Role And Mechanism Of FⅦ In The Resistance To Anoikis In Gastric Cancer

Background Tumor metastasis is the most complex and fatal event in tumor development.The initiation of tumor metastasis depends on the interaction of tumor cells with mesenchymal cells and the epithelial-mesenchymal transition（EMT）of individual cells.Interstitial transition and abnormally leaky blood vessels contribute to the intravascular infiltration of tumor cells,where tumor cells entering the blood rely on anti-anoikis and inhibition of immune cell killing to further metastasize.Anoikis is a death phenomenon in which tumor cells leave the extracellular matrix and then undergo apoptosis.The anti-anoikis properties of tumor cells are crucial for the survival of cancer cells in blood circulation,lymphatic circulation and distant metastasis.Studies have shown that coagulation factor 7（FⅦ）is related to tumor metastasis,so the effect of coagulation factor 7（FⅦ）on anoikis apoptosis is explored.Methods We used the TCGA biodata repository to explore the relationship between FVI expression and clinical features and prognosis of gastric cancer.The expression of FVI in cancer tissues,adjacent tissues and lymph nodes of 56 patients with gastric cancer was analyzed by immunohistochemical staining.And the relationship between the expression of FVI and the clinicopathological features and prognosis of patients.Gastric cancer cells were attached to the wall and cultured in suspension.The anoikis rate of gastric cancer cells was detected by flow cytometry.The down-regulation of FVI on gastric cancer MKN45 and AGS cells verified the effect of FVI on anoikis,apoptosis resistance,invasion and metastasis of gastric cancer cells,and verified the changes of apoptosis pathway and intracellular ROS activity after knockdown of FVI.The effect of FVI on the metastatic ability of gastric cancer cells was investigated by using SCID mouse liver metastasis model.Results（1）The bioinformatics database predicted that FVI was highly expressed in gastric cancer,and the prognosis of patients with high expression of FVI was worse.In gastric cancer patients with lymph node metastasis,the survival time of patients with high expression of FVI was shorter;（2）FⅦ was highly expressed in gastric cancer cells and gastric cancer tissues in gastric cancer tissue samples and at the cellular level.Gastric cancer patients with high expression of FⅦ have shorter survival time,lymph node metastasis,distant metastasis and high expression of FⅦ are independent risk factors for poor prognosis of gastric cancer patients;（3）Compared with normal gastric mucosal epithelial cells（GES-1）,the level of FⅦ protein expression in gastric cancer cells was high-rising,and the expression level of FⅦ was also increased in gastric cancer cells MKN-45 and AGS in the simulated anoikis state,but not in GES-1;（4）gastric cancer in the adherent state The apoptosis rate of cells was lower than that of GES-1 cells,but there was no statistical difference;while in the anoikis state,the apoptosis rate of gastric cancer cells was significantly lower than that of GES-1 cells;（5）MKN-45,AGS in the adherent state,the apoptosis rate did not change significantly after knockdown of FⅦ,but in the simulated anoikis state,the apoptosis rate increased significantly.After FⅦ silencing,the invasion,migration and proliferation of MKN-45 and AGS cells were significantly attenuated;（6）In the SCID mouse model of liver metastasis,the number and size of liver metastases in the down-regulated FⅦ group were significantly smaller than those in the control group;（7）After down-regulating the expression of FⅦ,the expression levels of apoptosis pathway-related proteins increased;（8）After down-regulating FⅦ,the ROS activity in gastric cancer cells increased,and the increase in ROS activity in gastric cancer cells in suspension state was statistically significant.Conclusion The invasion,metastasis and survival of gastric cancer are closely related to the expression of FⅦ.FⅦ participates in the anoikis resistance of gastric cancer cells by inhibiting the production of ROS and inhibiting the caspase-3apoptosis pathway.Specific targeted drugs targeting FⅦ are expected to be a therapeutic strategy to inhibit the metastasis of gastric cancer.