Expression Of Epidermal Growth Factor Receptor (EGFR)and Vascular Endothelial Growth Factor (VEGF) In Vocal Fold Polyps

Objective:The purpose of this study was investigation and quantitative analysis of the expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor(VEGF) in normal tissue and polyp of vocal cord expression to understand the roles of EGFR and VEGF onset of vocal cord polyps and their mutual relations, further explore the pathogenesis, provide a theoretical basis for prevention and treatment. Materials And Methods:The pathological diagnosis confirmed and the exclusion of other vocal cord lesions were37cases of vocal cord polyps specimens as the experimental group. The specimens of normal vocal cord were obtained from11autopsy cases for control group. All specimens were stained by HE, immunohistochemical staining of EGFR and VEGF were performed with monoclonal antibodies by MaxVisionTM method. The everage value of positive units that EGFR and VEGF had expressed in normal tissue of vocal cord and polyp of vocal cord was analyzed by means of quantitative analysis of computer images. Results:In normal vocal cords, EGFR and VEGF's expression were weak. But, in the vocal cord polyp, the expression were strong in epithelial cells, inflammatory cells, vascular endothelial cells, glandular cells, fibroblasts. The everage value of EGFR positive units in the vocal cord polyp group was higher (19.2109±9.1636) than normal vocal group (7.2109±4.2481), significantly different (p<0.05). The everage value of VEGF positive units in the vocal cord polyp group was higher (33.5317±6.1559) than normal vocal group (18.9507±5.5183), significantly different (p<0.05). Conclusion:①The formatoin of vocal cord polyp attributes to many factors. Various factor cause repeated damage in the vocal cords,and lead to local congestion, edema, hemorrhage, epithelial degeneration, necrosis, hyperplasia, inflammatory cell infiltration, vascular proliferation, expansion.②Vocal cord is damaged in the long-term process, because EGFR,VEGF and other related joint action of inflammatory mediators lead to chronic inflammation, vascular endothelial basement membrane damaged, permeability of blood vessel walls increased, some substance that they are difficult through the vessel wall have been into the tissue space, result in vocal cord lamina propria, in particular, Reinke's interstitial edema, inflammatory cells infiltration, fibroblast proliferation, hyaline degeneration in the lamina propria connective tissue disorder, layered structure disappeared, Thus, polyps are formated.③In the process of polyp's development, the synthesis of EGFR and VEGF promote angiogenesis and hyperplasia, polyps will obtain a lot of blood supply to continue to grow.④In the process of vocal cord injury, EGFR mediates extracellular matrix degradation and remodeling and deposited on the vocal cord tissue to reduce vocal cord elasticity, which is also a reason in vocal cord polyp development. Vitro some stimulus make EGFR overexpress, and continued to pass to the cell proliferation signal, which leads to increasing in DNA synthesis,and stimulate the the variety of cell to growth and proliferation. As a result, the polyps are formated.