Tissue inhibitor of metalloproteinases (TIMP)‐1 creates a premetastatic niche in the liver through SDF‐1/CXCR4‐dependent neutrophil recruitment in mice

Due to its ability to inhibit prometastatic matrix metalloproteinases, tissue inhibitor of metalloproteinases (TIMP)‐1 has been thought to suppress tumor metastasis. However, elevated systemic levels of TIMP‐1 correlate with poor prognosis in cancer patients, suggesting a metastasis‐stimulating role of TIMP‐1. In colorectal cancer patients, tumor as well as plasma TIMP‐1 levels were correlated with synchronous liver metastasis or distant metastasis‐associated disease relapse. In mice, high systemic TIMP‐1 levels increased the liver susceptibility towards metastasis by triggering the formation of a premetastatic niche. This promoted hepatic metastasis independent of origin or intrinsic metastatic potential of tumor cells. High systemic TIMP‐1 led to increased hepatic SDF‐1 levels, which in turn promoted recruitment of neutrophils to the liver. Both inhibition of SDF‐1‐mediated neutrophil recruitment and systemic depletion of neutrophils reduced TIMP‐1‐induced increased liver susceptibility towards metastasis. This indicates a crucial functional role of neutrophils in the TIMP‐1‐induced premetastatic niche. Conclusion : Our results identify TIMP‐1 as an essential promoter of hepatic premetastatic niche formation. (H epatology 2015;61:238–248)