Transcriptional profiling of macrophages in situ in metastatic melanoma reveals localization-dependent phenotypes and function

A topology perspective on macrophages in melanoma metastasis

“…In this issue of Cell Reports Medicine , Martinek et al. 1 present data exploring the diversity of myeloid cells (defined as cells expressing CD14) in relation to their localization in metastatic melanoma. They demonstrate that the transcriptional profile of CD14 + myeloid cells (including monocytes, macrophages, and dendritic cells) depends on their location, i.e., it is different whether they are localized in the tumor nests (iCD14+) or in the stroma (sCD14+).…”

“…Along this line, Martinek et al. 1 analyzed the transcriptome of iCD14+ and sCD14+ cells carefully harvested from distinct regions and found regional signatures, a relevant feature that was not present in CD3 + T cells, whose transcriptional program was irrespective of their localization. What emerged was that iCD14+ were more like tissue macrophages, while sCD14+ seemed involved in the organization of the tumor stroma.…”

“…By studying melanoma metastasis, Martinek et al. 1 provide some new insights of considerable significance. Proving the hypothesis that CD14 + macrophages may have distinct transcriptional profiles depending on their location was a demanding objective.…”

“…Martinek et al. 1 analyzed melanoma metastasis that were localized in different organs (lymph nodes, skin, lung, intestine). Interestingly, the transcriptome of the discrete CD14 populations (iCD14+ and sCD14+) were homogeneously conserved across tissues.…”

“… In this issue of Cell Reports Medicine , Martinek et al. 1 provide a window into the regional specialization of macrophages infiltrating metastatic melanoma. Combining histo-cytometry and transcriptomics, they identify a signature of stromal macrophages with dendritic cell features and clinical relevance.…”