OLIGONUCLEOTIDE DERIVATIVE, OLIGONUCLEOTIDE DERIVATIVE-CONTAINING PHARMACEUTICAL COMPOSITION FOR TREATMENT AND PHARMACEUTICAL COMPOSITION FOR DIAGNOSIS, AND OLIGONUCLEOTIDE DERIVATIVE FOR REGULATION OF miRNA FUNCTION
An oligonucleotide derivative comprises repeating structural units represented by the following general formula (wherein B represents adenine, guanine, cytosine, or uracil X represents a sulfur atom or an oxygen atom n represents an integer of 6 to 60 and B and X are independently represented in each of the repeating structural units), wherein X is a sulfur atom in at least one of the repeating structural units represented by the general formula: