Alterations in APC, BECN1, and TP53 gene expression levels in colon cancer cells caused by monosodium glutamate / Alterações nos níveis de expressão gênica APC, BECN1 e TP53 em células de câncer de cólon causadas por glutamato monossódico

Colorectal cancer (CRC) is a disease with high incidence worldwide. As of 2018, it is the second leading cause of cancer deaths in the world. In Saudi Arabia, the incidence of this disease has been increasing in the younger population. Both genetic and lifestyle factors may have contributed to its increased incidence and pathogenesis. Monosodium glutamate (MSG) is a food flavor enhancer that can be found in many commercial foods, and it can sometimes be used as a substitute to table salt. MSG has been investigated for its possible genotoxicity, yielding controversial results. In the present study, the effect of MSG on cell viability and its effect on expression of APC, BECN1, and TP53 genes in SW620 and SW480 colon cancer cell lines were studied. TP53 is a tumor suppressor gene that functions in modifying DNA errors and/or inducing apoptosis of damaged cells, and both APC and BECN1 genes are involved in CRC and are of importance in cellular growth and metastasis. Cancer cell viability was analyzed using MTT assay, and the results showed a significant increase in the number of viable cells after 24h of treatment with MSG with different concentrations (0.5, 1.0, 10, 50, and 100mM). Moreover, gene expression results showed a significant increase in the expression levels of APC and BECN1 under specified conditions in both cell lines; conversely, TP53 showed a significant decrease in expression in SW620 cells. Thus, it can be concluded that MSG possibly confers a pro-proliferative effect on CRC cells.

O câncer colorretal (CCR) é uma doença com alta incidência mundial. Desde 2018, é a segunda principal causa de mortes por câncer no mundo. Na Arábia Saudita, a incidência dessa doença vem aumentando na população mais jovem. Tanto fatores genéticos quanto de estilo de vida podem ter contribuído para o aumento da sua incidência e patogênese. O glutamato monossódico (MSG) é um intensificador de sabor de alimentos que pode ser encontrado em muitos alimentos comerciais e às vezes pode ser usado como um substituto do sal de cozinha. O MSG tem sido investigado por sua possível genotoxicidade, produzindo resultados controversos. Neste estudo, foram estudados o efeito do MSG na viabilidade celular e seu efeito na expressão dos genes APC, BECN1 e TP53 em linhas de células de câncer de cólon SW620 e SW480. TP53 é um gene supressor de tumor que atua modificando erros de DNA e/ou induzindo apoptose de células danificadas, estando os genes APC e BECN1 envolvidos no CRC e sendo importantes no crescimento celular e metástase. A viabilidade das células cancerosas foi analisada por meio do ensaio MTT, e os resultados mostraram um aumento significativo no número de células viáveis após 24 h de tratamento com MSG em diferentes concentrações (0,5; 1,0; 10; 50 e 100mM). Além disso, os resultados da expressão gênica mostraram um aumento significativo nos níveis de expressão de APC e BECN1 sob condições especificadas em ambas as linhagens celulares. Por outro lado, TP53 mostrou uma diminuição significativa na expressão em células SW620. Assim, pode-se concluir que, possivelmente, o MSG confere um efeito pró-proliferativo às células CRC.

Revisión: Factores asociados a cáncer colorrectal / Review: Associated factors with colorectal cancer

Resumen Introducción: El cáncer colorrectal (CCR) es la neoplasia de mayor frecuencia en vías digestivas, constituyendo del 9 al 10% de todos los cánceres en el mundo. Se considera que es multicausal, pues abarca factores intrínsecos del huésped como mutaciones genéticas, hormonales y condiciones inmunológicas; además de factores externos como dietas poco saludables, consumo de alcohol, obesidad, sedentarismo, tabaquismo y la exposición ambiental a carcinógenos. Las manifestaciones clínicas son poco específicas, razón por la cual el diagnóstico está enfocado en grupos de riesgo relacionados con la edad e historia familiar demostrada. Objetivo: Identificar los factores genéticos y de estilos de vida predisponentes al desarrollo de CCR. Metodología: Se realizó una búsqueda de la bibliografía respectiva en las bases de datos ScienceDirect, Google académico, Redalyc, Scielo, Proquest publicada durante el período 2004- 2019, mediante las palabras clave: Colorrectal cancer, risk factors, epidemiology, mortality, mutation, incidence. Resultados: Se observaron factores genéticos predisponentes entre un 20% a 25% de las personas con CCR asociados principalmente con la mutación de gen APC. En relación al cáncer esporádico, se identifica hasta en un 80% de los casos, relacionado con el consumo no controlado de alimentos como carnes rojas, embutidos, café, además de hábitos como el consumo de cigarrillo y alcohol conjuntamente con el estrés y comorbilidades como la obesidad y la diabetes. Conclusión: La multicausalidad del CCR está centrada en factores tanto internos como externos siendo de relevancia el seguimiento para personas genéticamente predispuestas y la implementación de estilos de vida saludables que reduzcan la mortalidad por esta causa.

