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Background: Immunohistochemical prognostic significance of the homologous recombination-related proteins RAD51, ATM, BRCA1, and BRCA2 is known in gastric adenocarcinoma, one of the deadliest cancers. Objective and design: This retrospective cohort study aimed to evaluate mRNA expression and promoter methylation of some homologous recombination-related genes in this neoplasm. Methods: We evaluated mRNA expression and methylation of RAD51, ATM, ATR, BRCA1, and BRCA2 in tumor and non-tumor frozen samples from gastrectomy specimens by RT-qPCR and MS-HRM, correlating our results with previous immunohistochemistry data and prognostic features. Results: RAD51, ATR, BRCA1, BRCA2, and ATM mRNA expression was detected in 93.75% (45/48), 93.75% (45/48), 91.67% (44/48), 83.33% (40/48), and 89.58% (43/48) of the tumors; partial or complete methylation, in 94.87% (37/39), 0 (0/42), 97.56% (40/41), 100% (41/41), and 0 (0/40), respectively. Most gene pairs showed significant weak to moderate positive correlations of tumoral mRNA expression with each other: RAD51 with ATR (P = .027), BRCA1 (P < .001), and BRCA2 (P < .001); ATR with BRCA1 (P = .007), and ATM (P = .001); BRCA1 with BRCA2 (P = 0.001). BRCA1 mRNA was reduced in tumors compared with non-neoplastic mucosa (0.345 vs 1.272, P = .015) and, excluding neoadjuvant therapy cases, in T3 to T4 tumors compared with T2 (0.414 vs 0.954, P = .035). Greater tumoral RAD51 mRNA levels correlated with perineural invasion (1.822 vs 0.725, P = .010) and death (1.664 vs 0.929, P = .036), but not with survival time. There was an inverse association between nuclear immunohistochemical positivity for ATR and its mRNA levels (0.487 vs 0.907, P = .032), and no significant correlation for the other markers. Conclusions: Our results suggest RAD51, BRCA1, and BRCA2 methylation as a frequent epigenetic mechanism in gastric cancer, support the hypothesis that reduced BRCA1 expression participates in disease progression, and show an association between RAD51 mRNA and perineural invasion and mortality that may be considered unexpected, considering the former immunohistochemical studies. The lack of correlation between immunohistochemistry and mRNA, and even the inverse association, for ATR, can be seen as indicative of action of post-transcriptional or post-translational regulatory mechanisms, to be better investigated.
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SUMMARY The occurrence of fractures in young individuals is frequently overlooked by physicians, especially when associated with exercise or trauma. Nevertheless, multiple fractures should always be investigated since underlying conditions can predispose to such events. We describe here the case of a young, healthy woman who sustained multiple fractures in the lower limbs, which were initially considered to be "stress fractures". Further investigation, including a panel of genes associated with osteogenesis imperfecta, revealed that the patient is a heterozygous carrier of a SERPINF1 variant. According to criteria recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, this variant is classified as likely benign (PM2, PP3, PP4, BP1, and BP4). The patient's mother and brother were also asymptomatic carriers of the variant and had sustained previous minor fractures. The patient had normal biochemical profile and bone density. This condition has been rarely described and is not associated with low bone mineral density or altered bone turnover markers. This case highlights the importance of investigating multiple fractures in young patients who are otherwise healthy since these may be a warning sign of rare genetic conditions associated with fragility fractures.
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Humanos , Masculino , Feminino , Osteogênese Imperfeita/genética , Fraturas de Estresse/genética , Fraturas de Estresse/diagnóstico por imagem , Densidade Óssea/genética , Predisposição Genética para Doença/genéticaRESUMO
The occurrence of fractures in young individuals is frequently overlooked by physicians, especially when associated with exercise or trauma. Nevertheless, multiple fractures should always be investigated since underlying conditions can predispose to such events. We describe here the case of a young, healthy woman who sustained multiple fractures in the lower limbs, which were initially considered to be "stress fractures". Further investigation, including a panel of genes associated with osteogenesis imperfecta, revealed that the patient is a heterozygous carrier of a SERPINF1 variant. According to criteria recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, this variant is classified as likely benign (PM2, PP3, PP4, BP1, and BP4). The patient's mother and brother were also asymptomatic carriers of the variant and had sustained previous minor fractures. The patient had normal biochemical profile and bone density. This condition has been rarely described and is not associated with low bone mineral density or altered bone turnover markers. This case highlights the importance of investigating multiple fractures in young patients who are otherwise healthy since these may be a warning sign of rare genetic conditions associated with fragility fractures.
