Curcumin Affecting Proliferation Of Human Colon Cancer Cell Line SW480 By Down-Regulating Notch1 Signal Pathway

Objective: To investigate molecular mechanism of curcumin influencing on proliferation of human colon cancer cell line SW480 through Notch1 signal pathway.Methods: 1. Immunohistochemistry method was used to test the expression of protein Notch 1 intracellular domain(NICD1) of Notch1 signal pathway on human colorectal cancer pathological tissues for estimating the relationship between the protein NICD1 and human colorectal cancer, and to infer the relation of Notch1 signal pathway and colorectal cancer. 2.To test the influence of proliferation and apoptosis of human colon cancer cell line SW480 treated by diverse concentrations of curcumin for 24 hours and 48 hours by MTT assay and flow cytometry method. 3.Western blot was used to test the expressions of protein Notch1, NICD1 and protein Hes-1 in Notch1 signal pathway of human colon cancer cell line SW480, which was treated by diverse concentrations of curcumin for 24 hours and 48 hours. 4.To detect the expressions of gene Notch1 and gene Hes-1 in Notch1 signal pathway of human colon cancer cell line SW480, which was treated by diverse concentrations of curcumin for 24 hours and 48 hours by RT-PCR.Results: 1.The immunohistochemistry results showed that NICD1 protein could be tested in both human colorectal cancer tissues( rate 100%) and adjacent normal intestinal mucosa tissues( rate 90.3%), but the level of NICD1 in colorectal cancer tissues was much higher than in normal intestinal mucosa tissues(P<0.05). 2.Both MTT assay and flow cytometry detection results showed that curcumin could suppress the proliferation activity of colon carncer cell line SW480 and accelerate its apoptosis, with a time-dose dependence(P<0.05). 3. Western blot results showed that cucumin could down-regulate the expressions of protein Notch1, NICD1, Hes-1 in Notch1 signal pathway of human colon cancer cell line SW480, with a time-dose dependence and the difference was statistically significant(P<0.05). 4.RT-PCR results showed that curcumin could decrease mRNA expression levels of both gene Notch1 and gene Hes-1 of colon cancer cell line SW480, with a time-dose dependence and the difference was statistically significant(P<0.05).Conclusion: 1.Notch1 signal pathway could express highly in human colorectal cancer tissues. 2.Curcumin inhibiting proliferation and promoting apoptosis of the colon cancer cell line SW480 may rely on down-regulating Notch1 signal pathway.