RESUMO
Therapy development for adult diffuse glioma is hindered by incomplete knowledge of somatic glioma driving alterations and suboptimal disease classification. We defined the complete set of genes associated with 1,122 diffuse grade II-III-IV gliomas from The Cancer Genome Atlas and used molecular profiles to improve disease classification, identify molecular correlations, and provide insights into the progression from low- to high-grade disease. Whole-genome sequencing data analysis determined that ATRX but not TERT promoter mutations are associated with increased telomere length. Recent advances in glioma classification based on IDH mutation and 1p/19q co-deletion status were recapitulated through analysis of DNA methylation profiles, which identified clinically relevant molecular subsets. A subtype of IDH mutant glioma was associated with DNA demethylation and poor outcome; a group of IDH-wild-type diffuse glioma showed molecular similarity to pilocytic astrocytoma and relatively favorable survival. Understanding of cohesive disease groups may aid improved clinical outcomes.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioma/genética , Glioma/patologia , Transcriptoma , Adulto , Neoplasias Encefálicas/metabolismo , Proliferação de Células , Análise por Conglomerados , DNA Helicases/genética , Metilação de DNA , Epigênese Genética , Glioma/metabolismo , Humanos , Isocitrato Desidrogenase/genética , Pessoa de Meia-Idade , Mutação , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Transdução de Sinais , Telomerase/genética , Telômero , Proteína Nuclear Ligada ao XRESUMO
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. Materials and methods: We used cellular cultures from surgery biopsies of ten patients with glioblastoma. MicroRNA expressions were analyzed through real-time polymerase chain reaction (PCR ) and correlated with mortality and recurrence. The ROC curve displayed the cutoff point of the respective microRNAs in relation to the clinical prognosis, separating them by group. Results: The miR-21 addressed high level of expression in the irradiated neurosphere group (p = 0.0028). However, miR-21 was not associated with recurrence and mortality. miR-326 can be associated with tumoral recurrence (p = 0.032) in both groups; every 0.5 units of miR-326 increased the chances of recurrence by 1,024 (2.4%). Conclusion: The high expression of miR-21 in the irradiated group suggests its role in the regulation of HIF-1α and in the radioresistant neurospheres. miR-326 increased the chances of recurrence in both groups, also demonstrating that positive regulation from miR-326 does not depend on ionizing radiation treatment.
RESUMO
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. These molecules have an important role in biological processes involving cancer, including glioblastoma. MATERIALS AND METHODS: Trypan blue was used to verify the cell viability, and real time PCR to quantify the expression of microRNAs and gene 24, 48 and 120â¯h after exposure to treatments. RESULTS: There was a statistically significant decrease of expression of miR-15a between 48 and 120â¯h in line T98â¯G treated with radiation, increased expression of miR-15a between 24 and 120â¯h in line U251 treated with radiation and temozolomide, and increased expression of miR-16 between 24 and 120â¯h in line U251 treated with radiation alone and when combined with temozolomide. There was a decrease in MGMT gene expression, between 24 and 48â¯h in U343 cells treated with temozolomide. CONCLUSIONS: Ionizing radiation and temozolomide modified the expression of miRNAs studied and MGMT.
RESUMO
Background: Non traumatic subdural hematomas are rare, especially those associated with intracranial meningiomas. Among the most common meningiomas associated with spontaneous bleeding are angioblastic and malignant meningioma variants. The pathophysiological mechanisms of this association are not yet fully understood. The association of chronic subdural hematoma with microcystic meningioma histological subtype has not yet been described in the literature. Case report: The authors present a case report of a patient with a spontaneous non traumatic chronic subdural hematoma associated with a microcystic subtype grade I meningioma of the parietal convexity. Epidemiological, etiology, natural history, pathophysiology, risk factors of bleeding and treatment options are reviewed. Conclusion: Spontaneous subdural hematomas associated with meningiomas are rare, specially related to the microcystic variant of meningioma. Careful pre-operative consideration of specific anatomy and pathophysiological features are paramount to their full treatment.
