RESUMO
Arboviruses have been reported over the years as constant threats to blood transfusion recipients, given the high occurrence of asymptomatic cases and the fact that the presence of viremia precedes the onset of symptoms, making it possible that infected blood from donors act as a source of dissemination. This work aims to identify the prevalence of dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection in blood donors during epidemic and non-epidemic periods; classify the donor as symptomatic or asymptomatic; and verify the need to include DENV, CHIKV and ZIKV in the nucleic acid test (NAT) platform in northern Brazil. We investigated 36,133 thousand donations in two years of collection in Northern Brazil. One donor was positive for DENV and one for CHIKV (0.002% prevalence). As the prevalence for arboviruses was low in this study, it would not justify the individual screening of samples from donors in a blood bank. Thus, DENV- and CHIKV-positive samples were simulated in different amounts of sample pools, and both were safely detected by molecular biology even in a pool of 14 samples, which would meet the need to include these three viruses in the routine of blood centers in endemic countries such as Brazil.
Assuntos
Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Humanos , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/diagnóstico , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/diagnóstico , Dengue/epidemiologia , Dengue/diagnóstico , Doadores de Sangue , Brasil/epidemiologia , PrevalênciaRESUMO
Identifying a microbiome pattern in gastric cancer (GC) is hugely debatable due to the variation resulting from the diversity of the studied populations, clinical scenarios, and metagenomic approach. H. pylori remains the main microorganism impacting gastric carcinogenesis and seems necessary for the initial steps of the process. Nevertheless, an additional non-H. pylori microbiome pattern is also described, mainly at the final steps of the carcinogenesis. Unfortunately, most of the presented results are not reproducible, and there are no consensual candidates to share the H. pylori protagonists. Limitations to reach a consistent interpretation of metagenomic data include contamination along every step of the process, which might cause relevant misinterpretations. In addition, the functional consequences of an altered microbiome might be addressed. Aiming to minimize methodological bias and limitations due to small sample size and the lack of standardization of bioinformatics assessment and interpretation, we carried out a comprehensive analysis of the publicly available metagenomic data from various conditions relevant to gastric carcinogenesis. Mainly, instead of just analyzing the results of each available publication, a new approach was launched, allowing the comprehensive analysis of the total sample amount, aiming to produce a reliable interpretation due to using a significant number of samples, from different origins, in a standard protocol. Among the main results, Helicobacter and Prevotella figured in the "top 6" genera of every group. Helicobacter was the first one in chronic gastritis (CG), gastric cancer (GC), and adjacent (ADJ) groups, while Prevotella was the leader among healthy control (HC) samples. Groups of bacteria are differently abundant in each clinical situation, and bacterial metabolic pathways also diverge along the carcinogenesis cascade. This information may support future microbiome interventions aiming to face the carcinogenesis process and/or reduce GC risk.
Assuntos
Microbioma Gastrointestinal/genética , Neoplasias Gástricas/microbiologia , Biologia Computacional , Mucosa Gástrica/microbiologia , Microbioma Gastrointestinal/fisiologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Redes e Vias Metabólicas , Metagenoma , Prevotella/genética , Prevotella/patogenicidadeRESUMO
Despite the advancements in cancer treatments, gastric cancer is still one of the leading causes of death worldwide. In this context, it is of great interest to discover new and more effective ways of treating this disease. Accumulated evidences have demonstrated the amplification of 8q24.21 region in gastric tumors. Furthermore, this is the region where the widely known MYC oncogene and different microRNAs are located. MYC deregulation is key in tumorigenesis in various types of tissues, once it is associated with cell proliferation, survival, and drug resistance. microRNAs are a class of noncoding RNAs that negatively regulate the protein translation, and which deregulation is related with gastric cancer development. However, little is understood about the interactions between microRNAs and MYC. Here, we overview the MYC role and its relationship with the microRNAs network in gastric cancer aiming to identify potential targets useful to be used in clinic, not only as biomarkers, but also as molecules for development of promising therapies.
Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Neoplasias Gástricas/patologia , Animais , Humanos , Proteínas Proto-Oncogênicas c-myc/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMO
Different from genetic alterations, the reversible nature of epigenetic modifications provides an interesting opportunity for the development of clinically relevant therapeutics in different tumors. In this study, we aimed to screen and validate candidate genes regulated by the epigenetic marker associated with transcriptional activation, histone acetylation, in gastric cancer (GC). We first compared gene expression profile of trichostatin A-treated and control GC cell lines using microarray assay. Among the 55 differentially expressed genes identified in this analysis, we chose the up-regulated genes BMP8B and BAMBI for further analyses, that included mRNA and histone acetylation quantification in paired GC and nontumor tissue samples. BMP8B expression was reduced in GC compared to nontumor samples (P < 0.01). In addition, reduced BMP8B expression was associated with poorly differentiated GC (P = 0.02). No differences or histopathological associations were identified concerning BAMBI expression. Furthermore, acetylated H3K9 and H4K16 levels at BMP8B were increased in GC compared to nontumors (P < 0.05). However, reduced levels of acetylated H3K9 and H4K16 were associated with poorly differentiated GC (P < 0.05). Reduced levels of acetylated H3K9 was also associated with diffuse-type histological GC (P < 0.05). Notably, reduced BMP8B mRNA and acetylated H4K16 levels were positively correlated in poorly differentiated GC (P < 0.05). Our study demonstrated that BMP8B seems to be a tumor suppressor gene regulated by H4K16 acetylation in poorly differentiated GC. Therefore, BMP8B may be a potential target for TSA-based therapies in this GC sample subset. J. Cell. Biochem. 118: 869-877, 2017. © 2016 Wiley Periodicals, Inc.
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Proteínas Morfogenéticas Ósseas/genética , Genes Supressores de Tumor , Histonas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Acetilação , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adulto , Diferenciação Celular/genética , Linhagem Celular Tumoral , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ácidos Hidroxâmicos/farmacologia , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Neoplasias Gástricas/tratamento farmacológicoRESUMO
Cancer is a multifactorial disease that involves many molecular alterations. Gastric cancer (GC) is the third leading cause of cancer death worldwide. GC is a highly heterogeneous disease with different molecular and genetics features. Therefore, this review focuses on an overview of the genetic aspects of gastric cancer by highlighting the important impact and role of deletions and/or duplications of chromosomal segments, genomic variants, H. pylori infection and interleukin variants, as found in gene expression and newly proposed molecular classification studies. The challenge is to better understand the mechanisms and different pathways that lead to the development and progression of GC.
Assuntos
Polimorfismo Genético , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética , Variações do Número de Cópias de DNA , Estudo de Associação Genômica Ampla , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Humanos , Interleucinas/genética , Interleucinas/metabolismo , Metanálise como Assunto , Transdução de Sinais , Neoplasias Gástricas/etiologiaRESUMO
Gastric cancer is a complex, heterogeneous, and multistep disease. Over the past decades, several studies have aimed to determine the molecular factors that lead to gastric cancer development and progression. After completing the human genome sequencing, proteomic technologies have presented rapid progress. Differently from the relative static state of genome, the cell proteome is dynamic and changes in pathologic conditions. Proteomic approaches have been used to determine proteome profiles and identify differentially expressed proteins between groups of samples, such as neoplastic and nonneoplastic samples or between samples of different cancer subtypes or stages. Therefore, proteomic technologies are a useful tool toward improving the knowledge of gastric cancer molecular pathogenesis and the understanding of tumor heterogeneity. This review aimed to summarize the proteins or protein families that are frequently identified by using high-throughput screening methods and which thus may have a key role in gastric carcinogenesis. The increased knowledge of gastric carcinogenesis will clearly help in the development of new anticancer treatments. Although the studies are still in their infancy, the reviewed proteins may be useful for gastric cancer diagnosis, prognosis, and patient management.
