Expression of LDOC1 and LDOC1S mRNAs assessed by RT-PCR. (A) Expression in cell lines, normal peripheral blood B cells, and CLL cells. Wild-type LDOC1 (464 and 649 bp) and LDOC1S (165 bp) mRNAs were detected in the MCF7 breast carcinoma cell line, 2 normal peripheral blood B-cell (NBC) samples, and 2 unmutated CLL samples. Little or no LDOC1 or LDOC1S mRNA were detected in the GA10 Burkitt lymphoma cell line, the Jurkat T-cell lymphoblastic lymphoma cell line, or 2 mutated CLL samples. (B) Expression in CLL cells. Wild-type LDOC1 (464 and 649 bp) and LDOC1S (165 bp) mRNAs were detected in 5 additional unmutated CLL samples. Little or no LDOC1 or LDOC1S mRNA were detected in 5 additional mutated CLL samples. The amount of cDNA amplified for each sample was comparable, as shown by the β-actin signal.