Antisense oligonucleotides complementary to immunoglobulin sequences of BCL-2/immunoglobulin fusion transcript induce apoptosis of t(14;18) lymphoma cells.

Antisense oligodeoxyribonucleotides directed at the bcl-2 translational start site downregulate bcl-2 and inhibit growth of the t(14;18)-positive lymphoma line WSU-FSCCL. Non-specific downregulation of bcl-2 expression is expected to be toxic to normal cells as well. The t(14;18) translocation results in a fusion transcript containing the entire bcl-2 coding sequence with a 3' breakpoint fused to the immunoglobulin J(H) region and the c mu heavy chain. We postulated that these immunoglobulin sequences would be a specific target for downregulation of the fusion gene. Here, we have demonstrated that antisense oligodeoxyribonucleotides targeted to immunoglobulin c(mu) sequences downregulate bcl-2 protein expression and induce apoptosis of WSU-FSCCL cells. Inhibiting growth of malignant cells by targeting non-oncogenic sequences other than breakpoints of fusion transcripts expands the potential for tumour-specific genetic manipulation.