BCL2 gene expression in DLBCL.

Each horizontal row represents a separate cDNA clone on the microarray and each vertical column a separate case. The results are represented as the ratios of the hybridization signals on each spot on the microarray generated by the experimental mRNA samples versus the reference mRNA sample. These ratios are a measure of the relative gene expression of the experimental sample versus the reference standard and are depicted according to the color scale shown at the bottom, from a fluorescence ratio of 0.25 to 4 (−2 to +2 in log-base 2 units). GC B and GC centroblasts indicate GC B cells and GC centroblasts from tonsil; FL, follicular lymphoma. Note that normal GC cells have very low levels of bcl-2 expression. All follicular lymphoma cases, the t(14;18)-positive SUDHL-6 cell line, and 6 of the 7 DLBCL cases with the t(14;18) translocation have overexpression of bcl-2 when assessed with clone 232714, which detects bcl-2 mRNA truncated at the 3′ end due to breakage at the mbr. The case DLCL-0018 has a breakpoint at the mcr by PCR assay and the intact message is detectable with all cDNA clones. The t(14;18)-negative DLBCLs that overexpress bcl-2 have bcl-2 mRNA detectable by clones other than 232714, indicating that the message is not truncated.