RESUMO
Gastric cancer is the subject of clinical and basic studies due to its high incidence and mortality rates worldwide. Due to the diagnosis occurring in advanced stages and the classic treatment methodologies such as gastrectomy and chemotherapy, they are extremely aggressive and limit the quality of life of these patients. CRISPR/Cas9 is a tool that allows gene editing and has been used to explore the functions of genes related to gastric cancer, in addition to being used in the treatment of this neoplasm, greatly increasing our understanding of cancer genomics. In this mini-review, we seek the current status of the CRISPR/Cas9 gene-editing technology in gastric cancer research and clinical research.
Assuntos
Edição de Genes , Neoplasias Gástricas , Humanos , Edição de Genes/métodos , Sistemas CRISPR-Cas/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Qualidade de Vida , TecnologiaRESUMO
BACKGROUND/AIM: Previous studies from our research group have shown that trisomy 8 and the amplification of the 8q24.21 region is very frequent in gastric cancer (GC). Little is known about the role of most genes located in this region. Thus, the aim of this study was to understand the possible impact of transcriptional alterations and copy number variation (CNV) of four genes located in the 8q24.21 region - FAM49B, FAM84B, GSDMC and miR-5194 - in GC. MATERIALS AND METHODS: Fifty-one to 85 matched pairs of tumoral and adjacent non-tumoral gastric tissues, from patients with primary GC, were used to analyze gene expression and CNV of the selected genes. We also included 29 H. pylori negative and gastritis negative gastric mucosa tissues from individuals without cancer obtained by endoscopy, as control samples. RESULTS: The expression of FAM49B, GSDMC and miR-5194 was higher in both tumoral and adjacent non-tumoral samples compared to the negative control. The expression of FAM84B showed no significant difference between tumoral samples and negative controls. However, the expression of FAM84B in the adjacent non-tumoral samples was higher compared to negative control and tumoral samples. Moreover, the higher expression of GSDMC was associated with T3 and T4 tumors, with tumors on stage III and IV and with advanced tumors. Higher copy numbers of FAM49B and GSDMC were associated with intestinal tumor type and with moderately or well-differentiated tumors. Higher copy number of FAM84B was associated with moderately or well-differentiated tumors. Furthermore, the expression of all four genes was positively correlated. CONCLUSION: All four genes are upregulated in GC and may play an important role in these neoplasms. GSDMC expression was associated with more aggressive tumors.
Assuntos
MicroRNAs , Neoplasias Gástricas , Biomarcadores Tumorais/genética , Cromossomos Humanos Par 8 , Variações do Número de Cópias de DNA/genética , Proteínas de Ligação a DNA/genética , Mucosa Gástrica/patologia , Humanos , MicroRNAs/genética , Proteínas Citotóxicas Formadoras de Poros , Neoplasias Gástricas/patologiaRESUMO
Gastric cancer (GC) is one of the leading types of fatal cancer worldwide. Epigenetic manipulation of cancer cells is a useful tool to better understand gene expression regulatory mechanisms and contributes to the discovery of novel biomarkers. Our research group recently reported a list of 83 genes that are potentially modulated by DNA methylation in GC cell lines. Herein, we further explored the regulation of one of these genes, LRRC37A2, in clinical samples. LRRC37A2 expression was evaluated by RT-qPCR, and DNA methylation was studied using next-generation bisulphite sequencing in 36 GC and paired adjacent nonneoplastic tissue samples. We showed that both reduced LRRC37A2 mRNA levels and increased LRRC37A2 exon methylation were associated with undifferentiated and poorly differentiated tumours. Moreover, LRRC37A2 gene expression and methylation levels were inversely correlated at the +45 exon CpG site. We suggest that DNA hypermethylation may contribute to reducing LRRC37A2 expression in undifferentiated and poorly differentiated GC. Therefore, our results show how some genes may be useful to stratify patients who are more likely to benefit from epigenetic therapy.Abbreviations: AR: androgen receptor; 5-AZAdC: 5-aza-2'-deoxycytidine; B2M: beta-2-microglobulin; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GC: gastric cancer; GLM: general linear model; LRRC37A2: leucine-rich repeat containing 37 member A2; SD: standard deviation; TFII-I: general transcription factor II-I; TSS: transcription start site; XBP1: X-box binding protein 1.
