Objective To study the expression of Snail in laryngeal carcinoma and to explore its relationship with invasion and metastasis in subgroup laryngeal carcinoma cells. Method The expression of Snail protein was examined by immunohistochemistry staining in the tissue of laryngeal carcinoma. The statistical evaluation was performed to detect the correlation between the Snail protein expression and clinical features. In different subgroups of laryngeal carcinoma cells (CD 44+CD 133+cells, CD 44 and CD 133-cells), the expression of Snail and adhesion molecules E-cadherin were detected by RT-PCR,Western blot test and immunochemical staining which were studied in the correlation with invasion and metastasis. Results The result of immunohistochemical staining revealed that Snail was moderately or highly expressed in the tissue of laryngeal carcinoma significantly and higher than those in adjacent non-cancerous tissues(P<0.01). Expression of Snail was highly correlated with lymph node metastasis, tumor differentiation and clinical classification(P<0.05).However, it was not related to the age , gender and clinical type. RT-PCR and Western blot test results confirmed that the expression level of Snail was significantly higher in CD 44+CD 133+laryngeal cancer cells than in CD 44-and CD 133-laryngeal cancer cells, otherwise the expression level of E-cadherin in CD 44+CD 133+laryngeal cancer cells was significantly lower than in the CD 44-and CD 133-laryngeal cancer cells. Cell immunohistochemical staining confirmed the expression of Snail and E-cadherin were negatively correlated in CD 44+CD 133+laryngeal cancer cells. Conclusion Over expression of Snail in laryngeal carcinoma is closely related to the development of laryngeal cancer and lymph node metastasis. The expression of Snail in the CD 44+CD 133+laryngeal cancer cell subgroup is negatively correlated with adhesion molecules E-cadherin, which is a close correlation with invasion and metastasis of laryngeal cancer cells.

T cell immune checkpoint pathways contribute to tumor immune escape. Many studies have shown that immune checkpoint is demonstrably correlated with tumor grade or prognosis in several types of malignancies and immune checkpoint has become a new biological index for tumor detection and prognosis. Immune checkpoint inhibitors have shown promising tumor outcomes in clinical trials for some advanced solid tumors and it will become a new target for cancer immunotherapy. In this review we will explore the correlation between expressions of immune checkpoint-associated genes and proteins in immune microenviroment and prognosis of head and neck squamous cell carcinoma, and specifically will discuss how this pathway can be manipulated with immune therapeutic drugs.