巨噬细胞移动抑制因子对结肠癌HT-29细胞增殖和血管生成因子表达的影响

目的研究巨噬细胞移动抑制因子(MIF)在体外对人结肠癌细胞HT-29增殖及VEGF和IL-8表达的影响。方法分别用25、50、100μg/L人重组MIF(rhMIF)对细胞进行处理后,采用MTT法检测细胞增殖,RT-PCR检测细胞VEGF、IL-8mRNA含量,ELISA测定细胞培养上清液中VEGF和IL-8的蛋白含量。结果rhMIF作用不同时间后,能够促进HT-29细胞生长,增殖活性随浓度增加、时间延长逐渐上升(P<0.05),呈现量—效、时—效关系。细胞VEGF和IL-8mRNA表达及上清液中VEGF和IL-8蛋白含量均明显增加,存在时间和浓度依赖性(P<0.05)。结论MIF能够促进结肠癌细胞增殖,MIF参与肿瘤血管形成有可能是通过上调VEGF和IL-8的表达发挥作用。     

姜黄素对人结肠癌细胞HT-29中β-catenin、血管内皮生长因子的影响

目的研究姜黄素对体外培养人结肠癌HT-29细胞增殖及对细胞株中β-catenin、血管内皮生长因子(VEGF)表达的影响。方法采用不同浓度的姜黄素作用于HT-29细胞,MTT法检测细胞增殖情况;Western印迹检测药物处理后β-catenin及VEGF蛋白的表达。结果姜黄素对HT-29细胞的增殖具有抑制作用,且呈剂量-时间依赖性(P<0.05),测得IC50为19.27μmol/L;在蛋白水平,姜黄素处理后,β-catenin、VEGF的蛋白表达水平降低。结论姜黄素能够抑制HT-29细胞的增殖,并下调结肠癌细胞HT-29中β-catenin、VEGF的表达。     

神经酰胺对结肠癌HT-29细胞凋亡和增殖细胞核抗原表达的影响

目的 探索神经酰胺(C_2-cer)影响人结肠癌HT-29细胞增殖、凋亡和增殖细胞核抗原(PCNA)表达.方法 12.5、25 μmol/L的C_2-cer处理HT-29细胞,用MTT法、流式细胞仪、激光共聚焦显微镜、Western印迹等方法检测HT-29细胞增殖、凋亡和PCNA表达.结果 以12.5、25 μmol/L的C_2-cer处理HT-29细胞,细胞增殖受到抑制,细胞凋亡明显增加,PCNA表达明显降低,并呈剂量-效应关系.结论 C_2-cer可诱导细胞凋亡,该效应可能与下调PCNA表达有关.     

姜黄素对结肠癌细胞HT-29中NDRG2基因表达的影响

目的探讨姜黄素对HT-29结肠癌细胞株中N-myc F下游调节基因(NDRG)2表达的影响及姜黄素不同浓度处理下NDRG2基因表达情况。方法应用不同浓度的姜黄素干预体外培养的HT-29细胞48 h后,提取总RNA,并运用RT-PCR技术检测姜黄素对HT-29细胞中NDRG2基因表达的影响。利用RIPA细胞裂解液提取细胞总蛋白,运用Western印迹技术,检测姜黄素对HT-29细胞中NDRG2蛋白质表达的影响。结果姜黄素不但能够在mRNA水平促进HT-29细胞中NDRG2基因的表达,且能够促进NDRG2蛋白质的表达,且均具有统计学意义。但有效浓度范围在20~100μmol/L,且80μmol/L效果最佳,表明姜黄素在一定浓度范围内对NDRG2基因上调(P0.05),RG2基因,并能有效抑制肿瘤细胞。结论姜黄素能够促进结肠癌细胞株HT-29细胞中NDRG2基因和蛋白的表达,且具有剂量依赖性,最佳浓度为80μmol/L。     

