CDH1 hypermethylation: a potential molecular pathway for invasiveness in glioblastoma.

Glioblastoma is the most aggressive central nervous system primary tumor. Prognosis is poor, mainly due to the malignant characteristics of the tumor, such as high cell proliferation and invasiveness. CDH1 hypermethylation is linked to the invasive potential in various cancer types, but its importance is still unknown in glioblastoma. In this context, the methylation status of CDH1 was analyzed using MSP-PCR (Methylation-specific Polymerase Chain Reaction) in glioblastoma (n = 34) and normal glial tissue samples (n = 11). CDH1 hypermethylation was found in 39.4% (13/34) of the tumor samples and none of the normal glial tissue, suggesting a relation between CDH1 hypermethylation and glioblastoma ( P = 0.0195). Finally, this study showed unprecedented information that could contribute to clarifying the molecular pathways involved in the invasiveness and aggressiveness of this type of cancer.

Metabolomics Approach Reveals Important Glioblastoma Plasma Biomarkers for Tumor Biology.

Glioblastoma (GB) is the most aggressive and frequent primary malignant tumor of the central nervous system and is associated with poor overall survival even after treatment. To better understand tumor biochemical alterations and broaden the potential targets of GB, this study aimed to evaluate differential plasma biomarkers between GB patients and healthy individuals using metabolomics analysis. Plasma samples from both groups were analyzed via untargeted metabolomics using direct injection with an electrospray ionization source and an LTQ mass spectrometer. GB biomarkers were selected via Partial Least Squares Discriminant and Fold-Change analyses and were identified using tandem mass spectrometry with in silico fragmentation, consultation of metabolomics databases, and a literature search. Seven GB biomarkers were identified, some of which were unprecedented biomarkers for GB, including arginylproline (m/z 294), 5-hydroxymethyluracil (m/z 143), and N-acylphosphatidylethanolamine (m/z 982). Notably, four other metabolites were identified. The roles of all seven metabolites in epigenetic modulation, energy metabolism, protein catabolism or folding processes, and signaling pathways that activate cell proliferation and invasion were elucidated. Overall, the findings of this study highlight new molecular targets to guide future investigations on GB. These molecular targets can also be further evaluated to derive their potential as biomedical analytical tools for peripheral blood samples.

Transcriptomic Profile of Canine Mammary Ductal Carcinoma.

Dogs can be excellent models for spontaneous studies about breast cancers, presenting similarities in clinical behavior and molecular pathways of the disease. Thus, analyses of the canine transcriptome can identify deregulated genes and pathways, contributing to the identification of biomarkers and new therapeutic targets, benefiting humans and animals. In this context, this study aimed to determine the transcriptional profile of canine mammary ductal carcinoma and contribute to the clarification of the importance of deregulated molecules in the molecular pathways involved in the disease. Therefore, we used mammary ductal carcinoma tissue samples and non-tumor mammary tissue from the radical mastectomy of six female dogs. Sequencing was performed on the NextSeq-500 System platform. A comparison of carcinoma tissue and normal tissue revealed 633 downregulated and 573 upregulated genes, which were able to differentiate the groups by principal component analysis. Gene ontology analysis indicated that inflammatory, cell differentiation and adhesion, and extracellular matrix maintenance pathways were mainly deregulated in this series. The main differentially expressed genes observed in this research can indicate greater disease aggressiveness and worse prognosis. Finally, the study of the canine transcriptome indicates that it is an excellent model to generate information relevant to oncology in both species.

Differential Plasma Metabolites between High- and Low-Grade Meningioma Cases.