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Transformação Celular Neoplásica , Proteínas de Neoplasias/análise , Proteômica/métodos , Neoplasias Gástricas/etiologia , Ensaios de Triagem em Larga Escala , Humanos , Proteínas de Neoplasias/classificação , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Processamento de Proteína Pós-Traducional , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Eletroforese em Gel Diferencial BidimensionalRESUMO
Maintaining water quality within tolerable limits is a basic need of the riverside communities in the Amazon. Using endemic aquatic organisms as biological models is useful for monitoring the environment. In this study, potential cytotoxic and genotoxic damages in Plagioscion squamosissimus (commonly known as silver croaker) from the Marajó Archipelago were evaluated using a flow cytometry assay and a survey of micronuclei (MN) frequency as well as other nuclear abnormalities (NA). P. squamosissimus specimens were collected at four locations in the Marajó Archipelago. Blood samples from these fish were used in the flow cytometry assay and piscine micronucleus test, and the resulting data were analyzed using analysis of variance (ANOVA). We did not observe a difference in the erythrocyte cell cycle distribution among the samples (P=0.9992), which suggests the absence of cytotoxic agent-induced apoptosis. The piscine micronucleus test exhibited differences in the samples from São Sebastião da Boa Vista (SSBV), and those from Anajás produced the highest mutagenicity indices. The MN frequencies were low for all groups, but the groups exhibited significantly different frequencies (P=0.0033). Reniform nuclei, nuclei with extensions, and lobed nuclei were combined and considered NA. The frequency differences for these NA were significant among sampling sites (P <0.0001). This report is the first to use flow cytometry in fish to evaluate cytotoxic agent-induced apoptosis. The micronucleus test results indicate the presence of pollutants that can change the genetic material of the fish studied. We also demonstrate that the Amazonian fish P. squamosissimus is important not only as a comestible species but also as an adequate model for biomonitoring in aquatic environments.
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Citotoxinas/toxicidade , Mutagênicos/toxicidade , Perciformes , Poluentes da Água/toxicidade , Animais , Apoptose/efeitos dos fármacos , Brasil , Ciclo Celular/efeitos dos fármacos , Dano ao DNA , Monitoramento Ambiental , Eritrócitos/efeitos dos fármacos , Testes para Micronúcleos , Perciformes/genética , RiosRESUMO
BACKGROUND: CANOVA(®) (CA) is a homeopathic immunomodulator. It contains several homeopathic medicines prepares according to the Brazilian Pharmacopoeia. CA is indicated in clinical conditions in which the immune system is impaired and against tumors. N-methyl-N-nitrosourea (NMU) is an N-nitroso compound, with genotoxic/mutagenic properties. Although several studies have shown promising results in the use of CA, there are no studies reporting possible antigenotoxic effects. METHOD: This study evaluated the in vitro antigenotoxic and anticytotoxic effects of CA in human lymphocytes exposed to NMU. Samples of human lymphocytes that were subjected to different concentrations of a mixture containing CA and NMU were used. The genotoxicity/antigenotoxicity of CA was evaluated by the comet assay, anticytotoxicity was assessed by quantification of apoptosis and necrosis using acridine orange/ethidium bromide. RESULTS: CA significantly reduced DNA damage induced by NMU and reduced significantly the frequency of NMU-induced apoptosis after 24 h of treatment. CONCLUSION: CA has an important cytoprotective effect significantly reducing the DNA damage and apoptosis induced by the carcinogen NMU.
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Venenos de Crotalídeos/farmacologia , Citoproteção , Dano ao DNA/efeitos dos fármacos , Homeopatia , Linfócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Adulto , Apoptose , Células Cultivadas , Feminino , Humanos , Masculino , Metilnitrosoureia/efeitos adversos , Testes de MutagenicidadeRESUMO
To verify the methylation status of THBS1, GPX3, and COX2 genes and to evaluate their association with Helicobacter pylori in gastric adenocarcinomas. Methylation-sensitive restriction enzyme PCR assay was performed in 16 diffuse type gastric cancer samples, 23 intestinal type, and 15 normal stomach tissue. The presence of H. pylori was performed by amplification of the fragment of the 16S rRNA. Statistical analyses were performed using Fisher's exact test. The hypermethylation of GPX3, THBS1, and COX2 occurred in 18 (n = 7), 5 (n = 2), and 36 % (n = 14) of gastric cancer samples, respectively, whereas in normal samples, it was found in 13, 7, and 67 %. The presence of H. pylori was detected in 67 % of gastric cancer samples and 67 % in normal gastric samples. The methylation of THBS1 and GPX3 was not significantly different between the types of tumors, normal sample, the presence of H. pylori, or clinicopathological variables studied (P > 0.05). However, the methylation status of the gene COX2 is significantly different between normal tissue and intestinal type gastric cancer (P = 0.02). Therefore, our results suggest that the methylation status of the gene COX2 is associated with the intestinal type of gastric cancer.