Assuntos
Hematoma Subdural Crônico/etiologia , Neoplasias Meníngeas/complicações , Meningioma/complicações , Idoso de 80 Anos ou mais , Hemorragia Cerebral/etiologia , Hemorragia Cerebral/prevenção & controle , Craniotomia/métodos , Feminino , Hematoma Subdural Crônico/cirurgia , Humanos , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Recidiva , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: The purpose of this study was to quantify and evaluate the expression response of miRNA-191 and miRNA-455-3p endovascular repair of abdominal aortic aneurysm (AAA) based in whole blood samples. METHODS: This report describes a prospective study of a single center of 30 patients with AAA who underwent endovascular repair. Blood samples were collected preoperatively and 6 months postoperatively. The differential expression of the miRNAs was performed by the real-time polymerase chain reaction method, after extraction of the RNA from the blood samples at the 2 moments. In addition, bioinformatic tools were used to determine pathophysiological pathways related to AAA. RESULTS: The miR-191 and miR-455-3p were overexpressed preoperatively. After 6 months postoperatively, miR-191 (median 0.98, IQR 0.5-2.1, P < 0.0001) and miR-455-3p (median 1.4, IQR 0.6-3.1, P = 0.0003) presented a significant reduction in their expressions. There was no correlation between the diameter of the aneurysm and the expression of the miRNAs studied. In addition, analysis of the influence of the various types of devices used for the endovascular treatment of AAA showed no significant differences in the expression of miR-191 and miR-455-3p. CONCLUSIONS: Exclusion of the aneurysmal sac after endovascular treatment induces a decrease in the expression of the studied miRNAs in whole blood samples, which suggests a possible use of them as biomarkers of therapeutic success.
Assuntos
Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular , MicroRNA Circulante/genética , Procedimentos Endovasculares , MicroRNAs/genética , Idoso , Aneurisma da Aorta Abdominal/sangue , Aneurisma da Aorta Abdominal/diagnóstico , Brasil , MicroRNA Circulante/sangue , Feminino , Marcadores Genéticos , Humanos , Masculino , MicroRNAs/sangue , Pessoa de Meia-Idade , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Tempo , Resultado do TratamentoRESUMO
Astrocytomas are the most common primary brain tumors. They are very resistant to therapies and usually progress rapidly to high-grade lesions. Here, we investigated the potential role of DNA repair genes in astrocytoma progression and resistance. To this aim, we performed a polymerase chain reaction array-based analysis focused on DNA repair genes and searched for correlations between expression patters and survival prognoses. We found 19 genes significantly altered. Combining these genes in all possible arrangements, we found 421 expression signatures strongly associated with poor survival. Importantly, five genes (DDB2, EXO1, NEIL3, BRCA2, and BRIP1) were independently correlated with worse prognoses, revealing single-gene signatures. Moreover, silencing of EXO1, which is remarkably overexpressed, promoted faster restoration of double-strand breaks, while NEIL3 knockdown, also highly overexpressed, caused an increment in DNA damage and cell death after irradiation of glioblastoma cells. These results disclose the importance of DNA repair pathways for the maintenance of genomic stability of high-grade astrocytomas and suggest that EXO1 and NEIL3 overexpression confers more efficiency for double-strand break repair and resistance to reactive oxygen species, respectively. Thereby, we highlight these two genes as potentially related with tumor aggressiveness and promising candidates as novel therapeutic targets.
