Identify the role of host ATF4 on CAFs in the tumor microenvironment of large size B16F10 tumors. Identify the role of host ATF4 on CAFs in the tumor microenvironment of large size B16F10 tumors

To delineate the role of host ATF4 in the sequence of events leading to tumor growth, we performed transcriptional profiling at the single-cell level (scRNA-seq) in larger (300 mm3) size B16F10 tumors grown in Atf4wt/wt and Atf4D/D mice. We surprisingly detected impaired CAFs activation in Atf4D/D mice, based on the expression levels of Acta2 and Pdgfrb, as one of the most commonly used CAF markers. Among our key findings, we identified the vascular CAFs (vCAFs), a spatially distinct CAF subcluster featured by the highest levels of aSMA and PDGFRb, that were reduced in Atf4D/D mice. Overall design: Large size B16F10 tumors (300 mm3) from four Atf4wt/wt and four Atf4D/D were harvested and submitted for scRNA-seq analysis.