Maryam etemadi
samareh gooshki

Introduction & Aim: Breast cancer affects one in eight women in the world. miRNA are major regulators of gene expression that play a role in almost all areas of the genome and cellular behaviors. , miRNA acts as oncogene or tumor suppressor in all cancers. they lose their adjusted activity in cancer. Methods: review article Results:One of the best treatments for patients is miRNAS that regulate geneexpression. Studies have shown that tumor miRNAs can be good biomarkers for the diagnosis of breast cancer. Use of miRNA as cancer treatment is based on two methods: 1) miRNA synthesis as a medicine to increase or decrease the amount of miRNAS in breast cancer. 2) miRNA mediates in combination with other factors to increase the efficacy of treatment. Conclusion; Some of MiRNAS are upregulated and some of them are downregulated in breast cancer. MicroRNAs act by inhibiting the function of the ribosome, decapping the 50 Cap structure, deadenylating the poly(A) tail, and degrading the target mRNA. They are also able to set hundreds of targets together. Therefore, they play a role in controlling cellular function, cell division. In addition to oncogene or tumor suppressor, miRNA can also play a role in metastasis One of the most important challenges in breast cancer is its rapid diagnosis in its early stages. An ideal biomarker should be accessible to trace and detect in all patient. The amount of miRNA expression in breast cancer.is one of the challenges ahead in the diagnosis and treatment of it.