Omental Adipocytes Enhance The Invasiveness Of Gastric Cancer Cells By Oleic Acid-induced Activation Of The PI3K-Akt Signaling Pathway

Part1 Transfer of 01 e i c Ac i d between Great Omentum Derived Ad i pocytes and Gastr i c Cancer Cells and Effects of Ad i pocytes on Invasive Capacity of Gastric Cancer CellsObjective:compare the fatty acid profile and invasive capacity of gastric cancer cells before and after co-cultured with omentum derived adipocytes.Methods:isolated adipocytes and pre-adipocytes from patients undergoing surgical procedures for benign conditions andconducted to the co-culture system with AGS cancer cells and MKN-45 cancer cells.Confirmed viability of adipocytes by fluorescence microscopy with Calcein AM and Lipid Transfer Assay showed the direct transfer of fatty acid between adipocytes and gastric cancer cells.Matrigel Invasion Assay was done to show the invasive capacity of gastric cancers.Fatty Acid Profile of gastric cancer cells was detected by GC-MS.Result:invasive capacities of AGS cancer cells and MKN-45 cancer cells enhanced after co-cultured with omentum derived adipocytes,direct transfer of fatty acid from adipocytes to gastric cancer cells in the co-culture system was observed by fluorescence microscope imaging and oleic acid were red.Conclusion:co-cultured with omentum derived adipocytes enhanced invasive capacity of gastric cancer cells and increased level of oleic acid in gastric cancer cells.Part 2 Oleic acid activated PI3K-Akt signaling pathway in gastric cancer hence enhance invasive capacity of gastric cancerObjective:Detect the effects of oleic acid on PI3K-Akt signaling pathway and invasive capacity of gastric cancer.Methods:Western Blotting the expression of key molecular of PI3K-Akt signaling pathway and MMP-2 with various concentration of oleic acid.Check the changes of invasive capacity of gastric cancer cells with various concentration of oleic acid treatment by Matrigel invasion assay.Examine the invasive capacity of MKN-45 cells with or without oleic acid treatment in vivo by Chick chorioalantoic membrane assay.Check the effects of PI3K inhibitor LY294002 on oleic acid induced changes of activation of PI3K-Akt signaling pathway,invasive capacity and expression of MMP-2 of gastric cancer cell.Result:25uM-50uM oleic acid enhanced invasive capacity of AGS cells,25uM-100uM oleic acid enhanced invasive capacity.CAM assay showed oleic acid enhanced the invasive capacity in vivo of gastric cancer cells.Oleic acid increased expression of MMP-2 in gastric cancer cells.PI3K inhibitor LY294002 significantly decreased the oleic acid induced elevation of expression of MMP-2 and invasive capacity of gastric cancer cells.Conclusion:oleic acid activated PI3K-Akt signaling pathway hence enhanced the invasive capacity of gastric cancer.