Role of p53 codon 72 polymorphism in the risk of development of distal gastric cancer.

Objective: Mutations in the codon 72 of exon 4 in the p53 gene have been associated with higher risk in the development of several types of cancer. This polymorphism occurs with two alleles encoding either arginine (CGC) or proline (CCC). The aim of this study was to assess the role of the codon 72 polymorphism of p53 in the risk for the development of distal gastric cancer (GC) in a Mexican population.

Plasticity of repetitive DNA sequences within a bacterial (Type IV) secretion system component.

DNA rearrangement permits bacteria to regulate gene content and expression. In Helicobacter pylori, cagY, which contains an extraordinary number of direct DNA repeats, encodes a surface-exposed subunit of a (type IV) bacterial secretory system. Examining potential DNA rearrangements involving the cagY repeats indicated that recombination events invariably yield in-frame open reading frames, producing alternatively expressed genes.