Abstract Introduction: Colorectal cancer (CRC) is the most frequent neoplasm in the digestive tract; it constitutes 9 of 10% of all cancer cases in the world. This type of cancer is considered multicausal since it is associated with intrinsic and extrinsic factors. Among the internal factors, there are genetic, hormonal mutations, and immunological conditions. On the other hand, the external factors are composed of unhealthy diets, alcohol consumption, obesity, sedentary lifestyle, smoking habits, and environmental exposure to carcinogens. The clinical symptoms are not very specific; that is why the diagnosis is focused on risk groups related to age and proven family medical history. Objective: To identify genetic factors and lifestyle factors related to the development of Colorectal cancer (CRC). Methodology: A literature search was carried out in databases such as ScienceDirect, Google Scholar, Redalyc, Scielo, Proquest, in a range of time between 2004 and 2019. The keywords: colorectal cancer, risk factors, epidemiology, mortality, mutation, and incidence were used as helpers for the search. Results: Predisposing genetic factors were observed in about 20% to 25% of people with CRC associated primarily with the APC gene mutation. In terms of sporadic cancer, the results showed that 80% of the cases were related to the uncontrolled consumption of red meat, sausages, and coffee. Additionally, smoking and alcoholic behaviors, stress, and comorbidities, such as obesity and diabetes, were also the cause of the development of this issue. Conclusion: CRC could be caused by internal and external factors. Based on this, the people with a genetic predisposition to this issue should monitor themselves frequently and implement a healthy lifestyle that reduces the probability of suffering from this type of cancer.

The fluctuation of APC gene in WNT signaling with adenine deletion of adenomatous polyposis coli, is associated in colorectal cancer / A flutuação do gene da APC na via de sinalização WNT com deleção de adenina na polipose adenomatosa do cólon está associada ao câncer colorretal

ABSTRACT Colorectal cancer is one of the most important malignancies in the classification of gastrointestinal cancers. One of the predisposing factors at molecular level for this cancer is via WNT signaling which is associated with the vast numbers of different genes. Thus, in this study, we aimed to investigate whether Adenomatous Polyposis Coli gene (APC) mutation of rs41115in two locations such as 132.002 and 131.989 acts as a trigger or cause of colorectal cancer. Relatively, 30 blood samples of colorectal cancer patients and 30 normal blood samples as control group after colonoscopy and also confirmation of pathology report at Rohani Hospital in Babol (Iran) were investigated. The primers were designed in order to be included the rs41115 to identify the particular polymorphisms of gene. The polymerase chain reaction (PCR direct sequencing method) was used. Conclusively, deletion of adenine in two specific locations such as 131.989 and 132.002 has been identified, but there was no relationship between rs41115 polymorphisms located in adenomatous polyposis coli gene and colorectal cancer.

RESUMO O câncer colorretal é uma das neoplasias malignas mais importantes na classificação dos cânceres gastrointestinais. Um dos fatores predisponentes no âmbito molecular para esse câncer é através da via de sinalização WNT, que está associada a um grande número de genes diferentes. Portanto, neste estudo, objetivamos investigar se a mutação rs41115 do gene da polipose adenomatosa do cólon (Adenomatous Polyposis Coli - APC) em dois locais como 132.002 e 131.989 atua como gatilho ou como causa do câncer colorretal. Relativamente, 30 amostras de sangue de pacientes com câncer colorretal e 30 amostras de sangue normal (grupo controle) foram analisadas após a colonoscopia, bem como a confirmação do laudo da patologia no Rohani Hospital em Babol (Irã). Os primers foram projetados de modo a incluir o rs41115 para identificar os polimorfismos particulares do gene. A reação em cadeia da polimerase (método de sequenciamento direto por PCR) foi utilizada. Conclusivamente, a deleção de adenina em dois locais específicos, como 131.989 e 132.002, foi identificada, mas não houve relação entre o polimorfismo rs41115 localizado no gene da polipose adenomatosa do cólon e o câncer colorretal.

Exome sequence analysis of Kaposiform hemangioendothelioma: identification of putative driver mutations

Abstract BACKGROUND: Kaposiform hemangioendothelioma is a rare, intermediate, malignant tumor. The tumor's etiology remains unknown and there are no specific treatments. OBJECTIVE: In this study, we performed exome sequencing using DNA from a Kaposiform hemangioendothelioma patient, and found putative candidates for the responsible mutations. METHOD: The genomic DNA for exome sequencing was obtained from the tumor tissue and matched normal tissue from the same individual. Exome sequencing was performed on HiSeq2000 sequencer platform. RESULTS: Among oncogenes, germline missense single nucleotide variants were observed in the TP53 and APC genes in both the tumor and normal tissue. As tumor-specific somatic mutations, we identified 81 candidate genes, including 4 nonsense changes, 68 missense changes and 9 insertions/deletions. The mutations in ITGB2, IL-32 and DIDO1 were included in them. CONCLUSION: This is a pilot study, and future analysis with more patients is needed to clarify: the detailed pathogenesis of this tumor, the novel diagnostic methods by detecting specific mutations, and the new therapeutic strategies targeting the mutation.

Identificação de mutações nos genes APC e MUTYH em famílias com polipose adenomatosa intestinal / Mutational screening of APC and MUTYH genes in families with adenomatous polyposis

