Abstract 2699: Transcriptome analysis identifies molecular markers of tumor-associated high endothelial venules that predict breast cancer survival

High endothelial venules (HEVs) are specialized post-capillary venules that recruit naïve lymphocytes to the lymph nodes and are essential for the development of adaptive immunity. HEVs can develop in tumors, and these specialized tumor blood vessels are thought to be important for recruiting naïve T cells and B cells into tumors and locally enhance anti-tumor immunity by promoting tertiary lymphoid structure formation. At present, the genes involved in the development and function of tumor-associated HEVs remain largely unknown. By a comparative transcriptome analysis in human breast cancer, we identified the expression of genes that represents the molecular signature of tumor-associated HEVs distinct from the rest of the tumor vasculature. Tumor vessels highly expressing these genes were associated with the accumulation of T and B lymphocytes and the occurrence of tertiary lymphoid structures, which is known to predict therapeutic response to immune checkpoint inhibitor therapies. Moreover, the Cancer Genome Atlas (TCGA) data show that the high expression of these genes is associated with a significant survival benefit in advanced breast cancer. The molecular signature of HEVs identified here may be useful for guiding immunotherapies and provide a new direction for investigating tumor-associated HEVs and their clinical significance. Citation Format: Junko Sawada, Nobuyoshi Hiraoka, Ashley Fournier-Goss, Masanobu Komatsu. Transcriptome analysis identifies molecular markers of tumor-associated high endothelial venules that predict breast cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2699.