Abstract <p>Breast cancer is one of the most common cancer types worldwide. It can potentially be treated with peptide therapy rather than chemotherapy and radiotherapy due to the adverse effects associated with the current treatments. Peptides are small units of proteins that do not induce an immune response.</p> Purpose <p>Thus, these biomaterials can be used to treat breast cancer for therapeutic approaches. Proline-rich peptides, such as VPP, can regulate cell behaviors, such as cell arrest or apoptosis. However, to our knowledge, there is no evidence that peptides have any effect on MCF-7 breast cancer cells.</p> Methods <p>In this study, we examined the effects of the different concentrations of VPP peptide on the MCF-7 cell line. It was performed the migration, viability, ROS, NO and ATP production and apoptotic gene expression capacity of VPP peptide on MCF-7 breast cancer.</p> Results <p>We observed that 0.01&#xa0;mM and 1&#xa0;mM concentrations of the VPP peptide induced cell death. These concentrations also limited cell proliferation, migration, and cellular activity. Additionally, they may trigger oxidative stress in breast cancer cells.</p> Discussions <p>Thus, the peptide could be a promising therapeutic agent for breast cancer cells if used at appropriate concentrations for cancer treatment.</p>