Atualmente, pacientes com múltiplos adenomas colorretais são avaliados para mutações germinativas em dois genes, APC e MUTYH. Pacientes com mutações em APC apresentam Polipose Adenomatosa Familiar Clássica ou Atenuada (FAP/AFAP), enquanto que pacientes portadores de mutações bialélicas em MUTYH apresentam Polipose Associada ao MUTYH (MAP). O espectro das mutações em APC e MUTYH, assim como as correlações genótipo-fenótipo nestas síndromes, apresentam importante impacto clínico e podem ser distintas em cada população, tornando necessária a obtenção de dados genéticos e clínicos de diferentes populações. Além disso, cerca de 10-15% dos pacientes com polipose não apresentam mutações nesses genes, o que sugere a existência de outros genes de predisposição ainda desconhecidos. Assim, os objetivos deste estudo foram caracterizar mutações germinativas nos genes APC e MUTYH em pacientes Brasileiros com polipose, além de identificar novos genes associados com a síndrome através de sequenciamento de exoma dos pacientes negativos. No total, 23 pacientes não relacionados foram avaliados para mutações pontuais na região codificante dos genes APC e MUTYH através de sequenciamento capilar, e para rearranjos genômicos nos mesmos genes por meio de MLPA (Multiplex Ligation-Dependent Probe Amplification), arrays de hibridação genômica comparativa (CGH-array), e PCR duplex quantitativo. Este último método de avaliação do número de cópias genômicas foi desenvolvido e validado no presente estudo. Foram identificados 21 pacientes mutados nesta coorte (91%) - 6 pacientes apresentaram mutações patogênicas em MUTYH, 14 apresentaram mutações patogênicas em APC e um paciente foi portador de uma nova variante missense de significado clínico desconhecido em APC (p.Val1789Leu); seis mutações foram descritas pela primeira vez neste trabalho. Em um destes pacientes identificamos a primeira grande deleção genômica descrita no gene MUTYH. Correlações genótipo-fenótipo dos dados...

Patients with multiple colorectal adenomas are currently screened for germline mutations in two genes, APC and MUTYH. APC-mutated patients present classic or attenuated familial adenomatous polyposis (FAP/ AFAP), while patients carrying biallelic MUTYH mutations exhibit MUTYH-associated polyposis (MAP). The spectrum of APC and MUTYH mutations as well as the genotype-phenotype correlations in polyposis syndromes present clinical impact and can be population specific, making important to obtain genetic and clinical data from different populations. Furthermore, up to 10-15% of polyposis patients do not harbor mutations in these genes, suggesting that other yet unknown polyposis-predisposing genes could exist. Thus, the aim of this study was to characterize germline mutations in APC and MUTYH genes in Brazilian polyposis and to investigate novel susceptibility genes by exome sequencing of negative patients. At total, 23 unrelated polyposis patients were screened for APC/MUTYH point mutations through DNA capillary sequencing, and for APC and MUTYH genomic rearrangements through MLPA (multiplex ligation-dependent probe amplification), array-comparative genomic hybridization, and duplex quantitative PCR. This last gene dosage method was developed and validated in this study. We identified 21 mutated patients in this cohort (91%) – 6 patients carried MUTYH pathogenic mutations, 14 carried APC pathogenic mutations and one carried a novel APC missense variant of unknown clinical significance (p.Val1789Leu); six mutations were described for the first time in this series. One of these patients harbored the first large genomic deletion identified in MUTYH gene...

APC protein immunoexpression in colorectal adenoma and adenocarcinoma / Imunoexpressão da proteína APC nos tecidos de adenoma e de adenocarcinoma colorretais

BACKGROUND: activation of the Wnt pathway by mutated APC gene is considered the initial event in colorectal carcinogenesis. The identification of these mutations can improve the specific treatment of the adenocarcinoma. OBJECTIVE: detect and evaluate wild-type APC protein in tissue from colorectal adenoma, adenocarcinoma and adjacent mucosa. METHODS: 42 patients that underwent surgery for adenocarcinoma and 53 patients with resected adenomas were studied. Tissue samples from the adenocarcinoma were obtained from the tumor and from adjacent non-neoplastic mucosa located 10 cm from the proximal margin of the tumor. Adenoma tissue was obtained from representative areas. Blocks of tissue microarray (TMA) were submitted to immunohistochemistry with anti-APC, with readings of positivity and intensity of immunostaining and the score of immune expression of APC protein was obtained. RESULTS: the APC protein immune expression score showed a significantly lower expression of APC protein in the adenoma when compared with the adenocarcinoma (p < 0.0001) and adjacent mucosa (p < 0.0001). The APC protein immune expression score in the colorectal mucosa and adjacent to the adenocarcinoma showed no significant difference (p = 0.24). CONCLUSIONS: the finding of decreased expression of APC protein in adenoma tissue may indicate that the mutated APC gene may contribute to the changes in the adenoma-carcinoma process of carcinogenesis sequence. The strong expression of protein APC in tissues from the carcinoma and adjacent mucosa suggests that in most patients in this series, the mutation of the APC gene did not participate in the oncogenesis mechanism. (AU)

RACIONAL: a ativação da via Wnt pelo gene APC mutado é considerado evento inicial da carcinogênese colorretal. A identificação dessas mutações pode tornar o tratamento do adenocarcinoma mais específico. OBJETIVO: detectar e avaliar a proteína APC não mutada em tecidos de adenoma, adenocarcinoma e mucosa adjacente. MÉTODO: estudados 42 doentes operados de adenocarcinoma e 53 com adenomas ressecados. Tecidos de adenocarcinoma foram obtidas da neoplasia e da mucosa adjacente não neoplásica situadas a 10 cm da margem proximal do tumor. Tecidos do adenoma foram obtidas de área representativa. Blocos de tissue microarray (TMA) foram submetidos a imuno-histoquímica com anticorpo anti-APC. Avaliadas a positividade e intensidade da expressão e obtidos escores da imunoexpressão da proteína APC. RESULTADOS: o escore da imunoexpressão da proteína APC no adenoma foi significantemente menor do que no adenocarcinoma (p < 0,0001) e na mucosa adjacente (p < 0,0001). O escore da imunoexpressão da proteína APC na mucosa adjacente e no adenocarcinoma não mostraram diferença significante (p = 0,24). CONCLUSÕES: a menor expressão da proteína APC no adenoma pode indicar que o gene APC mutado participa das alterações do processo adenoma-carcinoma. A forte expressão da proteína APC no CCR e na mucosa adjacente sugerem que a mutação do gene APC não participou da oncogênese. (AU)

