DNA methylation profile in diffuse type gastric cancer: evidence for hypermethylation of the BRCA1 promoter region in early-onset gastric carcinogenesis.

Diffuse type gastric carcinoma is the most aggressive type of gastric cancer. This type of tumor is not preceded by precancerous changes and is associated with early-onset and hereditary syndromes. To test the hypothesis that DNA methylation profile would be useful for molecular classification of the diffuse type gastric carcinoma, DNA methylation patterns of the CpG Island of 17 genes were studied in 104 cases and 47 normal adjacent gastric mucosa by Methylation-specific PCR, Immunohistochemistry and Hierarchical clustering analysis.

Analytical detection of immunoglobulin heavy chain gene rearrangements in gastric lymphoid infiltrates by peak area analysis of the melting curve in the LightCycler System.

Because it is difficult to differentiate gastric mucosa-associated lymphoid tissue (MALT) lymphoma from chronic gastritis in gastric lymphoid infiltrates, molecular detection of monoclonality through immunoglobulin heavy chain (IgH) gene rearrangements is commonly performed. However, heterogeneity in the performance and results obtained from IgH gene rearrangements has been reported. To improve the accuracy in the diagnosis of gastric lymphoid infiltrates, we developed an analytical approach based on one-peak area analysis of the melting curve in the LightCycler System.

Human papillomavirus in esophageal squamous cell carcinoma in Colombia and Chile.

Aim: To examine the presence of human papillomavirus (HPV) in esophageal squamous cell carcinoma (ESCC) specimens collected from Colombia and Chile located in the northern and southern ends of the continent, respectively.

Methods: We examined 47 and 26 formalin-fixed and paraffin-embedded ESCC specimens from Colombia and Chile, respectively. HPV was detected using GP5+/GP6+ primer pair for PCR, and confirmed by Southern blot analysis.

[Clinical and molecular features of cardial gastric cancer associated to Epstein Barr virus].

Background: Mortality caused by cardial gastric cancer in Chile, is increasing. Previously we demonstrated an association between Epstein Barr virus and this specific location of gastric cancer.

Aim: To perform a clinical and molecular characterization of cardial gastric cancer associated to Epstein Barr virus.

Association of a distinctive strain of Epstein-Barr virus with gastric cancer.

Epstein-Barr virus (EBV) has been linked to gastric carcinoma (GC) with worldwide geographical variations attributable to types and variants of EBV. Here, we compare EBV strains between EBVaGC and healthy donors in Latin America, a high frequency area for EBVaGC. Tumor samples from 73 EBVaGC cases and throat washings from 329 healthy adults were examined for types 1 and 2 EBV and polymorphism at BamHI-F and BamHI-W1/I1 boundary regions and XhoI restriction site in LMP1 gene.