黄芪多糖通过调控miR-20a/TGFBR2分子轴降低结直肠癌HT-29/DDP细胞的顺铂耐药性

目的:探讨黄芪多糖(APS)通过调控miR-20a/TGFBR2分子轴对结直肠癌(CRC)顺铂耐药细胞HT-29/DDP增殖、侵袭、凋亡和耐药性的影响及其机制。方法:以人CRC HT-29细胞、HT-29/DDP细胞为亲本和耐药细胞模型,将HT-29/DDP细胞随机分为4组:对照组、APS处理组、过表达miR-20a+APS组、沉默TGFBR2+APS组。用不同质量浓度的APS(0、0.5、1.0、1.5和2.0 mg/ml)处理HT-29/DDP细胞后,以qPCR和Wb实验检测细胞中miR-20a和TGFBR2的表达水平;用CCK-8、Transwell和Annexin V-FITC/PI染色流式细胞术检测对HT-29/DDP细胞增殖、侵袭和凋亡的影响;用双荧光素酶报告基因验证miR-20a与TGFBR2的靶向作用关系。构建裸鼠皮下CRC HT-29/DDP细胞移植瘤模型,观察APS对移植瘤生长的影响及其机制。结果:APS显著抑制HT-29/DDP细胞的增殖(P<0.01),且呈剂量依赖性。miR-20a在经APS处理后的HT-29/DDP细胞中低表达(P<0.01)、TGFBR2的表达水平显著上调(P<0.01)。双荧光素酶报告基因证实miR-20a靶向作用TGFBR2并下调其表达水平。体内外实验证实APS通过靶向下调miR-20a对TGFBR2的抑制作用,提高HT-29/DDP细胞的药物敏感性,进而抑制该细胞增殖、侵袭和促进凋亡(均P<0.01);同时发现,该作用与抑制PCNA、Bcl-2蛋白而促进Bax、Caspase-3蛋白表达有关联。结论:APS通过下调miR-20a对TGFBR2表达的抑制作用,从而逆转HT-29/DDP细胞对顺铂的耐药性。

Influence of paeonol on expression of COX-2 and p27 in HT-29 cells

AIM： To investigate the effect of paeonol on controlling the proliferation of colorectal cancer cell line HT-29 and to discuss its possible mechanism. METHODS： The inhibitory effect of paeonol on proliferation of HT-29 cells was detected by M-I-I- assay. The results of apoptosis were measured by flow cytometry. Immunocytochemical staining was performed to detect the expression of cyclooxygenase-2 （COX-2） and protein p27 in HT-29 cells treated with paeonol at different concentrations. Reverse transcription-polymerase chain reaction （RT- PCR） was used for mRNA analysis. RESULTS： From the data of both MTT and flow cytometry, we observed that cell proliferation was inhibited by different concentrations of paeonol. By immunocytochemical staining, we found that HT-29 cells treated with paeonol （0.024-1.504 mmol/L） reflected reduced expression of COX-2 and increased expression of p27 in a dose-dependent manner. RT-PCR showed that paeonol down-regulated COX-2 and up-regulated p27 in a dose- and time-dependent manner in HT-29 cells. CONCLUSION： One of the apoptotic mechanisms of paeonol is down-regulation of COX-2. p27 is upregulated simultaneously and plays an important part in controlling cell proliferation and is a crucial factor in the Fas/FasL apoptosis pathway.

Antitumor Activities and Apoptosis-regulated Mechanisms of Fermented Wheat Germ Extract in the Transplantation Tumor Model of Human HT-29 Cells in Nude Mice

Objective A subcutaneous transplantation tumor model of human HT-29 cells in nude mice was established to evaluate anticarcinogenic activities, and the apoptosis-regulated mechanism effect of aqueous extract of fermented wheat germ with Lactobacillus plantarum dy-1 （LFWGE）. Methods The HT-29 cells were transplanted via subcutaneous injection of 1×10^7cells into the right flank of each nude mouse. Then, nude mice were treated for 30 d with LFWGE （high-dose 2 g/kg/d; low-dose 1 g/kg/d） and for 7 d with 5-fluorouracil （5-FU, 25 mg/kg/d） by gavage and intraperitoneal injection, respectively. An inhibition of tumor growth was observed. Results Tumor volume and weights decreased significantly in both groups of nude mice treated with LFWGE. In addition, the cell apoptosis rate of the LFWGE group （2 g/kg/d, 60.2%＋4.4%; 1 g/kg/d, 58.6%＋6.9%） was significantly higher than that of the control group （11.5%＋1.6%） and 5-FU group （32.1%＋3.5%） as measured by the TUNEL assay. Moreover, the real-time fluorescent quantitative PCR and Western blot method further confirmed these enhancing apoptosis and growth inhibition effects. The involvement of LFWGE in inducing apoptosis was confirmed by the expression of Bax, Bcl-2, Caspase-3, and CyclinD1. Conclusion The results showed that LFWGE could induce subcutaneous transplantation tumor apoptosis in nude mice and could be as a natural nutrient supplements or chemopreventive agent in the treatment of human colon cancer.

