Abstract
In the study of tumorigenesis, the involvement of molecules within the extracellular matrix (ECM) is crucial. ADAMTSs (A Disintegrin and Metalloproteinase with Thrombospondin motifs), a group of secreted proteases known for their role in ECM remodeling, were primarily considered to be extracellular proteases. However, our research specifically detected ADAMTS-1, a member of this family, predominantly within the nucleus of mammary cells. Our main objective was to understand the mechanism of ADAMTS-1 translocation to the nucleus and its functional significance in this cellular compartment. Our investigation uncovered that nuclear ADAMTS-1 was present in cells exhibiting an epithelial phenotype, while cells of mesenchymal origin contained the protease in the cytoplasm. Moreover, disruption of ADAMTS-1 secretion, induced by Monensin treatment, resulted in its accumulation in the cytoplasm. Notably, our research indicated that alterations in the secretory pathways could influence the protease's compartmentalization. Additionally, experiments with conditioned medium from cells containing nuclear ADAMTS-1 demonstrated its internalization into the nucleus by HT-1080 cells and fibroblasts. Furthermore, heightened levels of ADAMTS-1 within the ECM reduced the migratory potential of mesenchymal cells. This highlights the potential significance of nuclear ADAMTS-1 as a critical component within the tumor microenvironment due to its functional activity in this specific cellular compartment.