Multitargeting interfering RNAs having two active strands and methods for their design and use

Abstract

Interfering RNA molecules are now designed and produced with specificity for multiple binding sequences present in distinct genetic contexts in one or more pre-selected target RNA molecules and are used to modulate expression of the target sequences. The multitargeting interfering RNA molecules have two strands that target multiple target sites on one or more pre-selected RNA molecules. Such a multitargeting interfering RNA approach provides a powerful tool for gene regulation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application Nos. 60 / 738,441 filed Nov. 21, 2005 and 60 / 738,640 filed Nov. 21, 2005, respectively, which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION [0002] The present invention concerns methods and reagents useful in modulating gene expression. Particularly, the invention relates to modulating gene expression using one multitargeting interfering RNA molecule having two strands each of which targets one or more sites on one or more pre-selected RNA molecules. BACKGROUND OF THE INVENTION [0003] It is now known that single and double-stranded RNA can modulate expression of or modify processing of target RNA molecules by a number of mechanisms. Some such mechanisms tolerate variation in the amount of sequence complementarity required between the modulatory (or interfering) RNA and the target RNA. Certain microRNAs can translationally repress tar...

AI Technical Summary

Benefits of technology

[0028] The designing methods of this invention may further comprise the step of modifying the multitargeting interfering RNA molecule, i) to improve the incorporation of the first and the second strands of the multitargeting interfering RNA molecule into the RNA induced silencing complex (RISC); ii) to increase or decrease the modulation of the expression of at least one target RNA molecule; iii) to decrease stress or inflammatory response when the multitargeting interfering RNA molecule is administered into a subject; iv) to alter half life in an expression system; or v) any combination of i) to iv).

Problems solved by technology

Thus, the use of single-gene targeting approaches may not succeed except where a single or dominant pathophysiologic pathway can be identified and interrupted.

Attempts to confirm that inhibiting single targets in isolation is therapeutically valuable have been disappointing.

Indeed, obtaining therapeutic effectiveness is proving to be extremely challenging, probably because of multiple levels of redundancy in most signaling pathways.

For example, therapeutic approaches to viral infections continue to be major challenges in agriculture, as well as in animal and human health.

Furthermore, although nucleic acid therapeutics such as interfering RNAs are candidates for viral therapy, in part because modern rapid gene sequencing techniques allow viral genome sequences to be determined even before any encoded functions can be assessed, the error-prone replication of viruses, particularly RNA viruses, means that substantial genomic diversity can arise rapidly in an infected population.

It is unclear whether these constructs are efficient at treating viral infection or preventing emergence of resistant viral clones.

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