Flexible and comprehensive phenotyping of tumor and peripheral blood mononuclear cells in endometrial carcinoma 3011

Abstract Description Endometrial carcinoma (EC) is the most common form of uterine cancer, with increasing prevalence in developed countries due to population aging and rising obesity rates. Identifying biomarkers that may enable more personalized medicine or immunotherapy discoveries is important to create more treatment options as well as to tackle aggressive EC subtypes. To that end, we developed a 58-parameter mass cytometry (CyTOF™) panel that enables deep phenotyping of both immune and non-immune cells in tumors as well as in PBMC. This was achieved by combining pre-optimized panels for pan-immune cell phenotyping, T cell profiling and cytokine and cytotoxic mediator detection with nine drop-in antibodies selected for their relevance in EC as biomarkers or potential immunotherapy and drug targets. Cell proliferation was assessed using IdU incorporation and Ki-67 staining, while tumor cell and tumor-infiltrating leukocytes (TILs) were further defined with EpCAM, Her2, β-catenin, CD69, CD103, PD-L1 and FoxP3. Live-cell universal barcoding with a tellurium-based 7-choose-3 strategy allowed multiplexing of samples during cell staining and acquisition. This high-parameter panel allows for deep phenotypic and functional profiling of circulating immune cells, tissue and tumor cells and TILs. By utilizing a flexible and modular assay designed to characterize both immune and non-immune cells, this CyTOF panel can facilitate biomarker discovery and accelerate drug development in cancer therapeutics. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)