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Fraturas de Estresse , Osteogênese Imperfeita , Densidade Óssea/genética , Feminino , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/genética , Predisposição Genética para Doença/genética , Humanos , Masculino , Osteogênese Imperfeita/genéticaRESUMO
BACKGROUND: Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disorder caused by the deficient activity of the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. BCKD is a mitochondrial complex encoded by four genes: BCKDHA, BCKDHB, DBT, and DLD. MSUD is predominantly caused by mutations in the BCKDHA, BCKDHB, and DBT genes which encode the E1α, E1ß, and E2 subunits of the BCKD complex, respectively. The aim of this study was to characterize the genetic basis of MSUD in a cohort of Chilean MSUD patients by identifying point mutations in the BCKDHA, BCKDHB, and DBT genes and to describe their impact on the phenotypic heterogeneity of these patients. METHODS: This manuscript describes a cross-sectional study of 18 MSUD patients carried out using PCR and DNA sequencing. RESULTS: Four novel pathogenic mutations were identified: one in BCKDHA (p.Thr338Ile), two in BCKDHB (p.Gly336Ser e p.Pro240Thr), and one in DBT (p.Gly406Asp). Four additional pathogenic mutations found in this study have been described previously. There were no correlations between the genotype and phenotype of the patients. CONCLUSION: If MSUD is diagnosed earlier, with a newborn screening approach, it might be possible to establish genotype-phenotype relationships more efficiently.
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Doença da Urina de Xarope de Bordo/genética , Mutação , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , Aciltransferases/genética , Criança , Chile , Di-Hidrolipoamida Desidrogenase/genética , Testes Genéticos/estatística & dados numéricos , Humanos , Doença da Urina de Xarope de Bordo/patologiaRESUMO
Non-syndromic intellectual disability (NS-ID or idiopathic) is a complex neurodevelopmental disorder that represents a global health issue. Although many efforts have been made to characterize it and distinguish it from syndromic intellectual disability (S-ID), the highly heterogeneous aspect of this disorder makes it difficult to understand its etiology. Long noncoding RNAs (lncRNAs) comprise a large group of transcripts that can act through various mechanisms and be involved in important neurodevelopmental processes. In this sense, comprehending the roles they play in this intricate context is a valuable way of getting new insights about how NS-ID can arise and develop. In this review, we attempt to bring together knowledge available in the literature about lncRNAs involved with molecular and cellular pathways already described in intellectual disability and neural function, to better understand their relevance in NS-ID and the regulatory complexity of this disorder.
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BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide; it is the fourth leading cause of death in the world and the third in Brazil. Mutations in the APC, DCC, KRAS and TP53 genes have been associated with the progression of sporadic CRC, occurring at defined pathological stages of the tumor progression and consequently modulating several genes in the corresponding signaling pathways. Therefore, the identification of gene signatures that occur at each stage during the CRC progression is critical and can present an impact on the diagnosis and prognosis of the patient. In this study, our main goal was to determine these signatures, by evaluating the gene expression of paired colorectal adenoma and adenocarcinoma samples to identify novel genetic markers in association to the adenoma-adenocarcinoma stage transition. METHODS: Ten paired adenoma and adenocarcinoma colorectal samples were subjected to microarray gene expression analysis. In addition, mutations in APC, KRAS and TP53 genes were investigated by DNA sequencing in paired samples of adenoma, adenocarcinoma, normal tissue, and peripheral blood from ten patients. RESULTS: Gene expression analysis revealed a signature of 689 differentially expressed genes (DEG) (fold-change> 2, p< 0.05), between the adenoma and adenocarcinoma paired samples analyzed. Gene pathway analysis using the 689 DEG identified important cancer pathways such as remodeling of the extracellular matrix and epithelial-mesenchymal transition. Among these DEG, the ETV4 stood out as one of the most expressed in the adenocarcinoma samples, further confirmed in the adenocarcinoma set of samples from the TCGA database. Subsequent in vitro siRNA assays against ETV4 resulted in the decrease of cell proliferation, colony formation and cell migration in the HT29 and SW480 colorectal cell lines. DNA sequencing analysis revealed KRAS and TP53 gene pathogenic mutations, exclusively in the adenocarcinomas samples. CONCLUSION: Our study identified a set of genes with high potential to be used as biomarkers in CRC, with a special emphasis on the ETV4 gene, which demonstrated involvement in proliferation and migration.