Meningiomas (MGMs) are currently classified into grades I, II, and III. High-grade tumors are correlated with decreased survival rates and increased recurrence rates. The current grading classification is based on histological criteria and determined only after surgical tumor sampling. This study aimed to identify plasma metabolic alterations in meningiomas of different grades, which would aid surgeons in predefining the ideal surgical strategy. Plasma samples were collected from 51 patients with meningioma and classified into low-grade (LG) (grade I; n = 43), and high-grade (HG) samples (grade II, n = 5; grade III, n = 3). An untargeted metabolomic approach was used to analyze plasma metabolites. Statistical analyses were performed to select differential biomarkers among HG and LG groups. Metabolites were identified using tandem mass spectrometry along with database verification. Five and four differential biomarkers were identified for HG and LG meningiomas, respectively. To evaluate the potential of HG MGM metabolites to differentiate between HG and LG tumors, a receiving operating characteristic curve was constructed, which revealed an area under the curve of 95.7%. This indicates that the five HG MGM metabolites represent metabolic alterations that can differentiate between LG and HG meningiomas. These metabolites may indicate tumor grade even before the appearance of histological features.

Relationship between EBV infection and expression of cellular proteins c-Myc, Bcl-2, and Bax in gastric carcinomas.

BACKGROUND: Epstein-Barr virus (EBV) has been related to tumorigenesis in about 10% of all gastric carcinomas. Several studies have demonstrated strong evidence of its involvement in this process, but most of the mechanisms used by the virus to control this process are still unknown. Previous studies in vitro have indicated a relationship between the virus and some cellular genes involved in processes such as proliferation and apoptosis. OBJECTIVE: The aim of the present study was to investigate a possible EBV-induced tumorigenic pathway involving the cellular proteins Bcl-2, Bax, and c-Myc. STUDY DESIGN: One hundred patients of gastric carcinoma, obtained from 2 hospitals in Fortaleza, Brazil were assessed for the presence of EBV by in situ hybridization, for the expression of Bcl-2, Bax, and c-Myc (nuclear and cytoplasmic staining) proteins by immunohistochemistry techniques, and for the apoptotic index. RESULTS: EBV was detected in 8 (8%) patients showing strong staining situated in the nuclei of the tumor cells, 6 of them displaying a diffuse pattern, and 2 demonstrating a focal pattern of staining. The correlation with the immunohistochemistry results demonstrated that none of the EBV-positive cases exhibited Bcl-2 staining. On the other hand, Bax and c-Myc (nuclear) proteins demonstrated a significant positivity index and staining scores (labeling index and H-score) in the EBV-positive group; however, the values were lower than those obtained in the EBV-negative group, notably for c-Myc nuclear protein. In contrast, the cytoplasmic staining of c-Myc protein revealed slightly higher staining values in the EBV-positive group. The balance between Bcl-2 and Bax proteins demonstrated that the majority of the evaluated cases exhibited apoptosis orientation; however, in 62.5% of the EBV-positive cases neither protein was observed. The average apoptotic index was 4.58%, demonstrating a slightly lower average in the EBV-positive group. CONCLUSIONS: EBV is not related to the overexpression of Bcl-2 and c-Myc (nuclear) in gastric carcinomas; however, the results point to a possible EBV involvement with the transport mechanisms of the nuclear membrane, resulting in cytoplasmic c-Myc accumulation. The suppression of Bax expression could represent an alternative viral mechanism for inhibition of apoptosis.

A transcript finishing initiative for closing gaps in the human transcriptome.

We report the results of a transcript finishing initiative, undertaken for the purpose of identifying and characterizing novel human transcripts, in which RT-PCR was used to bridge gaps between paired EST clusters, mapped against the genomic sequence. Each pair of EST clusters selected for experimental validation was designated a transcript finishing unit (TFU). A total of 489 TFUs were selected for validation, and an overall efficiency of 43.1% was achieved. We generated a total of 59,975 bp of transcribed sequences organized into 432 exons, contributing to the definition of the structure of 211 human transcripts. The structure of several transcripts reported here was confirmed during the course of this project, through the generation of their corresponding full-length cDNA sequences. Nevertheless, for 21% of the validated TFUs, a full-length cDNA sequence is not yet available in public databases, and the structure of 69.2% of these TFUs was not correctly predicted by computer programs. The TF strategy provides a significant contribution to the definition of the complete catalog of human genes and transcripts, because it appears to be particularly useful for identification of low abundance transcripts expressed in a restricted set of tissues as well as for the delineation of gene boundaries and alternatively spliced isoforms.