Publications by authors named "Juan A Rey"

We analyze the leukocyte telomere length (LTL) and telomerase activity in patients with major depressive disorder (MDD) before and after treatment with selective serotonin reuptake inhibitors (SSRIs). Before treatment, there was a reduction in the LTLs and expression levels of the human telomerase reverse transcriptase (hTERT) in the patients with MDD compared with controls. However, after 24 weeks of treatment with SSRIs, there was a significant increase in the LTLs and the expression levels of hTERT, with values approaching those observed in the controls.

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Article Synopsis
  • Glioblastoma multiforme is the most common and aggressive brain tumor, currently lacking effective therapies.
  • High levels of mesenchymal markers and increased autophagy are observed in glioblastoma cells, indicating a complex disease pathogenesis.
  • Silencing HDAC6 in glioblastoma cell lines showed reduced tumor cell growth and migration, reversed aggressive traits, and suggests HDAC6 as a potential therapeutic target.
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Glioblastoma is the most malignant brain tumor and presents high resistance to chemotherapy and radiotherapy. Surgery, radiotherapy and chemotherapy with temozolomide are the only treatments against this tumor. New targeted therapies, including epigenetic modulators such as 3‑deazaneplanocin A (DZ‑Nep; an EZH2 inhibitor) and panobinostat (a histone deacetylase inhibitor) are being tested in vitro, together with temozolomide.

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Background: Giant cell glioblastoma (gcGBM) is a rare morphological variant of IDH-wildtype (IDHwt) GBM that occurs in young adults and have a slightly better prognosis than "classic" IDHwt GBM.

Methods: We studied 36 GBMs, 14 with a histopathological diagnosis of gcGBM and 22 with a giant cell component. We analyzed the genetic profile of the most frequently mutated genes in gliomas and assessed the tumor mutation load (TML) by gene-targeted next-generation sequencing.

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Current treatment against glioblastoma consists of surgical resection followed by temozolomide, with or without combined radiotherapy. Glioblastoma frequently acquires resistance to chemotherapy and/or radiotherapy. Novel therapeutic approaches are thus required.

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overexpression is considered a driver event in gastric cancer (GC), and is frequently correlated with poor prognosis and metastasis. In this study, we evaluated the prognostic value of genes upregulated by MYC in patients with GC. Metastatic GC cells (AGP01) characterized by amplification, were transfected with siRNAs targeting .

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Glioblastoma or grade IV astrocytoma is the most common and lethal form of glioma. Current glioblastoma treatment strategies use surgery followed by chemotherapy with temozolomide. Despite this, numerous glioblastoma cases develop resistance to temozolomide treatments, resulting in a poor prognosis for the patients.

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This study aimed to explore the effect of topically administering an orabase gel containing cashew gum (CG), a complex polysaccharide from Anacardium occidentale L., on the transcription of important proinflammatory (COX-2, NOS-2, INF-γ, OSCAR, and MYD88) and anti-inflammatory genes (IL-10, IL-4, and TGFβ1) in the gingival tissues of rats with ligature-induced periodontitis, compared to the effect observed upon topically applying a well-known antibiofilm agent (chlorhexidine) under the same experimental conditions. The gene expression profile in the gingival tissues of rats with periodontitis treated with CG did not statistically significantly differ from that observed in the group of animals treated with chlorhexidine.

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is an oncogene responsible for excessive cell growth in cancer, enabling transcriptional activation of genes involved in cell cycle regulation, metabolism, and apoptosis, and is usually overexpressed in gastric cancer (GC). By using siRNA and Next-Generation Sequencing (NGS), we identified -regulated differentially expressed Genes (DEGs) in three Brazilian gastric cancer cell lines representing the histological subtypes of GC (diffuse, intestinal, and metastasis). The DEGs were picked using software, followed by Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis using KEGG.

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Glioblastoma (GBM) is the most common malignant adult primary brain tumor. Despite its high lethality, a small proportion of patients have a relatively long overall survival (OS). Here we report a study of a series of 74 GBM samples from 29 long-term survivors ([LTS] OS ≥36 months) and 45 non-LTS.

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Background/aim: Individuals with type 2 Neurofibromatosis are predisposed for the appearance of schwannomas. In the present study we analyzed the loss of heterozygosity and mutations in the NF2 gene in patients with sporadic Schwannoma without Neurofibromatosis type 2.

Materials And Methods: We analyzed 39 patients with sporadic spinal schwannoma.

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We previously observed reduced YWHAE (14-3-3ε) protein expression in a small set of gastric cancer samples. YWHAE may act as a negative regulator of the cyclin CDC25B, which is a transcriptional target of MYC oncogene. The understanding of YWHAE role and its targets is important for the better knowledge of gastric carcinogenesis.

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Medulloblastoma (MB) is a highly malignant tumor of childhood. MB seems to be initiated and maintained by a small group of cells, known as cancer stem cells (CSCs). The CSC hypothesis suggests that a subset of tumor cells is able to proliferate, sustain the tumor, and develop chemoresistance, all of which make of CSC an interesting target for new anticancer therapies.

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Glioblastoma (GBM) is the most prevalent malignant primary brain tumor, accounting for 60-70% of all gliomas. Current median patient survival time is 14-16 months after diagnosis. Numerous efforts in therapy have not significantly altered the nearly uniform lethality of this malignancy.

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Prostate cancer is the second most common cancer among men in western populations, and despite its high mortality, its etiology remains unknown. Inflammatory processes are related to the etiology of various types of tumors, and prostate inflammation, in particular, has been associated with prostate cancer carcinogenesis and progression. Human papillomavirus (HPV) is associated with benign and malignant lesions in the anogenital tract of both females and males.

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Kinases are downstream modulators and effectors of several cellular signaling cascades and play key roles in the development of neoplastic disease. In this study, we aimed to evaluate SRC, LYN and CKB protein and mRNA expression, as well as their promoter methylation, in gastric cancer. We found elevated expression of SRC and LYN kinase mRNA and protein but decreased levels of CKB kinase, alterations that may have a role in the invasiveness and metastasis of gastric tumors.

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Aim: To characterize APC gene mutations and correlate them with patient phenotypes in individuals diagnosed with familial adenomatous polyposis (FAP) in northern Brazil.

Methods: A total of 15 individuals diagnosed with FAP from 5 different families from the north of Brazil were analyzed in this study. In addition to patients with histopathological diagnosis of FAP, family members who had not developed the disease were also tested in order to identify mutations and for possible genetic counseling.

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Meningiomas are common intracranial tumors derived from arachnoid cells. Multiple meningiomas are occasionally present even in patients with no history of neurofibromatosis type 2, a condition that can cause the formation of this neoplasm. Previous studies have shown that most multiple meningiomas are monoclonal in origin.

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Clinical and molecular prognostic factors in gliomas include age, IDH mutation, the glioma CpG island methylator phenotype (G-CIMP+) and promoter methylation of the O(6)-methylguanine DNA-methyltransferase (MGMT) gene. Among these markers, a predictive value was reported in glioblastomas (GBM) for MGMT promoter methylation, in particular in elderly GBM patients. In this study, methylation data from 46 glioma samples with the Illumina 450K platform were obtained and extended using external data to include a total of 247 glioma samples.

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According to World Health Organization criteria, diffuse gliomas are divided into several histological subtypes, including astrocytomas, oligodendrogliomas, and oligoastrocytomas, and 4 malignancy grades (I-IV). Molecular alterations, such as the isocitrate dehydrogenase gene (IDH) mutation or 1p/19q loss, are found in these tumors but are not included in the current classification system. Recently, mutation of α thalassemia/mental retardation syndrome X-linked (ATRX) gene and its loss of expression have been reported in infiltrating gliomas.

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Schwannomas are tumors that develop from Schwann cells in the peripheral nerves and commonly arise from the vestibular nerve. Vestibular schwannomas can present unilaterally and sporadically or bilaterally when the tumor is associated with neurofibromatosis Type 2 (NF2) syndrome. The molecular hallmark of the disease is biallelic inactivation of the NF2 gene.

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Glioma constitutes one of the most common groups of brain tumors, and its prognosis is influenced by different genetic and epigenetic modulations. In this study, we demonstrated low or no expression of hedgehog interacting protein (HHIP) in most of the cell lines and primary glioma tumor samples. We further proceeded to promoter methylation study of this gene in the same cell lines and primary tumor samples and found 87 % (7/8) HHIP methylation in glioblastoma cell lines and 75 % (33/44) in primary tumor samples.

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Neuroblastoma has a very diverse clinical behaviour: from spontaneous regression to a very aggressive malignant progression and resistance to chemotherapy. This heterogeneous clinical behaviour might be due to the existence of Cancer Stem Cells (CSC), a subpopulation within the tumor with stem-like cell properties: a significant proliferation capacity, a unique self-renewal capacity, and therefore, a higher ability to form new tumors. We enriched the CSC-like cell population content of two commercial neuroblastoma cell lines by the use of conditioned cell culture media for neurospheres, and compared genomic gains and losses and genome expression by array-CGH and microarray analysis, respectively (in CSC-like versus standard tumor cells culture).

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Schwannomas and grade I meningiomas are non‑metastatic neoplasms that share the common mutation of gene NF2. They usually appear in neurofibromatosis type 2 patients. Currently, there is no drug treatment available for both tumors, thus the use of wide expression technologies is crucial to identify therapeutic targets.

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