Abstract: A method of reducing the level of a transcription product in a cell comprising contacting with the cell a composition comprising a double-stranded nucleic acid complex comprising a first nucleic acid strand annealed to a second nucleic acid strand, wherein: (i) the first nucleic acid strand hybridizes to the transcription product and comprises (a) a region consisting of at least 4 consecutive nucleotides that are recognized by RNase H when the strand is hybridized to the transcription product, (b) one or more nucleotide analogs located on 5? terminal side of the region, (c) one or more nucleotide analogs located on 3? terminal side of the region and (d) a total number of nucleotides and nucleotide analogs ranging from 8 to 35 nucleotides and (ii) the second nucleic acid strand comprises (a) nucleotides and optionally nucleotide analogs and (b) at least 4 consecutive RNA nucleotides.

Abstract: An oligonucleotide or a pharmacologically acceptable salt thereof according to the present invention contains a nucleotide sequence complementary to a continuous sequence of at least 12 bases in a target region constituted by a base sequence of SEQ ID No. 1, and induces N-exon skipping in human REST pre-mRNA processing. Such oligonucleotides are useful for manufacturing medicines for treatment of cancer, for example.

Abstract: The present invention aims to provide a nucleic acid compound that hardly forms non-Watson-Crick base pairs, and an oligonucleotide containing the nucleic acid compound and showing reduced non-specific binding with nucleic acids other than the target nucleic acid. The nucleic acid compound according to the present invention is characterized in that the 2-position carbonyl group of the pyrimidine base is functionally converted (X1 and X2 are each independently S or Se), and that the 2?-position and the 4?-position are bridged in a particular structure. The oligonucleotide according to the present invention is characterized in that at least one of thymidine and uridine is the nucleic acid compound.

Abstract: Disclosed is an oligonucleotide or a pharmacologically acceptable salt thereof, wherein the oligonucleotide comprises at least one defined nucleoside structure, can bind to a human nSR100 gene and has human nSR100 expression inhibiting activity. The oligonucleotide has a length of 12 to 20 mer, and is complementary to a defined target region. Further, disclosed is an nSR100 gene expression inhibitor and a cancer therapeutic agent containing the oligonucleotide or the pharmacologically acceptable salt thereof. The cancer therapeutic agent is used for treatment of small cell lung cancer, prostate cancer, or breast cancer.

Abstract: Disclosed are a bridged nucleoside and a nucleotide using the same. The nucleoside of the present invention is represented by the formula (I) below. The bridged nucleoside of the present invention is usable as a substitute for a phosphorothioate-modified nucleic acid, which has a risk of, for example, accumulation in a specific organ. The bridged nucleoside also has excellent industrial productivity.

Abstract: A prophylactic or therapeutic agent for an aneurysm comprising a miR-33b inhibiting substance, preferably an antisense oligonucleotide against miR-33b, as an active ingredient.

Abstract: A cross-linked nucleoside of the present invention is a compound represented by the formula (I) below. The cross-linked nucleoside of the present invention is usable as a substitute for a phosphorothioate-modified nucleic acid, which has a risk of, for example, accumulation in a specific organ. The cross-linked nucleoside also has excellent industrial productivity.

Abstract: The present invention provides an antisense oligomer having the base sequence depicted in SEQ ID NO: 26, an antisense oligomer having a base sequence resulting from substitution, deletion, insertion, or addition of 1 to 6 bases in the base sequence depicted in SEQ ID NO: 26, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable hydrate thereof, an oligonucleotide conjugate in which the antisense oligomer is bound with a molecule capable of binding to an asialoglycoprotein receptor, and a pharmaceutical composition containing the same.

Abstract: Disclosed are a 5?-modified nucleoside and a nucleotide using the same. The nucleoside of the present invention is represented by the formula (I) below. The 5?-modified nucleoside of the present invention is usable as a substitute for a phosphorothioate-modified nucleic acid, which has a risk of, for example, accumulation in a specific organ. The 5?-modified nucleoside also has excellent industrial productivity because a diastereomer separation step is not involved in the production process thereof.

Abstract: The present invention provides an antisense oligonucleotide for inhibiting biosynthesis of chondroitin sulfate. The antisense oligonucleotide comprises at least one modified nucleotide, wherein the antisense oligonucleotide suppresses expression of one or both of the chondroitin sulfate N-acetylgalactosaminyltransferase-1 (CSGalNAcT1) gene and the chondroitin sulfate N-acetylgalactosaminyltransferase-2 (CSGalNAcT2) gene.

Abstract: A nucleic acid medicine using an antisense nucleic acid to inhibit the expression of SYT13, which has better efficacy than siRNA for targeting peritoneal dissemination of gastric cancer is provided. An antisense oligonucleotide which consists of a nucleotide sequence substantially complementary to the nucleotide sequence of a specific region in human SYT13 mRNA and which can inhibit the expression of human SYT13 mRNA; and a pharmaceutical composition comprising the antisense oligonucleotide are also provided.