Assuntos
Astrocitoma/mortalidade , Neoplasias Encefálicas/mortalidade , Reparo do DNA , Apoptose , Astrocitoma/genética , Astrocitoma/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , N-Glicosil Hidrolases/genética , N-Glicosil Hidrolases/metabolismo , PrognósticoRESUMO
Background: Immunohistochemical prognostic significance of the homologous recombination-related proteins RAD51, ATM, BRCA1, and BRCA2 is known in gastric adenocarcinoma, one of the deadliest cancers. Objective and design: This retrospective cohort study aimed to evaluate mRNA expression and promoter methylation of some homologous recombination-related genes in this neoplasm. Methods: We evaluated mRNA expression and methylation of RAD51, ATM, ATR, BRCA1, and BRCA2 in tumor and non-tumor frozen samples from gastrectomy specimens by RT-qPCR and MS-HRM, correlating our results with previous immunohistochemistry data and prognostic features. Results: RAD51, ATR, BRCA1, BRCA2, and ATM mRNA expression was detected in 93.75% (45/48), 93.75% (45/48), 91.67% (44/48), 83.33% (40/48), and 89.58% (43/48) of the tumors; partial or complete methylation, in 94.87% (37/39), 0 (0/42), 97.56% (40/41), 100% (41/41), and 0 (0/40), respectively. Most gene pairs showed significant weak to moderate positive correlations of tumoral mRNA expression with each other: RAD51 with ATR (P = .027), BRCA1 (P < .001), and BRCA2 (P < .001); ATR with BRCA1 (P = .007), and ATM (P = .001); BRCA1 with BRCA2 (P = 0.001). BRCA1 mRNA was reduced in tumors compared with non-neoplastic mucosa (0.345 vs 1.272, P = .015) and, excluding neoadjuvant therapy cases, in T3 to T4 tumors compared with T2 (0.414 vs 0.954, P = .035). Greater tumoral RAD51 mRNA levels correlated with perineural invasion (1.822 vs 0.725, P = .010) and death (1.664 vs 0.929, P = .036), but not with survival time. There was an inverse association between nuclear immunohistochemical positivity for ATR and its mRNA levels (0.487 vs 0.907, P = .032), and no significant correlation for the other markers. Conclusions: Our results suggest RAD51, BRCA1, and BRCA2 methylation as a frequent epigenetic mechanism in gastric cancer, support the hypothesis that reduced BRCA1 expression participates in disease progression, and show an association between RAD51 mRNA and perineural invasion and mortality that may be considered unexpected, considering the former immunohistochemical studies. The lack of correlation between immunohistochemistry and mRNA, and even the inverse association, for ATR, can be seen as indicative of action of post-transcriptional or post-translational regulatory mechanisms, to be better investigated.
RESUMO
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. The ectopic or reminiscent expression of some master regulator genes of pluripotency has been indicated as the cause of the poorly differentiated state of tumors, and based on the evidence of some reports, can be used as a possible therapeutic target. Considering this information, a more detailed investigation of the expression of pluripotency-associated genes is necessary to evaluate the roles of these genes in the etiology of some tumors and their use targets of therapy. Methods: The expression of four pluripotency-related genes was investigated (OCT4, NANOG, SOX2, and CARM1) in the most malignant primary human brain tumor, glioblastoma (GBM). Results and Conclusion: The results demonstrated a signature of OCT4/SOX2/CARM1 genes and a significant increase of CARM1 expression in GBM cases.
RESUMO
Current scientific literature lacks data on the prognostic value of the expression of RAD51 and BRCA2 in gastric adenocarcinoma. Therefore, we aimed to evaluate those and other homologous recombination-related proteins (ATM, ATR, BRCA1, CHK2, γH2AX, p53) in gastric cancer, assessing their correlation with clinical prognosis. Paraffin-embedded samples were obtained from surgical specimens collected in total or subtotal gastrectomy procedures. Between 2008 and 2017, 121 patients with advanced gastric adenocarcinoma underwent surgical resection and were included in this study. Negativity for nuclear RAD51 correlated with vascular invasion, lymph node metastasis, larger tumor size, and lower overall survival and disease-free survival in univariate analysis. However, nuclear RAD51-negative cases presented better response rates to adjuvant therapy than the positive ones. Nuclear ATR negativity correlated with larger tumor size and a higher histological grade. Positivity for ATM was associated with more prolonged disease-free survival. Positivity for nuclear BRCA2 correlated with lower overall survival and diffuse histological type, whereas its high expression was associated with vascular invasion. Nevertheless, tumors positive for nuclear BRCA2 were more frequently low grade in the intestinal histological type. Our findings indicate that RAD51 and BRCA2 are valuable immunohistochemical prognostic markers in gastric adenocarcinoma.
