Study On Expression Of Polypeptide Growth Factors On Maxillofacial Proliferative Hemangioma

Objective : Hemangiomas, the most common benign vascular tumor of infancy and childhood,id characterized by a proliferation of endothelial cells histologically and by rapid uncontrolled growth clinically (proliferative phase) followed by slow, inevitable regression (involuting phase) . The pathogenesis of Hemangiomas has not yet been elucidated. The polypeptide growth factors , one group of cytokine ,are proteins released by one cell that may regulate the proliferation of vascular endothelial cells and angiogenesis through different signal pathways, which bind to their receptors. A lot of documents inferred that polypeptide growth factors had relation with vascular lesion, there were poor consensus, however ,as to relation between Hemangiomas and polypeptide growth factors or their receptors. So we projected to caned out an immunohistochemial study of cytokine and its receptors in maxillofacial hemangiomas, in an effort to understand the effect of polypeptide growth factors during the hemangiogenesis and regression, and offer a basic rational for clinical diagnosis and evaluating therapy result. Methods: In this experiment, we retrieved 19 cases of paraffin-embedded vascular lesion (including 11 cases of maxillofacial hemangiomas and 8 cases of vascular malformations), and 8 cases of control specimens were harvested during excisional surgery form pediatric patients. None of the patients in this study received other therapies. The expression of VEGF, bFGF and TGF- P and their receptors were detected respectively by immuohistochemial EnVision method. Results : VEGF ,bFGF and their receptors were expressed by majority of endothelial cells in maxillofacial hemangiomas , but not in vascular malformations or control group .The localization of VEGF was predominantly within the cytoplasm and membrane of endothelial cells and pericytes, and its receptor(flk-1/KDR) was localized predominantly to the membrane of endothelial cells. As far as bFGF, the localization was mainly to membrane ofendothe1ial cells, furthermore, the basement membranes and fibrocytes werepositive, which surroud neovascu1arization, and its receptor(bFGFR)was alsomainly localised to the membrane of endothe1ial cells. TGF- e staining wasobserved significantiy within the opp1sam of endothe1ial cells, in contrast,vascu1ar maiformations and contro1 specimens were low eXPressed. However,TGF- 6 RII was low eXPressed in either mallllofacial hemangiomas or vascuIarmalfOrmations or control group.. Conclu8lon:1.There is a close relation between poboeptide grotti factorsand mtal1lofacial hemangiomas, and the pathogenesis of hemangiomas mightbe dependent on some opklnes, such as VEGF.2. VEGF,bFGF and their receptors are imPortant markers of hemangiomas,which Play a role in regU1atinghe proliferation of tUmor grwt, the effect ofTGF- 6 to hemangiomas is insignificant, but it may inhibit pro1iferation andpromote regression of hemangiomas.3. VEGF(a specific mitOgen fOr endothelial cells)binds to its specificreceptOr flk-1/KDR and induces the proliferation and migration of endothe1ialcells, thus is the most important cause of growh of hemangiomas. thereby, thispattern should be an impotalt pole fOr gene forget theraPies of hemangiomas.