Expression of polysialic acid in primary laryngeal squamous cell carcinoma

Expression of polySia is associated with metastatic dissemination and progression of various malignant diseases. In particular, it may contribute to tumorigenesis by a negative modulatory effect on cellular signaling cascades responsible for cellular migration, differentiation and proliferation. In this study, we investigated the expression of polySia in primary metastatic and non-metastatic laryngeal squamous cell carcinoma (LSCC) tumor tissues and its potential impact on the LSCC progression. The expression of polySia in metastatic and non-metastatic primary laryngeal squamous cell carcinoma (LSCC) tumor biopsy specimens was investigated by immunohistochemistry, while the expression of polysialyltransferase IV (ST8SiaIV)(), fibroblast growth factor receptor 1 (FGFR1), extracellular signal regulated kinases 1 and 2 (Erk 1/2) and c-Raf was tested in metastatic and non-metastatic primary tumor tissues (including the corresponding non-tumor control tissues) by Western blot analysis. The expression of polySia was detected in LSCC biopsies specimens with generally stronger immunoreactivity in non-metastatic tumor LSCC sections and in histologically undifferentiated tumors. Also, increased polySia expression was observed in adjacent histologically unaltered laryngeal tumor-associated tissue of the metastatic sections. In addition, we provide an evidence of increased polysialyltransferase IV (ST8SiaIV) expression, involved in polySia synthesis in both metastatic and non-metastatic primary tumors which is accompanied by decreased levels of FGFR1, Erk 1/2 and c-Raf. We present for the first time the evidence for the polySia expression in LSCC biopsies specimens which suggests its potential impact on initial steps of LSCC malignant transformation.