Researchers identify new pathway to curb breast cancer metastasis

Researchers at the Universidad Complutense de Madrid have identified a potential new mechanism to prevent breast cancer metastasis by targeting the RAC1 protein. The study, published in ‘Signal Transduction and Targeted Therapy’, focuses on how tumor cells exploit RAC1—a molecular ‘switch’ responsible for cell growth and movement—to invade nearby tissues and spread to other organs.

Because RAC1 is also essential for normal cell function, blocking the protein entirely is difficult. However, the study found that preventing the ‘SUMOylation’ of RAC1 significantly reduced lung metastasis in experimental models without substantially affecting the growth of the primary tumor. Using the peptide TAT-PRASI, researchers were able to reduce the invasive capacity of breast cancer cells and organoids derived from HER2+ patients. These results were observed across various molecular subtypes, suggesting the mechanism may be broadly applicable.