Composition for suppressing expression of target gene

摘要

An object of the present invention is to provide a composition for suppressing expression of a target gene, and the like. A composition comprising an RNA-encapsulated liposome, wherein the RNA contains a sequence consisting of 15 to 30 contiguous bases of a target gene mRNA (hereinafter, sequence X) and a base sequence (hereinafter, complementary sequence X′) complementary to the sequence X, 1 to 90% of all sugars binding to the bases of the sequence X and the complementary sequence X′ being ribose substituted by a modifying group at 2′ position, and the lipid particle being capable of reaching a tissue or an organ containing an expression site of the target gene is provide.

主权项

1. A method for improving blood RNA concentration after a second administration to a mammal of a composition comprising a RNA-encapsulated lipid particle comprising a polyethylene glycolated lipid, a polyethylene glycol sorbitan fatty acid ester or a polyethylene glycol fatty acid ester, wherein the RNA comprises a sequence X consisting of 15 to 30 contiguous bases of a target gene mRNA and a base sequence X′ complementary to the sequence X, comprising twice administering to a mammal the composition
wherein 10 to 75% of all sugars in the RNA binding to the bases of the sequence X and the base sequence X′ are ribose substituted by a modifying group selected from the group consisting of 2′-fluoro, 2′-O-methyl, 2′-O-ethyl.