Accelerating RNA decay through intervention of RNase L: alternative synthesis of composite 2',5'-oligoadenylate-antisense.

Publisher Summary Unraveling the role of various human genes in disease and choosing appropriate targets for drug discovery will require robust prediction and validation paradigms. One such approach is the use of antisense to “knock out” or downregulate gene expression through interference with the translation of mRNA. The latter methodology relies on the use of an oligonucleotide, or analog thereof, with a sequence complementary (antisense) to that of a particular mRNA. Optimization of the antisense paradigm is the key to expression of its full potential for determining gene function as well as for the discovery of novel therapeutics. Oftentimes, the chemical structural modifications that can maximize target affinity, antisense metabolic stability, and cellular uptake may not be compatible with the catalytic mRNA degradation mediated by RNase H, which is specific for DNARNA hybrids. Previously, 2-5A-PNA antisense constructs were synthesized through a solid-phase stepwise approach similar to that employed for standard DNA machine synthesis. This chapter reports a different approach that employs a convergent synthetic scheme wherein the PNA and 2-5A are prepared separately and then linked in a final step.