GSE161769
JAGGED1 Promotes Tumor Progression through Recruitment of Macrophages and Functional Suppression of Tumor-killing T cells [scRNA-seq]
Breast cancer is one of the leading causes of cancer-related mortality in women. NOTCH signaling is a well conserved pathway which not only plays critical roles in normal development, but also in cancer progression. One of the Notch ligand, JAGGED1 is overexpressed in about 30% of breast cancer patients. However, the role of JAGGED1 in breast tumorigenesis has not been rigorously examined. By utilizing genetic engineered mouse models of mammary specific Jagged1 expression or knockout, we discover that Jagged1 promotes tumorigenesis in multiple spontaneous mammary tumor models. Jagged1 expression leads to increased infiltration of tumor associated macrophages and decreased presentation of T cells within tumor microenvironment. Depletion of macrophages or T cells by neutralizing antibodies diminishes the tumor-promoting effect caused by Jagged1. Mechanistically, Jagged1 activates Notch signaling in tumor cells, leads to increased expression and secretion of multiple cytokines, including IL-6 and WISP. These cytokines help recruit macrophages into the tumor microenvironment. Macrophages crosstalk with infiltrated T cells and inhibit their cytotoxic killing on tumor cells. In triple negative breast cancer patient samples, high expression level of JAGGED1 correlates with increased macrophage infiltration and decreased T cell infiltration within tumor tissues. JAGGED1 also promotes tumor progression in several other solid cancer types, including melanoma, and colon cancer in a T cell dependent manner. Co-administration of immune checkpoint inhibitor, PD-1 antibody with gamma-secretase inhibitor (GSI) significantly inhibits tumor growth. These findings identify a unique oncogenic crosstalk between tumor derived JAGGED1, Macrophages, and T cells to promote tumor progression. Overall design: 10X Genomics to analyze immune subtype infiltrated in the WT/PyMT and Jagged1/PyMT mice.