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Adenocarcinoma/genética , Adenoma/genética , Neoplasias Colorretais/genética , Genes Neoplásicos , Proteínas de Neoplasias/fisiologia , Proteínas Proto-Oncogênicas c-ets/fisiologia , Adenocarcinoma/química , Adenocarcinoma/patologia , Adenoma/química , Adenoma/patologia , Idoso , Biomarcadores Tumorais/genética , Brasil , Divisão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Transformação Celular Neoplásica/genética , Neoplasias Colorretais/química , Neoplasias Colorretais/patologia , DNA de Neoplasias/genética , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas c-ets/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-ets/genética , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Análise Serial de Tecidos , Transcriptoma , Ensaio Tumoral de Célula-TroncoRESUMO
BACKGROUND: Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disease caused by deficient activity of the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. BCKD is a mitochondrial complex encoded by BCKDHA, BCKDHB, DBT, and DLD genes. MSUD is predominantly caused by Variants in BCKDHA, BCKDHB, and DBT genes encoding the E1α, E1ß, and E2 subunits of BCKD complex, respectively. The aim of this study was to characterize the genetic basis of MSUD by identifying the point variants in BCKDHA, BCKDHB, and DBT genes in a cohort of Brazilian MSUD patients and to describe their phenotypic heterogeneity. It is a descriptive cross-sectional study with 21 MSUD patients involving molecular genotyping by Sanger sequencing. RESULTS: Eight new variants predicted as pathogenic were found between 30 variants (damaging and non-damaging) identified in the 21 patients analyzed: one in the BCKDHA gene (p.Tyr120Ter); five in the BCKDHB gene (p.Gly131Val, p.Glu146Glnfs * 13, p.Phe149Cysfs * 9, p.Cys207Phe, and p.Lys211Asn); and two in the DBT gene (p.Glu148Ter and p.Glu417Val). Seventeen pathogenic variants were previously described and five variants showed no pathogenicity according to in silico analysis. CONCLUSION: Given that most of the patients received late diagnoses, the study results do not allow us to state that the molecular features of MSUD variant phenotypes are predictive of clinical severity.
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Doença da Urina de Xarope de Bordo , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , Brasil , Estudos Transversais , Humanos , Doença da Urina de Xarope de Bordo/genética , FenótipoRESUMO
The Hospital of the Ribeirão Preto Medical School, University of São Paulo is one of the three screening centers in São Paulo State, Brazil, and has included a test for cystic fibrosis (CF) since February 6, 2010, by a court order. We evaluated the first five years of this CF-newborn screening program. The original immunoreactive trypsinogen (IRT)/IRT screening protocol was adopted in Brazil. A total of 173,571 newborns were screened, 1,922 (1.1%) of whom showed IRT1 ≥ 70ng/mL. Of these, 1,795 (93.4%) collected IRT2, with elevated results (IRT2 ≥ 70ng/mL) in 102 of them (5.2%). We identified a total of 26 CF cases during this period, including three CF cases that were not detected by the CF-newborn screening. The incidence of the disease among the screened babies was 1:6,675 newborns screened. Median age at the initial evaluation was 42 days, comparable to that of neonates screened with the IRT/DNA protocol. Almost all infants with CF already exhibited some manifestations of the disease during the neonatal period. The mutation most frequently detected in the CF cases was F508del. These findings suggest the early age at the beginning of treatment at our center was due to the effort of the persons involved in the program regarding an effective active search. Considering the false negative results of CF-newborn screening and the early onset of clinical manifestations of the disease in this study, pediatricians should be aware of the diagnosis of CF even in children with negative test.
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Fibrose Cística , Triagem Neonatal , Brasil/epidemiologia , Criança , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Regulador de Condutância Transmembrana em Fibrose Cística , Humanos , Lactente , Recém-Nascido , TripsinogênioRESUMO
OBJECTIVE: To report the frequency of Lynch syndrome (LS) in a cohort of patients from Southeast Brazil bearing endometrial cancer (EC), using a tumor screening universal approach. METHODS: A total of 242 endometrial carcinomas were screened by immunohistochemistry (IHC) and microsatellite instability (MSI) for detection of DNA mismatch repair deficiency (dMMR). MLH1 methylation was assessed to identify sporadic cases. Patients with dMMR tumors were recruited for germline variant analysis by next-generation sequencing of the MLH1, MSH2, MSH6, PMS2, and EPCAM genes. RESULTS: Ninety-three out of 242 tumors (38.5%) were classified as dMMR based on MSI and IHC results. Of these, 54 cases were selected for germline analysis, and 37/54 (68.5%) were available for sequencing. Ten patients (10/37, 27%) harbored germline pathogenic or likely pathogenic variants, most of them in the MSH6 gene (4/10, 40%). Seven variants of uncertain significance were found. Eight novel germline variants were identified. The LS prevalence in our cohort was of at least 4.1%. LS patients presented lower mean age at cancer diagnosis compared with patients diagnosed with sporadic EC. Individuals with dMMR tumors, without germline pathogenic variants detected in LS-genes ("Lynch-like" syndrome), had an intermediate mean age at cancer diagnosis between LS and sporadic cases. CONCLUSION: This is the first report of the LS prevalence in EC screened by a universal approach in Brazil. Our findings contribute to a better understanding of the mutational landscape of this syndrome in Brazil, which is relevant for improved identification, genetic counseling, prevention and control of cancer in LS.