Assuntos
Adenocarcinoma/diagnóstico , Proteína BRCA2/análise , Rad51 Recombinase/análise , Neoplasias Gástricas/diagnóstico , Adenocarcinoma/metabolismo , Proteína BRCA2/biossíntese , Estudos de Coortes , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Prognóstico , Rad51 Recombinase/biossíntese , Estudos Retrospectivos , Neoplasias Gástricas/metabolismoRESUMO
Caffeine consumption is able to interfere in cellular processes related to inflammatory mechanisms by acting through the adenosinergic system. This study aimed to recognize alterations related to adenosinergic system and inflammatory process in the cerebellum of University of Chile Bibulous (UChB) rats after the consumption of ethanol and caffeine. UChB and Wistar rats, males at 5 months old, were divided into the groups (n = 15/group): (i) Control (Wistar rats receiving water); (ii) Ethanol group (UChB rats receiving ethanol solution at 10%) and (iii) Ethanol+caffeine group (UChB rats receiving ethanol solution at 10% added of 3 g/L of caffeine). The cerebellar tissue was collected and processed for immunohistochemistry, Reverse transcription polymerase chain reaction (RT-PCR) and western blotting techniques for the adenosinergic receptors A1 and A2a and inflammatory markers, including Nuclear factor kappa B (NFkB), TLR4, TLR2, MyD88, TNF-α, COX-2, iNOS and microglial marker Iba-1. Results showed ethanol and caffeine consumption differentially altering the immunolocalization of adenosinergic receptors and inflammatory markers in the cerebellar tissue. The A2a receptor was overexpressed in the Ethanol group and was evident in the glial cells. The Ethanol group had increased protein levels for NFκB and TLR4, expressively in Bergmann glia and Purkinje cells. Caffeine reduced the expression of these markers to levels similar to those found in the Control group. The A1 gene was upregulated the Ethanol group, but not its protein levels, suggesting post-transcriptional interference. In conclusion, caffeine seems to attenuate ethanol-induced inflammation in the cerebellum of UChB rats through the A1 and A2a modulation, playing a neuroprotective role in the chronic context of ethanol consumption.
RESUMO
Diagnosis and treatment of pancreatic ductal adenocarcinoma (PA) remains a challenge in clinical practice. The aim of this study was to assess the role of microRNAs (miRNAs-21, -23a, -100, -107, -181c, -210) in plasma and tissue as possible biomarkers in the diagnosis of PA. Samples of plasma (PAp-n = 13), pancreatic tumors (PAt-n = 18), peritumoral regions (PPT-n = 9) were collected from patients during the surgical procedure. The control group consisted of samples from patients submitted to pancreatic surgery for trauma or cadaveric organs (PC-n = 7) and healthy volunteers donated blood (PCp-n = 6). The expression profile of microRNAs was measured in all groups using RT-PCR, serum CA19-9 levels were determined in PA and PC. In tissue samples, there was a difference in the expression of miRNAs-21, -210 (p < 0.05) across the PAt, PC and PPT groups. The PAp showed overexpression of miRNAs-181c, -210 (p < 0.05) when compared to PCp. The combination of miRNAs-21, -210 tissue expression and serum CA19-9 showed 100% accuracy in the diagnosis of PA, as well as miR-181c expression in the plasma (PApxPCp). The expression of microRNAs in plasma proved to be a promising tool for a noninvasive detection test for PA, as well as further studies will evaluate the utility of microRNAs expression as biomarkers for prognostic and response to therapy in PA.
RESUMO
Purpose To evaluate the gene expression of peroxisome proliferator activated receptors gamma (PPARG) in colorectal tumors and to correlate this data with clinical variables of the patients. Methods We analyzed the gene expression of PPARG in 50 samples of colorectal tumors using real-time reverse transcription polymerase chain reaction, and 20 adjacent normal tissue samples as control. The results of these quantifications were correlated with the respective patients' medical records' clinical information. Results PPARG expression was not different in the tumor tissue compared to the control tissue. Patients older than 60 years, histological type with mucinous differentiation, more advanced staging at the time of diagnosis, and patients who evolved with recurrence of the disease or death did not present higher PPARG expression. Conclusion Expression of PPARGD was not associated with worse prognosis.