Cáncer de tiroides y síndromes polipósicos intestinales Síndrome de Gardner / Thyroid cancer and intestinal polyposis syndromes Gardner syndrome

Resumen Presentamos el caso de una mujer de 22 años de edad, evaluada debido a que en su historia familiar a su madre se le encontró carcinoma de colon sigmoide. A la paciente se le diagnosticó poliposis colónica, que resolvió tras remoción endoscópica de las lesiones. Se realizó estudio de nódulo tiroideo y se realizó tiroidectomía total encontrándose un carcinoma papilar de tiroides como diagnóstico definitivo. Hicimos una revisión de la literatura. (Acta Med Colomb 2013; 38: 182-185).

Abstract We report the case of a 22-year-old woman evaluated because in her family history his mother had a sigmoid colon carcinoma. The patient was diagnosed with colonic polyposis, which resolved after endoscopic removal of the lesions. We made the study of a thyroid nodule and performed total finding a papillary thyroid carcinoma as definitive diagnosis. (Acta Med Colomb 2013; 38: 182-185).

Definição do perfil de alterações das sequências dos genes APC, CTNNB1, WT1, ETX e PLCG2 em tumores de Wilms / Wilms tumor genomic re-sequencing for evaluating gene loci of WTX, WT1, CTNNB1, APC and PLCG2

O tumor de Wilms (TW) origina-se das células precursoras do rim embrionário, e já foram observados eventos comuns a ambos os processos, tumorigênese e nefrogênese. A identificação de alterações moleculares durante esses processos é crucial para entender os eventos desencadeadores do TW. O gene WT1 codifica para um fator de transcrição com expressão finamente coordenada durante o desenvolvimento do rim, e mutações nesse gene são relatadas em 10% dos TWs esporádicos. Adicionalmente, desregulação no nível de expressão ou mutações de outros genes como a CTNNB1 também sugerem uma conexão entre TW e nefrogênese. Também são encontradas mutações de WTX em alguns casos de TWs. Atualmente, acredita-se que mutações de WTX, WT1 e CTNNB1 juntas estão associadas a cerca de 30% dos TWs, sendo que mutações gênicas não foram associados para a maioria dos casos. Resultados de um projeto desenvolvido em nosso laboratório apontaram os genes APC e PLCG2 como candidatos a estarem alterados nesse tumor. Nesse estudo anterior, o APC foi observado com localização predominantemente nuclear nos TWs, semelhante aos estágios iniciais do desenvolvimento normal do rim, e diferente do rim normal, que apresenta localização citoplasmática. O PLCG2 foi associado pela primeira vez a uma doença, sendo observada a ausência de marcação proteica na maioria dos TW, semelhante aos estágios iniciais do desenvolvimento, e diferente do rim diferenciado, que apresenta alta expressão da proteína. Com o advento de técnicas modernas de sequenciamento, velozes do ponto de vista de geração de bases e relativamente baratas, tornou-se factível a avaliação de toda a região que abrange o gene a um custo e tempo relativamente baixos. Com isso torna-se viável aplicar o método de sequenciamento de alta performance para avaliação de diversos pacientes...

Poliposis adenomatosa familiar: presentación de un caso y revisión de la literatura / Familial adenomatous polyposis: case report and literature review

Colorectal cancer (CRC) is a genetic and epigenetic disease. Approximately one third of the CRC has an hereditary component. Familial adenomatous polyposis (FAP) is an autosomal dominant inherited condition that has its origins in the line of APC gene mutation, which occurs with a frequency of approximately 1:10,000 live births. We report a case of a patient of 25 years with FAP. This review provides current knowledge on the broad clinical spectrum of this disease, also referring to the optimal method of diagnosis, differential diagnosis and management.

El cáncer colorrectal (CCR) es una enfermedad genética y epigenética. Aproximadamente un tercio del CCR tiene un componente hereditario. La poliposis adenomatosa familiar (PAF) es una condición hereditaria autosómica dominante que tiene su origen en la línea de mutación del gen APC, el cual ocurre con una frecuencia aproximada de 1:10.000 nacidos vivos. Se reporta el caso de una paciente de 25 años con PAF. La presente revisión proporciona los conocimientos actuales sobre el amplio espectro clínico de esta enfermedad, refiriéndose también al método óptimo de diagnóstico, diagnóstico diferencial y su manejo.

Adenomas aserrados: otro precursor de carcinoma de colon / Serrated adenoma: another precursor of colon cancer

En este estudio se describen 12 pacientes a quienes se le realizó Colonoscopia en el período de un año entre marzo 2009 y mayo 2010 (10/83,33% mujeres, 2/16,67% hombres) encontrándose lesiones planas, sésiles, sobre pliegues en colon derecho, patrón de Kudo I – II (criptas elongadas horizontalmente). La aplicación de la técnica de cromoscopia electrónica combinada con magnificación (FICE) constituye un área prometedora en la descripción de cambios patológicos mínimos de la mucosa y microvasculares. Permite incrementar la correlación entre las imágenes endoscópicas y los resultados histopatológicos. Los adenomas aserrados pueden constituir lesiones precursoras de carcinoma colorrectal con diferente secuencia a la clásica secuencia adenoma-carcinoma. Los estudios morfológicos y moleculares están identificando vías evolutivas relacionadas a metilación del ADN, mutación del BRAF e inestabilidad de microsatélites.

