Extracellular vesicle-mediated transfer of miRNA-1 from primary tumors represses the growth of distant metastases

Metastases originate from primary tumors and reach distant organs. Growing evidence suggests that metastases are under the control of primary tumors even outside the primary site; however, the mechanisms by which primary tumors remotely control metastases remain unclear. Here, we discovered a molecular mechanism by which primary tumors suppress metastatic growth. Interestingly, we found that extracellular vesicles (EVs) derived from the primary tumor can inhibit the growth of metastases both in vitro and in vivo. miR-1 was particularly enriched in primary tumor-derived EVs (pTDEs) and was found to be responsible for the suppression of metastatic growth. Mechanistically, intracellular reactive oxygen species (ROS) production and DNA damage were induced, which led to cell cycle arrest. Collectively, our data demonstrate that primary tumors restrict the growth of distant metastases via miR-1 in pTDEs and that miR-1 could potentially be used as an antimetastatic agent. Harnessing miR-1: A Potential Anticancer Drug to Combat Metastasis Cancer metastasis, or the movement of cancer cells from the initial tumor to other body parts, is a complicated process that we don't fully comprehend. This research aimed to explore how the original tumors manage the growth of metastatic, or spreading, cancer cells. The scientists discovered that extracellular vesicles (EVs - tiny particles released by cells) produced by cancer stem cells in the original tumors can slow the growth of spreading cells. Specifically, these EVs carry a molecule named miR-1, which can cause DNA damage and cell cycle arrest in spreading cells, reducing their multiplication. The study also found that the amount of miR-1 in EVs increases with the advancement of breast cancer, suggesting its potential use for diagnosis and treatment. This study offers new understanding into how cancer spreads and suggests new possibilities for cancer treatment. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.