Abstract: Provided is a method for producing a compound represented by formula (III) from a compound represented by formula (I) as a starting material.

Abstract: The present invention aims to provide an antisense oligonucleic acid with reduced hepatotoxicity. The antisense oligonucleic acid according to the present invention is characterized in that it has a base length of not less than 7 nt and not more than 30 nt, wherein nucleic acid residues of not less than 1 nt and not more than 5 nt respectively from the both terminals are 2?,4?-bridged nucleic acids, 2?,4?-non-bridged nucleic acid residue(s) is(are) present between the above-mentioned both terminals, and one or more bases in the nucleic acid residue(s) of the above-mentioned 2?,4?-non-bridged nucleic acid residue(s) is/are modified.

Abstract: The present invention aims to provide a nucleic acid compound that hardly forms non-Watson-Crick base pairs, and an oligonucleotide containing the nucleic acid compound and showing reduced non-specific binding with nucleic acids other than the target nucleic acid. The nucleic acid compound according to the present invention is characterized in that the 2-position carbonyl group of the pyrimidine base is functionally converted (X1 and X2 are each independently S or Se), and that the 2?-position and the 4?-position are bridged in a particular structure. The oligonucleotide according to the present invention is characterized in that at least one of thymidine and uridine is the nucleic acid compound.

Abstract: Provided is an oligonucleotide conjugate comprising an oligonucleotide and two or more linearly connected asialoglycoprotein receptor-binding molecules attached to the oligonucleotide, wherein the oligonucleotide comprises a locked nucleoside analog having a bridging structure between the 4? and 2? positions, is complementary to a human PCSK9 gene, and has inhibitory activity on the expression of the human PCSK9 gene. The oligonucleotide conjugate of the present invention can be used in the field of pharmaceutical products, in particular, the field of the development and production of therapeutic agents for diseases associated with a high LDL cholesterol level.

Abstract: Disclosed are a 5?-modified nucleoside and a nucleotide using the same. The nucleoside of the present invention is represented by the formula (I) below. The 5?-modified nucleoside of the present invention is usable as a substitute for a phosphorothioate-modified nucleic acid, which has a risk of, for example, accumulation in a specific organ. The 5?-modified nucleoside also has excellent industrial productivity because a diastereomer separation step is not involved in the production process thereof.

Abstract: The present invention aims to provide a nucleic acid compound that hardly forms non-Watson-Crick base pairs, and an oligonucleotide containing the nucleic acid compound and showing reduced non-specific binding with nucleic acids other than the target nucleic acid. The nucleic acid compound according to the present invention is characterized in that the 2-position carbonyl group of the pyrimidine base is functionally converted (X1 and X2 are each independently S or Se), and that the 2?-position and the 4?-position are bridged in a particular structure. The oligonucleotide according to the present invention is characterized in that at least one of thymidine and uridine is the nucleic acid compound.

Abstract: Provided is an oligonucleotide conjugate comprising an oligonucleotide and two or more linearly connected asialoglycoprotein receptor-binding molecules attached to the oligonucleotide, wherein the oligonucleotide comprises a locked nucleoside analog having a bridging structure between the 4? and 2? positions, is complementary to a human PCSK9 gene, and has inhibitory activity on the expression of the human PCSK9 gene. The oligonucleotide conjugate of the present invention can be used in the field of pharmaceutical products, in particular, the field of the development and production of therapeutic agents for diseases associated with a high LDL cholesterol level.

Abstract: The present invention aims to provide an antisense oligonucleic acid with reduced hepatotoxicity. The antisense oligonucleic acid according to the present invention is characterized in that it has a base length of not less than 7 nt and not more than 30 nt, wherein nucleic acid residues of not less than 1 nt and not more than 5 nt respectively from the both terminals are 2?,4?-bridged nucleic acids, 2?,4?-non-bridged nucleic acid residue(s) is(are) present between the above-mentioned both terminals, and one or more bases in the nucleic acid residue(s) of the above-mentioned 2?,4?-non-bridged nucleic acid residue(s) is/are modified.

Abstract: The present invention can provide a nucleic acid medicine which has a higher effect and a more prolonged effect of inhibiting the expression of ?-synudein can be provided. Disclosed is the oligonucleotide or a pharmacologically acceptable salt thereof, the oligonucleotide containing at least one nucleoside structure represented by Formula (I): (where each of Base and A are defined substituent or structure), can bind to an ?-synudein gene, has activity for inhibiting expression of the ?-synudein gene, and is complementary to the ?-synudein gene, and the oligonucleotide has a length of twelve to twenty bases.