Novel Strategy to Prevent Cancer Metastasis with Metastasis-Regulating miRNAs Found in Extracellular Vesicles Secreted from Stemness-High Cells.

Preventing metastasis and recurrence after cancer treatment remains a challenge. Extracellular vesicles (EVs) have long garnered attention as tools for vaccination. To develop high-performance vaccines, there has been an ongoing search for high-performance miRNAs and high-performance EVs as resources. In recent years, stemness-high cells have been reported to represent valuable resources for EVs, offering a level of performance not previously achieved. A differential miRNA analysis was performed between metastasis-suppressive EVs and metastasis-promoting EVs to predict miRNAs specific to metastasis regulation. These newly identified miRNAs were expected to show good performance in metastasis suppression. It is noticeable that these miRNAs seem to be categorized differently from the cancer-associated miRNAs that have been extensively studied to date. In order to further develop vaccine therapy, it is widely recognized that continuing to explore methods for further enhancing the metastasis-suppressive potential of EVs and mRNAs is a fundamental and urgent task. Significant progress has been made through the discovery of stemness-high cells as new EV resources and the results of miRNA exploration focused on metastasis regulation. This review aims to address current challenges by presenting relevant, up-to-date information and providing insights that may lead to new discoveries.