ABSTRACT
Aim To investigate the anti-proliferation effect of resveratrol (Res)on human colon cancer cells and dissect the possible mechanism underlaying this effect.Methods We introduced crystal violet staining and Western blot to analyse the anti-proliferation effect of Res on HCT1 1 6 cells.Then,we used flow cytome-try and Western blot assay to detect the Res induced apoptosis in HCT1 1 6 cells.Next,we employed the well established TCF4 /LEF luciferase reporter to meas-ure the effect of Res on Wnt/β-catenin signaling trans-duction.Finally,we took Western blot and PCR assay to analyse the effect of Res on the expression of β-cate-nin in HCT1 1 6 cells.Results Crystal violet staining and Western blot analysis showed that Res could inhib-it the proliferation of HCT1 1 6 cells in a concentration-and time dependent fashion.What’s more,Res could promote apoptosis in HCT1 1 6 cells.The transcriptional activities of TCF4 /LEF reporter were reduced by Res in a concentration-dependent fashion (P <0.05 when the concentration of Res was 20 μmol·L -1 ,and P <0.01 when the concentration of Res was 40 μmol·L -1 or 80 μmol·L -1 ).Res could decrease not only the protein level of β-catenin in HCT1 1 6 cells,but also the mRNA expression of β-catenin.Conclusion Res can inhibit the proliferation of HCT1 1 6 cells,which may be mediated at least by down-regulating the ex-pression of β-catenin to inhibit the Wnt/β-catenin sig-naling transduction.
ABSTRACT
Aim To investigate the anti-proliferating effect of tetrandrine ( Tet ) on colon cancer cells and its possible molecular mechanism. Methods We intro-duced crystal violet staining and flow cytometry to ana-lyze the effect of Tet on proliferation in LoVo cells. Flow cytometry was used to detect the effect of Tet on apoptosis in LoVo cells. Western blot assay was taken to analyze the effect of Tet on the expression of insulin-like growth factor binding protein 5 ( IGFBP5 ) . Final-ly, luciferase reporter assay, recombinant adenovirus mediated over-expression or silence of IGFBP5 were used to analyze the possible role of IGFBP5 in the anti-proliferating effect of Tet on colon cancer cells. Re-sults Crystal violet staining and flow cytometery anal-ysis results showed that Tet could exert an anti-prolifer-ating effect and induce apoptosis in LoVo cells. Tet de-creased the expression of IGFBP5 in a concentration-dependent manner. Tet inhibited the transcriptional ac-tivity of pTOP-luc reporter, which could be reversed by exogenous expression of IGFBP5 mostly. Similar results were found in the expression of c-Myc, but IGFPB5 knockdown couldn’ t reverse this effect. Conclusion Tet can inhibit the proliferation of colon cancer cells, and this effect may be mediated by down-regulating the expression of IGFBP5 to inhibit Wnt/β-catenin signa-ling transduction partly.
ABSTRACT
Aim To investigate the role of COX-2 in BMP9 induced osteogenic differentiation,and the pos-sible mechanism underlying this function of COX-2. Methods We introduced real-time PCR, Western blot, and immunocytochemical staing to detect the effect of BMP9 on COX-2 expression.We employed chemiluminescence technique to assay ALP activities, RT-PCR to detect the expression of Smad6 and Smad7 , and Western blot to measure the expression of Runx2, Dlx-5,total Smad1/5/8,and phosphorylated Smad1/5/8.Finally,BMPR-Smad luciferase reporter assay was applied to measure the activation of BMPs/Smads signaling.Results BMP9 could induce the expression of COX-2 in C3H10T1/2 cells.Either inhibiting enzy-matic activity of COX-2 or knockdown of the expression of COX-2 reduced the BMP9 induced ALP activities in C3H10T1/2 cells,and COX-2 knockdown also inhibited the ectopic bone formation induced by BMP9 in C3H10T1/2 cells.Moreover,COX-2 knockdown inhibi-ted BMPR-Smad reporter activities and the phosphoryl-ation of Smad1/5/8,so did the expression of Smad6 and Smad7 .Conclusion COX-2 may play an impor-tant role in BMP9 induced osteogenic differentiation in MSCs by regulating the BMPs/Smads signaling trans-duction.