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Biomarcadores Tumorais/genética , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Detecção Precoce de Câncer/estatística & dados numéricos , Neoplasias do Endométrio/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Brasil/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/prevenção & controle , Metilação de DNA , Reparo de Erro de Pareamento de DNA , Análise Mutacional de DNA , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/prevenção & controle , Endométrio/patologia , Feminino , Aconselhamento Genético/organização & administração , Aconselhamento Genético/estatística & dados numéricos , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Estudos RetrospectivosRESUMO
BACKGROUND: The Hereditary Breast and Ovarian Cancer Syndrome (HBOC) occurs in families with a history of breast/ovarian cancer, presenting an autosomal dominant inheritance pattern. BRCA1 and BRCA2 are high penetrance genes associated with an increased risk of up to 20-fold for breast and ovarian cancer. However, only 20-30% of HBOC cases present pathogenic variants in those genes, and other DNA repair genes have emerged as increasing the risk for HBOC. In Brazil, variants in ATM, ATR, CHEK2, MLH1, MSH2, MSH6, POLQ, PTEN, and TP53 genes have been reported in up to 7.35% of the studied cases. Here we screened and characterized variants in 21 DNA repair genes in HBOC patients. METHODS: We systematically analyzed 708 amplicons encompassing the coding and flanking regions of 21 genes related to DNA repair pathways (ABRAXAS1, ATM, ATR, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, MLH1, MRE11, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD50, RAD51, TP53 and UIMC1). A total of 95 individuals with HBOC syndrome clinical suspicion in Southeast Brazil were sequenced, and 25 samples were evaluated for insertions/deletions in BRCA1/BRCA2 genes. Identified variants were assessed in terms of population allele frequency and their functional effects were predicted through in silico algorithms. RESULTS: We identified 80 variants in 19 genes. About 23.4% of the patients presented pathogenic variants in BRCA1, BRCA2 and TP53, a frequency higher than that identified among previous studies in Brazil. We identified a novel variant in ATR, which was predicted as pathogenic by in silico tools. The association analysis revealed 13 missense variants in ABRAXAS1, BARD1, BRCA2, CHEK2, CDH1, MLH1, PALB2, and PMS2 genes, as significantly associated with increased risk to HBOC, and the patients carrying those variants did not present large insertions or deletions in BRCA1/BRCA2 genes. CONCLUSIONS: This study embodies the third report of a multi-gene analysis in the Brazilian population, and addresses the first report of many germline variants associated with HBOC in Brazil. Although further functional analyses are necessary to better characterize the contribution of those variants to the phenotype, these findings would improve the risk estimation and clinical follow-up of patients with HBOC clinical suspicion.
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Algoritmos , Simulação por Computador , Mutação em Linhagem Germinativa , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Mutação INDEL , Proteínas de Neoplasias/genética , Adulto , Idoso , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The Hospital of the Ribeirão Preto Medical School, University of São Paulo is one of the three screening centers in São Paulo State, Brazil, and has included a test for cystic fibrosis (CF) since February 6, 2010, by a court order. We evaluated the first five years of this CF-newborn screening program. The original immunoreactive trypsinogen (IRT)/IRT screening protocol was adopted in Brazil. A total of 173,571 newborns were screened, 1,922 (1.1%) of whom showed IRT1 ≥ 70ng/mL. Of these, 1,795 (93.4%) collected IRT2, with elevated results (IRT2 ≥ 70ng/mL) in 102 of them (5.2%). We identified a total of 26 CF cases during this period, including three CF cases that were not detected by the CF-newborn screening. The incidence of the disease among the screened babies was 1:6,675 newborns screened. Median age at the initial evaluation was 42 days, comparable to that of neonates screened with the IRT/DNA protocol. Almost all infants with CF already exhibited some manifestations of the disease during the neonatal period. The mutation most frequently detected in the CF cases was F508del. These findings suggest the early age at the beginning of treatment at our center was due to the effort of the persons involved in the program regarding an effective active search. Considering the false negative results of CF-newborn screening and the early onset of clinical manifestations of the disease in this study, pediatricians should be aware of the diagnosis of CF even in children with negative test.
O Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo é um dos três centros de triagem da fibrose cística (FC) no estado de São Paulo, tendo incluído esse teste desde 6 de fevereiro de 2010, a partir de uma liminar judicial. O estudo avalia os primeiros cinco anos desse programa de triagem neonatal da FC. O Brasil adota o protocolo de triagem original, com o tripsinogênio imunorreativo (IRT)/IRT. Foram triados um total de 173.571 recém-nascidos, dos quais 1.922 (1,1%) mostraram IRT ≥ 70ng/mL. Destes, 1.795 (93,4%) tiveram amostras coletadas para IRT2, com resultados elevados (IRT2 ≥ 70ng/mL) em 102 deles (5,2%). Identificamos um total de 26 casos de FC durante esse período, inclusive 3 casos de FC que não foram detectados com a triagem neonatal. A incidência da FC foi de 1 caso em cada 6.675 recém-nascidos triados. A idade mediana na avaliação inicial foi 42 dias, comparável à idade de recém-nascidos triados com o protocolo IRT/DNA. Quase todos os lactentes com FC já exibiam algumas manifestações da doença durante o período neonatal. A mutação mais comum nos casos de FC foi a F508del. Os resultados em nosso centro indicam que a idade precoce no início do tratamento foi devido aos esforços do programa na implementação de uma busca ativa eficaz. Considerando os resultados falsos-negativos no programa de triagem neonatal para FC e o início precoce das manifestações clínicas da doença neste estudo, os pediatras devem estar cientes da possibilidade de diagnóstico de FC, mesmo em crianças com teste negativo.
El Hospital das Clínicas de la Facultad de Medicina de Ribeirão Preto, São Paulo Universidad es uno de los tres centros de cribado de fibrosis cística (FC) en el estado de São Paulo, incluyendo este test desde el 6 de febrero de 2010, debido a una medida cautelar judicial. El estudio evalúa los primeros cinco años de este programa de cribado neonatal de FC. Brasil adopta el protocolo de cribado original, con el tripsinógeno inmunorreactivo (TIR)/IRT. Se cribaron un total de 173.571 recién nacidos, de los cuales 1.922 (1,1%) mostraron IRT ≥ 70ng/mL. De estos, se obtuvieron 1.795 (93,4%) muestras recogidas para IRT2, con resultados elevados (IRT2 ≥ 70ng/mL) en 102 de ellos (5,2%). Identificamos un total de 26 casos de FC durante ese período, inclusive 3 casos de FC que no fueron detectados con el cribado neonatal. La incidencia de la FC fue de 1 caso por cada 6.675 recién-nacidos cribados. La edad media en la evaluación inicial fue 42 días, comparable a la edad de recién nacidos cribados con el protocolo IRT/DNA. Casi todos los lactantes con FC ya manifestaban algunos síntomas de la enfermedad durante el período neonatal. La mutación más común en los casos de FC era el F508del. Los resultados en nuestro centro indican que la edad precoz en el inicio del tratamiento se debía a los esfuerzos del programa en la implementación de una búsqueda activa eficaz. Considerando los resultados falsos-negativos en el programa de cribado neonatal para FC, y el inicio precoz de las manifestaciones clínicas de la enfermedad en este estudio, los pediatras deben ser conscientes de la posibilidad de diagnóstico de FC, incluso en niños con test negativo.
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Humanos , Recém-Nascido , Lactente , Criança , Triagem Neonatal , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Tripsinogênio , Brasil/epidemiologia , Regulador de Condutância Transmembrana em Fibrose CísticaRESUMO
Melanoma is the deadliest form of skin cancer, and little is known about the impact of deregulated expression of long noncoding RNAs (lncRNAs) in the progression of this cancer. In this study, we explored RNA-Seq data to search for lncRNAs associated with melanoma progression. We found distinct lncRNA gene expression patterns across melanocytes, primary and metastatic melanoma cells. Also, we observed upregulation of the lncRNA ZEB1-AS1 (ZEB1 antisense RNA 1) in melanoma cell lines. Data analysis from The Cancer Genome Atlas (TCGA) confirmed higher ZEB1-AS1 expression in metastatic melanoma and its association with hotspot mutations in BRAF (B-Raf proto-oncogene, serine/threonine kinase) gene and RAS family genes. In addition, a positive correlation between ZEB1-AS1 and ZEB1 (zinc finger E-box binding homeobox 1) gene expression was verified in primary and metastatic melanomas. Using gene expression signatures indicative of invasive or proliferative phenotypes, we found an association between ZEB1-AS1 upregulation and a transcriptional profile for invasiveness. Enrichment analysis of correlated genes demonstrated cancer genes and pathways associated with ZEB1-AS1. We suggest that the lncRNA ZEB1-AS1 could function by activating ZEB1 gene expression, thereby influencing invasiveness and phenotype switching in melanoma, an epithelial-to-mesenchymal transition (EMT)-like process, which the ZEB1 gene has an essential role.
