TY - JOUR AU - G Gaidano, AU - D Capello, AU - A Gloghini, AU - L Fassone, AU - D Vivenza, AU - C Ariatti, AU - A Migliazza, AU - G Saglio, AU - A Carbone, PY - 1999/07/01 Y2 - 2024/03/28 TI - Frequent mutation of bcl-6 proto-oncogene in high grade, but not low grade, MALT lymphomas of the gastrointestinal tract JF - Haematologica JA - haematol VL - 84 IS - 7 SE - Articles DO - 10.3324/%x UR - https://haematologica.org/article/view/1413 SP - 582-588 AB - BACKGROUND AND OBJECTIVE: Knowledge regarding the molecular pathogenesis and histogenesis of gastrointestinal mucosa-associated lymphoid tissue non-Hodgkin's lymphomas (MALT-NHL) is limited. Mutations of BCL-6, a zinc finger transcription factor implicated in lymphoid development, occur frequently in lymphomas and represent a histogenetic marker of B-cell transit through the germinal center. The distribution of BCL-6 mutations in gastrointestinal MALT-NHL was analyzed in this study. DESIGN AND METHODS: This study was based on 26 gastrointestinal MALT-NHL, including 16 cases of low grade histology and 10 cases of high grade histology. Mutations of BCL-6 were investigated by a combination of polymerase chain reaction-single strand conformation polymorphism and DNA direct sequencing analysis. RESULTS: Mutations of BCL-6 occurred in 6/10 high grade MALT-NHL, whereas they were absent from all low grade cases tested (n = 16; p = 0.001). MALT-NHL harboring BCL-6 mutations included 5 cases of gastric MALT-NHL and 1 case of jejunal MALT-NHL. Mutations were predominantly represented by single nucleotide substitutions which were multiple in most cases. All sequence alterations were unique to individual cases of gastrointestinal MALT-NHL. INTERPRETATION AND CONCLUSIONS: Mutations of BCL-6 occur frequently in high grade gastrointestinal MALT-NHL and display characteristics similar to those of BCL-6 mutations harbored by other B-cell lymphomas. The association of high grade MALT-NHL with BCL-6 mutations corroborates their histogenetic derivation from germinal center-related B-cells and may be of potential pathogenetic relevance for these disorders. ER -