Molecmlar Mechanism Study Of Curcumin On The Angiogenesis In Medmlloblastoma Through Wnt/beta-catenin Signaling Patwhay

Objective: Angiogenesis is closely related to the growth,invasion and metastasis of tumor.It has been confirmed that in many kinds of epithelial malignant tumors,Curcumin can inhibit the expression of VEGF,and then inhibit the angiogenesis and tumor cell growth,but whether Curcumin has the same effects on med?lloblastoma(MB)and the mechanism is not clear.The study was aimed to 1)detect the expression and significance of ?-catenin,VEGF and VEGFR-2 protein in MB;2)observe the effects of Curcumin on the growth and vasc?lar growth factors(VEGF)in Daoy cells,and to explore the potential mechanisms.Methods: 1)Immunohistochemical staining was conducted to determine the expression of ?-catenin,VEGF and VEGFR-2 in 33 cases of MB and 10 adjacent normal cerebellar tissues;2)Human MB Daoy cells were c?ltured in vitro,ad-?-catenin and ad-?-catenin si RNA were transfected into the cells,respectively,western blot was used to detect the expression of VEGF and VEGFR2;3)Human MB Daoy cells were c?ltured in vitro,and treated with different concentration of Curcumin(5 ?M,10 ?M,20 ?M and 40 ?M)for different times(24 hr,48 hr,72 hr).MTT assays were used to detecting the effects of Curcumin on the proliferation of Daoy cells;ELISA was applied to detect the changes of VEGF and VEGFR2 levels in the supernatant,and western blot was carried out to determining the expression of ?-catenin of Wnt/?-catenin pathway and its downstream target gene VEGF at protein levels.Res?lts: 1)In MB tissues,the positive expression rates of ?-catenin,VEGF and VEGFR-2 were 66.7%(22/33),90.9%(30/33),87.9%(29/33),respectively;whereas in the adjacent normal tissues,the positive rates were 10%(1/10),10%(1/10),10%(1/10),respectively,there was a significant difference between them(P<0.01).Furthermore,there was a significantly positive correlation between ?-catenin and VEGF and VEGFR-2(r=0.346,p<0.05);2)In the Daoy cells transfected with ad-?-catenin,the expression of ?-catenin was high,and the expression of VEGF and VEGFR were both increased;while,in the cells tranfected with ad-?-catenin si RNA,the expression of ?-catenin was low,and the expression of VEGF and VEGFR2 were both decreased;3)MTT res?lts showed that Curcumin significantly inhibited the proliferation of Daoy cells,and they were in a concentration-and time-dependent manner;ELISA res?lts demonstrated that Curcumin co?ld decrease the generation of VEGF and VEGFR2;and western blot indicated that Curcumin not only reduced the expression of VEGF,but also reduced the expression of ?-catenin,and all of them were also in a concentration-and time-dependent manner.Conclusions: The positive expression of ?-catenin,VEGF and VEGFR-2 were highly expressed in MB,and VEGF and VEGFR2 were positive related with ?-catenin.Curcumin co?ld inhibit the proliferation of Daoy cells,the mechanisms may be related to the roles of curcumin on inhibition of Wnt/?-catenin pathway and its downstream VEGF,and it will provide a novel theoretical basis for MB treatment by Curcumin.