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Estudos de Associação Genética , Melanoma/genética , Invasividade Neoplásica/genética , RNA Longo não Codificante/genética , Transcriptoma/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Predisposição Genética para Doença , Humanos , Masculino , Melanoma/patologia , Invasividade Neoplásica/patologia , Metástase Neoplásica , Proto-Oncogene MasRESUMO
Dysregulation of miRNA expression is associated with multiple diseases, including cancers, in which small RNAs can have either oncogenic or tumor suppressive functions. Here we investigated the potential tumor suppressive function of miR-450a, one of the most significantly downregulated miRNAs in ovarian cancer. RNA-seq analysis of the ovarian cancer cell line A2780 revealed that overexpression of miR-450a suppressed multiple genes involved in the epithelial-to-mesenchymal transition (EMT). Overexpression of miR-450a reduced tumor migration and invasion and increased anoikis in A2780 and SKOV-3 cell lines and reduced tumor growth in an ovarian tumor xenographic model. Combined AGO-PAR-CLIP and RNA-seq analysis identified a panel of potential miR-450a targets, of which many, including TIMMDC1, MT-ND2, ACO2, and ATP5B, regulate energetic metabolism. Following glutamine withdrawal, miR-450a overexpression decreased mitochondrial membrane potential but increased glucose uptake and viability, characteristics of less invasive ovarian cancer cell lines. In summary, we propose that miR-450a acts as a tumor suppressor in ovarian cancer cells by modulating targets associated with glutaminolysis, which leads to decreased production of lipids, amino acids, and nucleic acids, as well as inhibition of signaling pathways associated with EMT. SIGNIFICANCE: miR-450a limits the metastatic potential of ovarian cancer cells by targeting a set of mitochondrial mRNAs to reduce glycolysis and glutaminolysis.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/13/3294/F1.large.jpg.
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Biomarcadores Tumorais/metabolismo , Metabolismo Energético , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Aconitato Hidratase/genética , Aconitato Hidratase/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Ciclo Celular , Movimento Celular , Proliferação de Células , Feminino , Humanos , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , NADH Desidrogenase/genética , NADH Desidrogenase/metabolismo , Neoplasias Ovarianas/genética , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: The goal of this study was to screen point mutations and deletions in APC and MUTYH genes in patients suspected of familial adenomatous polyposis (FAP) in a Brazilian cohort. METHODS: We used high-resolution melting, Sanger direct sequencing and multiplex ligation-dependent probe association (MLPA) assays to identify point mutations, and large genomic variations within the coding regions of APC and MUTYH genes. RESULTS: We identified 19 causative mutations in 40 Brazilian patients from 20 different families. Four novel mutations were identified in the APC gene and two in the MUTYH gene. We also found a high intra- and inter-familial diversity regarding extracolonic manifestations, and gastric polyps were the most common manifestation found in our cohort. CONCLUSION: We believe that the FAP mutational spectrum can be population-specific and screening FAP patients in different populations can improve pre-clinical diagnosis and improve clinical conduct.
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Proteína da Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/genética , Biomarcadores Tumorais/genética , DNA Glicosilases/genética , Predisposição Genética para Doença , Mutação , Polipose Adenomatosa do Colo/patologia , Adolescente , Adulto , Idoso , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Adulto JovemRESUMO
Multiple Sclerosis (MS) is an inflammatory neurodegenerative disease that affects approximately 2.5 million people globally. Even though the etiology of MS remains unknown, it is accepted that it involves a combination of genetic alterations and environmental factors. Here, after performing whole exome sequencing, we found a MS patient harboring a rare and homozygous single nucleotide variant (SNV; rs61745847) of the G-protein coupled receptor (GPCR) galanin-receptor 2 (GALR2) that alters an important amino acid in the TM6 molecular toggle switch region (W249L). Nuclear magnetic resonance imaging showed that the hypothalamus (an area rich in GALR2) of this patient exhibited an important volumetric reduction leading to an enlarged third ventricle. Ex vivo experiments with patient-derived blood cells (AKT phosphorylation), as well as studies in recombinant cell lines expressing the human GALR2 (calcium mobilization and NFAT mediated gene transcription), showed that galanin (GAL) was unable to stimulate cell signaling in cells expressing the variant GALR2 allele. Live cell confocal microscopy showed that the GALR2 mutant receptor was primarily localized to intracellular endosomes. We conclude that the W249L SNV is likely to abrogate GAL-mediated signaling through GALR2 due to the spontaneous internalization of this receptor in this patient. Although this homozygous SNV was rare in our MS cohort (1:262 cases), our findings raise the potential importance of impaired neuroregenerative pathways in the pathogenesis of MS, warrant future studies into the relevance of the GAL/GALR2 axis in MS and further suggest the activation of GALR2 as a potential therapeutic route for this disease.
