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.

苦参碱抑制大肠癌HT-29细胞环氧化酶-2表达的研究

目的从基因和蛋白水平探讨中药成分苦参碱 (matrine)对大肠癌HT-2 9细胞环氧化酶-2(COX-2 )表达的影响。方法分别采用RT-PCR、Western blot、ELISA等方法检测不同浓度苦参碱处理HT-2 9细胞前后COX-2mRNA、蛋白及其产物前列腺素E2 (PGE2 )水平的改变。结果苦参碱可抑制HT-2 9细胞COX-2mRNA、蛋白表达及PGE2 合成水平 ,但对COX 1无影响。当苦参碱 2 .0mg/ml处理时 ,COX 2mRNA表达在处理后 6h和 9h时抑制率均为 10 0 % ;细胞培养液PGE2 合成水平在 9h时抑制率为6 3.9% ;COX-2蛋白表达在 12h和 2 4h时抑制率分别为 4 8%和 10 0 %。结论苦参碱具有选择抑制HT-2 9细胞COX-2的基因转录、蛋白表达和功能活性等作用 ,在一定浓度和时间范围内 。

人结直肠癌耐药细胞株HT-29/CPT-11的构建及其生物学特性探讨

目的:建立耐伊立替康(CPT-11)的人结直肠癌细胞株(HT-29/CPT-11),并研究其生物学特性。方法:采用药物浓度梯度递增间歇诱导法建立人结直肠癌耐药株HT-29/CPT-11;CCK-8法检测CPT-11对亲本细胞HT-29和耐药细胞株HT-29/CPT-11细胞的半数抑制率(IC50);绘制细胞生长曲线,并计算细胞倍增时间;流式细胞术分析细胞周期分布;RT-PCR检测HT-29/CPT-11和HT-29细胞MDR-1 mRNA的表达。结果:(1)成功建立人结直肠癌耐药细胞株HT-29/CPT-11,耐药指数为6.51。(2)HT-29/CPT-11耐药细胞株倍增时间较原代细胞HT-29延长[分别为(41.29±1.69)h和(27.12±2.73)h,P<0.05]。(3)流式细胞术检测细胞周期结果显示,耐药细胞株HT-29/CPT-11 G1期细胞数目增加,S期细胞数目减少(P<0.05)。(4)耐药细胞HT-29/CPT-11的MDR-1 mRNA表达水平明显高于亲本细胞株HT-29,分别为1.086±0.054和0.416±0.02(P<0.05)。结论:成功构建了人结直肠癌耐药细胞株HT-29/CPT-11,为下一步研究耐药机制奠定实验基础。

戊地昔布对人结肠癌HT-29细胞凋亡的影响

目的观察戊地昔布(Valdecoxib)对COX-2高表达的人结肠癌HT-29细胞凋亡的影响。方法将体外培养HT-29细胞分为正常组(C)、药物处理组(V)及溶剂对照组(S)。采用流式细胞术检测细胞凋亡,Western blot检测COX-2、caspase-3、cleaved caspase-3、Bcl-2、p38 MAPK、p-p38MAPK。结果与正常组相比,药物处理组细胞凋亡明显增加(P<0.05),cleaved caspase-3和p-p38MAPK表达增高,Bax/Bcl-2比率明显升高(P<0.05)。Valdecoxib干预能够显著促进HT-29细胞凋亡,上调cleaved caspase-3和p-p38 MAPK的表达,增加Bax/Bcl-2比率。结论 COX-2选择性抑制剂Valdecoxib能够促进HT-29细胞凋亡部分可能是通过激活p38MAPK信号通路而实现的。

人参皂苷Rg3对HT-29细胞株MMP-1表达和迁移能力的影响

目的:研究人参皂苷Rg3对结肠癌细胞株HT-29基质金属蛋白酶-1(MMP-1)表达和细胞迁移能力的影响。方法:体外培养HT-29细胞,分为人参皂苷Rg3高剂量组(100μg/mL)、中剂量组(50μg/mL)、低剂量组(25μg/mL)和空白对照组,培养HT-29细胞24、48、72h,RT-PCR法测MMP-1 mRNA表达。利用划痕实验观察Rg3对HT-29细胞迁移能力的影响。结果:24h高剂量组与对照组相比,有显著的统计学差异(P<0.01);48h低、中、高剂量组与对照组相比均有显著的统计学差异(P<0.05、P<0.01、P<0.01);72h低、中、高剂量组与对照组相比均有显著的统计学差异(P<0.01、P<0.01、P<0.01)。划痕实验中空白对照组过河时间为(47.33±2.49)h,低、中、高剂量组过河时间分别为(55.33±2.49)h(P<0.01)、(64.00±1.63)h(P<0.01)和(73.33±1.89)h(P<0.01)。结论:人参皂苷Rg3能抑制HT-29细胞MMP-1的表达和抑制HT-29细胞的迁移能力,并且随着药物浓度的增加及时间的延长,抑制作用增强。

