Publications by authors named "Tatiana Simao"

Article Synopsis
  • Homeobox genes are important for organ development and differentiation, and in humans, they are divided into four clusters (HOXA, HOXB, HOXC, HOXD).
  • This study focused on the role of these genes in esophageal squamous cell carcinoma (ESCC), finding that while mutations were rare, seven specific homeobox genes were significantly different in ESCC tissues compared to non-cancerous ones.
  • The study revealed that these genes' dysregulation may affect cancer pathways and is linked to poor survival rates, suggesting their potential as prognostic biomarkers and targets for new therapies.
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Head and neck squamous cell carcinomas (HNSCC) are among the ten most frequent types of cancer worldwide and, despite all efforts, are still diagnosed at late stages and show poor overall survival. Furthermore, HNSCC patients often experience relapses and the development of second primary tumors, as a consequence of the field cancerization process. Therefore, a better comprehension of the molecular mechanisms involved in HNSCC development and progression may enable diagnosis anticipation and provide valuable tools for prediction of prognosis and response to therapy.

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Background/aim: A new set of LQB-nitrones and analogues was synthesized to evaluate anticancer activity based on the substitution of the terpenyl moiety of the antileukemic compound LQB-278 by the conformationally restricted cinnamyl ether.

Materials And Methods: A structure-activity relationship study was performed in vitro on Jurkat cells to screen the antileukemic activity of LQB-nitrones and analogues and elucidate the mechanisms of action of the most active derivatives.

Results: The cynamyl ramification and its ortho position aldehyde substitution improved the antileukemic activity.

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Upper aerodigestive tract (UADT) tumors present different biological behavior and prognosis, suggesting specific molecular mechanisms underlying their development. However, they are rarely considered as single entities (particularly head and neck subsites) and share the most common genetic alterations. Therefore, there is a need for a better understanding of the global DNA methylation differences among UADT tumors.

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Esophageal squamous cell carcinoma (ESCA) exhibits high intratumoral molecular heterogeneity posing a challenge to cancer therapy. Immune checkpoint blockade therapy has been approved for this disease, but with modest results. RNA-Seq data from paired tumor and surrounding nonmalignant tissue from 14 patients diagnosed with ESCA without previous treatment and from The Cancer Genome Atlas-ESCA cohort were analyzed.

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Background: V-ATPases are hetero-oligomeric enzymes consisting of 13 subunits and playing key roles in ion homeostasis and signaling. Differential expression of these proton pumps has been implicated in carcinogenesis and metastasis. To elucidate putative molecular signatures underlying these phenomena, we evaluated the expression of V-ATPase genes in esophageal squamous cell carcinoma (ESCC) and extended the analysis to other cancers.

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Endometrioid endometrial carcinomas (EEC) are the most common malignant gynecologic tumors. Despite the increase in EEC molecular knowledge, the identification of new biomarkers involved in disease's development and/or progression would represent an improvement in its course. High-mobility group A protein (HMGA) family members are frequently overexpressed in a wide range of malignancies, correlating with a poor prognosis.

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Article Synopsis
  • Esophageal squamous cell carcinoma (ESCC) has a poor prognosis and lacks targeted treatment options, prompting a study to identify potential therapeutic targets through transcriptome analysis of tumor and surrounding nonmalignant samples.
  • The transcription factor FOXM1 was highlighted due to its role in essential biological processes and was found to bind to a specific promoter, indicating it regulates gene expression relevant to ESCC.
  • Further analysis showed that overexpression of FOXM1 and its target PIK3R3 activates the PIK3/AKT pathway, with both being linked to poor prognosis in ESCC patients, although only PIK3R3 was an independent prognostic factor.
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Forensic strategies commonly are proceeding by analysis of short tandem repeats (STRs); however, new additional strategies have been proposed for forensic science. Thus, this article standardized the high-resolution melting (HRM) of DNA for forensic analyzes. For HRM, mitochondrial DNA (mtDNA) from eight individuals were extracted from mucosa swabs by DNAzol reagent, samples were amplified by PCR and submitted to HRM analysis to identify differences in hypervariable (HV) regions I and II.

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Objectives: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro.

Methods: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T.

