RESUMEN
OBJECTIVES: The purpose was to detected features of the expression levels of NKG2A and its ligand HLA-E, a new member of the immune checkpoints, in advanced laryngeal carcinoma and their clinicopathologic significance. MATERIAL AND METHODS: We analyzed the expression levels of HLA-E and NKG2A in multiple types of tumors utilizing the Tumor Immune Estimation Resource (TIMER) database and immunohistochemistry and qRT-PCR analysis of paraffin embedded tissue samples to reveal the correlations of the clinicopathological factors with the expression of these two proteins in advanced laryngeal carcinoma as well as their prognostic significance. RESULTS: KLRC1 (the coding gene of NKG2A) and HLA-E are substantially overexpressed in various human cancers than normal tissues. HNSCC is also included. KLRC1 is differentially expressed in different HPV subgroups of patients, with higher expression in the HPV-positive group. Consistent with this, immunohistochemical results also revealed the high expression of these two proteins in tumor tissue. In addition, immunohistochemical staining also displayed a preference for the distribution of NKG2A-positive cells in tumor tissue. Clinicopathological analyses also displayed that the density of NKG2A-positive cells of the HPV-positive group infiltrating laryngeal carcinoma tissue was larger than that in the HPV-negative group. Prognostic analyses indicated that the expression of this immune checkpoint does not affect the overall survival length of patients, but the highly expressed HLA-E is significantly correlated with local recurrence in the patients. CONCLUSIONS: The findings suggest that the expression levels of HLA-E and NKG2A is upregulated in advanced laryngeal carcinoma. The NKG2A-positive cells infiltrating the tumor are mainly distributed in the cancer nest, while infiltrating cell number may be regulated by HPV. The highly expressed HLA-E may promote local recurrence in patients with advanced laryngeal carcinoma.