The tumor microenvironment (TME) with the immune cells it contains plays a crucial role in promoting or inhibiting tumor progression. In addition to lymphocytes, which are the subject of current immunotherapeutic approaches, macrophages and mast cells have also been linked to tumor progression in various tumor entities. In a pilot study on tissue samples of 118 tumor patients we could show that a high mast cell density in the TME of oral squamous cell carcinoma (OSCC) is associated with a significantly longer patient survival. In contrast to other tumor entities, there is only a low mast cell degranulation in OSCC. In addition to the reduced release of proteases and vasoactive substances that promote tumor progression, mast cells seem to develop additional active tumor suppressive mechanisms in this special microenvironment. In this context, particularly soluble factors and/or direct interactions between mast cells and tumor cells via extracellular vesicles could play a decisive role. In order to evaluate the existence of such factors and extracellular vesicles from mast cells and their influence on the proliferation, migration, invasion and oxidative stress of OSCC cells, we are currently carrying out in vitro studies on the high and low proliferating cell lines PCI-13, BHY and UPCI-SCC-040, as well as the human mast cell line LUVA. We hope that our findings could provide important information for understanding the immune response in order to develop novel immunotherapeutic approaches for future treatment.
The presented project is being carried out in cooperation with the Extracellular Signaling Lab and the Institute of Pathology of the University Medical Center Göttingen, and the Institute of Pathology of the Helios Clinic Krefeld.