Antitumor Activities and Apoptosis-regulated Mechanisms of Fermented Barley Extract in the Transplantation Tumor Model of Human HT-29 Cells in Nude Mice

Objective A subcutaneous transplantation tumor model of human HT-29 cells was established in nude mice to study the anticarcinogenic activities and apoptosis-regulatory mechanistic effect of aqueous extract of fermented barley with Lactobacillus plantarum dy-1 （LFBE）. Methods HT-29 cells were transplanted via subcutaneous injection of 1 × 107cells into the right flank of each nude mouse. Then, nude mice were treated for 30 days with LFBE （high-dose 2 g·kg-1·d-1; low-dose 1 g·kg-1·d-1） and for 7 days with 5-fluorouracil （5-FU, 25 g·kg-1·d-1） by gavage and intraperitoneal injection, respectively. Results Tumor volume and weight decreased significantly in both groups of nude mice treated with LFBE. In addition, the cell apoptosis rate of the LFBE group was significantly higher than that of the control group and 5-FU groups as measured by the TUNEL assay. Moreover, the real-time fluorescent quantitative PCR and Western blot methods further confirmed these apoptosis-enhancing and growth-inhibiting effects. The involvement of LFBE in inducing apoptosis was confirmed by the expression of Bax, Bcl-2, caspase-3, and cyclin D1. Conclusion The results showed that LFBE could induce subcutaneous transplantation tumor apoptosis in nude mice and could be used as a natural nutrient supplement or chemopreventive agent in the treatment of human colon cancer.

Anti-cancer effect of ethylacetate fraction from Orostachys japonicus on HT-29 human colon cancer cells by induction of apoptosis through caspase-dependent signaling pathway

Objective: To investigate the anti-colon cancer effects of ethylacetate fraction from Orostachys japonicus(0. japonicus) on HT-29 cancer cells. Methods: The viability of HT-29 cells was assayed by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium(MTS) method. Apoptosis induction and cell cycle inhibition were confirmed by fluorescein isothiocyanate and propidium iodide staining using flow cytometry.Morphological changes in the nucleus were observed, using a fluorescence microscope with4',6-diamidino-2-phenylindole(DAPI) nuclear staining. The expression levels of the upstream and downstream proteins involved in the anti-cancer mechanism were confirmed by Western blotting. Results: After treating HT-29 cells with different concentrations of ethylacetate fraction from O. japonicus, the viability of cells decreased in a concentration-dependent manner,while apoptosis induction and apoptotic body formation increased. Cell cycle analysis showed that the arrest occurred at the sub-G_1 and S phase. Among the upstream and downstream proteins involved in anti-cancer activity, the level of B cell lymphoma-2 decreased, and the bcl-2-associated x protein increased. The level of pro-caspase-3, pro-caspase-8, and pro-caspase-9 decreased, while the level of cleaved-caspase-3, cleaved-caspase-8, and cleaved-caspase-9 increased. Moreover, the phosphorylation, that is, activation of extracellular signal regulated kinase 1/2, Jun-N-terminal kinase, and p38 increased. Conclusions: Combining the above results, it is thought that the survival of HT-29 cells is suppressed by ethylacetate fraction from0. japonicus through mitochondrial regulation-induced caspase cascade activation, induction of apoptosis and cell cycle arrest.