Assuntos
Ciclo-Oxigenase 2/genética , Glutationa Peroxidase/genética , Neoplasias Intestinais/genética , Neoplasias Gástricas/genética , Brasil , Ilhas de CpG/genética , Metilação de DNA/genética , Feminino , Estudos de Associação Genética , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/patogenicidade , Humanos , Neoplasias Intestinais/microbiologia , Neoplasias Intestinais/patologia , Masculino , Regiões Promotoras Genéticas , RNA Ribossômico 16S/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologiaRESUMO
Aberrant methylation has been reported in several neoplasias, including gastric cancer. The methyl-CpG-binding domain (MBD) family proteins have been implicated in the chromatin remodeling process, leading to the modulation of gene expression. To evaluate the role of MBD2 and MBD3 in gastric carcinogenesis and the possible association with clinicopathological characteristics, we assessed the mRNA levels and promoter methylation patterns in gastric tissues. In this study, MBD2 and MBD3 mRNA levels were determined by RT-qPCR in 28 neoplastic and adjacent nonneoplastic and 27 gastritis and non-gastritis samples. The promoter methylation status was determined by bisulfite sequencing, and we found reduced MBD2 and MBD3 levels in the neoplastic samples compared with the other groups. Moreover, a strong correlation between the MBD2 and MBD3 expression levels was observed in each set of paired samples. Our data also showed that the neoplastic tissues exhibited higher MBD2 promoter methylation than the other groups. Interestingly, the non-gastritis group was the only one with positive methylation in the MBD3 promoter region. Furthermore, a weak correlation between gene expression and methylation was observed. Therefore, our data suggest that DNA methylation plays a minor role in the regulation of MBD2 and MBD3 expression, and the presence of methylation at CpGs that interact with transcription factor complexes might also be involved in the modulation of these genes. Moreover, reduced mRNA expression of MBD2 and MBD3 is implicated in gastric carcinogenesis, and thus, further investigations about these genes should be conducted for a better understanding of the role of abnormal methylation involved in this neoplasia.
Assuntos
Proteínas de Ligação a DNA/genética , RNA Mensageiro/análise , Neoplasias Gástricas/etiologia , Adulto , Idoso , Ilhas de CpG , Metilação de DNA , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
Gastric cancer is still the second leading cause of cancer-related death worldwide, even though its incidence and mortality have declined over the recent few decades. Epigenetic control using histone deacetylase inhibitors, such as trichostatin A (TSA), is a promising cancer therapy. This study aimed to assess the messenger RNA (mRNA) levels of three histone deacetylases (HDAC1, HDAC2, and HDAC3), two histone acetyltransferases (GCN5 and PCAF), and two possible targets of these histone modifiers (MYC and CDKN1A) in 50 matched pairs of gastric tumors and corresponding adjacent nontumors samples from patients with gastric adenocarcinoma, as well as their correlations and their possible associations with clinicopathological features. Additionally, we evaluated whether these genes are sensitive to TSA in gastric cancer cell lines. Our results demonstrated downregulation of HDAC1, PCAF, and CDKN1A in gastric tumors compared with adjacent nontumors (P < 0.05). On the other hand, upregulation of HDAC2, GCN5, and MYC was observed in gastric tumors compared with adjacent nontumors (P < 0.05). The mRNA level of MYC was correlated to HDAC3 and GCN5 (P < 0.05), whereas CDKN1A was correlated to HDAC1 and GCN5 (P < 0.05 and P < 0.01, respectively). In addition, the reduced expression of PCAF was associated with intestinal-type gastric cancer (P = 0.03) and TNM stages I/II (P = 0.01). The increased expression of GCN5 was associated with advanced stage gastric cancer (P = 0.02) and tumor invasion (P = 0.03). The gastric cell lines treated with TSA showed different patterns of histone deacetylase and acetyltransferase mRNA expression, downregulation of MYC, and upregulation of CDKN1A. Our findings suggest that alteration of histone modifier genes play an important role in gastric carcinogenesis, contributing to MYC and CDKN1A deregulation. In addition, all genes studied here are modulated by TSA, although this modulation appears to be dependent of the genetic background of the cell line.
Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/administração & dosagem , Ácidos Hidroxâmicos/administração & dosagem , RNA Mensageiro/biossíntese , Neoplasias Gástricas/enzimologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes myc/genética , Histona Desacetilase 1/biossíntese , Histona Desacetilase 1/genética , Histona Desacetilase 2/biossíntese , Histona Desacetilase 2/genética , Histona Desacetilases/biossíntese , Histona Desacetilases/genética , Humanos , RNA Mensageiro/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Ativação Transcricional/efeitos dos fármacos , Fatores de Transcrição de p300-CBP/biossíntese , Fatores de Transcrição de p300-CBP/genéticaRESUMO
BACKGROUND: The process of gastric carcinogenesis still remains to be elucidated. The identification of genes related to this process may help to reduce mortality rates through early diagnosis and the development of new anticancer therapies. Nucleophosmin 1 (NPM1) acts in ribosome biogenesis, centrosome duplication, maintenance of genomic stability, and embryonic development. Recently, NPM1 has been implicated in the tumorigenesis processes. Here, we evaluated NPM1 gene and protein expression in gastric tumors and in corresponding non-neoplastic gastric samples. METHODS: NPM1 protein expression was determined by Western blot in 17 pairs of gastric tumors and corresponding non-neoplastic gastric tissue. The protein immunoreactivity was observed in 12 tumor samples. mRNA expression was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in 22 pairs of gastric tumors and in matched non-neoplastic gastric tissue. RESULTS: NPM1 protein expression was significantly reduced in gastric cancer samples compared to matched non-neoplastic gastric samples (P = 0.019). The protein level of NPM1 was reduced at least 1.5-fold in 35% of tumors compared to paired non-neoplastic gastric tissue. However, NPM1 immunoreactivity was detected in neoplastic and non-neoplastic cells, including in intestinal metaplastic, gastritis and inflammatory cells. NPM1 was mainly expressed in nucleus and nucleolus subcellular compartments. The staining intensity and the percentage of immunoreactive cells varied among the studied cases. The NPM1 mRNA level was reduced at least 1.5-fold in 45.5% of samples and increased in 27.3% of samples. An inverse correlation between protein and mRNA expression was detected (r = -0.509, P = 0.037). Intestinal-type gastric cancer presented higher mRNA levels than diffuse-type (P = 0.026). However, reduced NPM1 protein expression was associated with intestinal-type gastric cancer compared to matched non-neoplastic gastric samples (P = 0.018). In addition, tumors from patients with known distant metastasis presented reduced NPM1 protein levels compared to tumors from patients without distant metastasis (P < 0.001). CONCLUSION: Although the expression of NPM1 is heterogeneous in gastric tumors, our results suggest that NPM1 down-regulation may have a role in gastric carcinogenesis and may help in the selection of anticancer treatment strategies.