Assuntos
Galanina/genética , Esclerose Múltipla/genética , Receptor Tipo 2 de Galanina/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Estudos de Casos e Controles , Linhagem Celular , Feminino , Células HEK293 , Humanos , Fosforilação/genética , Polimorfismo de Nucleotídeo Único/genética , Transdução de Sinais/genética , Adulto JovemRESUMO
OBJECTIVE: Hereditary hearing loss (HL) is the most common sensorineural disorder in humans. Besides mutations in GJB2 and GJB6 genes, pathogenic variants in the SLC26A4 gene have been reported as a cause of hereditary HL due to its role in the physiology of the inner ear. In this research we wanted to investigate the prevalence of mutations in SLC26A4 in Brazilian patients with nonsyndromic prelingual sensorineural HL. We applied the high-resolution melting technique to screen 88 DNA samples from unrelated deaf individuals that were previously screened for GJB2, GJB6 and MT-RNR1 mutations. RESULTS: The frequency of mutations in the SLC26A4 gene was 28.4%. Two novel mutations were found: p.Ile254Val and p.Asn382Lys. The mutation c.-66C>G (rs17154282) in the promoter region of SLC26A4, was the most frequent mutation found and was significantly associated with nonsyndromic prelingual sensorineural HL. After mutations in the GJB2, GJB6 and mitochondrial genes, SLC26A4 mutations are considered the next most common cause of hereditary HL in Brazilian as well as in other populations, which corroborates with our data. Furthermore, we suggest the inclusion of the SCL26A4 gene in the investigation of hereditary HL since there was an increase in the frequency of the mutations found, up to 22.7%.
Assuntos
Perda Auditiva Neurossensorial/genética , Mutação , Transportadores de Sulfato/genética , Adolescente , Adulto , Brasil , Criança , Pré-Escolar , Conexina 26 , Conexinas , Feminino , Perda Auditiva , Humanos , Masculino , Proteínas de Membrana Transportadoras , Pessoa de Meia-Idade , Adulto JovemRESUMO
Despite being a healthy tissue, the constituent cells of the placenta, share similar characteristics with tumor cells, such as increased cell growth, migration, and invasion. However, while these processes are stochastic and uncontrolled in cancer cells, in placenta they are precisely controlled. Since miRNAs have been reported to regulate genes that control the molecular mechanisms necessary for the development of both human placenta and cancer, we addressed for miRNAs highly expressed in the placenta that could be involved in tumorigenesis. Here, we assessed the miRNA profile in placenta samples using microarray analysis. The results showed that miR-451 and miR-720, highly expressed placental miRNAs, presented very low or undetectable expression in cancer cell lines compared to the normal placenta and healthy tissues. Additionally, transfection of miR-451 or miR-720 mimics in choriocarcinoma cell line (JEG3) and colorectal adenocarcinoma cell line (HT-29) resulted in impaired cell proliferation, decreased cell migration and invasion and reduced ability of colony formation. These findings provide evidence that placenta may work as an alternative model to identify novel miRNAs involved in pathways controlling tumorigenesis.
RESUMO
PURPOSE: To describe the involvement of the lacrimal gland (LG) in blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). DESIGN: Observational, cross-sectional study. PARTICIPANTS: Twenty-one patients with BPES (10 female, 11 male) aged on average 15 years (range, 2-39 years), from 3 Brazilian medical centers and 1 Portuguese medical center. METHODS: Patients had their ocular surface evaluated with slit-lamp biomicroscopy, and tear production quantified with the Schirmer test I. The LG volumes were measured on computed tomography (CT) scans in the BPES sample and in a group of age-matched subjects imaged for nonorbital diseases. Sixteen patients were screened for mutations in the FOXL2 gene. MAIN OUTCOME MEASURES: Lacrimal meniscus height, Schirmer test I, presence of superficial punctate keratopathy (SPK), LG volume, and molecular analysis of the FOXL2 gene. RESULTS: Absence of LG was detected bilaterally in 9 patients (42.8%) and unilaterally in 2 patients (9.5%). When considering only patients with measurable LG, the median volume was 0.22 cm3 in the right eye (range, 0.06-0.36 cm3) and 0.24 cm3 in the left eye (range, 0.08-0.34 cm3). These values were significantly lower than those for the age-matched controls (median = 0.54 right eye and 0.53 left eye; P < 0.05). There was a significant association between deficiency of tear production and LG volume reduction and agenesis. Molecular analysis of the FOXL2 gene revealed the presence of 8 distinct mutations, 4 of them novel ones. A significant reduction of LG size or agenesis was associated with mutations affecting protein size (due to underlying changes in the stop codon location) or the DNA-binding forkhead domain (Fisher exact test, P = 0.021). In 3 probands, the underlying genetic defect was not found. CONCLUSIONS: This is the first study reporting LG volumes in BPES, describing a significant number of patients with LG agenesis. The association between alacrima and BPES is not incidental, and a thorough evaluation of tear production is recommended especially if ptosis surgery is planned.
