Low-dose cisplatin exposure and SNAIL, Vimentin, E-cadherin expression in HEPG2 cell line / Exposición a dosis bajas de cisplatino y expresión de SNAIL, Vimentina, E-cadherina en línea celular HEPG2

Cisplatin, the first platinum compound approved for cancer treatment, is widely used in the treatment of various cancers including hepatocellular carcinoma (HCC). HCC incidence rates rise globally. Epithelial mesenchymal transition (EMT) is implicated in cancer invasion and metastasis, which are associated with increased mortality. Cisplatin dose might influence cancer invasion and metastatic behavior of the cells. The aim of the study was to investigate the effect of low-dose cisplatin treatment on EMT- related changes in HepG2 cells. Following treatment with 4 µM cisplatin, HepG2 cells were evaluated morphologically. Gene expression of E-cadherin, Vimentin, Snail1 was assessed by quantitative PCR. Immunofluorescence analyses of NA-K ATPase were performed. Although the low-dose cisplatin treated cells exhibited a more stretched morphology, no statistical difference was detected in gene expression of E-cadherin, Vimentin, Snail1 and immunofluorescence of NA-K ATPase. Findings on low-dose cisplatin effects in HepG2 might contribute to the knowledge of antineoplastic inefficacy by further understanding the molecular mechanisms of drug action.

El cisplatino, el primer compuesto de platino aprobado para el tratamiento del cáncer, es ampliamente utilizado en el tratamiento de varios tipos de cáncer, incluido el carcinoma hepatocelular (CHC). Las tasas de incidencia de CHC aumentan a nivel mundial. La transición mesenquimal epitelial (EMT) está implicada en la invasión del cáncer y la metástasis, que se asocian con un aumento de la mortalidad. La dosis de cisplatino podría influir en la invasión del cáncer y el comportamiento metastásico de las células. El objetivo del estudio fue investigar el efecto del tratamiento con dosis bajas de cisplatino en los cambios relacionados con la EMT en las células HepG2. Tras el tratamiento con cisplatino de 4 µM, se evaluaron morfológicamente las células HepG2. La expresión génica de E-cadherina, vimentina, caracol1 se evaluó mediante PCR cuantitativa. Se realizaron análisis de inmunofluorescencia de NA-K ATPasa . Aunque las células tratadas con cisplatino en dosis bajas exhibieron una morfología más estirada, no se detectaron diferencias estadísticas en la expresión génica de E-cadherina, vimentina, Snail1 e inmunofluorescencia de NA-K ATPasa. Los hallazgos sobre los efectos del cisplatino en dosis bajas en HepG2 podrían contribuir al conocimiento de la ineficacia antineoplásica al comprender mejor los mecanismos moleculares de la acción del fármaco.

Variante patogénica en el gen PCDH19 en una paciente con epilepsia y discapacidad cognitiva / Pathogenic variant in the PCDH19 gene in a patient with epilepsy and cognitive disability

INTRODUCCIÓN: La asociación de casos familiares de epilepsia y discapacidad intelectual (DI) en mujeres fue reportada en 1971. El año 2008, se identificó el rol de variantes patogénicas del gen PCDH19 en algunas familias. La enfermedad se presenta con crisis febriles en cluster, DI y rasgos autistas. La mayoría se debe a variantes de novo, pero hay algunos casos heredados por un modo peculiar de transmisión ligada X. OBJETIVO: Comunicar el caso de una paciente con epilepsia portadora de una variante patogénica en el gen PCDH1 9, revisando la historia natural de la enfermedad y la evidencia disponible para su manejo. CASO CLÍNICO: Paciente femenina, con antecedentes de embarazo y período perinatal normal. A los 6 meses, estando febril, presentó crisis focales motoras en cluster que repitieron a los 14, 18, 21 meses y 3 años siempre asociadas a fiebre, presentando incluso estatus epiléptico. Mantiene biterapia con topiramato y ácido valproico, completando 13 años sin crisis. El estudio del gen SCN1A no mostró anomalías y el estudio del gen PCDH19 reveló una variante patogénica en heterocigosis, "de novo". La paciente ha evolucionado con DI y alteraciones conductuales severas que requieren aten ción de salud mental. CONCLUSIONES: Las variantes patogénicas PCDH19 tienen expresión fenotípica variada. El diagnóstico genético debe sospecharse con la clínica. La morbilidad psiquiátrica a largo plazo puede ser incapacitante.