Assuntos
Mucosa Gástrica/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas Nucleares/genética , RNA Mensageiro/metabolismo , Neoplasias Gástricas/genética , Adulto , Nucléolo Celular/química , Núcleo Celular/química , Feminino , Mucosa Gástrica/metabolismo , Gastrite/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Metaplasia/genética , Metaplasia/metabolismo , Pessoa de Meia-Idade , Metástase Neoplásica , Proteínas Nucleares/análise , Proteínas Nucleares/metabolismo , Nucleofosmina , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologiaRESUMO
BACKGROUND: Helicobacter pylori (HP) and Epstein-Barr virus (EBV) have been associated with cancer development. We evaluated the prevalence of HP, HP CagA+ and EBV infection in gastric cancer (GC) samples from adults and in gastric tissues from patients who underwent upper endoscopy (UE). METHODS: Samples from UE and GC were collected to investigate the presence of HP infection and the HP virulence factor CagA by a urease test and PCR. The presence of EBV was detected by Eber-1 in situ hybridization. RESULTS: In UE, 85.5% of juvenile patients showed some degree of gastritis (45.3% of patients with mild gastritis and 54.7% with moderate/severe gastritis) and patients with mild gastritis were younger than patients with moderate/severe gastritis. Among adults, 48.7% presented mild gastritis and 51.3% moderate/severe gastritis. HP infection was detected in 0% of normal mucosa, 58.5% of juvenile gastritis patients, 69.2% of adult gastritis patients and 88% of GC patients. In these same groups, HP CagA+ was detected in 0%, 37.7%, 61.5% and 67.2% of tissue samples, respectively. In juvenile patients, HP infection was more common in those with gastritis than in normal samples (p = 0.004). The patients with either HP or HP CagA+ were older than patients without these pathogens (p < 0.05). In juvenile patients, HP infection was more frequent in cases of moderate/severe gastritis than in cases of mild gastritis (p = 0.026). Moreover, in patients with GC, HP infection was more frequent in males than in females (p = 0.023). GC patients with HP CagA+ were older than patients with HP CagA- (p = 0.027). HP CagA+ was more common in intestinal-type than diffuse-type GC (p = 0.012). HP CagA+ was also associated with lymph-node (p = 0.024) and distal (p = 0.005) metastasis. No association between EBV infection and HP infection or any clinicopathological variable was detected. CONCLUSIONS: Our results suggest that HP is involved in the pathophysiology of severe gastric lesions and in the development of GC, particularly when CagA+ is present. EBV was not the primary pathogenic factor in our samples.
Assuntos
Infecções por Vírus Epstein-Barr/diagnóstico , Gastrite/diagnóstico , Infecções por Helicobacter/diagnóstico , Helicobacter pylori , Neoplasias Gástricas/microbiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/patologia , Gastrite/patologia , Gastroscopia , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Herpesvirus Humano 4/isolamento & purificação , Humanos , Lactente , Pessoa de Meia-Idade , Estômago/química , Estômago/microbiologia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/virologia , Adulto JovemRESUMO
BACKGROUND: Hereditary diffuse gastric cancer (HDGC) is a hereditary autosomal inherited syndrome associated with CDH1 germline mutations. In Brazil, gastrointestinal tumors are among the most prevalent tumor types and constitute a serious public health problem, especially in the northern and northeastern regions. This study aimed to investigate germline mutations, methylation pattern and genomic rearrangements in the CDH1 gene and quantitative changes in the DNA of HDGC patients in northern and northeastern Brazil. METHODS: Twenty-seven DNA samples from the members of four families affected by HDGC were analyzed using array comparative genomic hybridization (aCGH), DNA sequencing and methylation pattern. RESULTS: No evidence of gain and loss events or any rearrangements were found in any of the samples tested using aCGH. No promoter region hypermethylation was observed either. Two of the four families presented different types of germline mutations. The 185G > T and 1018A > G germline mutations detected in this study have been described in Asian and European families, respectively. The ancestors of the two families carrying these mutations had originated from those continents. CONCLUSION: This is the first study to evaluate CDH1 gene germline mutations in Brazilian families with HDGC. In our study, 50% of the families showed no CDH1 gene alterations, and it is possible that in regions with a high incidence of gastric cancer, such as northern and northeastern Brazil, environmental factors might have induced the different genetic alterations analyzed in this study.
