Study On The Mechanism Of PAR-2 Regulating The Proliferation Of Esophageal Squamous Cell Carcinoma

Proteinase-actived receptors 2 is a cell surface receptor that belongs to G protein-coupled receptor family.The activation of the receptor can lead to a series of biological behaviors of tumor growth,invasion and metastasis.Esophageal carcinoma is one of the most common malignant tumors in human being.The mechanism of tumor occurrence of esophageal carcinoma is still not clear,which is one of the most important aspects in the study of esophageal cancer.To investigate the effects of PAR-2 agonist and the negative regulation effect of PAR-2 shRNA on the expression of c-fos?CyclinD1?PCNA in human esophageal squamous cell carcinoma cell line EC-109 in the first part of this study.The results show that PAR-2 agonist SLIGKV can promote the mRNA and protein expression of c-fos,CyclinD1,PCNA in esophageal cancer cell line EC-109,and PAR-2 shRNA decreases the mRNA and protein expression.To investigate the effects of PAR-2 agonist on the protein expression and protein activity,the changes of intracellular [Ca²⁺] concentration in human esophageal carcinoma cell in the second part of this study.The results show that the PAR-2 agonist SLIGKV can promote the mRNA expression of ERK1 and the protein expression of phosphorylated ERK1?p-ERK1?in esophageal cancer cell.The agonist had no effect on the total protein expression of ERK1.The results also show that the PAR-2 agonist can increase the intracellular concentration of [Ca²⁺] in esophageal cancer cells,and inhibition of PAR-2 could inhibit the increase of intracellular [Ca²⁺] concentration.To investigate the effects of MAPK pathway inhibitor on the cell proliferation and cell cycle in human esophageal carcinoma cell in the third part of this study.The results of MTT experiment show that the MAPK pathway inhibitor PD98059 can inhibit the proliferation of esophageal cancer cell line EC-109 in a concentration-dependent manner.PD98059 can inhibit the cell proliferation induced by PAR-2 agonist in the esophageal carcinoma cell which was pretreated by PD98059 in the most effective drug concentration,and down the growth curve of cancer cell.The results of MTT experiment show that PD98059 can increase the percentage of G0/G1 phase of esophageal cancer cells,decrease the percentage of S and G2/M phase of esophageal cancer cells and decrease the cell proliferation index.The results also show that the MAPK pathway inhibitor PD98059 can down regulate the mRNA and protein expression of c-fos,CyclinD1,PCNA in esophageal cancer cells.In conclusion,the PAR-2 agonist SLIGKV can promote the expression of c-fos,CyclinD1,PCNA and p-ERK1 in esophageal cancer cell line EC-109,increase the activity of ERK1 protein,increase the intracellular concentration of [Ca²⁺] in esophageal cancer cells,and PAR-2 shRNA has the negative regulation effect.MAPK pathway inhibitor PD98059 can inhibit the cell proliferation,down the growth curve of cancer cell,increase the percentage of G0/G1 phase of esophageal cancer cells,decrease the percentage of S and G2/M phase of esophageal cancer cells and decrease the cell proliferation index and down regulate the mRNA and protein expression of c-fos,CyclinD1,PCNA in esophageal cancer cells.The above results show that PAR-2 may be regulate the expression of tumor proliferation related molecules and cell cycle related molecules such as c-fos?CyclinD1?PCNA through the ERK1 MAPK pathway,further regulate the proliferation of esophageal cancer cells through regulating cell cycle of cancer cells.