TRANSLOCATIONS OF 11Q13 IN MANTLE CELL LYMPHOMA FAIL TO DISRUPT THE S-MU-BP-2 GENE

We recently cloned a gene whose protein product binds to the Epstein-B arr virus BZLF1 gene promoter. The same gene has been previously clone d by another group who named it S mu bp-2 because its protein product binds to the S mu motif of the immunoglobulin heavy chain gene where i t is postulated to function in immunoglobulin class switching. In the current study, we confirm that the S mu bp-2 gene is located on chromo some 11q13, a locus known to be altered by translocation in 50-70% of mantle cell lymphomas. We used Southern blot analysis to determine whe ther the S mu bp-2 gene was structurally rearranged in any of 25 mantl e cell lymphomas. We found no evidence of rearrangement in any of thes e lymphomas including 18 that were proven to contain t(11;14) by cytog enetic analysis. These data suggest that structural alteration of the S mu bp-2 gene is not an underlying mechanism of tumorigenesis in mant le cell lymphomas.