Tumor-Derived Matrix Metalloproteinase-1 Targets Endothelial Proteinase-Activated Receptor 1 Promoting Endothelial Cell Activation

Abstract

In the vascular system, circulating tumor cells interact with endothelial cells. Tumor-endothelial cross-talk transforms the intravascular milieu to a prothrombotic, proinflammatory, and cell-adhesive state called endothelial cell activation (ECA). In the present study, we analyze the potential of metastatic tumor-derived soluble factors to transform the vascular endothelium into a prothrombotic and proinflammatory activated state. Supernatant from cultured melanoma and colon cancer cells (A375, WM9, A7, and HT-29) induced an acute activation of macrovascular and microvascular endothelial cells (human umbilical vein endothelial cells and human dermal microvascular endothelial cells) as shown by intracellular calcium flux and secretion of von Willebrand factor and interleukin-8, all markers of acute ECA. This process was inhibited using specific proteinase-activated receptor 1 (PAR1) inhibitors (RWJ-58259 and SCH-79797), indicating a mediating role for endothelial thrombin receptors. Immunofluorescence, Western blot analysis, and collagenase activity assay of tumor cells and culture supernatant revealed the presence of matrix metalloproteinase-1 (MMP-1), a recently described activator of PAR1. Inhibition of MMP-1 in supernatant from cultured tumor cells significantly attenuated ECA. Additional studies using isolated human MMP-1 (5 nmol/L) proved the presence of a functional MMP-1/PAR1 axis in tumor-endothelial communication. These findings show a new pathway of tumor-endothelial cross-talk via an intravascular MMP1/PAR1 axis in microvascular and macrovascular endothelium. Inhibition of this cross-talk may be a powerful means to prevent tumor-induced ECA and thus thrombotic and inflammatory cell adhesion. (Cancer Res 2006; 66(15): 7766-74)

Proteases as modulators of tumor–stromal interaction: Primary tumors to bone metastases

“…Activated MMP-1 is capable of cleaving and activating PAR-1 on prostate cancer cells which results in mitogenesis and drives migration of cancer cells towards the source of MMP-1 [21]. B) MMP-1 derived from breast and prostate cancer cells enters the vasculature where it can activate PAR-1 expressed by endothelial cells [36][37][38][39][40]. Activation of PAR-1 induces expression and release of von Willebrand Factor (vWF), IL-1, and P-selectin [40].…”

“…Importantly, an environment that favors thrombosis and inflammation facilitates tumor progression [38; 39]. Tumor-produced MMP-1 released into the vasculature has been shown to activate endothelial PAR-1 [40]. PAR-1 activation on endothelial cells triggers the release of proteins such as von Willebrand Factor, Interleukin (IL)-8, and P-selectin, and ultimately generates a prothrombotic and proinflammatory environment that favors tumor growth and progression [40].…”

Nuclear heparanase-1 activity suppresses melanoma progression via its DNA-binding affinity

“…1A). In the first set of experiments we investigated the invasive properties of all three cell lines with an electrophysiological cell-based invasion assay previously established in our laboratory 24,25 . One of the key features of this assay is the high sensitivity to evaluate very early steps of invasion 26 .…”

“…1A-C). To evaluate the progression of human malignant melanoma cells we applied a previously established electrophysiological invasion assay 24,25 .…”

“…We previously demonstrated that MMP-2 and MMP-9 secreted from melanoma cells are strongly involved in the breakdown of TEER 25,26 . Therefore, we analyzed the secreted amounts of both proteinases in supernatants of melanoma cells by gelatin gel zymography.…”