocorticoid on the IL-13-induced Muc5ac expression in airways of mice, and investigate its role in mucus secretion of airways, 24 pathogen-free BALB/c mice were randomly divided into 3 groups. IL-13 group received an nasal instillation of 100 microg of recombinant murine IL-13 solution on days 1, 3 and 5. In dexamethasone group, dexamethasone (0.5 mg/kg) was administered intraperitoneally 24 h before and 1 h before the first instillation of IL-13 and on 4 consecutive days (day 0 to day 5, 6 consecutive days in total), while control group was not treated with IL-13 or dexamethasone. Bronchoalveolar lavage fluid (BALF) was collected and eosinophils were counted, and expression of Muc5ac mRNA and protein in lungs were detected by reverse transcription-polymerase chain reaction (RT-PCR) technology and immunohistochemical assay respectively. Our results showed that the number of mice, with positve Muc5ac protein expression, expression of Muc5ac mRNA and eosinophils in BALF after IL-13 treatment were all significantly higher than that of control group (all P<0.01). Despite eosinophils reduced (P<0.01), the number of mice with positive Muc5ac protein expression, expression of Muc5ac mRNA afterdexamethasone treatment didn't decreas significantly as compared with that of IL-13 group. It is concluded that IL-13 can up-regulate the expression of Muc5ac mRNA and protein, which may play a pivotal role in the mucus overproduction of airways. Dexamethasone can suppress IL-13-induced eosinophilic infiltration in lung but can't inhibit the mucus overproduction.

Prophylactic Effect of Lactobacillus GG in Animal Colitis and Its Effect on Cytokine Secretion and Mucin Gene Expressions / 대한소화기학회지

BACKGROUND/AIMS: Lactobacillus rhamnosus GG (LGG) has been used in acute colitis treatment. However, it is unclear whether the LGG prevents chronic colitis. The aim of this study was to examine the prophylactic effect of LGG on animal colitis, cytokine secretion, and mucin gene expression. METHODS: BALB/c mice (n=64) were exposed to 5% dextran sulfate sodium (DSS) for 7 days followed by 10 days recovery period and repeatedly exposed for 4 days. Then, the mice were devided into three group; group of oral LGG adminstration throughout the recovery and repeated colitis period; PBS group of PBS administration; control group. Colon length, histologic score, tumor necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10) levels, mucin gene expressions were determined at each period. RESULTS: In acute colitis period, the LGG group showed higher levels of disease activity index (DAI), histologic score, TNF-alpha, IL-10, but shorter colon length, lower levels of mucin gene expressions than the control group. However, in repeated colitis period, the LGG group showed markedly lower levels of DAI and IL-10 but significantly longer colon length than PBS group (p<0.05). There was no difference in the mucin gene expression. CONCLUSIONS: These results suggest that LGG prevents chronic murine colitis. It may be associated with cytokine modulation and competitive inhibition of pathogenic bacteria. However, it may not be related with gene expression.

Análisis del polimorfismo Bsm I del gen receptor de la vitamina D (VDR) en pacientes venezolanas residentes del estado Zulia con osteoporosis

Resumen. Dentro de los genes implicados en el estudio de la genética de la osteoporosis, el más conocido es el gen receptor de la vitamina D (VDR), estudiado a través de la caracterización del polimorfismo Bsm I. En tal sentido, esta investigación tuvo como objetivo principal analizar el polimorfismo Bsm I del gen de VDR en una muestra de 133 mujeres posmenopáusicas distribuidas en tres grupos: 54 afectadas con osteoporosis, 24 con osteopenia y 55 controles normales para la enfermedad. De las mujeres con osteoporosis 28 presentaron el genotipo BB, asociado en otros países con disminución de la densidad mineral ósea, 20 presentaron el genotipo Bb y 6 el genotipo bb. Del grupo control sólo 11 mujeres presentaron el genotipo BB, 36 mostraron el genotipo heterocigoto Bb y 8 el genotipo bb. La frecuencia de los alelos B y b en la población general analizada resultó de 0,6 y 0,4, respectivamente. El genotipo BB se encontró en un 52% del grupo con osteoporosis y en un 20% en el grupo control normal, siendo estos hallazgos significativos estadísticamente, lo cual sugiere una asociación entre el genotipo BB y la osteoporosis.

Abstract. Among genes implied on the osteoporosis genetics, the most studied gene worldwide is the receptor gene of D vitamin (VDR), through the characterization of Bsm I polymorphism. The main objective of this research was to analyze the Bsm I polymorphism of the VDR gene in a sample of 133 postmenopausal women distributed in three groups: 54 with osteoporosis, 24 with osteopenia and 55 normal controls for the disease. 28 of the women with osteoporosis presented the BB genotype, which is related in others countries to bone mineral density decrease, 20 had the Bb genotype, and 6 the bb genotype. Of the control group only 11 women presented the BB genotype, 36 showed the heterozygote genotype and 8 the bb genotype. The frequencies of the B and b alleles in the analyzed population were 0.6 and 0.4 respectively. The BB genotype was found in 52% of the group with osteoporosis, and in 20% of the control group, these findings are statistically significant, which suggest an association between the BB genotype and osteoporosis.

Upregulation of the tracheobronchial mucin gene involves cyclic AMP response elements.

The cAMP response element (CRE)-binding transcription factor CREB can mediate induction of gene transcription in response to cAMP. Since the tracheobronchial mucin gene (TBM) 5'-flanking region contains CREs (located between residues -289 and -376) with an octamer-like motif (TGACGTCC), the cAMP responsiveness of the TBM CREs was investigated in human tracheal epithelial cells HBE1. These cells were isolated from non-cystic fibrosis subjects and immortalized with HPV18 genes E6 and E7 (ref. 1). HBE1 cells express a homolog of canine TBM (as demonstrated by TBM expression at the transcription and translation level). Electrophoretic mobility shift assay (EMSA) indicated that CREs provide a binding site for nuclear proteins. Transient transfection analysis [using the chloramphenicol acetyl transferase (CAT) reporter gene] and nuclear run on analysis indicated cAMP induced transcription of the TBM gene. The transcriptional activity of the HBE1 transfected cells containing CRE was selectively modulated by extracellular 8Br-cAMP in a dose-dependent manner; a 6-fold increase in activity was detected when cells were incubated for 12 hr in the presence of 2 microM vs 1 nM 8BrcAMP. Since mucin gene is over-expressed in diseases such as cystic fibrosis (CF) and asthma, the information presented here will help us understand the mechanisms involved in transcriptional regulation of mucin gene expression in disease states.