藤梨根提取物对HT-29荷瘤裸鼠的抑制及诱导凋亡作用的影响

目的:研究藤梨根提取物(ethanol extract from radix of Actinidia chinensis,EERAC)对人大肠癌HT-29荷瘤裸鼠移植瘤的抑制和诱导凋亡作用.方法:提取EERAC,以大肠癌HT-29细胞对40只Balb/c-nu/nu裸鼠进行荷瘤造模,并随机将分为3个EERAC处理组(低剂量组5mg/kg、中剂量组10mg/kg、高剂量组20mg/kg),空白对照组(生理盐水)和阳性对照组(5-Fu,25mg/kg),每组8只,连续用药8d后,测定各实验组的肿瘤抑制率、脾脏指数.通过脾脏效应细胞培养,测定NK细胞的活性度.免疫组织化学法测定各组荷瘤裸鼠体内凋亡相关基因Bcl-2、Bax、Caspase-3的蛋白表达水平.结果:与空白对照组相比,EERAC对HT-29移植瘤均有明显的抑制作用,各剂量组的抑瘤率为9.12%、20.13%、37.81%,与药物剂量呈正比;EERAC各剂量组对荷瘤裸鼠脾脏指数较生理盐水组和5-Fu组有显著增加(P<0.05);不同剂量的EERAC均可使NK细胞活性度增加(P<0.05);EERAC作用后,HT-29荷瘤裸鼠体内的Bcl-2表达减弱,Bax、Caspase-3表达水平增高,Bcl-2/Bax比值下降,其作用也呈剂量相关性.结论:EERAC对大肠癌细胞HT-29荷瘤裸鼠具有抑制瘤体生长和诱导癌细胞凋亡的作用,其作用机制可能为抑制荷瘤裸鼠体内Bcl-2的表达,提高Bax、Caspase-3表达水平,下调Bcl-2/Bax.EERAC对荷瘤裸鼠免疫系统无不良影响,且能一定程度上提高机体的免疫功能.     

抑制JNK信号通路对结肠癌HT-29细胞增殖和凋亡的影响

目的:研究抑制JNK 信号通路对结肠癌HT-29 细胞增殖和细胞凋亡的影响.方法:将人结肠癌细胞株HT-29分为正常对照组和JNK 抑制剂组(用SP600125 预处理细胞24 h),用四甲基偶氮唑盐比色法(MTT 法)检测细胞增殖水平,用脱氧核酸末端转移酶介导的缺口末端标记法(TUNEL 法)观察细胞凋亡情况.结果:...     

丁酸钠对结肠癌细胞株HT-29血管内皮生长因子表达水平的影响

目的 观察丁酸钠对结肠癌细胞株HT-29的生长抑制情况以及对血管内皮生长因子(VEGF)表达水平的影响。方法 运用细胞增生抑制实验(MTT法)，免疫细胞化学技术观察丁酸钠对HT-29细胞株的生长和对、VEGF表达水平的影响。结果 丁酸钠能抑制HT-29细胞株增生，并降低VEGF表达水平。结论 丁酸钠能够降低VEGF的表达水平，提示可用作抗血管生成物质降低肿瘤细胞侵袭力。     

血管抑制素基因抑制结肠癌细胞增殖及肿瘤血管生成的研究

目的:研究血管抑制素基因体外对结肠癌细胞增殖的抑制及体内对肿瘤血管生成的抑制,探讨血管抑制素基因对结肠癌的抑制作用。方法:构建重组质粒pcDNA3.1( )／angio,用脂质体转染法将重组质粒、空白载体导入结肠癌细胞Colo205,培养细胞观察细胞生长,绘制细胞生长曲线,计算增殖抑制率,然后将pcDNA3.1( )／angio、pcDNA3.1( )／Colo205、Colo205分别接种至裸鼠右侧颈部皮下,观察肿瘤的生长,测量肿瘤体积,计算抑瘤率,免疫组化检测肿瘤组织中微血管密度(MVD)、血管内皮生长因子(VEGF)的表达。结果:体外pcDNA3.1( )／angio组细胞的生长速度略慢于pcDNA3.1( )／Colo205、Colo205组,但差异无统计学意义(P>0.05);体内pcDNA3.1( )／angio组细胞的致力显著降低,瘤体增长缓慢,抑瘤率较高(P<0.01),瘤体组织中MVD及VEGF的表达较低(P<0.05);pcDNA3.1( )／Colo205、Colo205两组之间的差异无统计学意义(P>0.05)。结论:在体外血管抑制素不直接影响结肠癌细胞Colo205的生物学特性,但在体内可强烈抑制肿瘤的生长,其机制可能是通过降低血管生成因子而抑制肿瘤的新生血管生成,发挥抑制肿瘤作用。     

