ABSTRACT
Aim To study the relationship between the anti-proliferation effect of tetrandrine(Tet) and TGF-β1 in human colon cancer cells.Methods Cell viability assay, Western blot, flow cytometry and Annexin Ⅴ-EGFP staining were introduced to analyze the anti-cancer effect of Tet on HCT116 cells.Real-time PCR, Western blot,cell viability and immunofluorescent were employed to determine the relationship between the anti-cancer effect of Tet and TGF-β1 in HCT116 cells, the relationship between the anti-cancer effect of Tet and PI3K/Akt on HCT116 cells, and how TGF-β1 mediated the anti-cancer effect of Tet on HCT116 cells.Results Compared with the control groups, Tet apparently inhibited the proliferation, and induced cell cycle arrest at G1 phase and apoptosis in HCT116 cells.Tet greatly up-regulated the expression of TGF-β1 either the mRNA or protein level, and exogenous expression of TGF-β1 potentiated the anti-cancer effect of Tet in HCT116 cells, while TGF-β1 inhibitor attenuated it notably.Tet decreased the phosphorylation of Akt1/2/3, but no apparent effect was observed on total protein level of Akt1/2;PI3K inhibitor enhanced the anti-cancer effect of Tet in HCT116 substantially.Exogenous expression of TGF-β1 enhanced the Tet-induced decrease phorphorylation of Akt1/2/3, which was partly reversed by TGF-β1 inhibitor in HCT116 cells.Meanwhile, knockdown of PTEN elevated the level of phorphorylated Akt1/2/3, which was abolished by the exogenous expression of TGF-β1 in HCT116 cells.Conclusion Tet may be a potent candidate drug for colon cancer treatment, and the anti-cancer effect of Tet may be partly mediated by up-regulating TGF-β1 to inactivate PI3K/Akt signal.
ABSTRACT
Aim To investigate the role of TGF-β3 in the anti-proliferation effect of ursolic acid(UA)in co-lon cancer cells and the possible molecular mechanism underlying this effect.Methods We introduced crys-tal violet staining,flow cytometry and Western blot as-say to determine the effect of UA on proliferation and apoptosis in HCT1 1 6 cells.The levels of TGF-β3, Smad2 /3 and β-catenin in HCT1 1 6 cell were evaluated by RT-PCR and Western blot.Finally,TGF-β3 inhibi-tor and recombinant adenovirus,and luciferase reporter assay were used to analyze the possible mechanism through which TGF-β3 mediated the anti-cancer effect of UA in HCT1 1 6 cells.Results UA inhibited the proliferation and induced apoptosis apparently in HCT1 1 6 cells.UA down-regulated TGF-β3 both in mRNA and in protein level.Meanwhile,UA decreased the phosphorylation of Smad2 /3 concentration depend-ently,although no significant effect was found on the total protein level of Smad2 /3 in HCT1 1 6 cells.Over-expression of TGF-β3 attenuated the inhibitory effect of UA on the proliferation of HCT1 1 6 cells,while the TGF-β3 inhibitor potentiated this effect. UA sup-pressed the transconduction of Wnt/β-catenin signaling in HCT1 1 6 cells through decreasing the level of β-catenin.Exogenous expression of TGF-β3 increased the level of β-catenin and partly reversed the UA-in-duced decrease of β-catenin.However,TGF-β3 inhib-itor potentiated the inhibitory effect of UA on β-catenin in HCT1 1 6 cells.Conclusion The anti-proliferation activity of UA in colon cancer may be partly mediated through down-regulating TGF-β3 to suppress Wnt/β-catenin signaling at least.
