| Summary: | <p>Abstract</p> <p>Background</p> <p>This study evaluates the existence of numerical alterations of chromosome 17 and <it>TP53 </it>gene deletion in gastric adenocarcinoma. The p53 protein expression was also evaluated, as well as, possible associations with clinicopathological characteristics.</p> <p>Methods</p> <p>Dual-color fluorescence <it>in situ </it>hybridization and immunostaining were performed in twenty gastric cancer samples of individuals from Northern Brazil.</p> <p>Results</p> <p>Deletion of <it>TP53 </it>was found in all samples. <it>TP53 </it>was inactivated mainly by single allelic deletion, varying to 7–39% of cells/case. Aneusomy of chromosome 17 was observed in 85% of cases. Chromosome 17 monosomy and gain were both observed in about half of cases. Cells with gain of chromosome 17 frequently presented <it>TP53 </it>deletion. The frequency of cells with two chr17 and one <it>TP53 </it>signals observed was higher in diffuse than in intestinal-type GC. Immunoreactivity of p53 was found only in intestinal-type samples. The frequency of cells with two chr17 and two <it>TP53 </it>signals found was higher in samples with positive p53 expression than in negative cases in intestinal-type GC.</p> <p>Conclusion</p> <p>We suggest that <it>TP53 </it>deletion and chromosome 17 aneusomy is a common event in GC and other <it>TP53 </it>alterations, as mutation, may be implicated in the distinct carcinogenesis process of diffuse and intestinal types.</p>
|
|---|