Figure 3. CREBBP and EP300 expression in normal and transformed B-cells.
a, Immunofluorescence analysis of reactive tonsils. BCL6 identifies GC B-cells, and Dapi is used to detect nuclei. b, c, Immunohistochemistry analysis of CREBBP (b) and EP300 (c) protein expression in representative DLBCL biopsies (genomic status as indicated; scale bar, 100µm). Sample 2147, which harbors a homozygous CREBBP deletion, serves as negative control. d, Western blot and northern blot analysis of DLBCL cell lines carrying wild-type or aberrant CREBBP and EP300 alleles (color coded as indicated). The aberrant band in SUDHL10 corresponds in size to the predicted ~220kD CREBBP truncated protein. * non-specific bands. Tubulin and GAPDH control for total protein and RNA loading, respectively. e, Overall proportion of DLBCL biopsies showing defective CREBBP/EP300 function due to genetic lesions (red scale) and/or lack of protein expression (blue scale).