Scientists at University of Insubria target B-cell lymphoma genetics

   "In the present study, the frequency of the numeric and structural aberrations of the chromosomes 1, 3, 12, 18 and X and of the MALT1 gene as well as their potential clinical significance were analyzed by using fluorescent in situ hybridization on a tissue microarray containing 257 tissue samples from 203 cases of surgically resected primary gastric lymphomas including 115 cases of MALT lymphomas, 88 cases of diffuse large B-cell lymphomas (DLBCLs, 75 with an associated MALT lymphoma, so-called ex-MALT DLBCL, and 13 de novo), and 54 controls cases of Helicobacter pylori-associated chronic gastritis. Clinical follow-up information was available in 137 cases. Trisomies 1, 3, 12, and 18 were detected in 3.3%, 44.4%, 12.3%, and 19.2% of MALT lymphomas and in 11.1%, 42.2%, 26.5%, and 22.0% of ex-MALT DLBCLs, respectively. In addition, we found gains of the X chromosome in 36.4% of MALT lymphomas, in 34.5% of ex-MALT DLBCLs, and in 36.4% of de novo DLBCLs. Structural and/or numeric abnormalities of the MALT1 gene were observed in 37.0% of MALT lymphomas and in 22.2% of ex-MALT DLBCLs. In de novo DLBCL, trisomies for chromosomes 3, 12, 18, and X were found in 42.9%, 10.0%, 11.1%, and 36.4%, respectively, whereas alterations of MALT1 (namely, translocations) were found in 20.0% of the cases. An unexpected high and previously unreported gain of chromosome X in gastric MALT lymphomas was found. This tumor appears, therefore, to be a genetically unstable neoplasia," wrote B. Bernasconi and colleagues, University of Insubria.

   The researchers concluded: "Our results point out that t(11;18) and aneuploidy may be both involved in lymphomagenesis and that at least a subset of MALT lymphomas may progress toward high-grade neoplasia."

   Bernasconi and colleagues published their study in Human Pathology (Chromosomal instability in gastric mucosa-associated lymphoid tissue lymphomas: a fluorescent in situ hybridization study using a tissue microarray approach. Human Pathology, 2008;39(4):536-42).

   For additional information, contact B. Bernasconi, University of Insubria, Dept. of Human Morphology, Section of Human Pathology, 21100 Varese, Italy.

   Publisher contact information for the journal Human Pathology is: W B Saunders Co., Independence Square West Curtis Center, Ste. 300, Philadelphia, PA 19106-3399, USA.

   Keywords: Italy, Varese, B-Cell Lymphoma Genetics, B-Cell Lymphoma, Chromosomal Instability, Gastric Lymphoma, Gastritis, Gastroenterology, Gastrointestinal, Hematology, MALT lymphoma, Mucosa-Associated Lymphoid Tissue Lymphoma, Oncology, Pathology.

   This article was prepared by Gastroenterology Week editors from staff and other reports. Copyright 2008, Gastroenterology Week via NewsRx.com.

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