Zbtb46 coordinates angiogenesis and immunity to control tumor outcome
Tumor-angiogenesis and -immunity play critical roles in cancer progression and outcome. An inverse correlation of these two1 hints at common regulatory mechanism(s). Here, we report that Zbtb46, a repressive transcription factor and a widely accepted marker for classical dendritic cells (DCs)2, 3, constitutes one such regulatory mechanism. Zbtb46 was downregulated in both DCs and endothelial cells (ECs) by tumor-derived factors to facilitate robust tumor growth. Zbtb46 downregulation led to a hallmark pro-tumor microenvironment (TME), including dysfunctional vasculature and immunosuppressive cell accumulation. Analysis of cancer patient data revealed a similar association of low ZBTB46 expression with an immunosuppressive TME and a worse prognosis. In contrast, enforced Zbtb46 expression mitigated the pro-tumor TME features and restricted tumor growth. Mechanistically, Zbtb46-deficient ECs were highly angiogenic, and Zbtb46-deficient bone-marrow progenitors upregulated Cebpb and diverted the DC program to myeloid lineage output, potentially explaining the myeloid lineage skewing phenomenon in cancer4-7. Conversely, enforced Zbtb46 expression normalized tumor vessels and, by suppressing Cebpb, skewed bone-marrow precursors towards more DC generation over macrophages, leading to an immune-hot TME. Remarkably, Zbtb46 mRNA treatment synergized with anti-PD1 immunotherapy to improve tumor management in pre-clinical models. These findings identify Zbtb46 as a common regulatory mechanism for angiogenesis and for myeloid lineage skewing in cancer and suggest that maintaining its expression could have therapeutic benefits.