Biallelic deletion and loss of expression analysis of genes at FRA2G common fragile site in tumor-derived cell lines.

Common fragile sites (CFS) are regions of chromosome instability that show gaps or breaks when cells are exposed to particular culture condition. Much evidence suggests that CFSs are causally related to cancer as breakpoints in recurrent chromosome mutations and as sites of viral integration. We investigated the FRA2G CFS (2q31) for biallelic deletions and loss of expression in a panel of 19 tumor-derived cell lines. We found that Burkitt lymphoma-derived cell line DAUDI has a biallelic deletion of eight of the nine analyzed genes. Moreover, we observed loss of expression (LOE) of the DHRS9 gene (alias RDHL), one of the deleted genes in the DAUDI cell line, in MOLT-14 and Raji cell lines derived from Burkitt lymphoma and from T-cell acute lymphoblastic leukemia, respectively. DHRS9 is involved in development and differentiation pathways.