Biological and clinical significance of p75^NTRexpression in laryngeal squamous epithelia and laryngocarcinoma

Abstract

CONCLUSION: The apparent features of p75 neurotrophin receptor (p75(NTR)) expression indicated that p75(NTR) would serve as a potential stem cell marker for normal human laryngeal squamous epithelia. In human laryngeal squamous cell carcinoma (LSCC) p75(NTR) is differentially expressed. The abnormal expression and distribution of p75(NTR) may indicate malignant transformation. OBJECTIVE: To investigate the expression of p75(NTR) and its possible roles in normal laryngeal squamous epithelia and LSCC. METHODS: We used immunohistochemistry methods to examine normal laryngeal epithelia, para-cancer mucosa with dysplasia, laryngeal papilloma, and LSCC specimens for the expression of p75(NTR), nerve growth factor (NGF), -tyrosine kinase receptor (TrkA), p63, and Ki67. Immunocytochemistry and flow cytometry were used to examine the expression of p75(NTR) in Hep-2 cells. RESULTS: The expression of p75(NTR) was only located in basal cells of normal laryngeal epithelia, consistent with the staining features of epithelial stem cells as evidenced by parallel staining of p63, a putative keratinocyte stem cell marker. p75(NTR) is differentially expressed in LSCC, although no significant relationship was found with many clinicopathologic factors, this expression and distribution may correlate to malignant transformation and tumor proliferation. Co-expression of p75(NTR) and CD133 was confirmed, showing the association of p75(NTR)-positive cells with cancer stem cells in Hep-2 cells.