INTRODUCTION: The association of family cases of epilepsy and intellectual disability in women was reported in 1971. In 2008, the role of pathogenic variants of the PCDH19 gene in some families were identified. The disease presents with febrile seizure clusters, intellectual disability, and autistic features. Most cases are due to de novo variants, however, there are some inherited cases, with an atypical way of X-linked transmission. OBJECTIVE: To report the case of a patient with epilepsy carrier of a pathogenic variant of the PCDH19 gene, reviewing the natural history of this condition and the available evidence for its management. CLINICAL CASE: Female patient, with normal history of pregnancy and perinatal period. At 6 months, while febrile, she presented focal motor seizure clusters that repeated at 14, 18, 21 months and 3 years old, always associated with fever, even presenting status epilepticus. She is on therapy with topiramate and valproic acid, achieving 13 seizure-free years. The analysis of the SCN1A gene showed no abnormalities and the study of the PCDH19 gene revealed a de novo heterozygous pathogenic variant. The patient evolved with intellectual disability and severe behavioral disorders that require mental health team support. CONCLUSIONS: PCDH19 pathogenic variants have varied phenotypic expression. The genetic diagnosis should be guided with the clinical features. Long-term psychiatric morbidity can be disabling.

Hypotrichosis with juvenile macular dystrophy: a case report with molecular study / Hipotricose com distrofia macular juvenil: relato de caso com estudo molecular

ABSTRACT Hypotrichosis with juvenile macular dystrophy is a rare autosomal recessive disorder characterized by sparse scalp hair caused by hair follicle abnormalities as well as progressive retinal degeneration leading to blindness in the second or third decade of life. It is associated with mutations of the cadherin 3 (CDH3) gene, which result in abnormal expression of P-cadherin. Mutations in CDH3 are related to ectodermal dysplasia, ectrodactyly, and macular dystrophy. In this report, we describe an 11-year-old Iranian boy born with a missing left index fingernail and sparse scalp hair who later displayed macular pigmentary changes. Genetic testing of the CDH3 gene revealed a homozygous gene variant at exon 6 (640A>T). This novel in-frame mutation converts a lysine to a premature stop codon, altering synthesis of P-cadherin on chromosome 16q22.

RESUMO Hipotricose com distrofia macular juvenil (HDMJ) é uma doença autossômica recessiva rara caracterizada por rarefação capilar por alteração nos folículos pilosos e degeneracão progressiva da retina levando a cegueira na segunda e terceira década de vida. Associada a mutações no gene CDH3, resultando em expressão anormal de P-caderina. Mutações no gene CDH3 estão relacionados à displasia ectodérmica, ectrodactilia e distrofia macular. Neste relato descrevemos um menino Iraniano de 11 anos de idade, com ausência da unha na mão esquerda e rarefação capilar desde o nascimento, e que posteriormente apresentou alterações pigmentares maculares. Teste genético do gene CDH3 revelou uma variação homozigótica no exon 6 (640A>T). Essa mutação in-frame troca uma lisina por um codon de parada prematura, alterando a síntese da proteína P-caderina no cromossomo 16q22.

Efecto de las alteraciones genéticas y epigenéticas de la cadherina E y su expresión en la transcripción en la propensión al cáncer de mama / Effect of genetics, epigenetics and variations in the transcriptional expression of cadherin-E in breast cancer susceptibility

