About this Research Topic
Liquid biopsy, a non-invasive diagnostic technique, allows access to biomarkers found in bodily fluids, primarily blood-borne biomarkers. This sampling technique has received great attention in the field of oncology, where the term more precisely refers to the sampling of circulating tumor cells (CTCs), circulating-free tumor nucleic acids (ctNAs), and tumor-secreted extracellular vesicles (tEVs), all of which can be found in the blood of cancer patients. These biomarkers have been mainly studied due to their clinically informative value for diagnostic, prognostic, and monitoring of response to therapy. However, CTCs, ctNAs, and tEVs also play an active role in the metastatic process, suggesting that liquid biopsies might also provide new opportunities to explore the biological and molecular mechanisms of tumor dissemination.
CTCs that shed from the primary tumor site are able to extravasate and, within a favorable microenvironment, proliferate to form a new metastatic lesion. CTCs can be associated with blood cells (e.g. platelets, lymphocytes), and part of that interaction is seemingly mediated by specific proteins expressed by both cell types. ctNAs can be actively taken up by cells and ultimately associate with cell chromosomes, suggesting that they may act as mobile genetic elements. Furthermore, tEVs are critical mediators of intercellular communication between tumor and stromal cells in local as well as distant microenvironments. Taken together, this multifaceted communication between CTCs and the surrounding blood microenvironment, which seems to involve ctNAs and tEVs, appears to have a significant role in shaping tumor progression.
This Research Topic aims to highlight the different aspects of the biology of cancer metastasis that can be addressed with the application of liquid biopsies. We welcome Original Research and Review articles focused on, but not limited to, the nature of the interactions between CTCs, and other cell types during circulation in the bloodstream in which ctNAs and tEV play a key role. Potential sub-topics include:
1) Application of sensitive technologies for liquid biopsy.
2) Liquid biopsy and 3D culture, including organoid-based studies.
3) Circulating Tumour Cell-Derived Pre-Clinical Models.
4) CTCs, CNA and EVs molecular characterization.
5) CTCs, CNA and EVs interaction with both blood and tumor microenvironments.
6) CTCs, CNA and EVs impact in the metastatic process.
Keywords: liquid biopsy, metastasis, CTCs, cfDNA, cfmRNA, cfmiRNA, EVs, blood microenvironment