The Study Of Functions And Mechanisms Of Lipopolysaccharide In Head And Neck Squamous Cell Carcinoma Cells

Objective:Head and neck squamous cell carcinoma(HNSCC)are the seventh most common tumor.The key factors affecting the survival of patients with HNSCC are metastasis and recurrence.Studies have shown that the inflammatory tumor microenvironment has a promoting effect on tumor invasion and metastasis,but there are few studies on HNSCC.Lipopolysaccharide(LPS)is an important substance to construct the inflammatory tumor microenvironment.Therefore,this study aims to illustration the regulatory effect and mechanism of LPS and its induced inflammatory tumor microenvironment on HNSCC cells,and provide an innovative theoretical basis for the clinical diagnosis and therapy of HNSCC.It is expected to have a positive impact on improving the overall survival rate of patients.Methods:The HNSCC cells were treated with lipopolysaccharide,and the Transwell experiment and wound healing experiment were used to investigate the effects of lipopolysaccharide on the invasion and migration of HNSCC cells.Flow cytometry and CCK-8 analysis were used to investigate the effects of lipopolysaccharide on the cycle apoptosis and proliferation of HNSCC cells.QPCR was used to research the expression level of inflammatory factors TNF and IL-1β in HNSCC cells,and the expression of Toll-like receptor 4(TLR4)after lipopolysaccharide treatment.Western blotting was used to analyze the effect of lipopolysaccharide on the expression level of epithelial-mesenchymal transition markers in HNSCC cells.Finally,the correlation between the expression of TNF,IL-1β and TLR4 in the TCGA database and the survival time of HNSCC patients was analyzed.Results:Lipopolysaccharide can boost the invasion and migration of HNSCC cells.We found that lipopolysaccharide has different effects on the proliferation,cell cycle and apoptosis of HNSCC at different primary sites.Specifically,lipopolysaccharide promoted the proliferation of human laryngeal squamous cell carcinoma cells FD-LSC-1 but had no significant effect in the other two cell lines.The cycle experiment results showed that compared with the control group,CAL-27 cells increased in S phase cells and decreased in G2/M phase cells,and had no significant effect in the other two cell lines.The results of apoptosis experiments showed that in human tongue squamous cell carcinoma cells CAL-27 and human hypopharyngeal squamous cell carcinoma cells Fa Du,the apoptosis rate of lipopolysaccharide treatment increased,and it had no effect in FD-LSC-1 cell.The mechanism research results illustrated that lipopolysaccharide could induce the expression level of inflammatory microenvironment-related genes TNF and IL-1β in HNSCC cells,boost the expression level of epithelial-mesenchymal transition markers Vimentin and Slug,and down-regulate the expression level of E-cadherin.Survival analysis of TCGA data illustrated that high expression of TLR4 represented poor survival in HNSCC.Conclusion:Our results show that in HNSCC cells,lipopolysaccharide may promote cell invasion and migration by inducing an inflammatory microenvironment and epithelial-mesenchymal transition.The results of this study will clarify the invasion and metastasis of HNSCC.In addition,we found that lipopolysaccharide has different effects on the proliferation,cycle and apoptosis of head and neck tumors at different primary sites,and more in-depth research is needed to clarify the mechanism.Taken together,the molecular mechanism of this research gives a significant theoretical basis,and at the same time gives innovate ideas for the clinical treatment and prevention of HNSCC.