蛋白激酶C调控大肠癌HT-29细胞粘附、侵袭能力的研究

目的探讨蛋白激酶C(ProteinKinaseC,PKC)对大肠癌HT-29细胞体外粘附、侵袭能力的调控作用。方法采用体外细胞培养的方法,通过PKC激动剂佛波酯PMA和抑制剂Staurosporine(SP)对大肠癌HT-29细胞粘附人脐带静脉内皮细胞(HUVECs)能力、侵袭血管小块的形态学和侵袭人羊膜能力影响的研究,探讨PKC对HT-29细胞体外粘附、侵袭能力的调控作用。结果采用3H-TdR标记的同位素液闪测定发现,PMA不同浓度处理HT-29细胞可使其粘附HUVECs的能力增强,在一定浓度范围内,随着PMA浓度的增加,粘附作用也逐渐增强,SP可拮抗HT-29细胞粘附HUVECs的作用。侵袭血管小块的扫描电镜观察发现,PMA处理细胞后,细胞侵袭血管的能力增强,细胞伸出伪足,向血管内侵袭,而SP可拮抗PMA作用,细胞侵袭性下降。PMA可显著增强HT-29细胞侵袭人羊膜的能力,100nmol/LPMA诱导4h,可使HT-29细胞在体外获得最大的侵袭羊膜的能力,而SP则可拮抗PMA的这种诱导作用。结论PKC对HT-29细胞体外粘附、侵袭能力存在调控作用,PKC的激活使HT-29细胞粘附性、侵袭性增强,而PKC的抑制使HT-29细胞粘附性、侵袭性下降。

肌醇六磷酸对人结肠细胞系HT-29细胞周期的影响

目的:研究肌醇六磷酸(IP6)对HT-29细胞周期的影响并探讨其作用机制。方法:应用四甲基偶氮唑蓝实验(MTT法)观察IP6对HT-29细胞增殖的影响;流式细胞仪检测不同浓度IP6作用72h对HT-29细胞周期的影响;应用免疫细胞化学法检测IP6对HT-29细胞内突变型p53、细胞周期抑制蛋白p21表达的影响。结果:IP6对结肠癌细胞株的生长具有抑制作用,且具有浓度依赖和时间依赖关系。经IP6作用处理的HT-29细胞的细胞周期发生G1期阻滞。与对照组比,各IP6浓度组均能抑制突变型p53蛋白的表达(P<0.05),上调p21蛋白的表达(P<0.05)。结论:IP6对HT-29细胞的生长具有明显的抑制作用。其机制可能是IP6降低p53蛋白的异常表达,刺激p21蛋白的表达,使细胞周期发生G1期阻滞,从而起到抑制细胞增殖的作用。

pcDNA3.1/DLC-1重组质粒的构建及其在HT-29细胞中的表达

目的构建和表达DLC-1(deleted in liver cancer)基因重组质粒。方法用PCR法得到DLC-1基因片段,此基因片段带有XbaⅠ和BamHⅠ两个酶切位点,然后将此片段和真核表达载体pcDNA3.1连接,转化大肠杆菌DH5a,利用脂质体介导将pcDNA3.1/DLC-1重组质粒转染到结肠癌HT-29细胞中,再用RT-PCR法检测重组质粒的表达。结果重组质粒经XbaⅠ和BamHⅠ双酶切和测序与DLC-1基因序列一致;利用脂质体介导将pcDNA3.1/DLC-1重组质粒导入HT-29细胞,获得了DLC-1基因的表达。结论成功构建pcDNA3.1/DLC-1重组质粒并在HT-29细胞内表达。

