Detection of p53 Common Intron Polymorphisms in Patients with Gastritis Lesions from Iran

Abstract

<b>Background:</b> p53 alterations have been implicated in the development of many cancers, such as gastric cancer,but there is no evidence of p53 intron alterations in gastritis lesions. The aim of this study was to investigate thep53 intron alterations in gastritis along with p53 and mismatch repair protein expression and microsatellite status.Materials and <br/><b>Methods</b>: PCR-sequencing was conducted for introns 2-7 on DNA extracted from 97 paired samplesof gastritis lesions and normal adjacent tissue. Abnormal accumulation of p53 and mismatch repair proteins wasinvestigated using immunohistochemistry. In addition, microsatellite status was evaluated with reference to fivemononucleotide markers. <br/><b>Results</b>: Gastritis cases included 41 males and 56 females in the age range of 15-83years, 87.6% being H.pylori positive. IVS2+38, IVS3ins16 and IVS7+72 were the most polymorphic sites. Theirminor allele frequency values were as follows: 0.38, 0.21 and 0.06, respectively. Samples with GG genotype atIVS2+38 and CT at IVS7+72 had no insertion. Moreover, most of the stable samples (91.9 %) had a G allele atIVS2+38. All of the samples were IHC negative for p53 protein, microsatellite stable and expressed mismatchrepair proteins. p53 alterations were prominent in the H. Pylori+ group, but without statistical significance.<br/><b>Conclusions</b>: According to our results, some p53 polymorphisms such as IVS2+38, IVS3ins16 and IVS7+72,because of their correlations together or with microsatellite status may contribute to gastritis development.However, so far effects on p53 expression and function remain unclear. Therefore, a comprehensive survey isneeded to delineate their biological significance.