Angiogenesis in cutaneous disease: Part I

Abstract

After completing this learning activity, participants should be able to distinguish angiogenic growth factors and inhibitors, recognize angiogenic mediating agents and compare their mechanisms of action, and apply the use of angiogenic mediating agents in clinical and research situations.

Angiogenesis in Wound Healing

“…Platelets are essential in the coagulation cascade, and undergo degranulation induced by thrombin, releasing growth factors, such as platelet-derived growth factor (PDGF), transforming growth factor- (TGF-), epidermal growth factor (EGF), transforming growth factor- (TGF-), vascular endothelial growth factor (VEGF) and a adhesive glycoproteins such as fibronectin and thrombospondin, which are important constituents of the provisional extracellular matrix (Streit, Velasco et al 2000;Nguyen, Hoang et al 2009;Ribatti 2009). In fact, the coagulation cascade and growth factors released by platelets, together with the activation of the complement cascade and activation of parenchymal cell by injury, produce numerous vasoactive mediators and chemotactic factors, which together assist in the recruitment of inflammatory cells to the wound (Delavary, van der Veer et al 2011).…”

“…Thus, HIF-1-alpha-HIF-1-beta heterodimers promote angiogenesis, tumor growth, and metastasis regulating the expression of many angiogenic factors. Some studies position mTOR as an upstream activator of HIF-1 function in cancer cells and suggest that antitumor activity of sirolimus (see table 2) is mediated through the inhibition of cellular responses to hypoxic stress (Nguyen, Hoang et al 2009). …”

Analysis of GLUT-1, GLUT-3, and angiogenic index in syndromic and non-syndromic keratocystic odontogenic tumors

“…18,19,20 The formation of new blood vessels from pre-existing vascular structures, a process called angiogenesis, involves the participation of different intracellular signaling pathways with proangiogenic and antiangiogenic functions. 21,22 This complex process, which can be measured by determining the angiogenic index with antibodies against endothelial cell epitopes such as CD34, has been recognized as an important event in the development and progression of odontogenic cysts and tumors, including KOTs. 23,24,25 Although a crucial process in tumor progression, angiogenesis may not accompany the growth of tumor cells, with the consequent emergence of hypoxic areas in the tumor, a fact particularly highlighted in the case of malignant tumors.…”

“…In view of the limited diffusion capacity of oxygen and glucose from blood vessels, 36 angiogenesis is an essential event for tumor development and progression. 21,22 However, the formation of new blood vessels may not accompany the growth of neoplastic cells and may result in the emergence of hypoxic areas in the tumor. 26,27 In this respect, hypoxia-inducible factor 1 (HIF-1) plays a key role in the adaptation of neoplastic cells to hypoxia by promoting transcriptional activation of a repertoire of genes, such as those encoding GLUT-1 and vascular endothelial growth factor (VEGF).…”

“…26,27 In this respect, hypoxia-inducible factor 1 (HIF-1) plays a key role in the adaptation of neoplastic cells to hypoxia by promoting transcriptional activation of a repertoire of genes, such as those encoding GLUT-1 and vascular endothelial growth factor (VEGF). 22,26,37 The latter has been described as an important proangiogenic factor both under physiological and pathological conditions. 23,37 Taken together, the results reported herein emphasize the important relationship between hypoxia, glucose uptake into the intracellular medium, and angiogenesis, particularly in tumors.…”