Effect of genetic modification of extracellular matrix-related genes on B16F1 melanoma progression

Recent research highlighted the contribution of extracellular matrix, and particularly of ADAMTS proteases, in immune regulation. Now, our work with melanoma and mammary tumor models revealed that tumor blockade induced by the lack of Adamts1 led to an increased vascular deposition of its substrate, the basement membrane glycoprotein NIDOGEN-1 (NID1). Significantly, the overexpression of NID1 in the melanoma syngeneic model also blocked tumor progression, disclosing an overlapping phenotype with the absence of Adamts1. These tumors showed important alterations in their immune infiltrates, emphasizing an enhanced presence of antitumorigenic macrophages and a global inflammatory landscape. We corroborated in vitro that full length NID1, but not its fragments, promoted an M1-like macrophage polarization, mainly mediated by the αvβ3 integrin. Significantly, the projection of RNA-seq from our tumor models to two large human melanoma datasets allowed us to discover a new gene signature associated with good prognosis and the abundance of M1-like macrophages. These results support NID1 as a novel tumor suppressor with immunomodulatory properties, and unveil the existence of key oncological drivers in the extracellular scenario. To investigate the effect of glycoprotein Nidogen-1 (NID1) on B16F1 melanoma progression from a transcriptomic perspective, we developed clones of B16F1 cell line overexpressing NID1 (referred as B16Nid1). We then conducted in vivo experiments by subcutaneously injecting B16Nid1 and parental B16F1 cells in C57BL/6 mice. At day 21, mice were sacrificed, and tumor were collected for bulk RNA isolation and RNA-sequencing. In parallel, CD11b+ cells were isolated from tumors, that were also processed to approach RNA-seq analysis. To evaluate the impact of ADAMTS1 deficiency on B16F1 melanoma progression, we also injected B16F1 cells subcutaneously into ADAMTS1-knockout C57BL/6 mice. These tumors (identified as B16-Ats1KO) was also monitored until day 21, at which point mice were sacrified and RNA was isolated for sequencing. RNA-seq was conducted on whole tumors (n=3 per group) from B16F1 (control), B16Nid1 and B16-Ats1KO tumors. Additionally, CD11b+ cells were isolated from three tumors of B16F1 and B16Nid1 groups for further transcriptomic analysis.