中文摘要：

乳腺癌是最常见的癌症之一，尽管临床上对乳腺癌的治疗取得了较大的进展，然而固有的或后天获得的耐药性以及肿瘤的迁移和浸润会导致患者的治疗效果不理想最终死亡仍是目前函待解决的难题。和大多数肿瘤的发生发展一样，无论是乳腺肿瘤细胞的异常增殖、迁移和浸润还是多药耐药性（MDR），都与其细胞内特定基因的表达异常密切相关。目前也有很多研究发现肿瘤的发生发展与microRNA的异常表达有着密切的关系。因此，为了更好地理解乳腺癌发生发展的分子机制，进一步研究microRNA在乳腺癌中的作用功能十分必要。就microRNA在治疗乳腺癌中的应用做一综述，力求为今后选择控制肿瘤发展的新策略提供有效的思路。

英文摘要：

Breast cancer is one of the most common cancers. The clinical treatment of breast cancer has made great progress, but the inherent or acquired drug resistance, tumor migration and tumor infiltration, which lead to poor treatment efficiency and eventually death, are still the urgent problems to be solved. As with the occurrence and development of common tumors, the abnormal proliferation, migration and infiltration of breast tumor cells and muhidrug resistance （MDR） are closely related to the abnormal expression of specific genes in the cell. At present, many studies have found that the occurrence and development of tumor is closely related to the abnormal expression of microRNA. Therefore, in order to better understand the molecular mechanism of the occurrence and development of breast cancer, it is necessary to study the function of microRNA in breast tumor cells. In this paper, the application of microRNA in the treatment of breast cancer was reviewed, striving for providing effective ideas for the future selection of new strategies to control the development of tumors.