Increased Expression of Macrophage Migration Inhibitory Factor During Progression to Hypopharyngeal Squamous Cell Carcinoma

Background/Aim: To examine the presence of macrophage migration inhibitory factor (MIF) quantitatively in relation to neoplastic progression of hypopharyngeal squamous cell carcinoma (HSCC). Materials and Methods: The presence of MIF was analysed by quantitative immunohistochemistry in sections of 81 HSCCs, and compared to 15 specimens of tumour-free epithelia (TF_E), 29 low-grade dysplasias (Low_D) and 25 high-grade dysplasias (High_D). In parallel, MIF expression was studied using Western blotting on a series of 19 fresh biopsies. Results: A significant increase in MIF staining intensity (mean optical density) was observed in carcinoma samples compared to TF_E (p<10(-6)), Low_D (p=0.0006) or High_D (p=0.0006). Immunohistochemical MIF positivity was significantly higher in HSCCs than in TF_E (p=0.00001) or Low_D (p=0.001). The percentage of MIF-immunopositive cells (labelling index) significantly decreased in parallel with an apparent loss of histological differentiation (p=0.003). Conclusion: This study identified the presence of MIF as a parameter that positively correlates with neoplastic progression of HSCC and cell differentiation status.