The present invention is an antisense nucleotide sequence complementary to the IFN-α mRNA, comprises a sequence complementary to the nucleotide sequence of the SL2 regions and / or SL1 the IFN-α mRNA in particular, can enhance the expression of IFN-α IFN-α expression enhancer which comprises the antisense nucleotide, an agent for the prophylaxis or treatment of cancer or viral infections sequences complementary to the endogenous asRNA against IFN-α mRNA, SL1 or of IFN-α mRNA in particular I provide the IFN-α expression regulating agent, which comprises the sense oligonucleotide as well sense oligonucleotide contains a sequence homologous to the nucleotide sequence of the region SL2, can regulate the expression of IFN-α.本発明は、IFN-α mRNAに相補的な配列、特にIFN-α mRNAのSL1および/またはSL2領域内の塩基配列に相補的な配列を含み、IFN-αの発現を増強させ得るアンチセンスヌクレオチド;該アンチセンスヌクレオチドを含有してなるIFN-α発現増強剤、ウイルス感染症または癌の予防または治療剤;IFN-α mRNAに対する内因性asRNAに相補的な配列、特にIFN-α mRNAのSL1またはSL2領域内の塩基配列に相同な配列を含み、IFN-αの発現を調節し得るセンスオリゴヌクレオチド;並びに該センスオリゴヌクレオチドを含有してなるIFN-α発現調節剤を提供する。