ABSTRACT
Aim To investigated the possible effect of COX-2 on the BMP9-induced activation of PI3K/Akt signal in progenitor cells.Methods The activity of alkaline phosphatase(ALP) was measured using histochemical staining or chemiluminescence.The mRNA level of ALP was determined using real-time PCR assay.The protein levels of osteopontin(OPN), osteocalcin(OCN), COX-2, Akt1/2 and phosphorylated Akt1/2 were detected by Western blot.The mRNA level of COX-2 was assayed with RT-PCR, and the mineralization was measured with Alizarin Red staining.Results The ALP activity was apparently increased by BMP9 in C2C12 cells, as well as the protein level of OPN and OCN.The mineralization was also markedly induced by BMP9 in C2C12 cells.BMP9 increased the level of phosphorylated Akt1/2 greatly, although no substantial effect was observed on total protein level of Akt1/2.The BMP9-induced ALP activity was dramatically decreased by the inhibitor of PI3K.The mRNA and protein level of COX-2 were both increased by BMP9 in C2C12cells, and the BMP9-induced ALP activity and mineralization were greatly attenuated by the inhibitor of COX-2.The BMP9-induced phosphorylation level of Akt1/2 was increased by the exogenous expression of COX-2, but decreased by the inhibitor of COX-2.Conclusion Activation of PI3K/Akt signaling may be a critical event in BMP9-induced osteogenic differentiation, and this process may be mediated by the BMP9-upregulated COX-2 in stem cells at least.
ABSTRACT
Aim To study the anti-proliferation effect of resveratrol (Res)and the role of Res-induced bone morphorgenetic protein 9 (BMP9 )in this process in colon cancer cells.Methods Crystal violet staining and flow cytomtry were introduced to assay the anti-proliferation effect of Res in LoVo cells.The effect of Res on apoptosis in LoVo cells was also detected with flow cytometry.Then,RT-PCR and Western blot assay were employed to unveil the effect of Res on the ex-pression of BMP9 .The effect of BMP9 on the anti-pro-liferation of Res in LoVo cells was analyzed with crystal violet staining and flow cytometry too.Finally,the effect of Res on the expression of ALK2 and ALK3 was assayed with RT-PCR,and the inhibitor of ALK2 and ALK3 was used to figure out the possible mechanism of BMP9 on Res-induced proliferation inhibition in LoVo cells.Results Res apparently inhibited the prolifera-tion,arrested the cell cycle at S phase in LoVo and in-creased the percentage of apopotic cells in LoVo cells. Res increased the expression of mRNA and protein of BMP9 concentration dependently. Exogenous ex-pressed-BMP9 enhanced the anti-proliferation and ap-optosis inducing effects of Res in LoVo cells, but BMP9 knockdown decreased these effects of Res.Al-though Res had no apparent effect on increasing the phosphorylation of Smad1/5/8,it increased the ex-pression of ALK2 and ALK3 .Inhibition of ALK2 and ALK3 decreased the anti-proliferation effect of Res partly in LoVo cells.Conclusion Res is potent to in-hibit the proliferation of LoVo cells,Which may be mediated by up-regulating the expression of BMP9 and its receptor at least.
ABSTRACT
Aim To investigate the relationship be-tween the anti-proliferation effect of resveratrol ( Res ) and p38 MAPK in colon cancer cells .Methods Crys-tal violet staining , Western blot and flow cytometry were employed to analyze the effect of Res on the pro-liferation in LoVo cells.Western blot assay was used to detect the effect of Res on the apoptosis of LoVo cells and the phosphorylation of p 38 MAPK.Crystal violet staining and Western blot assay were used to analyze whether p38 MAPK was involved in the Res-induced proliferation inhibition and apoptosis in LoVo cells .Re-sults Res inhibited the proliferation , arrested cell cy-cle at S phase , and increased the protein level of PC-NA in LoVo cells apparently .Res increased the level of Bad in LoVo cells, but decreased the level of Bcl-2. Although Res exerted no substantial effects on total lev-el of p38 MAPK, it markedly increased the phospho-rylation level of p38 MAPK in LoVo cells.p38 MAPK inhibitor promoted the proliferation , and decreased the anti-proliferation effect of Res on LoVo cells .Moreo-ver , the effects of Res on the level of Bcl-2 and Bad were both reduced by the p 38 MAPK inhibitor .Con-clusions Res can inhibit the proliferation of LoVo cells, which may be partly mediated by promoting the phosphorylation of p38 MAPK.
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.