Activation Of The Notchl And Wnt/β-catenin Signal Pathways In The Proliferation Regulation Of Gastric Cancer Cells (BGC-823)

ObjectiveTo research the influence of the Notch1signal pathway and the classicWnt/β-catenin signal pathway activation on proliferation of gastric cancer cellscultured in vitro (BGC-823). To explore the interaction mechanisms between thetwo pathways in gastric cancer cells BGC-823.MethodsGastric cancer cells BGC-823cultured in vitro are divided into four groups.PBS buffer (1μl/ml) liquid is added to the first group as control group. Notch1signal pathway activation agent rhNF-κB (1gsu/ml) is added to the second group.Wnt/β-catenin signal pathway activation agent LiCl (10mmol/L) is added to thethird group. The rhNF-κB (1gsu/ml) and LiCl (10mmol/L) are added to the forthgroup. Transmission electron microscope is used to observe the ultrastructureof BGC-823. MTT method is used to detect the change of cell proliferation. FlowCytometric Analsis is used to test the cell cycle distribution.Western Blot methodis used to show the expression levels of Notch-1, Hes-1, β-catenin, CyclinD1,CyclinE, CDK2and c-Myc proteins.ResultsThere are differences in the ultrastructural structure of different BGC-823groups. In the second group, the microvilli of cell membrane have reduced.There are some physalides in the cells. The cell nucleuses are atrophied. We can see more necrosis cells in this group. In the other three groups, themembrane microvilli are developed. The organelles, such as the ribosomes andthe golgi apparatus, in cytoplasm are developed. The proportion of the nucleusis large. The nucleoli are obvious. The MTT detecting results reveal that theproliferation differences between different groups are statistically significant.Compared to the blank group, the cell proliferation in the second group issignificantly inhibited (F=9.627,P=0.036), while it is opposite in the thirdgroup(F=18.362,P=0.013) and in the forth group(F=16.058,P=0.016). FlowCytometric Analsis results reveal that the cell cycle distributions of gastriccancer cells BGC-823in every group are different to each other. The proportionof cells in the S group is30.60%in the blank group, and it is18.07%in thesecond group,41.69%in the third group,38.30%in the forth group.Comparedto the blank group, the expressions of Notch-1and Hes-1proteins in the secondgroup and the forth group are significantly high. The expressions of β-cateninand CyclinD1proteins in the third group and the forth group are significantlyhigh. The expressions of β-catenin and CyclinD1proteins in the second groupdo not change significantly, while the expressions of CyclinE、CDK2and c-Mycproteins in the second group are significantly low. The expressions of Notch-1and Hes-1proteins in the third group is significantly low, while the expression ofCyclinE、CDK2and c-Myc proteins in the second group are significantly high. Inthe forth group, the expressions of Notch-1and Hes-1proteins are higher thanthe blank group, but they are lower than the second group. The expressions ofβ-catenin、CyclinD1、CyclinE、CDK2and c-Myc proteins in the forth group aresignificantly high.ConclusionsThe activation of Notch1signal pathway can inhibit the proliferation ofgastric cancer cells BGC-823. The activation of Wnt/β-catenin signal pathwaycan promote the proliferation of gastric cancer cells BGC-823. The activation oftwo signal pathways at the same time can still promote the proliferation ofgastric cancer cells BGC-823. The Wnt/β-catenin signal pathway and the Notch1signal pathway produce antagonism action in gastric cancer cellsBGC-823.