Techniques: Integrin expression profiling of tumor-secreted exosomes to predict organ-specific cancer metastases

TECHNOLOGY: Plasma markers

Integrin expression profiles of tumor-secreted exosomes could help predict organ-specific metastases of cancer. In mice, exosomes derived from human cancer cell lines that metastasize to the lung or liver homed to the lung or liver, and expressed high levels of integrin β4 or integrin αvβ5, respectively. Levels of integrin β4 on circulating exosomes were higher in rhabdomyosarcoma, breast cancer and pancreatic cancer patients with lung metastases than in patients with liver or no metastases, whereas levels of integrin αvβ5 on circulating exosomes were higher in the patients with liver metastases than in those with lung or no metastases. In breast cancer patients, pre-metastatic levels of integrin β4 on circulating exosomes were associated with later lung metastases, and in pancreatic cancer patients, integrin αvβ5 levels on circulating exosomes at diagnosis were associated with lung metastases within three years. Next steps could include identifying exosomal proteins that are associated with metastases in other organs...