MicroRNA-204 inhibits the proliferation and metastasis of breast cancer cells by targeting PI3K/AKT pathway

Purpose: Breast cancer is one of the deadliest malignancies in women. Lack of biomarkers and the unavailability of reliable therapeutic targets are main hurdles in the treatment of breast cancer. The present study was therefore designed to assess the role and therapeutic potential of miR-204 in the treatment of breast cancer. Methods: The expression of miR-204 was checked by qRT-PCR. The transfections were performed by Lipofectamine 2000 reagent. Cell viability was determined by WST-1 col-orimetric assay. The effect of miR-204 was evaluated on the breast cancer metastasis by cell migration and invasion transwell assays. Immunoblotting was used to determine the protein expression in breast cancer cells. Results: The results revealed that the expression of miR-204 was downregulated in all the tested breast cancer cell lines. Overexpression of miR-204 in the MCF7 breast cancer cell line suppressed the proliferation of these cells by triggering apoptotic cell death and G2/M cell cycle arrest. Furthermore, miR-204 overexpression inhibited the migration and invasion of the MCF7 breast cancer cells. Bioinformatic analysis revealed PTEN to be the target of miR-204. Since, PTEN regulates the PI3K/AKT signalling pathway, the effect of miR-204 overexpression was also assessed on this pathway and showed that miR-204 overexpression inhibits the expression of p-AKT and p-PI3K significantly in MCF7 breast cancer cells. Conclusion: We conclude that miR-204 regulates the proliferation and metastasis of the breast cancer cells and as such may prove to be an important therapeutic target.