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Background/Aim: Although the reciprocal translocation t(9;22)(q34;q11) is a hallmark of chronic myeloid leukemia (CML), it is also present in acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Depending on the gene's breakpoint, it is possible to obtain three isoforms, among which p190 stands out for the poor prognosis it induces whenever it appears. Due to the genomic instability induced by BCR::ABL1, it is proposed to expand the applicability of poly-ADP-ribose polymerase-1 (PARP1) and its inhibitors in hematological neoplasms. Materials and Methods: We measured the expression levels of PARP1 by quantitative real-time PCR (qPCR) using TaqMan®, correlating its expression with BCR::ABL1 p190+, to evaluate its influence in the clinic of adult patients. Results: We found that PARP1 is expressed differently in ALL, AML and CML and that p190 transcripts do not follow a linear pattern in these populations. We also found that PARP1 expression is not correlated with age, white blood cell and the amount of p190 transcripts. Conclusion: Despite the lack of statistical correlation between the variables analyzed, the role of PARP1 in BCR::ABL1 leukemia cannot be ruled out, given the instability profile promoted by this translocation. Finally, further studies involving a larger sample of patients are needed, as well as investigations into other molecular pathways that may impact on the pathogenesis of different BCR::ABL1 leukemic subtypes.
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BACKGROUND: MYC deregulation is a common event in gastric carcinogenesis, usually as a consequence of gene amplification, chromosomal translocations, or posttranslational mechanisms. FBXW7 is a p53-controlled tumor-suppressor that plays a role in the regulation of cell cycle exit and reentry via MYC degradation. METHODS: We evaluated MYC, FBXW7, and TP53 copy number, mRNA levels, and protein expression in gastric cancer and paired non-neoplastic specimens from 33 patients and also in gastric adenocarcinoma cell lines. We also determined the invasion potential of the gastric cancer cell lines. RESULTS: MYC amplification was observed in 51.5% of gastric tumor samples. Deletion of one copy of FBXW7 and TP53 was observed in 45.5% and 21.2% of gastric tumors, respectively. MYC mRNA expression was significantly higher in tumors than in non-neoplastic samples. FBXW7 and TP53 mRNA expression was markedly lower in tumors than in paired non-neoplastic specimens. Moreover, deregulated MYC and FBXW7 mRNA expression was associated with the presence of lymph node metastasis and tumor stage III-IV. Additionally, MYC immunostaining was more frequently observed in intestinal-type than diffuse-type gastric cancers and was associated with MYC mRNA expression. In vitro studies showed that increased MYC and reduced FBXW7 expression is associated with a more invasive phenotype in gastric cancer cell lines. This result encouraged us to investigate the activity of the gelatinases MMP-2 and MMP-9 in both cell lines. Both gelatinases are synthesized predominantly by stromal cells rather than cancer cells, and it has been proposed that both contribute to cancer progression. We observed a significant increase in MMP-9 activity in ACP02 compared with ACP03 cells. These results confirmed that ACP02 cells have greater invasion capability than ACP03 cells. CONCLUSION: In conclusion, FBXW7 and MYC mRNA may play a role in aggressive biologic behavior of gastric cancer cells and may be a useful indicator of poor prognosis. Furthermore, MYC is a candidate target for new therapies against gastric cancer.
Assuntos
Adenocarcinoma/genética , Proteínas de Ciclo Celular/genética , Variações do Número de Cópias de DNA , Proteínas F-Box/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Proto-Oncogênicas c-myc/genética , Neoplasias Gástricas/genética , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/cirurgia , Adulto , Idoso , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proteínas F-Box/metabolismo , Proteína 7 com Repetições F-Box-WD , Feminino , Perfilação da Expressão Gênica , Humanos , Metástase Linfática/genética , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-myc/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/cirurgia , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Artemisinin is a sesquiterpene lactone endoperoxide, obtained from Artemisia annua, and extensively used as an antimalarial drug. Many studies have reported the genotoxic and cytotoxic effects of artemisinins; however, there are no studies that compare such effects between cancer cell lines and normal human cells after treatment with artemether, an artemisinin derivative. Gastric cancer is the fourth most frequent type of cancer and the second highest cause of cancer mortality worldwide. Thus, the aim of this study was to evaluate the in vitro genotoxic and cytotoxic effects induced by artemether in gastric cancer cell line (PG100) and compare them with the results obtained in human lymphocytes exposed to the same conditions. We used MTT (3-(4,5-methylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide) assay, comet assay and ethidium bromide/acridine orange viability staining to evaluate the cytotoxic and genotoxic effects of artemether in PG100. MTT assay showed a decrease in the survival percentages for both cell types treated with different concentrations of artemether (P < 0.05). PG100 also showed a significant dose-dependent increase in DNA damage index at concentrations of 119.4 and 238.8 µg ml(-1) (P < 0.05). Our results showed that artemether induced necrosis in PG100 at concentrations of 238.8 and 477.6 µg ml(-1), for all the tested harvest times (P < 0.05). In lymphocytes, artemether induced both apoptosis and necrosis at concentrations of 238.8 and 477.6 µg ml(-1), for all the tested harvest times (P < 0.05). In conclusion, human lymphocytes were more sensitive to the cytotoxic effects of the antimalarial drug than the gastric cancer cell line PG100.
