This invention provides compounds, compositions and methods for modulating the expression of human p21 using RNA interference. The RNA interference molecules can be used in methods for preventing or treating diseases such as malignant tumor. Provided are a range of siRNA structures, having one or more nucleotides being modified or chemically-modified. Advantageous structures include siRNAs with 2-deoxy nucleotides located in the seed region, as well as other nucleotide modifications.本發明提供使用RNA干擾之用於調節人類p21表現之化合物、組成物及方法。該RNA干擾分子可用於預防或治療諸如惡性腫瘤之疾病的方法中。所提供者係一系列具有一或多個經修飾或化學修飾的核苷酸之siRNA結構。有利的結構包括位於種子區(seed region)之具有2-去氧核苷酸的之siRNA及其他核苷酸修飾。
