Frequency of Epstein-Barr virus DNA sequences in human gliomas.

CONTEXT AND OBJECTIVE: The Epstein-Barr virus (EBV) is the most common cause of infectious mononucleosis and is also associated with several human tumors, including Burkitt's lymphoma, Hodgkin's lymphoma, some cases of gastric carcinoma and nasopharyngeal carcinoma, among other neoplasms. The aim of this study was to screen 75 primary gliomas for the presence of specific EBV DNA sequences by means of the polymerase chain reaction (PCR), with confirmation by direct sequencing. DESIGN AND SETTING: Prevalence study on EBV molecular genetics at a molecular pathology laboratory in a university hospital and at an applied genetics laboratory in a national institution. METHODS: A total of 75 primary glioma biopsies and 6 others from other tumors from the central nervous system were obtained. The tissues were immediately frozen for subsequent DNA extraction by means of traditional methods using proteinase K digestion and extraction with a phenol-chloroform-isoamyl alcohol mixture. DNA was precipitated with ethanol, resuspended in buffer and stored. The PCRs were carried out using primers for amplification of the EBV BamM region. Positive and negative controls were added to each reaction. The PCR products were used for direct sequencing for confirmation. RESULTS: The viral sequences were positive in 11/75 (14.7%) of our samples. CONCLUSION: The prevalence of EBV DNA was 11/75 (14.7%) in our glioma collection. Further molecular and epidemiological studies are needed to establish the possible role played by EBV in the tumorigenesis of gliomas.

Promoter hypermethylation of death-associated protein kinase and p16 genes in vulvar lichen sclerosus.

OBJECTIVE: The purpose of this study was to discuss our investigation of the hypermethylation of promoter regions of tumor suppressor genes, such as death-associated protein kinase (DAPK) and p16, in vulvar lichen sclerosus (LS), in comparison with a control group. MATERIALS AND METHODS: Promoter hypermethylation of DAPK and p16 was investigated using 24 vulvar biopsies of patients with LS who had received no previous treatment. The control group was composed of 15 patients with no vulvar disease. The DNA of subjects was treated with sodium bisulphate, and the genes under study were subjected to methylation-specific polymerase chain reaction. The resulting polymerase chain reaction products were amplified and analyzed using a 10% polyacrylamide gel. RESULTS: The mean age of the patients with LS was 57 years (the majority were postmenopausal). In the control group, the mean age of the patients was 50 years (p = .151). Methylation of the promoter region of DAPK was found in 4 (17%) of the 23 patients analyzed, and p16 promoter region methylation was found in 8 patients (35%). Two cases of methylation of the DAPK gene were also found to be methylated for the p16 gene. In the control group, no methylation was found in the patients analyzed for the DAPK gene and methylation was found in 3 (21%) of the 14 patients analyzed for the p16 gene (p = .190 and p = .316, respectively). CONCLUSIONS: Methylation of the DAPK and p16 genes, although not sufficient to dictate prognosis of the disease, should not be underestimated because it may form part of a process of genetic and epigenetic alterations that in the future could become relevant to malignant transformation.

Promoter hypermethylation patterns of death-associated protein kinase and p16 genes in vulvar lichen sclerosus.

OBJECTIVE: This article aimed to investigate the hypermethylation of promoter regions of tumor suppressor genes, such as death-associated protein kinase (DAPK) and p16, in vulvar lichen sclerosus (LS). MATERIALS AND METHODS: The promoter hypermethylation of DAPK and p16 was investigated from 15 vulvar biopsies of patients with LS who had had no previous treatment. DNA was treated with sodium bisulfate and underwent methylation-specific polymerase chain reaction of these genes. The amplified polymerase chain reaction products were analyzed by 10% polyacrylamide gel. RESULTS: The mean age of the patients was 57 years (most were postmenopausal). Methylation of the promoter region of DAPK was found in 2 (13%) of 15 patients analyzed, and p16 promoter region methylation was found in 7 patients (47%). The samples that showed DAPK methylation also showed p16 methylation. CONCLUSIONS: Methylation of DAPK and p16 represent alterations that might occur in cell cycle control in LS. The hypothesis is that patients who had methylated genes in this study, mainly the 2 cases in which there has been methylation in both studied genes, may be more susceptible to the development of differentiated vulvar intraepithelial neoplasia or vulvar cancer. Methylation may play a role in progress of vulvar carcinogenesis.

Differential protein expression patterns obtained by mass spectrometry can aid in the diagnosis of Hodgkin's disease.

More than 90% of patients with cancer, if diagnosed early, can be promptly treated; however diagnosis usually occurs after cancer cells have metastasized. Recent technological advances in mass spectrometry challenges the field of machine learning to model such high dimensional datasets for clinical diagnosis and prognosis. Here we use support vector machines recursive feature elimination to hunt for protein expression patterns in the serum mass spectra of Hodgkin's disease (HD) patients and control subjects (CS) that could aid in diagnosing-the disease. Based on eight selected features, support vector machines was able to correctly classify among all CS and HD patients based on the leave-one-out. We also correctly classified an independent dataset, acquired from the same samples, with the previously generated SVM model.