Naked antisense double-stranded DNA oligonucleotide efficiently suppresses BCR-ABL positive leukemic cells.

Oligonucleotide-based gene silencing, using molecules such as antisense oligonucleotides (ASOs), small interfering RNA, and aptamers, is widely studied. Another approach uses DNA/RNA heteroduplex oligonucleotides (HDOs). Here, we developed an antisense double-stranded DNA oligonucleotide (ADO) by modification of the complementary RNA in an HDO to generate DNA for increasing resistance to nucleases. Naked BCR-ABL-targeting ADO was significantly more potent than siRNA at reducing BCR-ABL chimeric mRNA expression in chronic myeloid leukemia (CML) cell lines. Further, naked BCR-ABL-targeting ADO suppressed BCR-ABL protein levels in a dose-dependent manner, inhibited CML cell proliferation, and augmented the inhibitory effects of imatinib mesylate. In conclusion, ADO technology is an attractive method for therapeutic application.