Assuntos
Antimaláricos , Antineoplásicos , Apoptose/efeitos dos fármacos , Artemisininas , Dano ao DNA , Mutagênicos , Antimaláricos/farmacologia , Antimaláricos/toxicidade , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Artemeter , Artemisininas/farmacologia , Artemisininas/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Relação Dose-Resposta a Droga , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Microscopia de Fluorescência , Mutagênicos/farmacologia , Mutagênicos/toxicidade , NecroseRESUMO
OBJECTIVES: To evaluate the prevalence, distribution and association of HPV with histological pattern of worse prognosis of penile cancer, in order to evaluate its predictive value of inguinal metastasis, as well as evaluation of other previous reported prognostic factors. MATERIAL AND METHODS: Tumor samples of 82 patients with penile carcinoma were tested in order to establish the prevalence and distribution of genotypic HPV using PCR. HPV status was correlated to histopathological factors and the presence of inguinal mestastasis. The influence of several histological characteristics was also correlated to inguinal disease-free survival. RESULTS: Follow-up varied from 1 to 71 months (median 22 months). HPV DNA was identified in 60.9% of sample, with higher prevalence of types 11 and 6 (64% and 32%, respectively). There was no significant correlation of the histological characteristics of worse prognosis of penile cancer with HPV status. Inguinal disease-free survival in 5 years did also not show HPV status influence (p = 0.45). The only independent pathologic factors of inguinal metastasis were: stage T ≥ T1b-T4 (p = 0.02), lymphovascular invasion (p = 0.04) and infiltrative invasion (p = 0.03). CONCLUSIONS: HPV status and distribution had shown no correlation with worse prognosis of histological aspects, or predictive value for lymphatic metastasis in penile carcinoma.
Assuntos
Carcinoma/virologia , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Neoplasias Penianas/patologia , Neoplasias Penianas/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Carcinoma/patologia , Carcinoma/secundário , Intervalo Livre de Doença , Humanos , Canal Inguinal , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Gastric cancer is a serious public health problem in Northern Brazil and in the world due to its high incidence and mortality. Despite the severity of the disease, more research is needed to better understand the molecular events involved in this intestinal-type gastric carcinogenesis process. Since precancerous lesions precede intestinal-type gastric cancer, here, we evaluated the hTERT, MYC, and TP53 mRNA and protein expression, as well as TP33 copy number, in gastric preneoplastic lesions. METHODS: We evaluated 19 superficial gastritis, 18 atrophic gastritis, and 18 intestinal metaplasia from cancer-free individuals of Northern Brazil. Quantitative reverse transcription PCR was used to analyze the mRNA expression and immunohistochemical methods were used to assess protein immunoreactivity in tissue samples. The number of TP53 gene copies was investigated in gastric diseases by quantitative PCR. RESULTS: We observed hTERT, MYC, and p53 immunoreactivity only in intestinal metaplasia samples. The immunoreactivity of these proteins was strongly associated with each other. A significantly higher MYC mRNA expression was observed in intestinal metaplasia compared to gastritis samples. Loss of TP53 was also only detected in intestinal metaplasia specimens. CONCLUSIONS: We demonstrated that hTERT, MYC, and TP53 are deregulated in intestinal metaplasia of individuals from Northern Brazil and these alterations may facilitate tumor initiation.