The roles of insuline like growth factor receptor I-II expression level in the development of pleomorphic adenoma of parotid gland

Pleomorphic adenoma is a benign and slowly-growing salivary gland tumor which generally arises due to parotid gland. The aim of this study is to investigate the role of Insulin-like Growth Factor I-II Receptor (IGF-I, IGF-IIR) in development of pleomorphic adenoma arising from parotid gland by measuring the level of IGF-IR and IGF-IIR. This study was conducted with 20 female and 20 male patients with ages between 20 and 50 who had undergone superficial parotidectomy in Fırat University Otorhinolaryngology Clinic between years 2000 and 2011 whose pathology results were reported as pleomorphic adenoma. The control group was formed by taking 0.5x0.5 cm unilateral biopsies from 5 male and 5 female cadavers who had normal gland. IGFI-R and IGF-IIR expression was analyzed both in tumor tissue and in gland which didn?t include tumor in study group, they were compared with biopsies taken from cadavers in control group. Into the tissue incisions in study and control groups, primer polyclonal antibodies developed against IGF-I and IGF-IIR proteins were applied immunohistochemically via ?Streptavidin-Biotin complex? method. In this study, it was determined that levels of both of IGF-IR and IGF-IIR were significantly high in tumor tissue (p<0.05). Also, IGF-I and IGF-II uptakes were higher in parotid tissue without tumor than normal parotid tissues taken from cadavers. The difference wasn?t statistically significant (p>0.017). As a result of this study, a significant relationship was determined between pleomorphic adenoma arising from parotid gland and IGF-I and IGF-II uptakes. The higher levels of IGF-I and IGF-II uptakes in pleomorphic adenoma tissue than those in parotid tissue without tumor and in normal parotid tissue taken from cadavers showed that IGF-I and IGF-II may be important factors in pathogenesis of pleomorphic adenoma. Keywords: Pleomorphic adenoma, IGF-I, IGF-II