Antimicrobial Peptides as Novel Inhibitors of the Epithelial–Mesenchymal Transition in Cancer Progression

Metastasis is responsible for the majority of cancer-related deaths. During metastasis, cancer cells undergo a series of biological events that allow them to invade surrounding tissues, disseminate through the bloodstream or lymphatic system, and colonize secondary sites. Cancer cells’ phenotypic plasticity facilitates this process by enabling them to adapt to diverse microenvironments. Unlike localized tumors, metastasis is more challenging to treat because it represents a systemic disease that can no longer be managed solely through surgery or radiotherapy. Additionally, specific mechanisms underlying metastasis may contribute to resistance to conventional chemotherapy. Therefore, identifying new therapeutic strategies to regulate the key processes underlying metastasis is essential. In recent years, antimicrobial peptides (AMPs) have garnered increasing interest because of their anticancer properties. AMPs are small molecules that are part of the innate immune system of virtually all living organisms and are characterized by their ability to selectively interact with the cell membranes of pathogens and cancer cells. Diverse AMPs have been shown to induce cancer cell death, inhibit proliferation, and interfere with processes associated with metastasis. This review discusses the potential of AMPs as metastasis modulators, highlighting their proposed mechanisms of action, their advantages over conventional therapeutic approaches, and the conceptual framework governing their dual pro- and anti-metastatic activities.