M-Trap: Exosome-Based Capture of Tumor Cells as a New Technology in Peritoneal Metastasis

Background: Remodeling targeted tissues for reception of tumor cells metastasizing from primary lesions is a consequence of communication between the tumor and the environment that governs metastasis. This study describes a novel approach that aims to disrupt the process of metastasis by interfering with this intense dialogue. Methods: Proteomics and adhesion assays identified exosomes purified from the ascitic fluid of ovarian cancer patients (n = 9) as intermediaries of tumor cell attachment. A novel tumor cell capture device was fabricated by embedding exosomes onto a 3D scaffold (metastatic trap [M-Trap]). Murine models of ovarian metastasis (n = 3 to 34 mice per group) were used to demonstrate the efficacy of M-Trap to capture metastatic cells disseminating in the peritoneal cavity. Kaplan-Meier survival curves were used to estimate cumulative survival probabilities. All statistical tests were two-sided. Results: The exosome-based M-Trap device promoted tumor cell adhesion with a nonpharmacological mode of action. M-Trap served as a preferential site for metastasis formation and completely remodeled the pattern of peritoneal metastasis in clinically relevant models of ovarian cancer. Most importantly, M-Trap demonstrated a statistically significant benefit in survival outcomes, with mean survival increasing from 117.5 to 198.8 days in the presence of M-Trap; removal of the device upon tumor cell capture further improved survival to a mean of 309.4 days (P < .001). Conclusions: A potent artificial premetastatic niche based on exosomes is an effective approach to impair the crosstalk between metastatic cells and their environment. In the clinical setting, the capacity to modulate the pattern of dissemination represents an opportunity to control the process of metastasis. In summary, M-Trap transforms a systemic, fatal disease into a focalized disease where proven therapeutic approaches such as surgery can extend survival.