Context: MicroRNAs (miRNAs) are small noncoding RNAs, functioning as antisense regulators of gene expression by targeting mRNA and contributing to cancer development and progression. More than 50% of miRNA genes are located in cancer-associated genomic regions or in fragile sites of the genome. Objective: The aim of the study was to analyze the differential expression of let-7a, miR-15a, miR-16, miR-21, miR-141, miR-143, miR-145, and miR-150 in corticotropinomas and normal pituitary tissue and verify whether their profile of expression correlates with tumor size or remission after treatment. Material and Methods: ACTH-secreting pituitary tumor samples were obtained during transphenoidal surgery from patients with Cushing disease and normal pituitary tissues from autopsies. The relative expression of miRNAs was measured by real-time PCR using RNU44 and RNU49 as endogenous controls. Relative quantification of miRNA expression was calculated using the 2−ΔΔCt method. Results: We found underexpression of miR-145 (2.0-fold; P = 0.04), miR-21 (2.4-fold; P = 0.004), miR-141 (2.6-fold; P = 0.02), let-7a (3.3-fold; P = 0.003), miR-150 (3.8-fold; P = 0.04), miR-15a (4.5-fold; P = 0.03), miR-16 (5.0-fold; P = 0.004), and miR-143 (6.4-fold; P = 0.004) in ACTH-secreting pituitary tumors when compared to normal pituitary tissues. There were no differences between miRNA expression and tumor size as well as miRNA expression and ratio of remission after surgery, except in patients presenting lower miR-141 expression who showed a better chance of remission. Conclusion: Our results support the possibility that altered miRNA expression profile might be involved in corticotrophic tumorigenesis. However, the lack of knowledge about miRNA target genes postpones full understanding of the biological functions of down-regulated or up-regulated miRNAs in corticotropinomas.
Glioblastoma is the most lethal primary malignant brain tumor. Although considerable progress has been made in the treatment of this aggressive tumor, the clinical outcome for patients remains poor. Histone deacetylases (HDACs) are recognized as promising targets for cancer treatment. In the past several years, HDAC inhibitors (HDACis) have been used as radiosensitizers in glioblastoma treatment. However, no study has demonstrated the status of global HDAC expression in gliomas and its possible correlation to the use of HDACis. The purpose of this study was to evaluate and compare mRNA and protein levels of class I, II and IV of HDACs in low grade and high grade astrocytomas and normal brain tissue and to correlate the findings with the malignancy in astrocytomas. Forty-three microdissected patient tumor samples were evaluated. The histopathologic diagnoses were 20 low-grade gliomas (13 grade I and 7 grade II) and 23 high-grade gliomas (5 grade III and 18 glioblastomas). Eleven normal cerebral tissue samples were also analyzed (54 total samples analyzed). mRNA expression of class I, II, and IV HDACs was studied by quantitative real-time polymerase chain reaction and normalized to the housekeeping gene β-glucuronidase. Protein levels were evaluated by western blotting. We found that mRNA levels of class II and IV HDACs were downregulated in glioblastomas compared to low-grade astrocytomas and normal brain tissue (7 in 8 genes, p < 0.05). The protein levels of class II HDAC9 were also lower in high-grade astrocytomas than in low-grade astrocytomas and normal brain tissue. Additionally, we found that histone H3 (but not histone H4) was more acetylated in glioblastomas than normal brain tissue. Our study establishes a negative correlation between HDAC gene expression and the glioma grade suggesting that class II and IV HDACs might play an important role in glioma malignancy. Evaluation of histone acetylation levels showed that histone H3 is more acetylated in glioblastomas than normal brain tissue confirming the downregulation of HDAC mRNA in glioblastomas.
1 July 2015 in Journal of Neuropathology & Experimental Neurology
✓ The clinical course of 69 patients with neurocysticercosis who underwent surgery to control increased intracranial pressure (ICP) or cyst removal is analyzed. Increased ICP was caused by hydrocephalus in 63 patients, by cerebral edema in four, and by giant cysts in two. Skull x-ray films showed calcifications in 14% and signs of elevated ICP in 46%. Examination of cerebrospinal fluid (CSF) revealed pleocytosis with eosinophils in 52% of cases and a positive complement fixation test for cysticercosis in 66%. Ventriculography allowed localization of the CSF obstruction and ventricular cysts, and generally differentiated between an obstruction due to cysts and an inflammatory process. Computerized tomography showed cysts in the cerebral parenchyma and ventricular dilatation. Ventricular cysts were best seen when intraventricular metrizamide was used. Intracranial shunting and posterior fossa exploration were less effective in the treatment of hydrocephalus than was ventriculoatrial (VA) or ventriculoperitoneal (VP) shunting, although VA or VP shunting was associated with a high percentage of complications. Quality of survival was good in 87% of the cases in the first 3 postoperative months and in 93% of patients who survived 2 years after surgery. Fortyseven patients (68%) were readmitted one or more times for CSF shunt revision; 14 of them for shunt infection (meningitis). The early operative mortality rate was 1.8% for patients with VA or VP shunt placement and 5.3% for those with posterior fossa exploration. The authors conclude that placement of CSF shunts is indicated in the treatment of hydrocephalus, and cyst removal is indicated only when the cyst exhibits tumor-like behavior. Surgical exploration is also indicated when the diagnosis is uncertain.
1 September 2006 in Seizure: European Journal of Epilepsy
Summary: Purpose: Posterior cortex epilepsies (PCEs) encompass a group of epilepsies originating from the occipital, parietal, or occipital border of the temporal lobe, or from any combination of these regions. When their seizures are refractory to pharmacologic treatment, these patients are usually referred for surgery. The aim of our study was to analyze clinical characteristics of all PCE patients referred for surgery from 1994 to 2003, and to search for predictors of surgical outcome. Methods: We performed a retrospective analysis of clinical and laboratory data from 81 consecutive refractory PCE patients referred for surgery. Surgical and nonsurgical groups of patients were compared, and detailed analyses of all variables of the surgical cases were performed in the search for predictors of seizure outcome. Results: Risk factors for PCEs included gliosis (34.56%), malformations of cortical development (33.33%), tumors (8.64%), brain trauma (3.70%), Sturge–Weber disease (4.93%), vascular malformations (3.70%), family history of epilepsy (3.70%), history of CNS infections (2.46%), and low IQ (2.46%). Of the 81 patients, 44 were submitted to surgery at the time of the completion of this study. Surgical treatment was highly effective in improving seizures (p < 0.001) when compared with previous pharmacologic treatment alone. Twenty‐eight (65.11%) patients became seizure free after surgery versus none in the nonsurgical group. Regarding outcome predictors, patients with shorter duration of epilepsy and those without neurologic abnormalities on clinical examination had higher chances of favorable evolution. Conclusions: Surgical treatment is effective for the treatment of PCEs and superior to pharmacologic therapy alone. In our series, shorter duration of epilepsy and normal neurologic examination were the only independent variables that predicted better surgical outcome.