Molecular Analysis of the p53 Gene in Patients with Intestinal Metaplasia of the Cardia and Barrett's Esophagus: Characterization by Sequencing

Excerpt

To the Editor: Contrary to Dr. Novotna's findings (Digestive Disease and Sciences, Vol. 51, No. 1, pp. 110–113, January 2006), we believe that TP53 gene mutations can occur before transition from low-grade to high-grade dysplasia. In this sense, we analyze the main molecular alterations present in exons 5 to 8 of TP53 in patients with intestinal metaplasia of the cardia (IMC) and Barrett's esophagus (BE) without displasia. Sixteen patients were evaluated (eight women and eight men; ages, 23 to 72 years; average, 54.3 years). These individuals had GERD symptoms diagnosed by upper digestive endoscopy and confirmed by biopsy. The biopsies were analyzed as described by Segal et al. [1]. Patients had DNA extracted from 10 ml of peripheral blood collected in EDTA using the modified salt precipitation technique described by Miller et al. [2]. The same protocol was performed with respect to tissue samples collected at the time of endoscopy. The long PCR technique of exons 5 to 8 of the p53 gene was set as standard. The purified PCR products were used directly for DNA sequencing. The reactions were performed using the Big Dye Terminator v 3.1 kit (Applied Biosystems) …