The Mechanism Of 12-lipoxygenase Promotes Invasion And Metastasis Of Human Gastric Cancer By Epithelial-to-mesenchymal Transition

【Objective 】:1. To build a gastric cancer cell line SGC-7901 of high express 12-LOX.2. To analyze the relationship of 12-LOX and the ability of invasion and metastasis of gastric cancer cell and relevance to the EMT.3. To investigate the expression of 12-LOX, E-cadherin and N-cadherin protein in gastric cancer tissue, and the relationship between 12-LOX, E-cadherin, N-cadherin protein and the clinical pathological characteristics.【Methods】:Q-PCR, Western blot method to screen out 12-LOX lower expression gastric cancer cell lines. The high expression 12-LOX virus infected gastric cancer SGC-7901 cells, building a high expression of 12-LOX gastric cancer cell lines;Scratch test and Transwell method to detect cell migration and invasion ability of the Control SGC-7901, Mock group and 12-LOX group; Q-PCR, Western blot method to detect the expression of 12-LOX, N-cadherin and E-cadherin in the three groups cells and relationship between each other; Immunohistochemical to analyze the expression of 12-LOX, E-cadherin and N-cadherin in 105 gastric cancer tissues and 43 conctrol normal gastric tissues; Statistics to analyze the correlation between 12-LOX,E-cadherin, N-cadherin immunostaining and clinicopathologic features in 105 cases of gastric cancer tissues, and the correlation between 12-LOX, N-cadherin and E-cadherin.【Results】:1. Achieved the high expression of 12-LOX gastric cancer cell line SGC-7901.2. The migration and invision of gastric cancer cell experiments showed that:migrated or invaded into the under room cells of 12-LOX group was significantly higher than the Mock group and the Control group, the difference was statistically significant,(p < 0.05). Then the Mock group and the Control group did not see obvious difference.3. Q-PCR and Western blot experimental results showed that the m RNA and protein expression of E-cadherin, N-cadherin in 12-LOX group were significantly higher than Mock group and Control group, the difference was statistically significant,(p<0.05).12-LOX were positively correlated with E-cadherin, N-cadherin respectively.4. 12-LOX and N-cadherin showed significantly higher expression in gastric cancer tissues relative to adjacent normal gastric mucosa(P<0.05). E-cadherin, by contrast,showed reduced expression levels in gastric cancer tissues with respect to adjacent normal mucosa(p<0.05). There were close correlations between the levels of E-cadherin and age and differentiation of tumor. There were close correlations between the levels of N-cadherin and the size of tumor(P<0.05); the expression levels of 12-LOX were positively correlated with that of E-cadherin or N-caderin in gastric cancer tissues.【Conclusions】 :1. Up-regulation of 12-LOX promotes invasion and metastasis of human gastric cancer but not by epithelial-to-mesenchymal transition.2. High expression of 12-LOX and N-cadherin in gastric cancer tissues, E-cadherin,by contrast, showed reduced expression; N-cadherin Expression is associated with tumor size, E-cadherin associated with patient’s age and differentiation of tumor.