Figure 2.

Molecular events promoting the expression and persistence of MMP-9 in tumor tissues. Summary of the molecular pathways leading to MMP-9 overexpression in a wide variety of human tumors. Arrows symbolize directions of connections. Abbreviations: AKT, protein kinase B; AP, activator protein; EMT, epithelial-to-mesenchymal transition; ERK, extracellular-signal-regulated kinase; HIF, hypoxia-inducible factor; IC, inflammatory cytokines; LDLRP, low-density lipoprotein receptor-related protein; MAPK, mitogen-activated protein kinase; MMP, matrix metalloproteinase; NF-kB, nuclear factor-kappa B; NO, nitric oxide; PI3K, phosphoinositide 3 kinase; Sp, specificity protein; TIMP, tissue inhibitor of matrix metalloproteinase; VEGF, vascular endothelial growth factor.