Assuntos
Metilação de DNA , Neoplasias Gástricas , Linhagem Celular Tumoral , Ilhas de CpG , Decitabina , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMO
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/metabolismoAssuntos
Adenocarcinoma/genética , Biomarcadores Tumorais/genética , Mucosa Gástrica/metabolismo , MicroRNAs/genética , MicroRNAs/normas , Neoplasias Gástricas/genética , Adenocarcinoma/secundário , Adulto , Estudos de Casos e Controles , Feminino , Seguimentos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Padrões de Referência , Neoplasias Gástricas/classificação , Neoplasias Gástricas/patologiaRESUMO
Epigenetics is the study of the heritable changes on gene expression that are responsible for the regulation of development and that have an impact on several diseases. However, it is of equal importance to understand how epigenetic machinery works. DNA methylation is the most studied epigenetic mark and is generally associated with the regulation of gene expression through the repression of promoter activity and by affecting genome stability. Therefore, the ability of the cell to interpret correct methylation marks and/or the correct interpretation of methylation plays a role in many diseases. The major family of proteins that bind methylated DNA is the methyl-CpG binding domain proteins, or the MBDs. Here, we discuss the structure that makes these proteins a family, the main functions and interactions of all protein family members and their role in human disease such as psychiatric disorders and cancer.
Assuntos
Ilhas de CpG , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Epigenômica/métodos , Pessoas Mentalmente Doentes , Carcinogênese/genética , Transformação Celular Neoplásica/genéticaRESUMO
Gastric cancer (GC) is a multifactorial disease with a high mortality rate in Brazil and worldwide. This work aimed to evaluate single nucleotide polymorphisms (SNP) rs1695, in the Glutathione S-Transferase Pi (GSTP1) gene in GC samples by comparative analysis Specific PCR - ASP and Dideoxy Single Allele-Specific PCR - DSASP methods. The DSASP is the proposed new method for allelic discrimination. This work analyzed 60 GC samples, 26 diffuse and 34 intestinal types. The SNP rs1695 of the GSTP1 gene was significantly associated with GC analyzed by DSASP method (χ2 = 9.7, P < 0.05). A comparative analysis of the data obtained from both methods did not differ significantly (χ2 = 0.08, P > 0.05). These results suggest that the SNP rs1695 of the GSTP1 gene was a risk factor associated with gastric carcinogens is and the DSASP method was a new successfully low-cost strategy to study allelic discrimination.
RESUMO
Cancer is considered one of the major health issues worldwide, and gastric cancer accounted for 8% of total cases and 10% of total deaths in 2008. Gastric cancer is considered an age-related disease, and the total number of newly diagnosed cases has been increasing as a result of the higher life expectancy. Therefore, the basic mechanisms underlying gastric tumorigenesis is worth investigation. This review provides an overview of the epigenetic mechanisms, such as DNA methylation, histone modifications, chromatin remodeling complex and miRNA, involved in gastric cancer. As the studies in gastric cancer continue, the mapping of an epigenome code is not far for this disease. In conclusion, an epigenetic therapy might appear in the not too distant future.
Assuntos
Montagem e Desmontagem da Cromatina/genética , Metilação de DNA/genética , Infecções por Helicobacter/genética , Histonas/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Fatores Etários , Transformação Celular Neoplásica/genética , Epigênese Genética , Epigenômica , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/fisiologia , Histonas/metabolismo , Humanos , Processamento de Proteína Pós-Traducional , Neoplasias Gástricas/complicações , Neoplasias Gástricas/microbiologiaRESUMO
Emergence of depressive symptoms in schizophrenia results in a deteriorating course and poor prognosis. Schizophrenia and depressive disorder are both associated with low levels of brain-derived neurotrophic factor (BDNF) and with a longstanding low grade inflammatory state. The objective of this study is to analyze the relationship between these serum biomarkers and depressive and psychotic symptoms in schizophrenic patients. Thirty-nine individuals diagnosed with schizophrenia or schizoaffective disorder by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), assessed by Structured Clinical Interview for DSM-IV (SCID), were included. Interviews were conducted with The Positive and Negative Syndrome Scale (PANSS) and The Calgary Depression Scale for Schizophrenia (CDSS). Blood samples were collected for determination of BDNF, IL-1beta, IL-6, IL-8, IL-10, IL-12 and TNF-alpha measurements. Positive correlations between BDNF and CDSS and between IL-1beta and severity in PANSS scores were found. BDNF levels were not correlated with any cytokine or with PANSS scores. The results of this study suggest that depressive and psychotic symptoms may be associated with different profiles of biomarkers in the association between schizophrenia and depression.