Abstract. Tissue angiogenesis is a complex phenomenon that results in the growth of new blood vessels from the microcirculation. This process has been known to play a crucial role in tumor growth as well as several benign diseases. The aim of this study was to assess mRNA expression of various angiogenic factors and chemokines in nasal polyps and compare the results to normal nasal mucosa. mRNA expression was measured using real-time RT-PCR for the following angiogenic factors and chemokines: VEGF, VEGFR-1, Ang-1, Ang-2, Tie-2A, Tie-2B, SDF-1α, SDF-1β, CXCR4 and YY1. Biopsy specimens from nasal polyps in the polyposis group and middle turbinates in the control group were studied. A total of 18 nasal polyposis patients were studied and compared to 10 control subjects. Results showed VEGF, VEGFR-1, Ang-1, Ang-2, Tie-2A, Tie-2B, SDF-1α and SDF-1β mRNA expression to be significantly higher in nasal polyposis patients compared to the control group (p<0.05). The findings of this study support the role of angiogenic growth factors in the pathogenenesis of nasal polyposis. Further studies are required to confirm these results and evaluate potential clinical implications.
IntroductionNasal polyposis (NP) constitutes a chronic inflammatory disease of the nose and sinuses characterized by the appearance of protruding tissue swellings of the nasal mucosa. These swellings most commonly originate from the middle meatus and anterior ethmoids. On histologic examination, they are typically characterized by proliferation of the epithelial layer, glandular hyperplasia, thickening of the basal membrane, focal fibrosis, edema and cellular infiltration of the stromal layer. Nasal polyps are relatively common in the general population and significantly affect patient quality of life. Despite these facts, etiology of the disease remains largely unknown (1-4).Tissue angiogenesis is a complex phenomenon that results in the growth of new blood vessels from the microcirculation (5-7). This process has been known to play a crucial role in tumor growth, where it is regarded as a prerequisite allowing for the expansion of tumor populations beyond the size restricted by oxygen and nutrient diffusion (6). It also facilitates tumor progression and metastasis by causing degradation of the epithelial basement membrane and providing cancer cells with new capillaries for entering the circulation (7,8).Increasing evidence shows that angiogenesis may also play a critical role in benign disorders (9,10). The phenomenon, appearing in the form of growth of new blood vessels or the enlargement of existing ones, has been strongly associated with airway remode ling in chronic asthma and chronic obstructive pulmonary disease (11,12). In addition, using immunohistochemistry it has been shown that vascular endothelial growth factor (VEGF), possibly the most important driver of angiogenesis, along with its receptors, are strongly expressed in nasal polyp tissues, thus supporting a role in the development of chronic inflammation and edema in this disease (13).Re...