Immunohistochemical expression of markers Ki-67, neun, synaptophysin, p53 and HER2 in medulloblastoma and its correlation with clinicopathological parameters.

Medulloblastoma (MB) is the most common malignant brain tumor in childhood. The alterations found include: presence of oncoproteins p53 and HER2, elevated mitotic index, and presence of neuronal differentiation. The aim of this study was to determine the immunohistochemical expression of markers Ki-67, NeuN, synaptophysin, HER2 and p53 in 40 MB samples and their correlation with clinicopathologic parameters and survival. In 29 patients (72.5%), >20% of cells were positive for Ki-67. Males showed greater ki-67 expression (p=0.02) and smaller survival rates (p=0.002). NeuN and synaptophysin were negative in 16 (40%) and 8 (20%) cases, respectively. P53 was positive in 18 (45%) cases, with 11 (61%) weakly positive and 7 (39%) strongly positive. HER2 was positive in 23 (57.5%) of the samples and did not show statistical association with survival (p=0.07).

The effect of taurine and enriched environment on behaviour, memory and hippocampus of diabetic rats.

Diabetes mellitus (DM) has been studied recently as a major cause of cognitive deficits, memory and neurodegenerative damage. Taurine and enriched environment have stood out for presenting neuroprotective and stimulating effects that deserve further study. In this paper, we examined the effects of taurine and enriched environment in the context of diabetes, evaluating effects on behaviour, memory, death and cellular activity. Eighty-eight Wistar rats were divided into 2 groups (E=enriched environment; C=standard housing). Some animals (24/group) underwent induction of diabetes, and within each group, some animals (half of diabetics (D) and half of non-diabetics (ND)/group) were treated for 30days with taurine (T). Untreated animals received saline (S). In total, there were eight subgroups: DTC, DSC, NDTC, NDSC, DTE, DSE, NDTE and NDSE. During the experiment, short-term memory was evaluated. After 30th day of experiment, the animals were euthanized and was made removal of brains used to immunohistochemistry procedures for GFAP and cleaved caspase-3. As a result, we observed that animals treated with taurine showed better performance in behavioural and memory tasks, and the enriched environment had positive effects, especially in non-diabetic animals. Furthermore, taurine and enriched environment seemed to be able to interfere with neuronal apoptosis and loss of glial cells, and in some instances, these two factors seemed to have synergistic effects. From these data, taurine and enriched environment may have important neurostimulant and neuroprotective effects.

MYC amplification is associated with poor survival in small cell lung cancer: a chromogenic in situ hybridization study.

PURPOSE: Small cell lung cancer (SCLC) is a highly aggressive tumor, and few studies have examined the amplification status of the MYC gene in tumor samples using chromogenic in situ hybridization (CISH). Emerging target treatments associated with MYC status in SCLC necessitates the evaluation of MYC using current methodologies, such as CISH. In this study, we evaluated tissue samples from untreated patients to determine the relation between MYC amplification and clinical and pathological factors, including survival. METHODS: Formalin-fixed paraffin-embedded tumor samples were obtained from 77 patients with SCLC who underwent a diagnostic biopsy for SCLC. The samples were analyzed by CISH using a MYC probe (ZytoDot(®) CISH probe). The relationship between cytogenetic analysis, pathologic characteristics and survival time was evaluated using the Chi-square test, Fisher's test and Mann-Whitney method. A regression model was constructed to exclude any confounding factors. RESULTS: Of 77 samples, 64.9 % were from bronchi biopsy and the remainder was from the mediastinal, cervical and supraclavicular lymph nodes. The MYC oncogene was amplified in 20 % of the tumors. After the multivariate regression analysis, patients with MYC amplification had a significantly shorter survival time (4.67 weeks) versus patients without MYC amplification (26.15 weeks) (p = 0.02, CI 1.355-10.261). CONCLUSION: MYC amplification is a frequent event in SCLC and is related to a short survival time. MYC amplification may be an independent prognostic factor for SCLC. Further studies are required to support this finding and clarify the role of MYC in SCLC tumorigenesis.

The potential role of extracellular regulatory kinase in the survival of patients with early stage adenocarcinoma.

BACKGROUND: Lung cancer is among the most common types of neoplasias, and adenocarcinoma is the most frequent histological type. There is currently an extensive search for prognostic biomarkers of nonsmall cell lung cancer (NSCLC). METHODS: We analyzed the correlation of clinical data and patient survival with the levels of activated extracellular regulatory kinase (ERK) in histological samples of surgically resected early stage lung adenocarcinoma. We randomly selected 36 patients with stage I or II lung adenocarcinoma who underwent pulmonary lobectomy between 1998 and 2004. Patients were divided into the following two groups according to immunohistochemical profile: a group with <15% ERK-positive tumor cells and a group with ≥15% ERK-positive tumor cells. For data comparison, an enrichment analysis of a microarray database was performed (GSE29016, n=72). RESULTS: Activated ERK levels were ≥15% and <15% in 21 (58%) and 15 (42%) patients, respectively. There were no statistically significant differences in age, sex, smoking history, and body mass index (BMI) among the groups stratified by ERK levels. The survival rate was lower in the ERK ≥15% group than in the ERK <15% group (P=0.045). Enrichment analyses showed no correlation between variations in gene expression of ERK in patients with adenocarcinoma and survival rates in patients with stage I and combined stage II + III disease. CONCLUSIONS: Our findings suggest that high ERK positivity in cells from biological samples of lung adenocarcinoma is related with tumor aggressiveness and a poorer prognosis.

Evaluation of the expression of C-kit (CD117) in ependymomas and oligodendrogliomas.

C-kit is a proto-oncogene located on the long arm of chromosome 4. Its product, CD117, is a specific immunohistochemical (IHQ) marker that is associated with response to a potent tyrosine kinase inhibitor therapy with STI-571 (Gleevec®) in chronic myelogenous leukemia and GISTs. In our study, we aimed to evaluate the expression of CD117 in glial tumors as this finding may guide therapeutic approaches for these brain tumors. Ependymomas and oligodendrogliomas, in formalin fixed and paraffin embedded blocks were assayed for CD117 immunoreactivity using anti-c-kit (CD117, DAKO). GISTs were used as positive control. We observed immunoreactivity of CD117 protein in 25.5% of tumors in both histological types. In oligodendrogliomas, there was an association between older age at diagnosis and positivity for CD117 (P=0.039). In addition, we observed an association between higher tumor grade (grade III) and positivity for CD117 (P=0.007). No clinical association was observed in ependymomas (P>0.05). This study encourages further investigations, considering that CD117 may be a possible oncogenic factor in some glial tumors. In this case, tumors that express this marker may eventually benefit from a therapy with selective inhibitors of receptor kinases.

Comparison between proliferative and neuron-like SH-SY5Y cells as an in vitro model for Parkinson disease studies.

The molecular mechanisms underlying the cellular lost found in the nigrostriatal pathway during the progression of Parkinson's disease (PD) are not completely understood. Human neuroblastoma cell line SH-SY5Y challenged with 6-hydroxydopamine (6-OHDA) has been widely used as an in vitro model for PD. Although this cell line differentiates to dopaminergic neuron-like cells in response to low serum and retinoic acid (RA) treatment, there are few studies investigating the differences between proliferative and RA-differentiated SH-SY5Y cells. Here we evaluate morphological and biochemical changes which occurs during the differentiation of SH-SY5Y cells, and their responsiveness to 6-OHDA toxicity. Exponentially growing SH-SY5Y cells were maintained with DMEM/F12 medium plus 10% of fetal bovine serum (FBS). Differentiation was triggered by the combination of 10 microM RA plus 1% of FBS during 4, 7 and 10 days in culture. We found that SH-SY5Y cells differentiated for 7 days show an increase immunocontent of several relevant neuronal markers with the concomitant decrease in non-differentiated cell marker. Moreover, cells became two-fold more sensitive to 6-OHDA toxicity during the differentiation process. Time course experiments showed loss of mitochondrial membrane potential triggered by 6-OHDA (mitochondrial dysfunction parameter), which firstly occurs in proliferative than neuron-like differentiated cells. This finding could be related to the increase in the immunocontent of the neuroprotective protein DJ-1 during differentiation. Our data suggest that SH-SY5Y cells differentiated by 7 days with the protocol described here represent a more suitable experimental model for studying the molecular and cellular mechanisms underlying the pathophysiology of PD.

Immunohistochemical expression of markers Ki-67, neun, synaptophysin, p53 and HER2 in medulloblastoma and its correlation with clinicopathological parameters / Expressão imunoistoquímica dos marcadores Ki-67, neun, sinaptofisina, p53 e HER2 em meduloblastoma e sua correlação com os parâmetros clínico-patológicos

Medulloblastoma (MB) is the most common malignant brain tumor in childhood. The alterations found include: presence of oncoproteins p53 and HER2, elevated mitotic index, and presence of neuronal differentiation. The aim of this study was to determine the immunohistochemical expression of markers Ki-67, NeuN, synaptophysin, HER2 and p53 in 40 MB samples and their correlation with clinicopathologic parameters and survival. In 29 patients (72.5 percent), >20 percent of cells were positive for Ki-67. Males showed greater ki-67 expression (p=0.02) and smaller survival rates (p=0.002). NeuN and synaptophysin were negative in 16 (40 percent) and 8 (20 percent) cases, respectively. P53 was positive in 18 (45 percent) cases, with 11 (61 percent) weakly positive and 7 (39 percent) strongly positive. HER2 was positive in 23 (57.5 percent) of the samples and did not show statistical association with survival (p=0.07).

Meduloblastoma (MB) é o tumor maligno encefálico mais freqüente na infância. dentre as alterações encontradas estão: a presença das oncoproteínas p53 e HER2, elevado índice mitótico e presença de diferenciação neuronal. o objetivo deste estudo foi determinar a expressão imunoistoquímica (IMQ) dos marcadores Ki-67, NeuN, sinaptofisina, HER2 e p53 em 40 amostras de MB, correlacionando-as com parâmetros clinicopatológicos e com a sobrevida. Vinte e nove pacientes (72,5 por cento) apresentaram 20 por cento ou mais das células positivas para Ki-67. os pacientes do sexo masculino apresentaram maior expressão do Ki-67 (p=0,02) e também menor sobrevida (p=0,002). NeuN e sinaptofisina foram negativos em 16 (40 por cento) e 8 (20 por cento) casos, respectivamente. P53 foi positivo em 18 (45 por cento) casos, sendo 11 (61 por cento) fracamente positivos e 7 (39 por cento) fortemente positivos. HER2 foi positivo em 23 (57,5 por cento) das amostras e não demonstrou associação estatística com a sobrevida (p=0.07).