c-myc反义寡核苷酸对结肠癌HT-29细胞增殖、凋亡及化疗敏感性的影响

目的:研究体外c-myc反义寡核苷酸(ASODN)对人结肠癌HT-29细胞增殖、凋亡及化疗敏感性的影响.方法:利用脂质体LipofectamineTM2000介导将c-myc ASODN转染入大肠癌HT-29细胞中, 逆转录多聚酶链反应(RT-PCR)、Westernblot方法检测c-myc基因mRNA及蛋白的表达,MTT、流式细胞仪(FCM)检测c-myc ASODN对人结肠癌HT-29细胞增殖抑制及其对奥沙利铂敏感性影响.结果:转染c-myc ASODN后, HT-29细胞内c-myc mRNA水平显著降低(0.464±0.029 vs0.974±0.027, 0.945±0.012, 均P<0.01). 在HT-29细胞中存在分子质量62 kDa的特异性条带, 与c-myc分子质量相符, ASODN组在PVDF膜上的特异性条带明显弱于对照组; MTT结果显示转染c-myc ASODN 48 h后的HT-29细胞的增殖速度较对照组细胞明显减慢. FCM显示c-myc ASODN转染后72 h后, 奥沙利铂+ c-myc ASODN组细胞凋亡率显著高于对照组( P<0.05).结论:体外c-myc ASODN可抑制c-myc mRNA及蛋白的表达, 阻断c-myc可抑制HT-29细胞增殖并增强其对奥沙利铂的敏感性, 可能为大肠癌的基因治疗提供新的靶点.     

薏苡仁油联合奥沙利铂对结肠癌细胞增殖、凋亡的影响

目的 分析薏苡仁油联合奥沙利铂对结肠癌HT-29细胞株增殖、凋亡的影响及其作用机制。方法 将人结肠癌HT-29细胞株作为研究对象,采用四甲基偶氮唑蓝(MTT)法测定不同浓度注射用薏苡仁油和奥沙利铂联合作用对人结肠癌HT-29细胞株增殖的影响,采用流式细胞术检测细胞凋亡情况,采用逆转录聚合酶链反应(RT-PCR)检测Suvivin表达水平。结果 薏苡仁油组、奥沙利铂组、奥沙利铂+薏苡仁油组均会对人结肠癌HT-29细胞增殖产生一定抑制作用,且薏苡仁油浓度越高,作用时间越长,细胞增殖抑制率越高,差异有统计学意义(P<0.05);与薏苡仁油组、奥沙利铂组相比,奥沙利铂+薏苡仁油组细胞增殖抑制率更高,差异有统计学意义(P<0.05);薏苡仁油组、奥沙利铂组、奥沙利铂+薏苡仁油组细胞凋亡率均明显高于空白对照组(P<0.05);薏苡仁油浓度越高,细胞凋亡率也越高,差异有统计学意义(P<0.05);奥沙利铂+薏苡仁油组细胞凋亡率明显高于单独奥沙利铂组、薏苡仁油组,差异有统计学意义(P<0.05);空白对照组中Survivin mRNA为阴性表达,将不同浓度薏苡仁油加入行4...     

