Involvement of TIMP-1 in PECAM-1-mediated tumor dissemination.

Platelet endothelial cell adhesion molecule‑1 (PECAM‑1) is expressed on the vascular endothelium and has been implicated in the late progression of metastatic tumors. The activity of PECAM‑1 appears to be mediated by modulation of the tumor microenvironment (TME) and promotion of tumor cell proliferation, rather than through the stimulation of tumor angiogenesis. The present study aimed to extend those initial findings by indicating that the presence of functional PECAM‑1 on the endothelium promotes a proliferative tumor cell phenotype in vivo, as well as in tumor cell (B16‑F10 melanoma and 4T1 breast cancer cell lines) co‑culture assays with mouse endothelial cells (ECs) or a surrogate EC line (REN‑MP).