Asymmetric siRNA for inhibiting expression of male pattern hair loss target gene
Inventors
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11118184-B2
Publication Date
2021-09-14
Expiration Date
Abstract
The present invention relates to an asymmetric siRNA which inhibits an expression of male pattern hair loss target genes and a use thereof and, more particularly, to an asymmetric siRNA which inhibits an expression of 3-oxo-5-alpha-steroid-4-dehydrogenase 1 (SRD5A1) gene, 3-oxo-5-alpha-steroid-4-dehydrogenase 2 (SRD5A2) gene or androgen receptor (AR) gene, and a composition for prevention or treatment of hair loss comprising the asymmetric siRNA.
Core Innovation
The invention relates to an asymmetric shorter duplex siRNA (asiRNA) for male pattern hair loss. The asiRNA specifically binds mRNA of an androgen receptor (AR)-encoding gene, including an AR-encoding gene having SEQ ID NO: 673, with a sense strand sequence of SEQ ID NO: 500 and an antisense strand complementary to the sense strand with a sequence of SEQ ID NO: 618. The duplex is configured such that a 3′-terminus of the sense strand and a 5′-terminus of the antisense strand form a blunt end.
The disclosed asiRNA design uses an asymmetric shorter duplex length arrangement, in which the sense strand has 15–17 nt and the complementary antisense strand has ≥19 nt. The longer complementary antisense strand forms a blunt end at the 3′/5′ termini, aligning with the stated AR mRNA-binding configuration. The disclosure further supports variants described as cell-penetrating asiRNA (cp-asiRNA) to enable intracellular delivery, including designs that incorporate a delivery-related moiety.
The invention further provides modified asiRNA variants in which the sense strand and/or antisense strand comprises chemical modifications intended to improve stability and intracellular delivery. The disclosed modification set includes 2′-O-methyl (2′OMe) modifications and phosphorothioate (PS) nucleotide bond modifications, and optionally includes cholesterol binding. The document reports sequence designs (SEQ ID NOs) and inhibitory performance in cell-based assays with thresholds for inhibitory effects.
Claims Coverage
The document includes one independent claim defining a specific AR-targeting siRNA sequence with a blunt-end termini configuration, plus dependent claims that refine the siRNA with chemical and delivery-related modifications and optionally use it in a hair-loss prevention/treatment composition. The inventive features across the claim set mainly cover sequence specificity, blunt-end formation, and optional chemical modification/delivery moieties.
Sequence-specific blunt-end AR siRNA duplex
An siRNA specifically binding to mRNA of an androgen receptor (AR)-encoding gene having SEQ ID NO: 673, comprising a sense strand consisting of SEQ ID NO: 500 and an antisense strand complementary to the sense strand and consisting of SEQ ID NO: 618, wherein a 3′-terminus of the sense strand and a 5′-terminus of the antisense strand form a blunt end.
Chemically modified siRNA strands
The siRNA where the sense strand and/or antisense strand comprises one or more chemical modifications.
Selected chemical modifications and optional delivery-related binding
The siRNA wherein the chemical modification includes one or more selected modifications affecting nucleotide sugar structures and phosphate/bond types, including options described as sugar substitution at a 2′ carbon position and selectable backbone chemistries (e.g., PNA, LNA, UNA), and further includes an optional cholesterol and/or a cell-penetrating peptide binding moiety.
2′-O methyl and phosphorothioate/cholesterol option set
The siRNA with specified chemical modifications including 2′-O methyl substitution, a phosphorothioate-modified nucleotide bond, or cholesterol binding.
Positional and quantitative phosphorothioate and cholesterol constraints
The siRNA with chemical modifications including 2′-O-methyl substitutions at designated termini or multiple nucleotides, and at least 25% phosphorothioate modification of bonds between nucleotides in the sense or antisense strand, and cholesterol binding at the 3′-terminus of the sense strand.
Hair-loss prevention or treatment composition containing the siRNA
A composition for preventing or treating hair loss that includes the siRNA specified in the independent claim.
Overall, the claims cover a sequence-defined, blunt-end AR-targeting siRNA duplex, with dependent claims extending scope to siRNA variants having defined chemical modifications (including 2′OMe and phosphorothioate) and optional delivery-related moieties such as cholesterol, and further covering a hair-loss prevention/treatment composition containing the claimed siRNA.
Stated Advantages
Improved stability and intracellular delivery for modified asiRNA variants, as stated in the disclosed design rationale.
Inhibitory performance in cell-based assays, including reported IC50 values and % knockdown thresholds.
Documented Applications
Hair-loss prevention and/or treatment using the claimed AR-targeting siRNA, including compositions containing the siRNA.
Cell-based inhibitory performance evaluation in HuH-7 and A549 cells (mRNA inhibition and protein inhibition are referenced in the provided content).
Interested in licensing this patent?