中文摘要：

由于微小RNA（miRNA）在肿瘤中发挥重要调控作用及其自身特点，使其可能成为基因靶向治疗的有效工具。因此，人们致力于寻找调节关键癌基因或抑癌基因的miRNA。研究发现miR-221及miR-222在多种人类肿瘤中不仅表达异常，而且在不同类型的肿瘤中也发挥着不同的癌基因或抑癌基因样作用，通过调控miR-221和miR-222的表达可能成为肿瘤治疗的有效方法。

英文摘要：

Because of the characteristics of microRNAs （miRNAs） and their important regulative roles in human tumor diseases, they may be novel approaches for gene target therapy. Most studies focus on finding critical regulator miRNAs of oncogenes or tumor suppressor genes. Recent researches show that the expression of miR-221 and miR-222 are abnormal, and they play different roles in different types of human tumors. The regulation of miR-221 and miR-222 may be a novel effective therapy for tumor.