Expression of microRNAs miR-21 and miR-326 associated with HIF-1α regulation in neurospheres of glioblastoma submitted to ionizing radiation treatment.

Background: Glioblastoma is an incurable neoplasm. Its hypoxia mechanism associated with cancer stem cells (CSCs) demonstrates hypoxia-inducible factor 1α (HIF-1α) expression regulation, which is directly related to tumor malignancy. The aim of this study was to identify a possible tumor malignancy signature associated with regulation of HIF-1α by microRNAs miR-21 and miR-326 in the subpopulation of tumor stem cells which were irradiated by ion in primary culture of patients diagnosed with glioblastoma.

Expression of pluripotency-related genes in human glioblastoma.

Background: Cancer is a group of heterogeneous diseases characterized by several disruptions of the genetic and epigenetic components of cell biology. Some types of cancer have been shown to be constituted by a mosaic of cells with variable differentiation states, with more aggressive tumors being more undifferentiated. In most cases, undifferentiated tumor cells express associated embryonic markers such as the OCT4, NANOG, SOX2, and CARM1 genes.

Apoptosis related microRNAs and MGMT in glioblastoma cell lines submitted to treatments with ionizing radiation and temozolomide.

Aim: To evaluate the effect of radiotherapy and temozolomide on the expression of miRNAs apoptotic (miRNAs-21, -221, -222 (anti-apoptotic) and miRNAs-15a, -16 (pro-apoptotic)) and the gene MGMT in glioblastoma cell lines.

Background: The limited knowledge of the molecular biology of malignant gliomas may hinder the development of therapeutic modalities. In this scenario, one of the greatest advances of recent years was the identification of microRNAs.

microRNA-181d associated with the methylation status of the MGMT gene in Glioblastoma multiforme cancer stem cells submitted to treatments with ionizing radiation and temozolomide.

Despite the increased understanding of the oncological mechanisms underlying Glioblastoma multiforme (GBM) pathophysiology, and recent advances in therapeutic strategies such as maximal surgical resection and post-operative radiotherapy with concomitant and adjuvant temozolomide chemotherapy, the prognosis for patients with brain tumors remains limited. Evidences indicate that the assessment of DNA methylation status in cancer stem cells would allow identifying molecules expressed in these cells, to lead to targeted elimination of this critical population from brain tumors, making the glioblastoma treatment more effective. This study aimed to analyze the role of microRNA-181d associated with the methylation status of the O-methylguanine methyl transferase (MGMT) gene in Glioblastoma multiforme cancer stem cells subjected to treatment with temozolomide and ionizing radiation.

High expression of XIAP and Bcl-2 may inhibit programmed cell death in glioblastomas.

Unlabelled: Glioblastoma (GBM) is the most malignant glioma and represents 29% of all brain tumors. Tumorigenesis is intimately connected with characteristics acquired in the physiologic pathway of cellular death.

Objective: In the present study, the expression of anti-apoptotic (XIAP and Bcl-2) and apoptotic (cytochrome C, caspase 9, APAF-1), caspase 3 and the Smac/DIABLO genes related to the apoptosis pathway were evaluated in 30 samples of glioblastoma.

High expression of anti-apoptotic genes in grade I and II meningiomas.

Objective: To evaluate the expression of c-FLIP, XIAP, Bcl-2, caspase 3, 8 and 9, cytochrome c, APAF 1 and Smac/DIABLO genes related to apoptosis pathways.

Methods: The gene expression was evaluated in 30 meningiomas (WHO grades I and II) and in 10 normal samples (from arachnoid tissue) through PCR-RT.

Results: The results showed higher expression of anti-apoptotic genes in meningiomas when compared to the control group, which had a low expression of pro-apoptotic genes.

Expression of NMDA receptor and microRNA-219 in rats submitted to cerebral ischemia associated with alcoholism.

Objective:: To evaluate the microRNA-219 and NMDA expression in brain tissue and blood of animals subjected to cerebral ischemia associated with alcoholism.

Methods:: Fifty Wistar rats were divided into groups: control, sham, ischemic, alcoholic, and ischemic plus alcoholic. The expression of microRNA-219 and NMDA were analyzed by real-time PCR.

Morphological and immunohistochemical analysis of apoptosis in the cerebellum of rats subjected to focal cerebral ischemia with or without alcoholism model.

Purpose:: To evaluated histopathological changes, morphometric and expression of proteins CASPASE-3, BCL-2 and XIAP related to apoptosis in the cerebellum after induction of temporary focal cerebral ischemia followed by reperfusion, with or without a model of chronic alcoholism.

Methods:: Fifty Wistar rats were used and divided into: control group (C), sham group (S), ischemic group (I), alcoholic group (A), and ischemic and alcoholic group (IA). The cerebellum samples collected were stained for histopathological and morphometric analysis and immunohistochemistry study.