Mutations of the BIK gene in human peripheral B-cell lymphomas.

BIK, a BH (Bcl2 homology domain)3-only protein, is a proapoptotic member of the BCL2 family. We performed single-strand conformational polymorphism and sequencing analysis of the entire coding region of the BIK gene (exons 2-5) in 71 B-cell lymphomas [27 follicular lymphomas (FLs), 13 marginal cell lymphomas (MZLs), 7 small lymphocytic lymphomas (SLLs), 6 mantle cell lymphomas (MCLs), 2 lymphoplasmacytic lymphomas, and 16 diffuse large B-cell lymphomas (DLBCLs)]. Missense BIK gene mutations were observed in 3 of 27 (11%) FLs, in 2 of 13 (15%) MZLs, and in 1 of 16 (6%) DLBCLs. Sequence alterations in intronic regions were observed in 4 of 27 (14.8%) FLs, in 7 of 13 (53%) MZLs, and in 3 of 16 (18%) DLBCLs. These data indicate that mutation of the BIK gene is a frequent feature of B-cell lymphomas.