This study includes 12 consecutive patients who had a colonoscopy performed between Mar 2009 and May 2010 (10/83,33% females, 2/16,67% males), finding sessile lesion have a predilection for the proximal colon, pits patterns I – II (crypt dilatation and horizontal extension of crypts immediately above the muscularis mucosae). The application of this new technology electronic chromoendoscopy combined with high resolution endoscopy has promising areas of development in the description of pathologic mucosal changes and microvessels. This advanced technology allows an increased correlation between the images processed and the histological results. The serrated pathway neoplastic encompasses a morphologically and molecularly distinct group of colorectal neoplasms and represents an alternative molecular pathway to colorectal cancer. The sequence appears to begin with a non-dysplastic serrated polyp to a serrated adenoma and ultimately to carcinoma. Morphological and molecular studies are distinguishing a separate evolutionary pathway for colorectal cancer with extensive DNA methylation, mutation of BRAF and microsatellite instability.

Análise do perfil de expressão gênica de carcinoma ductal in situ e invasivo em tumores de mama através da técnica de microarray / Gene expression profile analysis of ductal carcinoma in situ and invasive of the breast cancer by Microarray techonology

O câncer de mama está entre as neoplasias de maior incidência e é responsável pela alta taxa de mortalidade entre as mulheres no mundo todo. O carcinoma ductal é o tipo histológico mais freqüente. O carcinoma ductalin situ (DCIS) inclui um grupo de tumores de mama pré-invasivos com potencial maligno distinto, podendo progredir rapidamente para carcinoma invasivo ou não apresentar evolução durante um longo período da doença. ... Neste estudo foram analisados 40 casos de mama, sendo 5 amostras de tecido de mamário não neoplásico(N), 16 casos de amostras pareadas de carcinoma ductal (in situ e invasivo), 5 DCIS puro, 9 DCIS coexistindo com o componente invasor (DCIS/IDC) e 5 carcinomas ductais invasivos (IDC). .... Dois delineamentos experimentais foram usados: comparação entre lesões in situ e invasivo da mesma amostra (DCIS e IDC); e comparação de grupos de lesões que mimetizam a progressão de câncer ductal de mama, utilizando amostras independentes [células epiteliais de mama capturadas de amostra não neoplásica (N), células tumorais capturadas das lesões: DCIS puro, DCIS/IDC e IDC]. ... Na comparação entre as 3 lesões (DCIS puro, DCIS/IDC e IDC), o DCIS puro mostrou maior divergência molecular, contradizendo os aspectos morfológicos. ... Esse resultado confirmou que o padrão de expressão entre essas lesões é semelhante mesmo avaliando genes sabidamente envolvidos no processo. ... Assim, baseado nos dados desse estudo, demonstramos que as células do carcinoma ductal in situ que coexistem com as células do carcinoma invasivo apresentam alterações moleculares antes da modificação morfológica da lesão, e isso pode ser explorado para se identificar genes alterados que possam predizer a capacidade de invasão. Além disso, esse estudo identificou vários genes candidatos a marcadores moleculares de prognóstico e também preditivos do risco de progressão de doença não invasiva.

Breast carcinoma is one of the most incidence neoplasias and is responsible for a high death-rate among women worldwide. The ductal carcinoma is the most frequent histological type. Ductal carcinoma in situ (DCIS) includes a group of preinvasive breast tumors with distinct malignant potentials. DCIS can have different outcomes, progressing rapidly to invasive cancer or slowly changing over a long period of the disease. Lately, one of the most challenges in molecular research in this field is to identify genes able to predict the risk of progression to invasive disease and prognostic marker. In this study were used 40 breast cases, being 5 non-neoplasic mammary tissues samples (N), 16 matched pairs of ductal carcinoma (in situ and invasive), 5 pure DCIS, 9 DCIS coexisting with invasive ductal carcinoma (DCIS/IDC) e 5 IDC. The RNA from epithelium cells laser capture microdissected were amplified and hybridized using reference design with dye swap in two distinct customized cDNA microarrays platforms. One containing 4.608 cDNA that represent human genes (4.8K) and other containing 390 genes belonging to WNT, PI3K signaling pathways and EMT process (Epithelial-mesenchymal transition). Two designing assays were used: comparisons between lesions in situ and invasive from the same patient (DCIS e IDC) and comparison among lesion groups that mimics the progression of breast ductal carcinoma using independent samples (breast epithelium cells microdissected of non-neoplasic tissues (N), tumoral cells microdissected of lesions: DCIS puro, DCIS/IDC e IDC. In the 4.8k platform, 16 matched-pair samples were used to compare the tumor cells expression profile of DCIS and IDC from the same patient. It was identified 33 candidates differentially expressed (t de Student pairwise - Fold >⎜1,5⎥ e pvalue<0,01), being candidates' genes to be involved in transition from DCIS to IDC. To 4 (LUM, RDH-E2, CXCL13 e POSTN) of 8 selected genes was confirmed differential expression through quantitative RT-PCR (qRT-PCR). Two genes (LUM and CRABP2) over expressed in IDC were selected to verify association with others molecular markers and/or clinicopathological parameters through Tissue Microarray. The LUM protein expression showed positive association with CKs 5/6, CK 14, CK8 e 18 and HER2/neu positive, while CRABP2 showed positive association with ER, PR, CK8, CK18, luminal A, p53 and negatively with CK14. Seeking to characterize molecular aspects of ductal carcinoma in situ of the breast progression, the general gene expression profile among 4 groups that mimics the progression was analyzed (N, DCIS pure, CIS/IDC e IDC) performing ANOVA test (pFDR<0,01) and followed by Tukey´s test, being characterized as most diverge the N group, as expected. The comparison among the 3 lesions (DCIS pure, DCIS/IDC e IDC), the pure DCIS showed the most molecular divergence, contradicting the morphological aspects. To identify genes able to predict the potential risk of invasion of DCIS, it was compared the expression profile of two morphologically identical lesions (DCIS pure e DCIS/IDC), identifying 147 genes (ANOVA - Fold >⎜2⎥ e pFDR<0,01). Hierarchical cluster based on expression profile of those genes could segregate the samples into two distinct groups in which 100% of non-neoplasic samples and 60% of pure DCIS remained in the same group and discriminated from DCIS/IDC (100%). Five (C16orf5, SULF-1, LOX, GOSR2 and TXNL2) candidates were confirmed through qRT-PCR as predict markers of DCIS progression. To assess the functional aspects of invasion process, it was used a platform containing genes belonging to WNT, PI3K signaling pathways and EMT process. The same experimental designing was used for 10 matched-pair, resulting in 32 differentially expressed genes between DCIS e IDC (t de Student pairwise - pvalue <0,05). This result confirmed that expression profile between the lesions is similar even assessing genes involved in this process. Between pure DCIS and DCIS/IDC were identified 15 differentially expressed genes (Wilcoxon ­ p<0,05) whose expression profile could segregate the samples in the same way as for the 147 genes. Triple classifiers were built seeking to segregate the DCIS pure and DCIS/IDC samples. One gene triple belonged to each signaling pathways, WNT (CSNK1A1L, LRP3 and SDC2), PI3K (PLCG2, INPP1 and DGKA) and EMT process (HDGF, CDH13 e TWIST1) were able to segregate the samples being predictor candidates of DCIS progression. Hence, based on this study data, we showed that ductal carcinoma in situ coexisting with invasive ductal carcinoma presents molecular alteration before lesion morphological modifications, and this may be exploited to identify altered genes able to predict invasion capacity. Furthermore, this study identified many candidate genes to molecular markers for outcome and also predicting the risk of noninvasive disease progression.

Imunoexpressão de WT1, ß-cateinina, E-caderina e APC em tumor de Wilms esporádico / Expression of WT1, p53, Beta-catenina, E-cadherina and APC in sporadic Wilms tumor

O tumor de Wilms é uma neoplasia embrionária, constituída classicamente por três componentes histológicos: blastema, epitélio e mesênquima (estroma), os quais podem ser encontrados em diferentes proporções em cada tumor. ... Este estudo tem como principal objetivo determinar a freqüência da expressão das proteínas WT1, p53, Beta-catenina, E-caderina e APC nos diferentes componentes histológicos do tumor de Wilms, assim como correlacionar estes achados com o prognóstico. Para estudar a expressão dos marcadores, foi utilizado a imunoistoquímica, através da construção de Tissue Macroarray (TMA), o qual permite a análise de muitas amostras teciduais em uma única lâmina, otimizando custo e tempo. Nos nossos resultados, WT1 e p53 foram mais freqüentemente expressos no componente blastema (WT1: 97% e p53: 63% dos casos) e epitélio (WT1: 87% e p53: 58% dos casos), quando comparados com o estroma (WT1: 13% e p53: 22% dos casos) e com o tecido renal não tumoral (ausência de expressão em todos os casos estudados). ... A imunoexpressão nuclear ocorreu principalmente nos componentes blastematoso e estromal. Houve imunoexpressão de E-caderina na membrana em 47% dos casos, em citoplasma em 44% e em núcleo em 12%. O acúmulo em núcleo foi encontrado principalmente nos componentes blastema e mesênquima, 21 e 25% respectivamente. A imunoexpressão do APC ocorreu em núcleo em 95% dos tumores avaliados, em citoplasma em 9% e nenhum apresentou expressão em membrana. Nos componentes blastematoso e epitelial houve imunopositividade nuclear em 100% dos casos avaliados. No componente mesenquimal a positividade nuclear ocorreu em 89% dos casos. Os pacientes com estádios precoces tiveram mais freqüentemente positividade do WT1. Não houve associação dos outros fatores clínicos, epidemiológicos e evolução dos pacientes com expressão dos marcadores estudados.

Wilms tumor is a triphasic malignant neoplasm compromised of variable proportions of epithelial, blastemal and mesenchymal (stromal) elements. Different components have different clinical behavior. Patients with tumors predominant epithelial and/or stromal has more frequently low stage while predominant blastema has advanced disease. This study was undertaken to evaluate the expression of WT1, beta-catenins, E-cadherin and APC in Wilms tumor and correlate this expression with clinical characteristics, histologic cell type and prognosis. We studied the immunohistochemical expression of WT1, p53, beta-catenins, E-cadherin in different component of Wilms tumor using a tissue array. WT1 and p53 were more often expressed on blastema component (WT1: 97% and p53: 63% of cases) and on epithelial (WT1: 87% and p53: 58% of cases), when compare with the stromal component (WT1: 13% and p53: 22% of cases) and the normal renal tissue where it was not expressed. Immunopositivity of WT1 and p53 were significantly correlated. Immunopositivity of ß-catenina was seen in 85 % at the membrane (85%), 94% cytoplasm and 24% nuclear. Nuclear immunoexpression was detected specially on blastema and stromal component. Immunohistochemical expression of E-cadherina was detected in 47% at the membrane, 44% cytoplasm and 12% nuclear. Nuclear expression was seen more often at the blastema and stromal component (21%, 25% respectively). Immunopositivity of APC occurs at 95% on nucleus, cytoplasm (9%) and none at membrane. Among the blastema and the epithelial component 100% was positive on nucleus. On the stromal component 89% was positive at the nucleus. Immunoexpression of WT1 was correlated with local stage. The expression status of WT1, E-cadherin, ßcatenina, APC in this cohort was not of prognostic value.

