Human KIT+ myeloid cells facilitate visceral metastasis by melanoma

Metastasis of melanoma significantly worsens prognosis and therefore therapeutic interventions that prevent, or slow metastasis could improve patient outcomes. Here, we show using humanized mice that colonization of distant visceral organs with melanoma is dependent upon a human CD33+CD11b+CD117+ progenitor cell subset comprising <4% of the human CD45+ leukocytes. Metastatic tumor-infiltrating CD33+ cells from patients and humanized (h)NSG-SGM3 mice showed converging transcriptional profiles. Single-cell RNAseq analysis identified a gene signature of a KIT/CD117 expressing CD33+ subset that correlated with decreased overall survival in TCGA melanoma samples. Thus, human CD33+CD11b+CD117+ myeloid cells represent a novel candidate biomarker as well as a therapeutic target for metastatic melanoma. We examed the transcriptomic of CD33pos cells in NSG-SGM3 mice transplated with human hematopoietic stem cells for their capacity to facilitate human melanoma metastasis