Abstract 1363: Breast pericytes: A newly identified driver of tumor cell proliferation

Abstract A crucial problem limiting our progress to a cure for breast cancer is understanding what drives tumor growth. While we are aware that potent regulators of tumor development include non-malignant cells coexisting in tumors, not all cell types are easily recognized—nor have they been examined rigorously as potential contributors to malignancy. An obstacle in approaching this problem has been an inability to isolate and purify each cell type from the tissue. Recently our laboratory developed models of each cell type in the breast, allowing us the opportunity to investigate the contributions of primary cell types to tumor cell growth through co-culture. We have discovered that pericytes secrete a potent factor that drives tumor cell expansion directly— and dramatically more than controls (isogenic fibroblasts). The effects of this factor are dose-dependent, and we find that it is protease- and heat-inactivated. Furthermore, tissue immunostaining reveals that pericytes expand into tumor stroma, where they may interact directly with tumor cells. Single-cell RNA sequencing uncovers the heterogeneity of pericytes, which exist on a perivascular spectrum. Citation Format: Katelyn Del Toro, Yamhilette Licon-Munoz, William C. Hines. Breast pericytes: A newly identified driver of tumor cell proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1363.