Role of tumor-derived exosomes in cancer metastasis.

The highlights of cancer research include the discovery of exosomes, which are small (30-100 nm) sized vesicular nanoparticles released virtually by all cells. Tumor-derived exosomes (TDEs) are notoriously known for orchestrating the invasion-metastasis cascade via systemic pathways that we have previously proposed (1), resulting in a paradigm shift of our understanding about the pathobiology of metastases. In principle, exosomes serve as transport medium for proteins, mRNAs and miRNAs to transmit targeted cues from the primary cell to distant sites via horizontal transfer or cell-receptor interaction. In this chapter, we seek to explore in-depth the mechanisms engendering TDE in the metastatic cascade, along with experimental models to augment our understanding. The aforementioned has also paved way for parallel advancements in the therapeutic armamentarium, as evident from pronounced efforts to exploit the metastatic process for therapeutic targeting. In this light, we aim to examine potential anti-metastatic therapeutic opportunities derived from exosomal research. Lastly, exosomes may play a crucial role in the contemporary era of "liquid biopsies", given the array of molecular information with diagnostic and predictive indications. We thus intend to end this chapter off by exploring future applications of exosomes that could illuminate shortcomings and propel advancements in biomarker research.