Assuntos
Neoplasias Colorretais , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , PPAR gama , PrognósticoRESUMO
Mesial temporal lobe epilepsy with hippocampal sclerosis is the most frequent form of focal epilepsy in adults, and it is often refractory to drug treatment. Regardless of the efforts on developing new antiepileptic drugs for refractory cases, studies suggest a need for better understanding the molecular bases of epilepsy. The microRNAs have been progressively investigated as potential targets for both epilepsy mechanisms elucidation and treatment. Therefore, the goal of this study was to evaluate the differential expression of miR-219, miR-181b, and miR-195, previously described as regulators of the excitatory neurotransmitter receptors NMDA-R1 and AMPA-GluR2 and inhibitory neurotransmitter GABAA (α2, ß3, and γ2 subunits) in the amygdala and hippocampus of patients with mesial temporal lobe epilepsy. Based on genes and miRNAs' quantitative Polymerase Chain Reaction (qPCR) from 18 patients with epilepsy, our results showed an inverse relationship between miR-219 and NMDA-NR1 expression in both the amygdala and hippocampus in comparison to their expression in controls. NR1 and GluR2 were upregulated in the amygdala of epileptic patients. Low miR-195 expression was observed in the amygdala of patients with epilepsy. Our findings indicate that miR-219 has a possible regulatory role in excitatory neurotransmission in patients with epilepsy, contributing to the new avenue of miRNA biology in drug-resistant epilepsy, reserving huge potential for future applications and clinical interventions in conjunction with existing therapies.
Assuntos
Epilepsia do Lobo Temporal/metabolismo , MicroRNAs/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Tonsila do Cerebelo/metabolismo , Epilepsia do Lobo Temporal/genética , Regulação da Expressão Gênica/genética , Hipocampo/metabolismo , Humanos , Regulação para CimaRESUMO
PURPOSE: To evaluate the effects of alcohol exposure and diabetes on apoptotic process in the corpus cavernosum. METHODS: Forty eight male Wistar rats were divided into four groups: control, diabetic, alcoholic and diabetic-alcoholic. Samples of the corpus cavernosum were prepared to study protein expression of apoptotic genes (Caspases-3 and 9) by immunohistochemistry and Real-Time PCR. RESULTS: The immunoreactivity of Caspases-3 and -9 was diffuse and higher in the treated groups though there was no significant difference between the experimental groups, only when compared with the control group. An increase was observed in the gene expression of Caspases-9 in the diabetic and ethanol-diabetic groups when compared with control and ethanol groups. CONCLUSIONS: The association of these factors (ethanol and diabetes) probably can affect the apoptosis mechanism in lesions of the cavernous tissue in the rat penis. Both gene and protein expression of Caspase-9 in diabetic and ethanol-diabetic groups suggest the involvement of the apoptosis cascade from this study model.
Assuntos
Alcoolismo , Apoptose , Diabetes Mellitus Experimental , Alcoolismo/complicações , Animais , Masculino , Pênis , Ratos , Ratos WistarRESUMO
PURPOSE: To evaluate the effect of chronic alcoholism on morphometry and apoptosis mechanism and correlate with miRNA-21 expression in the corpus cavernosum of rats. METHODS: Twenty-four rats were divided into two experimental groups: Control (C) and Alcoholic group (A). After two weeks of an adaptive phase, rats from group A received only ethanol solution (20%) during 7 weeks. The morphometric and caspase-3 immunohistochemistry analysis were performed in the corpus cavernosum. The miRNA-21 expression was analyzed in blood and cavernous tissue. RESULTS: Chronic ethanol consumption decreased cavernosal smooth muscle area of alcoholic rats. The protein expression of caspase 3 in the corpus cavernosum was higher in A compared to the C group. There was no difference in the expression of miRNA-21 in serum and cavernous tissue between the groups. CONCLUSION: Chronic ethanol consumption reduced smooth muscle area and increased caspase 3 in the corpus cavernosum of rats, without altered serum and cavernosal miR-21 gene expression.
