Abstract A094: Characterization of pancreatic cancer endothelial cells: Approach to enhance immune cell infiltration for immunotherapy

The hurdles in realizing immunotherapy success for cure stem from the fact that cancer patients are either refractory to immune response and/or develop resistance. We previously proposed that these phenomena are due, in part, to the deployment of tumor-associated antigens, or employment of tumor-associated endothelium acting as a gatekeeper for immune cell infiltration into the cancer tissue (Nakajima et al, Cancer Res 2017;77:5441-4). Here, an extensive study unveiled functional/molecular differences of endothelium derived from pancreatic cancer and normal pancreas. They were isolated from fresh surgical specimen by magnet-based selection. The primary culture of tumor-associated endothelial cells was confirmed by double positive expressions of endothelial markers, CD31 and ERG1. They showed the short vessel formations and the narrow area of capillary network, indicating the low potential of angiogenesis. Further, peripheral blood–derived lymphocytes were less adhering to the tumor-associated endothelial cells. To find the molecular differences, microarray analysis was performed, and identified 2748 molecules distinct from endothelial cells of noncancerous tissues (p Citation Format: Kosei Nakajima, Yashunori Ino, Toshimitsu Iwasaki, Nobuyoshi Hiraoka. Characterization of pancreatic cancer endothelial cells: Approach to enhance immune cell infiltration for immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A094.