Splicing factor SRP20 is a novel partner of BCL6 in a t(3;6)(q27;p21) translocation in transformed follicular lymphoma.

The BCL6 gene mapped at chromosome band 3q27 encodes a zinc-finger transcription factor and is frequently rearranged and deregulated in B-cell non-Hodgkin's lymphoma (NHL) by promiscuous chromosomal translocations which involve diverse genes. We identified a novel t(3;6)(q27;p21) in a follicular lymphoma (FL) with histologic evidence of transformation and, by cloning the translocation junction, determined that the SRP20 gene was the partner. In this translocation, the 5' regulatory region of the BCL6 was substituted by a putative regulatory region of SRP20. Previously, we hypothesized that substitution of BCL6 promoter by those of the partner genes that were constitutively expressed throughout B-cell development led to persistent and inappropriate expression of BCL6. We examined the expression pattern of SRP20 during B-cell development by Northern blot analysis of a panel of B-cell lines representing various stages of B-cell development and noted that SRP20 mRNA was expressed throughout B-cell development. The SRP20 gene plays an important role in regulation of pre-mRNA splicing, and is expressed specifically in lymphoid tissues. This study provides the first evidence of SRP20 gene rearrangement in human hematopoietic malignancies. Copyright 2001 Wiley-Liss, Inc.