Serum and tissue levels of insulin-like growth factor-I in women with dysplasia and HPV-positive cervical cancer

Abstract

Abstract. The ectocervical epithelium is the target of the oncogenic human papillomavirus (HPV), which acts as an etiological agent in the development of cervical carcinoma. However, the HPV-mediated transformation of human epithelial cells is a multi-step process dependant on unknown factors additional to the virus, which is a necessary but, in and of itself, insufficient catalyst. In the present study, we characterized the role of insulin-like growth factor-I (IGF-I) in this process. IGF-I is an endocrine hormone with an autocrine and paracrine role in many tissues. Our data demonstrated that autocrine secretion of IGF-I can contribute to HPV-induced carcinogenesis of the epithelium. An immunohistochemical study showed that IGF-I was present in the nuclei of the reproductive layer of the paraepidermal epithelium in 89% of cases of intraepithelial neoplasia (CIN I-III) and 60% of cases of invasive cervical cancer. The presence of IGF-I at a nuclear localization in the cells studied suggests that it may also have intranuclear actions.