Abstract: MicroRNA (miRNA) controls the proliferation of breast cancer cells in many ways such as cell apotosis, cell cycle and methyltransferase. Also, it controls the metastasis of breast cancer cells in many ways such as microenvironment, epithelial-mesenchymal transition and vessel formation. Large amounts of recent studies indicate that miRNAs are specifically expressed in breast cancer tissue and play important roles in proliferation, metastasis and treatment of breast cancer.

Key words: MicroRNAs, Breast neoplasms, Neoplasm metasis, Cell proliferation