Assuntos
Blefarofimose/diagnóstico por imagem , Anormalidades do Olho/diagnóstico por imagem , Fatores de Transcrição Forkhead/genética , Aparelho Lacrimal/anormalidades , Anormalidades da Pele/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Anormalidades Urogenitais/diagnóstico por imagem , Adolescente , Adulto , Blefarofimose/genética , Criança , Pré-Escolar , Estudos Transversais , Análise Mutacional de DNA , Éxons/genética , Anormalidades do Olho/genética , Feminino , Proteína Forkhead Box L2 , Amplificação de Genes , Estudos de Associação Genética , Humanos , Masculino , Anormalidades da Pele/genética , Microscopia com Lâmpada de Fenda , Lágrimas/fisiologia , Anormalidades Urogenitais/genéticaRESUMO
BACKGROUND: Classical Galactosemia (CG) is an inborn error of galactose metabolism caused by the deficiency of the galactose-1-phosphate uridyltransferase enzyme. It is transmitted as an autosomal recessive disease and is typically characterized by neonatal galactose intolerance, with complications ranging from neonatal jaundice and liver failure to late complications, such as motor and reproductive dysfunctions. Galactosemia is also heterogeneous from a molecular standpoint, with hundreds of different mutations described in the GALT gene, some of them specific to certain populations, reflecting consequence of founder effect. METHODS: This study reviews the main clinical findings and depicts the spectrum of mutations identified in 19 patients with CG, six with Duarte Galactosemia and one with type 2 Galactosemia in Brazil. Some individuals were diagnosed through expanded newborn screening test, which is not available routinely to all newborns. RESULTS: The main classical Galactosemia mutations reported to date were identified in this study, as well as the Duarte variant and seven novel mutations - c.2 T > C (p.M1T), c.97C > A (p.R33S), c.217C > T (p.P73S), c.328 + 1G > A (IVS3 + 1G > A), c.377 + 4A > C (IVS4 + 4A > C), c.287_289delACA (p.N97del) and c.506A > C (p.Q169P). This was expected, given the high miscegenation of the Brazilian population. CONCLUSIONS: This study expands the mutation spectrum in GALT gene and reinforces the importance of early diagnosis and introduction of dietary treatment, what is possible with the introduction of Galactosemia in neonatal screening programs.
Assuntos
Galactosemias/genética , Galactosemias/patologia , Mutação , UTP-Hexose-1-Fosfato Uridililtransferase/genética , Alelos , Sequência de Bases , Brasil , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Genótipo , Humanos , Lactente , Recém-Nascido , Polimorfismo GenéticoRESUMO
LINC00629 and MIR503HG are long intergenic non-coding RNAs (lincRNAs) mapped on chromosome X (Xq26), a region enriched for genes associated with human reproduction. Genes highly expressed in normal reproductive tissues and cancers (CT genes) are well known as potential tumor biomarkers. This study aimed to characterize the structure, expression, function and regulation mechanism of MIR503HG and LINC00629 lincRNAs. According to our data, MIR503HG expression was almost exclusive to placenta and LINC00629 was highly expressed in placenta and other reproductive tissues. Further analysis, using a cancer cell lines panel, showed that MIR503HG and LINC00629 were expressed in 50% and 100% of the cancer cell lines, respectively. MIR503HG was expressed predominantly in the nucleus of JEG-3 choriocarcinoma cells. We observed a positively correlated expression between MIR503HG and LINC00629, and between the lincRNAs and neighboring miRNAs. Also, both LINC00629 and MIR503GH could be negatively regulated by DNA methylation in an indirect way. Additionally, we identified new transcripts for MIR503HG and LINC00629 that are relatively conserved when compared to other primates. Furthermore, we found that overexpression of MIR503HG2 and the three-exon LINC00629 new isoforms decreased invasion and migration potential of JEG-3 tumor cell line. In conclusion, our results suggest that lincRNAs MIR503HG and LINC00629 impaired migration and invasion capacities in a choriocarcinoma in vitro model, indicating a potential role in human reproduction and tumorigenesis. Moreover, the MIR503HG expression pattern found here could indicate a putative new tumor biomarker.