RESUMEN Introducción. La cadherina E (CDH1) cumple un papel importante en la transición epitelio-mesénquima y está relacionada con la invasión y las metástasis en varios tipos de carcinomas. Sin embargo, el efecto de las mutaciones y 'epimutaciones' germinales en la propensión al cáncer de mama no es claro. Objetivo. Evaluar el polimorfismo rs5030625, los cambios en el patrón de metilación del promotor y la expresión en la transcripción del gen CDH1 en pacientes con cáncer de mama. Materiales y métodos. Se tomaron muestras de sangre periférica de 102 pacientes con cáncer de mama y 102 mujeres de control. La genotipificación del polimorfismo rs5030625 se hizo mediante reacción en cadena de la polimerasa (PCR) y análisis de polimorfismos de longitud del fragmento de restricción; la PCR y el análisis de disociación de alta resolución sensible a metilación se emplearon para determinar el estado y el nivel de metilación del promotor del CDH1; por último, el nivel de expresión en la transcripción del CDH1 se evaluó mediante PCR cuantitativa con transcripción inversa. Resultados. Los resultados no evidenciaron asociación entre el polimorfismo rs5030625 y el cáncer de mama. Se encontraron perfiles aberrantes de metilación del promotor del CDH1 en las pacientes con cáncer de mama relacionados con las primeras etapas de desarrollo del cáncer. La disminución de la expresión del CDH1 se asoció con la presencia de metástasis y el estado de metilación del promotor. Conclusión. Las alteraciones en el CDH1 se asociaron con la invasión y las metástasis en el cáncer de mama. Se proporcionó evidencia adicional sobre la relevancia del CDH1 en el desarrollo y la progresión del cáncer de mama.

ABSTRACT Introduction: Cadherin-E (CDH1) is an important regulator of epithelial-mesenchymal transition, invasion and metastasis in many carcinomas. However, germinal epimutations and mutations effect in breast cancer susceptibility is not clear. Objective: To evaluate rs334558 polymorphism, promoter methylation status and CDH1 expression profile in breast cancer patients. Materials and methods: We collected peripheral blood samples from 102 breast cancer patients and 102 healthy subjects. The identification of rs334558 polymorphism was performed using PCR-RFLP, while methylation-specific PCR (MSP) and methylation-sensitive high-resolution melting (MS-HRM) were used to explore CDH1 methylation status; finally, CDH1 transcriptional expression profile was evaluated using RT-qPCR. Results: We found no association between rs334558 polymorphism and breast cancer. Aberrant promoter methylation profile was found in breast cancer patients and it was related with early cancer stages. CDH1 down-regulation was significantly associated with metastasis and promoter methylation. Conclusion: CDH1 alterations were associated with invasion and metastasis in breast cancer. Our results offer further evidence of CDH1 relevance in breast cancer development and progression.

Síndrome de Wiskott-Aldrich: Caso clínico / Wiskott-Aldrich syndrome: Case report

El síndrome de Wiskott-Aldrich es una inmunodeficiencia primaria; con una incidencia de 3,5 a 5,2 por cada millón de recién nacidos masculinos. Se caracteriza por tener un patrón de herencia recesiva ligada al cromosoma X. En estos pacientes; se ha descrito la tríada clásica de inmunodeficiencia; microtrombocitopenia y eczema. Presentamos un paciente de 5 años de edad; hispánico; con antecedentes de numerosas infecciones desde el primer año de vida. Actualmente; presenta desnutrición crónica; talla baja secundaria y retraso en el desarrollo del lenguaje. Se diagnosticó una mutación poco frecuente del gen asociado al síndrome de Wiskott-Aldrich.

The Wiskott-Aldrich syndrome is a rare X-linked recessive immunodeficiency, with an estimated incidence of 3.5 to 5.2 cases per million males. It is characterizedby immunodeficiency, microthrombocytopenia and eczema. We present a 5-year-old Hispanic male, with a medical history of numerous infectious diseases, compromised health, chronic malnutrition, language delay and failure to thrive. An infrequent mutation in the Wiskott-Aldrich syndrome gene was found.

Expresión de cadherinas E y P en los tipos moleculares de cáncer de mama / Cadherins E and P expression in the molecular types of breast cancer.