Assuntos
Alcoolismo/complicações , Apoptose/efeitos dos fármacos , Pênis/efeitos dos fármacos , Pênis/patologia , Animais , Caspase 3/análise , Modelos Animais de Doenças , Disfunção Erétil/induzido quimicamente , Disfunção Erétil/patologia , Expressão Gênica , Imuno-Histoquímica , Masculino , MicroRNAs/análise , Músculo Liso/efeitos dos fármacos , Ratos Wistar , Valores de ReferênciaRESUMO
The aim of this study was to analyze the expression profiles of the microRNAs (miRNAs) miR-145, miR-181c, miR-199a and miR-1183 in the hippocampus and blood of patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and to investigate whether these can be used as diagnosis and prognosis biomarkers for epilepsy. Hippocampus and blood samples were collected from 20 patients with MTLE-HS, ten of whom had a favorable surgical outcome (Engel I) and ten with an unfavorable surgical outcome (Engel III-IV). Hippocampus samples from autopsied individuals with no neurological or psychiatric medical history (necropsy samples) and blood samples from healthy individuals were used as controls. Real-time quantitative PCR (RQ-PCR) was used to analyze miRNA expression. The results showed that the expressions of these miRNAs differed quantitatively in the hippocampus and blood of patients with MTLE-HS in comparison to the respective control. This difference was most pronounced for miR-145, which was hypo-expressed in the hippocampus and hyper-expressed in the blood of MTLE-HS patients. MiRNAs miR-145, miR-181c, miR-199a and miR-1183 were hyper-expressed in the blood of patients with MTLE-HS. No statistical differences in the levels of these miRNAs in the blood or hippocampus were found between Engel I patients and Engel III-IV patients. These results suggest that the analyzed microRNAs are potential circulating biomarkers for epilepsy diagnosis.
Assuntos
Epilepsia do Lobo Temporal/diagnóstico , Hipocampo/metabolismo , MicroRNAs/genética , Adulto , Biomarcadores/sangue , Biomarcadores/metabolismo , Epilepsia do Lobo Temporal/sangue , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Feminino , Humanos , Masculino , MicroRNAs/sangue , MicroRNAs/metabolismo , Pessoa de Meia-IdadeRESUMO
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 O6-methylguanine methyl transferase (MGMT) gene in Glioblastoma multiforme cancer stem cells subjected to treatment with temozolomide and ionizing radiation. Such responses were analyzed in terms of cell survival, evaluation of the MGMT gene methylation status by MS-HRM (Methylation-Sensitive High Resolution Melting), and analysis of miRNA-181d and MGMT gene expression by relative quantification of mRNA levels in cancer stem cells subjected to treatment with temozolomide and ionizing radiation, isolated or combined. We showed that ionizing radiation and temozolomide reduced the viability of cancer stem cells from GBM patients, as well as modified MGMT gene and miRNA-181d expression in cancer stem cells, suggesting that miRNA-181d interferes in the glioblastoma cancer stem cell response to treatment with temozolomide and ionizing radiation.
