Expression and localization of hepatocyte growth factor and its receptor c-Met in inverted papillomas

Conclusions. The results suggest that elevated c-Met expression in combination with the co-expression of hepatocyte growth factor (HGF) in the epithelial cells of inverted papilloma may proliferate the epithelial cells of inverted papilloma. Objectives. HGF and its receptor, c-Met, have been identified in a variety of neoplastic and normal tissue types, implicating these factors in tissue regeneration and tumor progression. We investigated the expression and distribution of HGF and c-Met in normal nasal mucosa and inverted papilloma, to evaluate the possible influence of HGF and c-Met on the development of inverted papilloma. Materials and methods. Normal inferior turbinate mucosa and inverted papilloma were examined for expression of HGF and c-Met using RT-PCR, immunohistochemistry and Western blot analysis. Results. Using immunohistochemistry, moderate to high levels of HGF and c-Met protein were localized in epithelial cells in inverted papillomas tested in the present study. In normal turbinate mucosa immunopositive HGF was detected in the submucosal glands where faint staining was found. However, c-Met was noted in the epithelial cells and submucosal glands of normal turbinate mucosa. RT-PCR and Western blot analysis showed that the expression levels of HGF and c-Met were increased in inverted papilloma in comparison with the normal turbinate mucosa.