Curcumin suppresses PPARδ expression and related genes in HT-29 cells

AIM:To investigate the effects of curcumin on the expression of peroxisome proliferator-activated receptorδ(PPARδ)and related genes in HT-29 cells. METHODS:HT-29 cells were treated with curcumin (0-80μmol/L)for 24 h.The effects of curcumin on the morphology of HT-29 cells were studied by Hoechst 33342 staining.The activity of caspase-3 was determined using DEVD-p NA as substrate.The levels of peroxisome PPARδ,14-3-3εand vascular endothelial growth factor(VEGF)in HT-29 cells were determined by Western blotting analysis and their mRNA expression was determined by real-time quantitative RT-PCR. RESULTS:Treatment with 10-80μmol/L curcumin induced typical features of apoptosis and activated the caspase-3 in HT-29 cells.The expression of PPARδ, 14-3-3εand VEGF was reduced and the activity of β-catenin/Tcf-4 signaling was inhibited by curcumin treatment. CONCLUSION:Curcumin can induce apoptosis of HT-29 cells and down-regulate the expression of PPARδ,14-3-3εand VEGF in HT-29.

Tetrandrine:A Potent Abrogator of G_2 Checkpoint Function in Tumor Cells and Its Mechanism

Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcinoma p53-mutant HT-29 as well as in C26 colorectal carcinoma-bearing BALB/c mice. Methods MCF-7/ADR, HT-29 and MCF-7 cells were exposed to irradiation in the absence or presence of tetrandrine. The effect of Tet on the cytotoxicity of X-irradiation in these three cells was determined and the effect of tetrandrine on cell cycle arrest induced by irradiation in its absence or presence was studied by flow cytometry. Moreover, mitotic index measurement determined mitosis of cells to enter mitosis. Western blotting was employed to detect cyclin B1 and Cdc2 proteins in extracts from irradiated or non-irradiated cells of MCF-7/ADR, HT-29 and MCF-7 treated with tetrandrine at various concentrations. Tumor growth delay assay was conducted to determine the radio-sensitization of tetrandrine in vivo. Results Clonogenic assay showed that tetrandrine markedly enhanced the lethal effect of X-rays on p53-mutant MCF-7/ADR and HT-29 cells and the sensitization enhancement ratio （SER） of tetrandrine was 1.51 and 1.63, but its SER was only 1.1 in p53-wt MCF-7 cells. Irradiated p53-mutant MCF-7/ADR and HT-29 cells were only arrested in G2/M phase while MCF-7 cells were arrested in G1 and G2/M phases. Radiation-induced G2 phase arrests were abrogated by tetrandrine in a concentration-dependent manner in MCF-7/ADR and HT-29 cells, whereas redistribution within MCF-7 cell cycle changed slightly. The proportion of cells in M phase increased from 1.3% to 14.7% in MCF-7/ADR cells, and from 1.5% to 13.2% in HT-29 cells, but 2.4% to 7.1% in MCF-7 cells. Furthermore, the levels of cyclin B 1 and Cdc2 expression decreased after X-irradiation in MCF-7/ADR and HT-29 cells, and the mitotic index was also lower. Tet could reverse the decrease and induce the irradiated cells to enter mitosis （M phase）. Endosomatic experiment showed that tetrandrine caused tumor growth delay in irradiated mice. Conclusion Tetrandrine boosts the cell killing activity of irradiation both in vitro and in vivo. Tetrandrine is a potent abrogator for G2 checkpoint control and can sensitize the cells to radiation.

Effects of compound 209 on colorectal cancer cell HT-29 in vivo and in vitro

Compound 209 is a newly synthesized dithiocarbamate derivative with antiproliferation activity in vitro, however, its antitumor effect in vivo and the underlying mechanisms have yet to be identified. We explored the antitumor effect of compound 209 and the possible mechanisms for its inhibition of the growth of HT-29 xenograff tumor and proliferation of HT-29 cells. Cell proliferation was evaluated with SRB assay in vitro. The results showed that compound 209 had significant antiproliferation activity on HT-29 cells. Furthermore, the xenograff HT-29 nude mouse model was used to study the antitumor effect of compound 209 in vivo. We found that compound 209 significantly inhibited tumor growth and did not cause loss of body weight or leukocytopenia. Analysis by flow cytometry indicated that compound 209 arrested HT-29 cell cycle in G~ phase. Western blotting analysis suggested that compound 209 increased the expression of p27, cyclin E, CDK2, cyclin D1 and CDK4. These results demonstrated the antitumor effect of compound 209 and its potential use as an anticancer drug.

Curcumin induces apoptosis through the mitochondria-mediated apoptotic pathway in HT-29 cells

Objective： To investigate the effects of curcumin on release of cytochrome c and expressions of Bcl-2, Bax, Bad, Bcl-xL, caspase-3, poly ADP-ribose polymerase （PARP）, and survivin of HT-29 cells. Methods： HT-29 cells were treated with curcumin （0-80 μmol/L） for 24 h. The release of cytochrome c from the mitochondria and the apoptosis-related proteins Bax, Bcl-2, Bcl-xL, Bad, caspase-3, PARP, and survivin were determined by Western blot analysis and their mRNA expressions by reverse transcriptase-polymerase chain reaction （RT-PCR）. Results： Curcumin significantly induced the growth inhibition and apoptosis of HT-29 cells. A decrease in expressions of Bcl-2, Bcl-xL and survivin was observed after exposure to 10-80 μmol/L curcumin, while the levels of Bax and Bad increased in the curcumin-treated cells. Curcumin also induced the release of cyto- chrome c, the activation ofcaspase-3, and the cleavage of PARP in a dose-dependent manner. Conclusion： These data suggest that curcumin induced the HT-29 cell apoptosis possibly via the mitoehondria-mediated pathway.

Pien Tze Huang(片仔癀)-Induced Apoptosis in Human Colon Cancer HT-29 Cells Is Associated with Regulation of the Bcl-2 Family and Activation of Caspase 3

Objective：To investigate the cellular effects of Pien Tze Huang（片仔癀,PZH） in the HT-29 human colon carcinoma cell line.Methods：The viability of HT-29 cells was determined by MTT assay.A fluorescence-activated cell sorting（FACS） analysis with annexin-V/propidium iodide（PI） and JC-1 staining were performed to determine cell apoptosis and the loss of mitochondrial membrane potential,respectively.Activation of caspase 3 was evaluated by a colorimetric assay.The mRNA expression levels of Bcl-2 and Bax were measured by reverse transcription polymerase chain reaction（RT-PCR）.Results：PZH,in a dose- and time-dependent manner,reduced viability and induced apoptosis of HT-29 cells.Moreover,PZH treatment resulted in the collapse of the mitochondrial membrane potential,activation of caspase 3,and an increase in the Bax/Bcl-2 ratio.Conclusion：PZH inhibits the growth of HT-29 cells by inducing cancer cell apoptosis via regulation of the Bcl-2 family and activation of caspase 3,which may,in part,explain its anticancer activity.

Gambogic acid induces apoptosis and inhibits colorectal tumor growth via mitochondrial pathways

AIM: To investigate the effect of gambogic acid(GA) on apoptosis in the HT-29 human colon cancer cell line. METHODS: H-29 cells were used for in vitro experiments in this study. Relative cell viability was assessed using MTT assays. Cell apoptosis was detected by terminal deoxynucleotidyl transferase d UTP nick end labeling and Hoechst 33342 staining, and quantified by flow cytometry. Cellular ultrastructure was observed by transmission electron microscopy. Real-time PCR and Western blot analyses were used to evaluate gene and protein expression levels. For in vivo experiments, BALB/c nude mice received subcutaneous injections of HT-29 cells in the right armpit. When well-established xenografts were palpable with a tumor size of 75 mm3, mice were randomly assigned to a vehicle(negative) control, positive control or GA treatment group(n = 6 each). The animals in the treatment group received one of three dosages of GA(in saline; 5, 10 or 20 mg/kg) via the caudal vein twice weekly, whereas animals in the negative and positive control groups were given equal volumes of 0.9% saline or 10 mg/kg docetaxel, respectively, via the caudal vein once weekly. RESULTS: The cell viability assay showed that GA inhibited proliferation of HT-29 cells in a dose- and time-dependent manner after treatment with GA(0.00, 0.31, 0.62, 1.25, 2.50, 5.00 or 10.00 μmol/L) for 24, 48 or 72 h. After 48 h, the percentage of apoptotic cells in cells treated with 0.00, 1.25, 2.50 and 5.00 μmol/L GA was 1.4% ± 0.3%, 9.8% ± 1.2%, 25.7% ± 3.3% and 49.3% ± 5.8%, respectively. Ultrastructural analysis of HT-29 cells treated for 48 h with 2.5μmol/L GA revealed apoptotic bodies and condensed and fragmented nuclei. Levels of caspase-8,-9 and-3 m RNAs were significantly increased after treatment with GA(1.25, 2.50 or 5.00 μmol/L) for 48 h(P < 0.05 for all). Protein levels of apoptosis-related factors Fas, Fas L, FADD, cytochrome c, and Apaf-1 were increased in GA-treated cells, whereas levels of pro-caspase-8,-9 and-3 were significantly decreased(P < 0.05 for all). Furthermore, GA significantly and dose-dependently inhibited the growth of HT-29 tumors in a mouse xenograft model(P < 0.05).CONCLUSION: GA inhibits HT-29 proliferation via induction of apoptosis. The anti-cancer effects are likely mediated by death receptor(extrinsic) and mitochondrial(intrinsic) pathways.