La transición epitelial-mesenquimal es un proceso mediante el cual las células tumorales pierden sus marcadores epiteliales y facilita la migración a órganos distantes. En este proceso intervienen diversas proteínas de adhesión celular, tales como la cadherina E y la cadherina P. El presente estudio se realizó en 354 pacientes diagnosticadas de carcinoma ductal infiltrante de mama en seguimiento, en el Instituto de Oncología “Dr. Miguel Pérez Carreño” de Valencia, Venezuela. Se analizó la expresión de las dos moléculas por matrices de tejidos y se compararon los resultados obtenidos con las clases moleculares definidas por inmunohistoquímica, de acuerdo a la expresión de receptores de estrógeno (RE), receptores de progesterona (RP) y receptor del factor de crecimiento epidérmico humano 2 (HER2) y con la supervivencia global (SG). Con base a los resultados de RE, RP y HER2 se establecieron las clases moleculares, obteniendo los siguientes porcentajes: Luminal A 42,4%, Luminal B 20,3%, HER2 9% y triple negativo (TN) 28,2%. La expresión de cadherina E se observó conservada en la mayoría de los tumores de esta serie, 92,5% de los casos. Los tumores de fenotipo TN presentaron un porcentaje elevado (41,7%) con expresión ausente o reducida. La cadherina P se expresó en el 40,5% de los casos, y aunque expresada en todas las clases, la proporción fue significativamente mayor en los casos TN. No se apreció valor pronóstico significativo al analizar la SG a 5 años de las pacientes con tumores con ausencia o expresión reducida de cadherina E. La expresión de cadherina P presentó relación negativa con la SG.

The epithelial-mesenchymal transition is a process by which tumor cells lose their epithelial markers and migrate to distant organs. This process involves several cell adhesion proteins such as E-cadherin and P-cadherin. The present study was performed in 354 pacients diagnosed with breast infiltrating ductal carcinoma in the Oncology Institute “Dr. Miguel Pérez Carreño”, Valencia, Venezuela. The expression of 22 molecules was analyzed by tissue micro-arrays and the results were compared with the molecular clases established by immunohistochemistry, according to the expression of estrogen receptor (ER), progesterone (PR) and human epidermal growth factor receptor type 2 (HER2), and with the overall survival (OS). Based on the results of ER, PR and HER2 molecular classes according to the following percentages were established: Luminal A 42.4%, Luminal B 20.3%, 9% HER2 and 28.2% triple negative (TN). E-cadherin expression was observed conserved in most of the tumors of this series, 92.5% of cases. TN phenotype tumors showed a high percentage (41.7%) with absent or reduced expression. The P-cadherin was expressed in 40.5% of cases, although expressed in all classes; the proportion was significantly higher in cases TN. No significant prognostic value was observed when analyzing the overall five-year survival of patients with tumors with absent or reduced expression of E-cadherin. The P-cadherin expression had a negative relationship with the OS.

Isolated Schwannoma of the Olfactory Groove: A Case Report

Introduction Schwannoma of the olfactory groove is an extremely rare tumor that can share a differential diagnosis with meningioma or neuroblastoma. Objectives The authors present a case of giant schwannoma involving the anterior cranial fossa and ethmoid sinuses. Case Report The patient presented with a 30-month history of left nasal obstruction, anosmia, and sporadic ipsilateral bleeding. Computed tomography of the paranasal sinuses revealed expansive lesion on the left nasal cavity extending to nasopharynx up to ethmoid and sphenoid sinuses bilaterally with intraorbital and parasellar extension to the skull base. Magnetic resonance imaging scan confirmed the expansive tumor without dural penetration. Biopsy revealed no evidence of malignancy and probable neural cell. Bifrontal craniotomy was performed combined with lateral rhinotomy (Weber-Ferguson approach), and the lesion was totally removed. The tumor measured 8.0 4.3 3.7 cm and microscopically appeared as a schwannoma composed of interwoven bundles of elongated cells (Antoni A regions)mixed with less cellular regions (Antoni B). Immunohistochemical study stained intensively for vimentin and S-100. Conclusion Schwannomas of the olfactory groove are extremely rare, and the findings of origin of this tumor is still uncertain but recent studies point most probably to the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. .

Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure

Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13BN rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats, and this relationship might depend on the increase in blood pressure.

Gene expression in SK-Mel-28 human melanoma cells treated with thesnake venom jararhagin

Alternative approaches to improve the treatment of advanced melanomas are highly needed.The disintegrin domain of metalloproteinases binds integrin receptors on tumor cells,blocking migration, invasion, and metastatization. Previous studies showed that jararhagin,from the Bothrops jararaca snake venom, induces changes in the morphology and viability ofSK-Mel-28 human melanoma cells, and decreases the number of metastases in mice injected with pre-treated cells. The purpose of this study was to evaluate the molecular effects ofjararhagin on SK-Mel-28 cells and fibroblasts, concerning the expression of integrins, cadherins, caspases, and TP53 genes. Sub-toxic doses of jararhagin were administered to confluent cells. RT-PCR was performed following extraction of total RNA. Jararhagin treatmentsinduced similar morphological alterations in both normal and tumor cells, with higher IC50 values for fibroblasts. Integrin genes were downregulated in untreated cells,except for ITGA6a,b, ITGAv, and ITGB3 which were highly expressed in SK-Mel-28. The integrin expression profiles were not affected by the toxin. However, jararhagin 30 ng/mlupregulated genes TP53, CDKN1A, CDKN2A, CASP3, CASP5, CASP6, CASP8, and E-CDH in SKMel-28, and genes ITGB6, ITGB7, CASP3, TP53, and CDKN1B in fibroblasts. Appropriate jararhagin concentration can have apoptotic and suppressant effects on SK-Mel-28 cells, ratherthan on fibroblasts, and can be used to develop potential anti-cancer drugs.

Methylation status of CDH1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by Helicobacter pylori

CONTEXT: Gastric cancer is one of the top list of cancer types that most leads to death in Brazil and worldwide. Helicobacter pylori(H. pylori) is a class I carcinogen and infect almost 90 percent of chronic gastritis patients. Some genotypes confer different virulent potential to H. pylori and can increase the risk of gastritis development. Methylation of CpG islands can inactivate tumor suppressor genes and therefore, it can be involved in the tumorigenic process. CDH1 is a tumor suppressor gene that encodes the E-cadherin protein, which is important in maintaining cell-cell contacts. The inactivation of this gene can increase the chance of metastasis. Promoter methylation of CDH1 at early steps of gastric carcinogenesis is not yet completely understood. OBJECTIVE: In this study, we investigated the methylation status of CDH1 in chronic gastritis samples and correlated it with the presence of H. pylori. METHODS: Sixty gastric mucosal biopsies were used in this study. The detection of H. pylori was performed with the PCR primers specific to urease C gene. H. pylori genotyping was performed by PCR to cagA and vacA (s and m region). The methylation status of these gene CDH1 was analyzed using methylation-specific polymerase chain reaction and direct sequencing of the PCR products was performed using primers methylated and unmethylated in both forward and reverse directions. RESULTS: H. pylori was detected in 90 percent of chronic gastritis samples; among these 33 percent were cagA positive and 100 percent vacA s1. The genotype vacA s2/m1 was not detected in any sample analyzed. Methylation of CDH1 was detected in 63.3 percent of chronic gastritis samples and 95 percent of them were also H. pylori-positive. CONCLUSION: This work suggests that CDH1 gene methylation and H. pylori infection are frequent events in samples from Brazilian patients with chronic gastritis and reinforces the correlation between H. pylori infection and CDH1 inactivation ...

CONTEXTO:O câncer gástrico é uma das principais neoplasias que causam o óbito no Brasil e no mundo. Helicobacter pylori é um carcinógeno do tipo I relacionado à gastrite crônica. Diferenças no grau de virulência de suas cepas levam a maior risco de desenvolvimento de doenças gástricas. A metilação de ilhas CpGs está envolvida com o processo de tumorigênese em diferentes tipos de câncer. CDH1 é um gene supressor tumoral que, quando inativado, pode aumentar as chances de metástase. A metilação deste gene em estágios precoces da carcinogênese gástrica ainda não é totalmente compreendida. OBJETIVO: Investigar o padrão de metilação do gene CDH1 em amostras de gastrites crônicas e correlacionar com a presença do H. pylori. MÉTODOS: Foram usadas 60 biopsias de mucosas gástricas. A detecção de H. pylori foi realizada por PCR para o gene da urease C e a genotipagem com PCR para os genes cagA e vacA (região s e m). O padrão de metilação do gene CDH1 foi analisado usando a técnica de PCR e específica para a metilação e sequenciamento direto dos produtos de PCR. RESULTADOS: A bactéria H. pylori foi detectada em 90 por cento das amostras de gastrites crônicas; destas, 33 por cento portavam o gene cagA e 100 por cento vacA s1. O genótipo vacA s2/m1 não foi detectado nas amostras analisadas. Metilação de CDH1 foi detectada em 63,3 por cento das amostras de gastrites e 95 por cento delas eram portadoras de H. pylori. CONCLUSÃO: Os resultados deste estudo sugerem que a metilação em CDH1 e a infecção pelo H. pylori são eventos frequentes em amostras de pacientes brasileiros com gastrite crônica e reforça a correlação entre infecção por H. pylori e inativação do gene CDH1 em estágios precoces da tumorigênese gástrica.

