Abstract: A single-stranded antisense oligonucleotide, or a pharmaceutically acceptable salt thereof, capable of modulating expression and/or function of RPS25 gene, wherein nucleotides of the single-stranded antisense oligonucleotide are bonded to each other via a phosphate group and/or a modified phosphate group, the single-stranded antisense oligonucleotide includes a gap region, a 3? wing region bonded to a 3? end of the gap region, and a 5? wing region bonded to a 5? end of the gap region, the gap region is a deoxyribose-based nucleic acid optionally including a nucleic acid having a modified sugar moiety, each of the 3? wing region and the 5? wing region is a modified nucleotide, the single-stranded antisense oligonucleotide has a base length of 12- to 30-mer, and a base sequence of the antisense oligonucleotide is: a base sequence with a sequence identity of 90% to 100% to a base sequence complementary to at least one target region of the same base length as the antisense oligonucleotide present in the base sequ

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 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.