Molecular genetics of gastrointestinal non-Hodgkin's lymphomas: unusual prevalence and pattern of c-myc rearrangements in aggressive lymphomas.
Thirty-two extranodal lymphomas of the gastrointestinal (GI) tract underwent molecular genetic analysis by Southern blotting using probes for the immunoglobulin genes and the bcl-1, bcl-2, and c-myc loci, commonly involved in lymphomagenesis. No bcl-1 rearrangements were found. There was only one large-cell lymphoma with a bcl-2 rearrangement. A rearrangement of the c-myc gene was found in six of eight Burkittlike lymphomas of the intestine. In five of these six cases, a chromosomal translocation t(8;14) with an unusual breakpoint was demonstrated by comigration of the rearranged c-myc and a rearranged JH sequence. This pattern of rearrangement has not been previously associated with a specific group of non-Hodgkin's lymphomas. In contrast to all six low-grade lymphomas, c-myc rearrangements were found in 6 of 12 large-cell or high-grade mucosa-associated lymphomas of the stomach. No comigration of c-myc and immunoglobulin heavy-chain gene sequences were found. We conclude that primary GI lymphomas have different molecular genetic characteristics compared with node-based follicle center-cell lymphoma and as a group are not related to these lymphomas. In addition, the prevalence and patterns of c-myc rearrangements in the gastric large-cell lymphomas and ileocecal Burkittlike lymphomas are noteworthy and suggest a different and distinct pathogenesis for these tumors.
Department of Pathology, University of Leiden, The Netherlands.
J H
JH
van Krieken
M
M
Raffeld
S
S
Raghoebier
E S
ES
Jaffe
G J
GJ
van Ommen
P M
PM
Kluin
D015139:Blotting, Southern; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000378:metabolism; D015321:Gene Rearrangement; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc