The Role And Mechanism Of CXCR-2 In The Invasion And Metastasis Of Esophageal Squamous Carcinoma

Research BackgroundEsophageal cancer is one of the more common and high-prone gastrointestinal cancers in China.Its incidence and mortality rate are increasing year by year,and the prognosis is poor and the five-year survival rate is low.Especially in the Linzhou area of Henan Province,the incidence of esophageal cancer is the highest in the country.The occurrence of esophageal cancer has many related factors,including heredity,living environment,chemical factors,biological factors,personal habits,and so on.Esophageal squamous cell carcinoma is an esophageal tumor with a high incidence in esophageal cancer.The metastatic and invasive mechanism of esophageal squamous cell carcinoma is a crucial step in the development of esophageal squamous cell carcinoma.To understand the key factors involved in the invasion and metastasis of esophageal squamous cell carcinoma is key factor to study esophageal squamous cell carcinoma and treat it effectively.Chemokines and their related receptors play an important role in the development of many malignancies,infiltration and metastasis.Chemokines are members of a family of small-molecule proteins that are involved in cytoskeletal remodelling and mediation.A variety of cell migrations of the body participate in various physiological and pathological processes through interactions with G protein-coupled receptors.CXC chemokines belong to a class of chemokine superfamily and play an important role in the occurrence,development,angiogenesis,infiltration and metastasis of various human tumors.The chemokine receptor(CXC receptor2,CXCR-2)is widely distributed in human tissues,and there are currently dozens of human malignant tumors that have CXCR-2 expression.CXCR-2 plays an important role in the growth and migration of tumor cells,and has an important influence on the occurrence and development of tumors.The expression of CXCR-2 is significantly associated with malignant metastasis.As one of the most important chemokine receptor families,the significance of the expression level of CXCR-2 in esophageal squamous cell carcinoma patient tissue has been rarely studied to guide clinical prognosis.Recent studies have found epithelial-mesenchymal transition(EMT).It is one of the important mechanisms of malignant tumor invasion and metastasis.Studies have found that CXCR-2 can promote the invasion and metastasis of breast cancer through EMT.However,up to now,it is unclear whether CXCR-2 is involved in the invasion and metastasis of esophageal squamous cell carcinoma and the possible mechanism.This study first detected the expression of CXCR-2 in esophageal squamous cell carcinoma tissues and adjacent normal esophageal mucosa tissues by immunohistochemistry.Then,different concentrations of IL-8 were added to esophageal squamous cell carcinoma cell lines KYSE-450 and EC-1,and their receptor CXCR-2 and EMT markers E-cadherin and vimentin were detected at different times.(Vimentin)and Snail protein expression and mRNA expression,and the detection and selection of the best time and concentration of IL-8 stimulated cells for migration and invasion experiments to observe cell migration and invasion ability.Research methods1.The expression of CXCR-2 in 190 cases of esophageal squamous cell carcinoma tissue and 154 normal tissues was detected by immunohistochemical method.The expression of CXCR-2 was analyzed,and the sex,age,tumor differentiation,depth of invasion,and location were analyzed.The relationship between clinical pathological parameters such as lymph node metastasis and tumor pTNM staging,and analysis of the relationship between CXCR-2 and prognosis of patients.2.Different concentrations of IL-8,the ligand of CXCR-2(0,0.05ug/ml,0.1ug/ml)were used to treat esophageal squamous carcinoma cells(EC-1 and KYSE-450).After different time(0h,24 h,48h),Western blotting and The expression of CXCR-2,Vimentin,Snail and E-cadherin protein and mRNA were detected by Real-time PCR.3.After treatment of esophageal squamous cell carcinoma cells(EC-1 and KYSE-450)with IL-8,the ligand of CXCR-2(0.1ug/ml)for 48 hours,the invasion and migration ability of the cells was detected by invasion chamber assay and migration assay.Result1.The positive rate of CXCR-2 in normal esophageal mucosa was 16%(25/190)in 190 cases of esophageal squamous cell carcinoma and 154 cases of normal esophageal mucosa control group,and positive for CXCR-2 in esophageal squamous cell carcinoma.The rate was 58%(110/190),which was significantly higher than that in normal esophageal mucosa and the difference was statistically significant(P<0.05).The expression of CXCR-2 was not related to gender,age,location of tumor,differentiation of tumor,and depth of invasion(P>0.05).It was positively correlated with lymph node metastasis and pTNM stage(P<0.05),ie patients with CXCR-2 positive expression.More easily associated with lymph node metastasis,higher stage.The survival analysis showed that the survival rate of CXCR-2 positive patients was low,and the statistics were statistically significant(P<0.05).2.Different concentrations of IL-8(0,0.05 ug/ml,0.1 ug/ml)were used to treat esophageal squamous carcinoma cells(EC-1,KYSE-450)at different times(0h,24 h,48h)and observed after CXCR-2,E-Changes in protein and mRNA expression of cadherin,Vimentin,and Snail.The results showed that in EC-1 and KYSE-450 cells,the expression levels of CXCR-2,Vimentin,and Snail proteins and mRNA as a whole at the same concentration increased with time compared to control cells without IL-8.There was an increasing trend,the difference was statistically significant(P<0.05),but the mRNA and protein expression of E-cadherin showed a decreasing trend,the difference was statistically significant(P<0.05).3.Transwell in vitro migration assay results showed that compared with the blank group(97.333±15.011 and 139.333±12.055),the number of membrane penetrations of KYSE-450 and EC-1 cells added with IL-8(145.333±7.023 and 305.000±17.691)was obvious.The increase was statistically significant(P<0.05).Transwell in vitro invasion assay results showed that compared with the blank group(83.333±10.263 and 120.000±13.114),the number of membrane penetrations of KYSE-450 and EC-1 cells added with IL-8 was significantly increased(123.000±7.549 and 210.000±15.874).The difference was statistically significant(P<0.05).Conclusion1.The high expression of CXCR-2 can promote the invasion and metastasis of esophageal squamous cell carcinoma and is likely to related to the poor prognosis of patients.2.Inflammatory mediator IL-8 up-regulated CXCR-2 expression in esophageal squamous cell carcinoma.3.CXCR-2 promotes the invasion and metastasis of esophageal squamous cell carcinoma maybe involving the EMT pathway.