Expression of E-cadherin, Snail and Hakai in epithelial cells isolated from the primary tumor and from peritumoral tissue of invasive ductal breast carcinomas

Epithelial intercellular cohesion, mainly mediated by E-cadherin (CDH1) expression and function, may be deregulated during cancer cell invasion of adjacent tissues and lymphatic and vascular channels. CDH1 expression is down-modulated in invasive lobular breast carcinomas but its regulation in invasive ductal carcinomas (IDC) is less clear. CDH1 expression is repressed by transcription factors such as Snail (SNAI1) and its product is degraded after Hakai ubiquitination. We compared CDH1, SNAI1 and HAKAI mRNA expression in IDC and paired adjacent normal breast tissue and evaluated its relation with node metastasis and circulating tumor cells. Matched tumor/peritumoral and blood samples were collected from 30 patients with early IDC. Epithelial cells from each compartment (tumor/peritumoral) were recovered by an immunomagnetic method and gene expression was determined by real time RT-PCR. There were no differences in CDH1, SNAI1 and HAKAI mRNA expression between tumor and corresponding peritumoral samples and no differential tumoral gene expression according to nodal involvement. Another 30 patients with a long-term follow-up (at least 5 years) and a differential prognosis (good or poor, as defined by breast cancer death) had E-cadherin and Snail protein detected by immunohistochemistry in tumor samples. In this group, E-cadherin-positive expression, but not Snail, may be associated with a better prognosis. This is the first report simultaneously analyzing CDH1, SNAI1 and HAKAI mRNA expression in matched tumor and peritumoral samples from patients with IDC. However, no clear pattern of their expression could distinguish the invasive tumor compartment from its adjacent normal tissue.

Models for the recent evolution of protocadherin gene clusters

The clustered protocadherins (Pcdhs) are single-pass transmembrane proteins that constitute a subfamily within the cadherin superfamily. In mammals, they are arranged in three consecutive clusters named alpha, beta, and gamma. These proteins are expressed in the nervous system and are targeted to mature synapses.Interestingly, different neurons express different subsets of isoforms; however, little is known about the functions and expression of the clustered Pcdhs. Previous phylogenetic analyses that compared rodent and human clusters postulated the recent occurrence of gene duplication events. Using standard phylogenetic methods, I confirmed the prior observations, and I show that duplications are likely to occur through unequal crossing-over events between two, and sometimes three, different Pcdh genes. The results are consistent with the fact that these genes undergo gene conversion. Recombination events between different clustered Pcdh genes appear to underlie concerted evolution through gene conversion and gene duplications through unequal crossing-over. In this work, I provided evidence that the unit of duplication of these genes in both the mouse and the human and within each cluster is the same. The unit of duplication includes the extracellular domain-coding sequence of an isoform and its promoter along with the cytoplasmic domain-coding region of the immediately upstream isoform in the cluster.

Estudio de patrones de metilación génica en tumores del tubo digestivo / Gene methylation patterns in digestive tumors

Background: The loss of tumor suppresor gene function damages the defensive mechanisms that protect the indemnity of genetic material. Promoter gene methylation is one of the inactivation mechanisms of suppressor genes. Aim: To study the methylation pattern of a group of genes in biopsy samples of gastrointestinal tumors. Material and methods: Forty eight gastric, 25 gallbladder, 24 colon and 6 pancreas cancer biopsy samples were randomly selected. The methylation pattern of CDH1, FHIT, CDKN2A, APC and MLH1 genes, was studied using a specific polymerase chain reaction test for methylation. Demographic, morphological and follow up variables of patients bearing the tumors were also analyzed. Results: The general methylation frequency of CDH1, FHIT, CDKN2A, APC and MLH1 genes was 64.1, 56, 39.8, 18.1 and 34 percent respectively. In gastric cancer samples there was a correlation between APC gene methylation and well differentiated tumors; between CDH1 methylation and Lauren diffuse type and the presence of three or more metastasic lymph nodes; between FHIT, CDKN2A and CDH1 gene methylation and male gender. In ¡ess differentiated gallbladder tumors, the frequency of CDH1 methylation was higher. There was a tendency towards a lower survival in colon and gastric cancer when MLH1 (p =0.07) y CDKN2A (p= 0.06) were methylated, respectively. Conclusions: An abnormal methylation pattern was associated with morphological features in gastric and gallbladder cancer and with a tendency towards a lower survival in colon and gastric cancer.