Synthesis, Characterization and Biological Screening of Ferulic Acid Derivatives

According to WHO, cancer is a leading cause of death worldwide, accounting for 8.2 million deaths in 2012. Among several factors involved in the pathogenesis of cancer, free radical formation followed by damage to DNA and cell protein is one of the causes. Natural plant products have gained enormous interest in the prevention or treatment of chronic diseases. Ferulic acid, like other phenolic acids (caffeic acid, sinapic acid) possess anti cancer activity. A series of ferulic esters (FE1 - FE11) and ferulic amides (FA1 - FA10) were synthesized and evaluated for their cytotoxic activity.

Tong xie yao fang relieves irritable bowel syndromein rats via mechanisms involving regulation of5-hydroxytryptamine and substance P

AIM To investigate the influence of lipopolysaccharide（LPS） through the p38/c-Jun N-terminal kinase （JNK）signalling pathway on aquaporin 3 （AQP3） expressionin HT-29 human colon epithelial cells.METHODS： HT-29 cells were treated with LPS, andthen the membrane localisation of AQP3 was examinedby immunofluorescence staining. The mRNA andprotein expression of AQP3 with LPS exposure wasmeasured by real-time reverse transcription-PCR andWestern blot, respectively. Activation of p38 and JNKwas evaluated by detection of phosphorylation ofp38 and JNK using Western blot assay. AQP3 proteinexpression was determined by Western blot in cellsafter treatment with SB203580, a selective p38 MAPKinhibitor, or SP600125, a selective JNK inhibitor.RESULTS： In HT-29 cells, the transcription and proteinexpression of AQP3 were decreased by LPS in adose- and time-dependent manner, the expression ofAQP3 was significantly decreased with the increasedconcentration of LPS, and at a dose of 100 μg/mLLPS, AQP3 mRNA and protein levels were decreasedby a maximum （P 〈 0.05） of 1.51-fold and 1.49-fold,respectively. When cells were treated with 100 μg/mLLPS for 0, 3, 6, 12, and 24 h, the AQP3 mRNA levelwas significantly decreased at an early time point of3 h, and reached about 10% of the control level at24 h post-treatment （P 〈 0.05）. Down-regulation ofAQP3 expression was significantly inhibited by the p38inhibitor （SB203580） and JNK inhibitor （SP600125）.CONCLUSION： p38 and JNK may be promising targetsfor the preservation of AQP3 expression and may bebeneficial to the clinical management of diarrhoea.

Two sides to colon cancer: mice mimic human anatomical region disparity in colon cancer development and progression

Aim:Strong evidence reveals important differences between cancers in the proximal vs.distal colon.Animal models of metastatic colon cancer are available but with varying degrees of reproducibility and several important limitations.We explored whether there were regional differences in the location of murine colon cancers and assessed the utility of murine models to explore the biological basis for such differences.Methods:We re-analyzed data from our previous studies to assess the regional distribution of murine colon cancer.In survival surgery experiments,we injected HT-29 human colon cancer cells into the wall of the cecum or distal colon of Nu(NCr)-Foxn1 nu or NOD.Cg-Prkdc scid Il2rg Tim1Wji/SzJ mice and compared the development of primary tumors and metastases.Results:Within 7-17 weeks after intramural cecal injection of HT-29 cells,eight mice failed to develop solid primary tumors or metastases.In contrast,within four weeks after cell injection into the distal colon,13 mice developed metastases-12 mice developed subcutaneous metastases;of these,four developed liver metastases and one developed both liver and lung metastases.One mouse developed liver metastases only.Histological examination confirmed these lesions were adenocarcinomas.Conclusion:Our findings reveal the preferential growth of murine colon neoplasia and invasive human orthotopic xenografts in the distal mouse colon.The new approach of injecting cells into the distal colon wall results in a pattern of colon cancer development that closely mimics the progression of metastatic colon cancer in humans.This novel model of colon neoplasia has great potential for exploring anatomical differences in colon cancer and testing novel therapeutics.