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The majority of endometrioid endometrial carcinomas (EEC) is diagnosed at stage I. Among these, 30% present myometrial invasion (stage IB), which is associated with tumor spread and relapse after primary treatment. Although an increased expression of RUNX1/AML1 and ERM/ETV5 in EEC have been suggested to be associated with early events of myometrial infiltration, there is no data regarding its expression along the evolution of EEC and possible associations with other clinicopathological parameters.

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Aim: To analyze the prevalence of thiopurine-methyltransferase (TPMT) genotypes and their association with drug toxicity in inflammatory bowel disease (IBD) patients from southeastern Brazil.

Methods: A total of 219 consecutive patients with IBD, of which 146 had Crohn's disease and 73 had ulcerative colitis, regularly seen at the outpatient unit of the Division of Gastroenterology at the University Hospital Pedro Ernesto of the State University of Rio de Janeiro, a tertiary referral center, were enrolled in this study from February 2009 to January 2011. We analyzed the presence of major TPMT genetic variants (TPMT 2, 3A, 3C) in IBD patients by means of a specific allele and RFLP-PCR.

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Background: Esophageal squamous cell carcinoma (ESCC) shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients.

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The role of HPV in esophageal squamous cell carcinoma (ESCCs) is controversial. Therefore, we determined, through different methodologies, the prevalence of HPV in 264 ESCC samples from Brazil, and correlated it with the presence of surrogate markers and clinicopathological characteristics. HPV is present in 13% of ESCC, and with a 3-fold variation between high and medium incidence areas.

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Esophageal squamous cell carcinoma (ESCC) is believed to arise from esophageal mucosa through accumulation of both genetic and epigenetic changes. DNA methylation is a critical epigenetic mechanism involved in key cellular processes and its deregulation has been linked to many human cancers, including ESCC. The aim of this study is to examine the global deregulation of methylation states in ESCC and identify potential early biomarkers.

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Background: Gluconacetobacter diazotrophicus Pal5 is an endophytic diazotrophic bacterium that lives in association with sugarcane plants. It has important biotechnological features such as nitrogen fixation, plant growth promotion, sugar metabolism pathways, secretion of organic acids, synthesis of auxin and the occurrence of bacteriocins.

Results: Gluconacetobacter diazotrophicus Pal5 is the third diazotrophic endophytic bacterium to be completely sequenced.

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It has been suggested that the blood clotting initiator protein, tissue factor (TF), participates in tumor growth, metastasis and angiogenesis. In addition, a family of G protein-coupled-receptors known as protease-activated receptors (PARs) has also been implicated in tumor biology. These receptors might be activated by blood coagulation proteases thus eliciting a number of pro-tumoral responses, including the expression of interleukin-8 (IL-8).

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Oesophageal squamous cell carcinoma (ESCC) is one of the most common malignancies and is the sixth cause of cancer-related death in the world. Inactivation of cell-cycle regulating genes, such as p14ARF and p16INK4a, and cell adhesion genes, such as E-cadherin, is common in cancer, and results from genetic and/or epigenetic alterations. Therefore, we have analysed the mRNA expression of p14ARF, p16INK4a and E-cadherin in 17 matched ESCC and normal mucosal samples obtained from Brazilian patients by semi-quantitative RT-PCR.

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Bothrops jararaca is a pit viper responsible for the majority of snake envenoming accidents in Brazil. As an attempt to describe the transcriptional activity of the venom gland, ESTs of a cDNA library constructed from B. jararaca venom gland were generated and submitted to bioinformatics analysis.

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To obtain a better understanding of the mechanisms involved in the up-regulation of the Fas apoptotic signaling cascade induced by P. aeruginosa type III secretion system (TTSS), human umbilical vein endothelial cells (HUVEC) were infected with P. aeruginosa PAO-1 or its TTSS-negative mutant PAO-1::exsA.

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Somatic mutations in the TP53 gene are the most frequently observed genetic alterations in human malignancies, including breast cancer, which is one of the leading causes of death among women in Brazil. In our study, we determined the frequency and the pattern of TP53 mutations in malignant breast tumors from 120 patients living in Rio de Janeiro, Brazil. TP53 mutations were found in 20% of the tumors, which contained a diversity of mutation types: missense (62.

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