Differential expression of E-cadherin gene in human neuroepithelial tumors

Cadherins are cell-to-cell adhesion molecules that play an important role in the establishment of adherent-type junctions by mediating calcium-dependent cellular interactions. The CDH1 gene encodes the transmembrane glycoprotein E-cadherin which is important in maintaining homophilic cell-cell adhesion in epithelial tissues. E-cadherin interacts with catenin proteins to maintain tissue architecture. Structural defects or loss of expression of E-cadherin have been reported as a common feature in several human cancer types. This study aimed to evaluate the expression of E-cadherin and their correlation with clinical features in microdissected brain tumor samples from 81 patients, divided into 62 astrocytic tumors grades I to IV and 19 medulloblastomas, and from 5 white matter non-neoplasic brain tissue samples. E-cadherin (CDH1) gene expression was analyzed by quantitative real-time polymerase chain reaction. Mann-Whitney, Kruskal-Wallis, Kaplan-Meir, and log-rank tests were performed for statistical analyses. We observed a decrease in expression among pathological grades of neuroepithelial tumors. Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than did neuroepithelial tumors. Expression of E-cadherin gene was higher in astrocytic than embryonal tumors (P = 0.0168). Low-grade malignancy astrocytomas (grades I-II) showed higher CDH1 expression than did high-grade malignancy astrocytomas (grades III-IV) and medulloblastomas (P < 0.0001). Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than grade I malignancy astrocytomas, considered as benign tumors (P = 0.0473). These results suggest that a decrease in E-cadherin gene expression level in high-grade neuroepithelial tumors may be a hallmark of malignancy in dedifferentiated tumors and that it may be possibly correlated with their progression and dissemination.

Estudo da relação entre a imunoexpressão das proteínas caderina-E e DCC com o grau de diferenciação celular e o estadiamento TNM do adenocarcinoma colorretal / Study of the expression of E-cadherin and DCC proteins with cell differentiation degree and staging in colorectal adenocarcinoma

OBJETIVO: Avaliar a relação de duas proteínas que participam do mecanismo de adesão celular com o grau de diferenciação celular e os estadiamentos TNM (T: tumor, N: linfonodo, M: metástase) I e IV no câncer de cólon e reto. MÉTODOS: Foram estudados cem pacientes (54 homens e 46 mulheres) tratados por adenocarcinoma colorretal, estádios I (44) e IV (56). Os cortes histológicos do tecido tumoral foram examinados por técnica de imuno-histoquímica em relação à imunoexpressão das proteínas caderina-E e delect in colon cancer (DCC), sendo classificados como positivos quando se detectou a imunoexpressão dessas proteínas em 50 por cento ou mais das células tumorais. RESULTADOS: Para o TNM, imunoexpressão da caderina-E estádio I: positiva em 72,7 por cento e negativa em 35,7 por cento ; estádio IV: positiva em 64,3 por cento e negativa em 35,7 por cento. Proteína DCC: 43,2 por cento positiva e 56,8 por cento negativa no estádio I, e 50 por cento positiva e 50 por cento negativa no estádio IV. Em relação ao grau de diferenciação celular, imunoexpressão da caderina-E - GI: positiva em 70 por cento e negativa em 30 por cento; GII: positiva em 68,4 por cento e 31,6 por cento negativa; GIII: 63,6 por cento positiva e 36,4 por cento negativa. Imunoexpressão da DCC - GI: 40 por cento positiva e 60 por cento negativa; GII: 46,8 por cento positiva e 53,2 por cento negativa; GIII: 54,5 por cento positiva e 45,5 por cento negativa. Não houve diferença significativa entre os grupos. CONCLUSÃO: Os resultados dessa pesquisa permitem concluir que não há relação da imunoexpressão das proteínas caderina-E e DCC com o estadiamento TNM (I e IV) e o grau de diferenciação celular no carcinoma colorretal.