Assuntos
Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Glioblastoma/genética , MicroRNAs/genética , Proteínas Supressoras de Tumor/genética , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/metabolismo , Brasil , Metilação de DNA , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Feminino , Glioblastoma/metabolismo , Humanos , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Prognóstico , Radiação Ionizante , Temozolomida/metabolismo , Temozolomida/uso terapêutico , Proteínas Supressoras de Tumor/metabolismoRESUMO
OBJECTIVE: This study aimed to analyze the cerebellum of rats submitted to an experimental focal cerebral ischemia, by middle cerebral artery occlusion for 90 minutes, followed by reperfusion for 48 hours, associated with an alcoholism model. METHODS: Fifty adult Wistar rats were used, subdivided into five experimental groups: control group (C): animals submitted to anesthesia only; sham group (S): animals submitted to complete simulation of the surgical procedure; ischemic group (I): animals submitted to focal cerebral ischemia for 90 minutes followed by reperfusion for 48 hours; alcoholic group (A): animals that received daily absolute ethanol diluted 20% in water for four weeks; and, ischemic and alcoholic group (I + A): animals receiving the same treatment as group A and, after four weeks, submitted to focal cerebral ischemia for 90 minutes, followed by reperfusion for 48 hours. The cerebellum samples were collected and immunohistochemical analysis of Caspase-9 protein and serum analysis by RT-PCR of microRNAs miR-21, miR-126 and miR155 were performed. RESULTS: The expression of Caspase-9 was higher in groups I, A and I + A. In the microRNAs analyses, miR-126 was higher in groups A and I + A, miR-155 was higher in groups I and I + A. CONCLUSIONS: We conclude that apoptosis occurs in the cerebellar cortex, even if it is distant from the ischemic focus, and that microRNAs 126 and 155 show a correlation with cellular apoptosis in ischemic rats and those submitted to the chronic alcohol model.
Assuntos
Alcoolismo/patologia , Apoptose , Isquemia Encefálica/patologia , Caspase 9/análise , Cerebelo/patologia , MicroRNAs/sangue , Alcoolismo/sangue , Animais , Isquemia Encefálica/sangue , Cerebelo/química , Imuno-Histoquímica , Infarto da Artéria Cerebral Média , Masculino , Distribuição Aleatória , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Traumatismo por Reperfusão/patologia , Fatores de TempoRESUMO
PURPOSE: To evaluate histopathological and ultrastructural changes and expression of proteins related to apoptosis CASPASE 3 and XIAP after experimental induction of temporary focal cerebral ischemia (90 minutes) due to obstruction of the middle cerebral artery in alcoholism model. METHODS: Forty adult Wistar rats were used, subdivided into 5 experimental groups: control group (C); Sham group (S); Ischemic group (I); Alcoholic group (A); and Ischemic and Alcoholized group (I+A): animals submitted to the same treatment of group A and after four weeks were submitted to focal cerebral ischemia during 90 minutes, followed by reperfusion of 48 hours. Were processed for histopathological analysis and immunohistochemistry (for the protein expression of CASPASE -3 and XIAP). RESULTS: Greater histopathological changes were observed in the animals of groups I and I+A in the three areas analyzed. The neuronal loss was higher in the medial striatum region of the animals of groups I and I + A. The protein expression of CASPASE -3 was higher than that of XIAP in the groups I and I + A for both proteins. CONCLUSION: The expression of XIAP was slightly higher where the histopathological changes and expression of CASPASE -3 was less evident.
Assuntos
Alcoolismo/patologia , Caspase 3/análise , Proteínas Inibidoras de Apoptose/análise , Ataque Isquêmico Transitório/patologia , Alcoolismo/metabolismo , Animais , Apoptose , Edema , Eletromiografia/métodos , Imuno-Histoquímica , Ataque Isquêmico Transitório/metabolismo , Masculino , Microscopia Eletrônica de Transmissão , Artéria Cerebral Média , Mitocôndrias/patologia , Distribuição Aleatória , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Fatores de TempoRESUMO
Hydrocephalus is one of the most frequent and complex neurological diseases characterized by the abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain, due to an altered CSF dynamics. To detect possible ultrastructural alterations of the lateral ventricles choroid plexus (responsible for the CSF production), rats seven days after birth were submitted to an intracisternal injection of 20% kaolim (hydrated aluminum silicate) for the hydrocephalus induction. Twenty-eight or 35 days after injection, injected animals and respective controls were processed for observation under a transmission electron microscopy. Alterations found: presence of concentric cell membrane fragments, larger number of primary and secondary lysossomes, vacuoles, and cytoplasmic vesicles, and an enlargement of the intercellular space and between the basolateral interdigitation of the choroid epithelium. The alterations observed are probably associated to an increase of the ventricular pressure, inducing morpho-functional effects on the choroid plexus integrity.