Selective B-RAF V600E Inhibitor PLX4032 Inhibits the Growth of Breast Cancer Cell Lines through Cell Cycle Arrest

Purpose Breast cancer is the most common invasive cancer and the second common cause of death among women worldwide. Many researchers have focused on the effective treatment of advanced breast cancer using new drugs. Herein, we analyzed whether PLX4032, a B-RAF V600E inhibitor, could be used as a novel treatment for advanced breast cancer. Methods Two breast cancer cell lines, MCF7 and MDA-MB-231, were treated with the selective B-Raf inhibitor PLX4032 under adherent culture conditions and the effects of PLX4032 on cell growth, cell cycle duration, apoptosis and cell cycle related genes expression were evaluated. Results We found that PLX4032 dose-dependently inhibited cell growth in both cell lines through cell cycle arrest at phase G0/G1. However, PLX4032 treatment did not have a significant effect on cell apoptosis. In addition, CCNA2 gene expression was significantly decreased in the MCF7 cells in a dose-dependent manner. Conclusion Our data demonstrated that treatment of breast cancer with PLX4032 could inhibit proliferation through cell cycle arrest. Therefore, PLX4032 might be a novel anticancer drug that can be used in the treatment of advanced breast cancer. Keywords: Breast neoplasms; Cell cycle checkpoints; Human CCNA2 protein; PLX4032