OBJECTIVE: Evaluate the relationship of two proteins, which take part in the same mechanism of cell adhesion, with the cell differentiation degree and TNM staging I and IV in colorectal cancer. METHODS: One-hundred patients (54 men and 46 women), who have received treatment for colorectal cancer, stages I (44) and IV (56), have been studied. Histological cuts of tumor tissue were examined by the immunohistochemical technique as to the expression of E-cadherin and delect in colon cancer (DCC) proteins, being classified as positive whenever it was detected immunoexpression of such proteins in 50 percent or more tumor cells. RESULTS: For TNM, E-cadherin immunoexpression for stage I: positive in 72.7 percent and negative in 35.7 percent; stage IV: positive in 64.3 percent and negative in 35.7 percent. For DCC protein: 43.2 percent positive and 56.8 percent negative in stage I, and 50 percent positive and 50 percent negative in stage IV. Regarding the cell differentiation degree, the immunoexpression of E-cadherin - GI: positive in 70 percent and negative in 30 percent; GII: positive in 68.4 percent and negative in 31.6 percent; GIII: positive in 63.6 percent and negative in 36.4 percent. The immunoexpression of DCC - GI: 40 percent positive and 60 percent negative; GII: 46.8 percent positive and 53.2 percent negative; GIII: 54.5 percent positive and 45.5 percent negative. There was no significant difference among groups. CONCLUSION: The results of this research make it possible to come to the conclusion that there is no relationship between the immunoexpression of E-cadherin and DCC proteins with TNM staging (I and IV) and cell differentiation degree in colorectal cancer.

Cáncer gástrico difuso hereditario (CGDH): presentación de una familia con una nueva mutación del gen CDH1 / Hereditary diffuse gastric Cancer (HDGC): presentation of a family with a new mutation of the CDH1 GENE

Introducción: el CGDH se hereda en forma autosómica dominante. Su sospecha se basa en los antecedentes familiares y su confirmación requiere estudios moleculares. En el 40% de las familias se logra identificar una mutación en el gen CDH1 de la caderina- E que permite discriminar a los portadores y no portadores. La prevención para los portadores de la mutación incluye la gastrectomía profiláctica o la vigilancia endoscópica cada 6 a 12 meses. Objetivo: presentar el caso de una familia con CGDH portadora de una mutación en gen CDH1 no previamente reportada. Caso: mujer de 28 años, gastrectomizada por cáncer gástrico de tipo difuso con antecedentes familiares de cáncer gástrico que mostraba un patrón de herencia autosómico dominante (afectación de 9 miembros en 5 generaciones). Con sospecha de CGDH se comenzó un plan de vigilancia endoscópica y se analizó el ADN purificado de la sangre periférica de la paciente afectada mediante la secuenciación directa del gen CDH1, en la cual se dentificó una mutación sin sentido (non-sense) en la posición 1913 G>A (W638X) del exón 12. Conclusión: la recolección detallada de los antecedentes familiares permitió sospechar una entidad hereditaria muy poco frecuente. Los estudios moleculares confirmaron el diagnóstico, lo que posibilitará la estimación del riesgo individual en los familiares consanguíneos.

Introduction: HDGC is a hereditary cancer syndrome with an autosomic dominant pattern. It may be clinically diagnosed by family background, and confirmed by genetic testing. In 40% of the families, a mutation in the CDH1 gene (E-cadherin) can be identified. Furthermore, the identification of the pathogenic mutation enables the segregate non-carriers (having population risk) and carriers. Prevention for the latter group includes prophylactic gastrectomy or surveillance endoscopy every 6 to 12 months. Objective: to present the case of an HDGC family with identified CDH1 mutation. CASE: 28 yearold woman who underwent gastrectomy for a diffuse ype gastric cancer. Her family background showed multiple gastric cancers with inherited autosomaldominant pattern (affectation of 9 members in 5 generations). Suspecting HDGC, a plan of surveillance endoscopy was iniciated, and a her DNA sample was sequenced for CDH1 gene finding a non-sense mutation in position 1913 G>A (W638X) of exon 12. Conclusion: the detailed recollection of the family background allowed to identify a rare inherited entity. The molecular testing confirmed the diagnosis and will allow future tailored counselling among relatives.

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.