miR-150-5p靶向GHSR调控结直肠癌细胞HT-29凋亡的研究

目的:探讨miR-150-5p是否靶向GHSR调控结直肠癌细胞HT-29的凋亡。方法:TargetScan在线分析miR-150-5p与GHSR的相关性;将GHSR的3端非编码区克隆进pMir-Glo miRNA载体,利用双荧光素酶报告系统检测miR-150-5p是否靶向调控GHSR;在缺氧以及过表达或敲低miR-150-5p的情况下,通过Western Blot检测GHSR/AMPK/Sirt1/PGC-1α/UCP2通路蛋白表达量和细胞凋亡标志蛋白的表达量。使用Annexin-V染色检测结直肠癌细胞HT-29的凋亡水平。结果:miR-150-5p靶向GHSR的3’-UTR的66-72的位置。缺氧条件下,敲低miR-150-5p后,GHSR、Sirt1、UCP2、p-AMPK、PGC-1α的表达量和细胞凋亡相关蛋白BCL2的表达量均上升(P<0.05)、BAX、Cleaved caspase3表达量和细胞凋亡水平均下降(P<0.05);缺氧条件下,过表达miR-150-5p后,GHSR、Sirt1、UCP2、p-AMPK、PGC-1α的表达量和细胞凋亡相关蛋白BCL2的表达量均下降(P<0.05)、BAX和Cleaved caspase3表达量上升(P<0.05),细胞凋亡水平上升(P<0.05)。结论:缺氧条件下miR-150-5p通过靶向GHSR的mRNA调控GHSR/AMPK/Sirt1/PGC-1α/UCP2通路来促进结直肠癌细胞HT-29的凋亡。

塞来昔布对大肠癌细胞株HT-29增殖和凋亡的影响

目的 :体外观察塞来昔布对大肠癌细胞株HT 2 9细胞增殖和凋亡的影响 ,并探讨其可能的作用机制。方法采用噻唑蓝 (MTT)比色法 ,流式细胞仪 (FCM)、吖啶橙 /溴化乙啶染色结合荧光显微镜、Western印迹法等技术 ,研究塞来昔布对HT 2 9细胞增殖抑制的影响。结果 :体外塞来昔布抑制HT 2 9细胞生长 ,呈浓度和时间依赖性。DNA直方图示典型的亚二倍体“凋亡峰” ,凋亡率在 (7.31± 2 .37) %～ (4 8.30± 2 .86 ) % ;塞来昔布使G0 /G1期细胞比例升高 ,S期和G2 /M期比例下降 ,呈一定剂量效应关系。典型的凋亡形态学改变 :细胞体积缩小、细胞核固缩、凋亡小体形成等。凋亡比例呈剂量和时间依赖。塞来昔布下调细胞周期素依赖蛋白激酶CDK2 ,CDK4蛋白表达、上调细胞周期素依赖蛋白激酶抑制因子P2 1WAF1/CIP1蛋白表达。结论 :塞来昔布抑制HT 2 9细胞增殖、诱导凋亡可能与阻止细胞周期进展有关。

布氏镜检查丁酸钠影响HT-29细胞动态变化的研究

目的观察丁酸钠对结肠癌HT-29细胞形态和生物学特性的影响。方法多功能透射显微镜(布氏镜)动态观察丁酸钠作用前后HT-29细胞的生长状态、细胞运动及贴壁过程的变化。结果丁酸钠5 mmol/L作用24 h后,HT-29细胞数量明显减少,细胞巢变小,巢内细胞数减少;细胞变成圆形,细胞大小趋于一致;细胞核内染色质呈块状聚集,折光性降低,呈现出凋亡细胞形态;贴壁过程明显变缓。结论丁酸钠可以改变HT-29的生长状态,抑制其生长;布氏镜可以动态地观察药物作用前后培养细胞的形态、微细结构及运动的变化,是一项先进的、具有实用价值的检查技术。

5-氨基水杨酸对人结肠癌细胞株HT-29增殖、凋亡以及细胞周期的影响

背景:溃疡性结肠炎相关结直肠癌(Uc CRC)是溃疡性结肠炎(UC)最严重的并发症,5-氨基水杨酸(5-ASA)能降低Uc CRC的发生风险。目的:探讨5-ASA对人结肠癌细胞株HT-29增殖、凋亡以及细胞周期的影响,明确5-ASA对Uc CRC的抑制作用。方法:以不同浓度(0、10、20、30、40 mmol/L)5-ASA作用于HT-29细胞,采用CCK-8法检测细胞增殖情况;采用TUNEL法检测细胞凋亡情况;采用流式细胞术检测细胞周期;采用免疫组化法检测细胞有丝分裂调节因子Aurora B、BubR1蛋白表达。结果:5-ASA 10、20、30、40 mmol/L组HT-29细胞增殖抑制率、凋亡率随5-ASA浓度升高而升高(P<0.05)。5-ASA 30、40 mmol/L组G0/G1期细胞比例显著低于0、10、20 mmol/L组(P<0.05);5-ASA 0、10、20、30 mmol/L组S期细胞比例均显著低于40 mmol/L组(P<0.05);5-ASA 30、40 mmol/L组G2/M期细胞比例显著高于0、10、20 mmol/L组(P<0.05)。Aurora B、BubR1平均光密度(MOD)值随5-ASA浓度升高而降低(P<0.05)。5-ASA浓度与细胞增殖抑制率、凋亡率呈正相关(P<0.05),与Aurora B、BubR1 MOD值呈负相关(P<0.05)。Aurora B、BubR1 MOD值与细胞增殖抑制率、凋亡率、G2/M期细胞比例呈负相关(P<0.05),与G0/G1期细胞比例呈正相关(P<0.05)。Aurora B与BubR1 MOD值呈正相关(P<0.05)。结论:5-ASA可抑制HT-29细胞增殖并诱导凋亡,其机制可能与5-ASA抑制Aurora B、BubR1表达,继而影响细胞周期有关。

干扰RNA对HT-29细胞周期和凋亡活性的影响

目的:研究干扰RNA质粒载体对肿瘤细胞的作用。方法:制备了针对FGF3基因的干扰RNA质粒载体(pRNATU6.1/NeoGFP-FGF3),并选用大肠癌细胞株HT-29为实验对象,流式细胞仪观察干扰RNA质粒载体对HT-29细胞周期和凋亡活性的影响。结果:细胞周期分析发现转染pRNATU6.1/NeoGFP-FGF3后,HT-29细胞增殖能力减弱;细胞凋亡实验表明干扰RNA质粒载体有明显的促进肿瘤细胞凋亡作用。结论:干扰RNA质粒载体能明显抑制HT-29肿瘤细胞的增殖,并且能显著促进细胞凋亡。

在裸鼠体内连续传代的人类大肠癌HT-29细胞系分化程度逐渐增高现象的发现及研究

对在裸鼠体内连续传代的HT-23细胞系对宿主间质细胞影响的研究中,偶尔发现随着传代次数的增加,移植瘤细胞的分化程度逐渐增高,移植瘤逐渐由未分化癌变为高分化腺癌,表现为瘤细胞呈腺腔样排列,腺腔内有粘液分泌,间质细胞增多。第5代移植瘤出现了类似结肠绒毛样结构。带瘤裸鼠血清中单位瘤体积癌胚抗原(CEA)含量也逐渐下降。这一结果提示:异体恶性细胞在免疫缺陷动物体内连续传代有可能导致恶性的逆转。

人类大肠癌HT-29细胞系分泌物对小鼠间质纤维母细胞作用的研究

在HT-29细胞系分泌物对原代纤维母细胞作用的研究中,发现HT-29细胞系无血清培养液提取物对体外培养的BALB/C小鼠原代纤维母细胞有明显的影响。它不仅使原代纤维细胞形态异常,而且使纤维母细胞体外存活时间较对照组明显延长。对此种提取物的层析分析以及SDS-聚丙烯酰胺凝胶电泳研究表明提取物中含有3个蛋白组分,分子量分别为38 904、25 704和15 311。

大蒜素对人结肠癌HT29细胞增殖影响及作用机制研究

目的:探讨大蒜素对体外培养结肠癌HT29细胞增殖的影响,并探讨其作用机制。方法:采用四甲基偶氮唑蓝(MTT)法测定不同浓度大蒜素对HT29细胞增殖抑制率;流式细胞术测定细胞周期变化及凋亡相关蛋白Bcl-2与Bax的表达。结果:MTT显示大蒜素能抑制人结肠癌HT29细胞的增殖,并具有时间-剂量依赖性;流式细胞术测定结果显示10μg/ml大蒜素可明显诱导HT29细胞凋亡,并将细胞周期阻滞在G2/M期;可降低癌基因蛋白Bcl表达,而促进Bax表达。结论:大蒜素对人结肠癌HT29细胞增殖具有抑制作用,可能与细胞周期阻滞和凋亡相关蛋白表达有关。