The Study On The Migration And Invasion Of SGC-7901 Gastric Cancer Cells Induced By LPA Through The LPA2 And Notch Signaling Pathways

Lysophosphatidic acid(LPA),a simple water-soluble glycerophospholipid with growth factor-like activity,regulates some behaviors of multiple cancers by blinding to its receptor,LPA2.Notch1 is a key molecule in the tumorigenesis pathway.However,the interaction between LPA2 and Notch1 in gastric cancer remains unclear.OBJECTIVE To investigate the specific mechanism by which LPA induces the invasion and migration of SGC-7901 gastric cancer cells through the regulation of LPA2 and Notch1.METHODS The experimental concentration of LPA and duration time of effective invasion and migration of SGC-7901 cells were determined by wound scratch assay and transwell assay.The expressions of LPA2 and Notch1 in SGC-7901 cells and normal gastric glandular epithelial cells GES-1 were detected by qrt-PCR and western blotting.LPA was used to stimulate SGC-7901 cells,and qrt-PCR and western blotting were used to detect the expression of LPA2 and related molecules of Notch pathway.LPA stimulated SGC-7901 cells to detect the expression of related molecules in the EMT process by western blotting,and the cytoskeleton morphology was detected by IFA.The expressions of LPA2 and Notch1 in SGC-7901 cells were down-regulated by small interfering RNAs,and the transfection was detected by qrt-PCR and western blotting.Qrt-PCR and western blotting were used to detect whether LPA2 and Notch1 were involved in the regulation of invasion and migration,EMT and morphological changes of LPA-induced SGC-7901 cells.Co-immunoprecipitation was used to investigate whether LPA2 and Notch1 molecules interact in SGC-7901 cells.RESULTS 15 μM LPA and 24 h were determined to be the experimental concentration and duration time that could cause the maximum invasion and migration of SGC-7901 cells in this study.The relative expression level of LPA2 and Notch1 in SGC-7901 cells was significantly higher than that in GES-1 cells(p<0.05).After 24 h of stimulation with 15 μM LPA,the expression levels of LPA2,Notch1 and Hes-1 which belong to Notch pathway were significantly higher(p<0.05),and Akt was stimualted into its active form p-Akt.In SGC-7901 cells,the expression of E-Cadherin was decreased,and the expression of Vimentin was increased under LPA stimulation,and the occurrence of EMT was achieved by the formation of pseudopodias due to the change of cytoskeleton.LPA2 and Notch1 can regulate the invasion and migration,EMT and morphological changes of SGC-7901 cells,respectively.Synergistic interaction between LPA2 and Notch1 exists in SGC-7901 cells,which can be enhanced under LPA stimulation.CONCLUSION This study confirmed for the first time that LPA could regulate the invasion and migration of SGC-7901 gastric cancer cells through LPA2 and Notch signaling pathways,which mainly depended on the interaction between LPA2 and Notch1,and linked the G-protein-coupled signaling pathway with the Notch tumorigenesis pathway,providing a basis for the molecular pathological diagnosis and treatment of gastric cancer in the future.