Marginal zone lymphomaにおける遺伝子異常の解析

抄録

The t (11; 18) (q21; q21) translocation is a characteristic chromosomal aberration in lowgrade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. We previously identified a YAC clone y789F3 encompassing the breakpoint at 18q21 in MALT lymphoma patient. BAC and PAC contigs were constructed on the YAC, and BAC 193f9 was found to encompass the breakpoint region. We further narrowed down the breakpoint region at 18q21 in five MALT lymphoma patients by means of FISH and Southern blot analyses using the plasmid contig constructed from the BAC 193f9. The breakpoints at 18q21 in three of the five MALT patients were found to be clustered within approximately 20kb region. By using exon amplification and cDNA library screening, we identified a novel cDNA spanning the breakpoint region that exhibited aberrant mRNA signals in four of five MALT lymphoma patients. We refer to the gene encoding this transcript as MALT1 (Mucosa-Associated Lymphoid Tissue lymphoma translocation gene 1). The alteration of MALT1 by translocation is strongly suggested to play an importance role in the development of MALT lymphoma.