Identificación de asociaciones clínico-patológicas e hipermetilación de genes supresores de tumores en cáncer gástrico difuso a través de análisis de Hierarchical clustering / Hierarchical clustering analysis to detect associations between clinical and pathological features of gastric tumors and hypermethylation of suppressor genes

Background:Methylation is an inactivation mechanism for tumor suppressor genes, that can have important clinical implications. Aim: To analyze the methylation status of 11 tumor suppressor genes in pathological samples of diffuse gastric cancer. Material and methods: Eighty three patients with diffuse gastric cancer with information about survival and infection with Epstein Barr virus, were studied. DNA was extracted from pathological slides and the methylation status of genes p14, p15, p16, APC, p73, FHIT, E-caderin, SEMA3B, BRCA-1, MINT-2 y MGMT, was studied using sodium bisulphite modification and polymerase chain reaction. Results were grouped according to the methylation index or Hierarchical clustering (TIGR MultiExperiment Viewer). Results: Three genes had a high frequency of methylation (FHIT, BRCA1, APC), four had an intermediate frequency (p15, MGMT, p14, MINT2) and four had a low frequency (p16, p73, E-cadherin, SEMA3B). The methylation index had no association with clinical or pathological features of tumors or patients survival. Hierarchical clustering generated two clusters. One grouped clinical and pathological features with FHIT, BRCA1, and APC and the other grouped the other eight genes and Epstein Barr virus infection. Two significant associations were found, between APC and survival and p16/p14 and Epstein Barr virus infection. Conclusions: Hierarchical clustering is a tool that identifies associations between clinical and pathological features of tumors and methylation of tumor suppressor genes.

Cáncer colorrectal hereditario: análisis molecular de los genes APC y MLH1 / Hereditary colorectal cancer: Molecular analysis of APC and MLH1 genes

Background: Among colorectal cancer hereditary variants, two syndromes show a predisposition to the disease based on germline mutations: Familial Adenomatous Polyposis (FAP) and Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Aim: To screen mutations in FAP and HNPCC families in Chile. Materials and Methods: Two FAP and one HNPCC families were studied. The APC gene (for FAP patients) and the MLH1 gene (for HNPCC patients), were screened for mutations on genomic DNA. The molecular analysis was performed through polymerase chain reaction, Single Strand Conformer Polymorphism (SSCP) and DNA sequencing. Mutations were defined as changes in the DNA sequence leading into a stop codon and a truncated protein. Results: In the two FAP families the analysis revealed a mutation consisting in the deletion of five nucleotides named c.3927_3931delAAAGA. The genetic study of the HNPCC family demonstrated the insertion of one adenine in codon 168 of exon 6, named c.504insA. Discussion: Germ-line mutations were identified in the three families. The relevance of these studies in a better knowledge of cancer susceptibility, and the possibility of identifying in relatives in risk by molecular diagnosis.

Poliposis familiar: Alternativas terapéuticas y estudio de los familiares / Treatment of familial adenomatous polyposis and family screening

Background: To reduce the mortality associated to Familial Adenomatous Polyposis (FAP), screening of close relatives of patients with the disease is crucial. Aim: To analyze the results of the surgical treatment of patients with FAP, and to evaluate the family screening. Patients and Methods: Clinical records of patients operated in our institution since 1977, were reviewed analyzing surgical and pathological results, and follow up. In their family members, we evaluated and analyzed the performance of screening tests, former surgeries, history of disease-related cancer and mortality, all due to FAP. Results: Between January 1977 and August 2002, 15 patients were operated on. Of these, only 33 percent consulted on the setting of a familial screening. A proctocolectomy and terminal ileostomy was performed in 27 percent of patients; 20 percent had a proctocolectomy and ileal pouch, and 53 percent underwent a total colectomy with ileo-rectal anastomosis. Morbidity and mortality were 7 percent and 0 percent, respectively. Twenty percent had a colorectal cancer. During a median of 68 months follow-up, the disease-related survival was 92 percent; no cancer of the rectal stump was detected. Of the 122 family members identified, only 33 percent with clear indication of screening underwent a colonoscopy. Twenty-nine percent had a confirmed FAP and were operated: in 61 percent of them a colorectal cancer was found, and 91 percent of these died. Conclusions: The results of the surgical treatment of FAP are satisfactory. Nevertheless, family screening should be improved to reduce the high rates of mortality revealed in the study of other family members (Rev Méd Chile 2005; 133: 1043-50).

Patrón de metilación génico en el cáncer de mama / Promoter methylation profile in breast cancer

BACKGROUND: Genomic DNA methylation, mutations and allelic deletions explain the inactivation of genes involved in cell proliferation and cell cycle control mechanisms. AIM: To analyze the methylation pattern of important genes related to different carcinogenic mechanisms in patients with breast cancer and the relationship with its biological behavior. MATERIAL AND METHODS: Seventy fresh-frozen breast cancer samples were selected. The methylation specific PCR (MSP) test was used to analyze promoter methylation status for genes CDKN2A (p16), hMLH1, APC, CDH1 (Cadherin E) and FHIT. RESULTS: We found methylation in at least one of the genes studied in 88% of cases and in 3 or more genes in 40.5% of cases. The frequencies of promoter hypermethylation of CDKN2A, hMLH1, APC, CDH1 and FHT were 41.4%, 11.4%, 52.9%, 70% and 42.9%, respectively. We found a relationship between CDKN2A methylatlon and better survival (p=0.002). CDH1 methylation and poor histological differentiation (p=0.007), hMLH1 methylation and non-Mapuche ethnicity (p=-0.03), APC methylation and larger tumor size (p<0.05), FHIT methylatton and lack of estrogen rectptor IHC expression (p<0.05). CONCLUSIONS: The high frequency of promoter methylation in patients with breast cancer confirms its role in breast carcinogenesis. The finding of alterations in the methylation pattern of genes studied and its association with prognostic factors is a helpful tool in the search of new criteria for clinical and therapeutic decision making.

P53 and Rb tumor suppressor gene alterations in gastric cancer

A inativação de genes supressores tumorais tem sido freqüentemente observada na carcinogênese gástrica. O nosso objetivo foi estudar o envolvimento dos genes p53, APC, DCC e Rb no câncer gástrico. MÉTODO: Vinte e dois casos de câncer gástrico foram estudados por PCR-LOH (reação de polimerase em cadeia- perda de alelo heterozigoto) dos genes p53, APC, DCC e Rb; e por PCR-SSCP (reação de polimerase em cadeia- polimorfismo de conformação de cadeia única) dos exons 5-6 e exons 7-8 do gene p53, empregando 35S-dATP e expressão de p53 por imunoperoxidase com monoclonal anti-p53. RESULTADOS E DISCUSSAO: Perda de alelo heterozigoto não foi detectada nos genes estudados; deleção homozigótica foi observada no gene Rb em 23% (3/13) dos casos de câncer gástrico do tipo intestinal. Desvio de motilidade de banda nos exons 5-6 e/ou exons 7-8, indicando mutação do gene p53 foi encontrada em 18 casos (81.8%). A expressão de p53 foi positiva nas células de câncer gástrico em 14 casos (63.6%). A mucosa gástrica normal não corou com anti-p53, portanto, a reatividade imune deve representar formas mutantes. A correlação de desvio de motilidade de banda e expressão imune de p53 não foi significante (p=0.90). Não houve correlação entre as alterações genéticas e a extensão da doença. CONCLUSAO: A inativação dos genes p53 e Rb tem papel na carcinogênese gástrica no nosso meio. A perda do gene Rb observada apenas no câncer gástrico do tipo intestinal deve ser avaliada posteriormente em associação com infecção pelo Helicobacter pylori. O gene p53 estava afetado em ambos os tipos histopatológicos.

Actualización del registro de poliposis del Hospital de Gastroenterología Dr. Carlos Bonorino Udaondo / Up to date Dr. Carlos Bonorino Udaondo Hospital's poliposis register

Antecedentes: La poliposis adenomatosa familiar (PAF) es una enfermedad hereditaria autosómica dominante con características genéticas y clínicas deteminantes que nos permiten modificar su evolución natural (el 100 por ciento de los pacientes portadores del gen APC mutado desarrollaran cáncer colorrectal de no ser operados). En los últimos años se ha descripto que tanto el Peutz Jeghers como la poliposis juvenil tienen potencial maligno variable. Objetivos: Actualizar y demostrar que un registro es capaz de hacer detección precoz de estas enfermedades preneoplásicas y consecuentemente disminuir la prevalencia de cáncer en estos grupos. Material y métodos: Se registraron 843 individuos, pertenecientes a 172 familias (157 con diagnóstico de PAF, 8 con poliposis juvenil y 7 con Peutz Jeghers), durante un período comprendido entre comienzos del año 1995 y abril de 2003. Resultados: En el año 2003 el Registro del Hospital de Gastroenterología cuenta con 330 pacientes con diagnóstico de PAF (235 vivos), 11 con poliposis juvenil y 9 con Peutz Jeghers. Se encuentran en riesgo 475 individuos. Las manifestaciones extracolónicas observadas fueron: 38 poliposis gástrica sobre 126 pacientes estudiados; 25 poliposis duodenal (5 de ellos adenomatosos); hipertrofia del epitelio pigmentario de la retina en 14 (de 47 pacientes); osteomas en 21 (de 76); 11 lipomas; 10 tumores desmoides; 16 quistes epidermoides. De los individuos registrados que fueron citados sólo en 14 de ellos se diagnóstico cáncer (5,36 por ciento). Se realizaron en el mismo lapso 205 cirugías. De ellas 189 fueron colorrectales: 117 colectomías totales con ileorrectoanastomosis, 27 coloproctectomías con pouch ileal y 34 coloproctectomías con ileostomía definitiva, 3 Ravitch, 3 Soave y 5 proctectomías. Se analizó genéticamente a 78 casos índices, identificando la mutación en 39 de ellos. Conclusiones: Registrar en forma ordenada y metódica a los pacientes con síndromes polipósicos hereditarios nos permite citar a los familiares en riesgo en forma precoz, disminuyendo la prevalencia de cáncer colorrectal en la PAF. Del mismo surge también la necesidad de realizar la pesquisa de adenomas duodenales ya que es la segunda causa de muerte en los pacientes colectomizados.