Dual role of podoplanin in oral cancer development

Podoplanin plays a crucial role for normal and pathological tissue development. Known as a lymphatic endothelial marker, podoplanin has been found to be overexpressed in tumor cells of various cancers with a certified involvement in tumor progression, invasion and metastasis. Oral cancer includes a heterogeneous group of malignancies with unpredictable behaviour and sometimes poor prognosis. Based on these facts, development of new molecular markers with a more reliable impact on therapy and prognosis is required. The present study was designed to characterize podoplanin expression in tumor cells of lip, oral cavity, tongue and pharynx squamous cell carcinomas, together with lymphatic vessels distribution, morphology, density and their impact on tumor progression. Evaluation of podoplanin by D2-40 immunohistochemistry assessement on 56 cases of oral cancers, revealed two different expression patterns in tumor cells depending on their location. Peri-tumor and intra-tumor lymphatic vessels density, morphology and distribution were correlated with lymph node status but not with tumor stage. The highest number of lymphatic vessels was observed in grade 3 squamous cell carcinomas. Dual expression of podoplanin in tumor cells and lymphatics with particular patterns correlated with histopathology and lymph node status in oral cancer, representing the molecular basis for testing podoplanin as a potential target for anti D2-40 antibody based therapy.