Generation of in vivo labelling tumour cell lines

Abstract The characterization of the tumour microenvironment is highly desirable in order to get a better understating on how the tumour cells exploit their neighbours to support their own growth. In Ombrato et al., Nature 2019 we describe a novel strategy that allows 4T1 breast tumour cells to label their lung metastatic niche in vivo. The labelled cells surrounding the tumour cells can be freshly isolated within the all tissue and used for ex vivo assays. Here, we describe how we generated Labelling-4T1 cells. The same procedure can be used to generate labelling cells from other cell lines, but it might require optimization. This protocol is a suggested guide.