Purified intestinal alkaline sphingomyelinase inhibits proliferation without inducing apoptosis in HT-29 colon carcinoma cells

Purpose Sphingomyelin (SM) hydrolysis by sphingomyelinase (SMase) has become an important signalling pathway, with the product ceramide implicated in regulation of cell growth, differentiation and apoptosis. Alkaline SMase is specifically located in the intestinal tract. Marked reductions of the enzyme activity have been found in sporadic colorectal carcinomas and in both adenomas and flat mucosa of patients with familial adenomatous polyposis, indicating an anti-proliferative role in colonic cell growth.Methods We examined the effects of a purified alkaline SMase from rat intestine and a bacterial neutral SMase on cell growth parameters in HT-29 colonic carcinoma cells.Results Alkaline SMase was found to inhibit proliferation of HT-29 cells in both dose-dependent and time-dependent manners. The threshold concentration of the enzyme was approximately 2.5 U/ml, and the maximum effect was obtained at approximately 20 U/ml, which inhibited the cell growth by 50%. The inhibition occurred rapidly, and maximum effect was reached after 12 h of incubation. Dose-dependent inhibition of DNA synthesis was also demonstrated. The effect of alkaline SMase was preceded and accompanied by increased hydrolysis of SM and production of ceramide. Neutral SMase with equivalent hydrolytic capacity did not inhibit cell growth. Alkaline SMase did not induce apoptosis in HT-29 cells. Alkaline SMase did not inhibit growth of IEC-6 cells.Conclusion Alkaline SMase, at doses that induce SM hydrolysis, inhibits growth of colon cancer cells. The inhibition is attributed to an anti-proliferative effect rather than an apoptotic effect.     

Cellular mechanisms involved in the melatonin inhibition of HT-29 human colon cancer cell proliferation in culture

The antiproliferative and proapoptotic properties of melatonin in human colon cancer cells in culture were recently reported. To address the mechanisms involved in these actions, HT-29 human colon cancer cells were cultured in RPMI 1640 medium supplemented with fetal bovine serum at 37 degrees C. Cell proliferation was assessed by the incorporation of [(3)H]-thymidine into DNA. Cyclic nucleotide levels, nitrite concentration, glutathione peroxidase and reductase activities, and glutathione levels were assessed after the incubation of these cells with the following drugs: melatonin membrane receptor agonists 2-iodo-melatonin, 2-iodo-N-butanoyl-5-methoxytryptamine, 5-methoxycarbonylamino-N-acetyltryptamine (GR-135,531), and the antagonists luzindole, 4-phenyl-2-propionamidotetralin, and prazosin; the melatonin nuclear receptor agonist CGP 52608, and four synthetic kynurenines analogs to melatonin 2-acetamide-4-(3-methoxyphenyl)-4-oxobutyric acid, 2-acetamide-4-(2-amino-5-methoxyphenyl)-4-oxobutyric acid, 2-butyramide-4-(3-methoxyphenyl)-4-oxobutyric acid and 2-butyramide-4-(2-amino-5-methoxyphenyl)-4-oxobutyric acid. The results show that the membrane receptors are not necessary for the antiproliferative effect of melatonin and the participation of the nuclear receptor in this effect is suggested. Moreover, the antioxidative and anti-inflammatory actions of melatonin, counteracting the oxidative status and reducing the production of nitric oxide by cultured HT-29 cells seem to be directly involved in the oncostatic properties of melatonin. Some of the synthetic kynurenines exert higher antiproliferative effects than melatonin. The results reinforce the clinical interest of melatonin due to the different mechanisms involved in its oncostatic role, and suggest a new synthetic pathway to obtain melatonin agonists with clinical applications to oncology.     

脂联素对结肠癌HT-29细胞的增殖及凋亡研究

目的探讨脂联素对结肠癌HT-29细胞的增殖、凋亡的影响。方法以不同浓度脂联素干预细胞,MTT法检测细胞增殖能力;AnnexinV／PI双染后流式细胞仪检测细胞凋亡。结果随着脂联素浓度的不断升高和培养时间的延长,HT-29细胞的生长逐渐受到抑制,脂联素可以诱导细胞凋亡。结论脂联素可抑制HT-29细胞增殖,诱导细胞凋亡。     

Mir-483 inhibits colon cancer cell proliferation and migration by targeting TRAF1

MicroRNAs are important regulators during human growth and development. Emerging evidence indicates that microRNAs play important roles in colorectal cancer. The aim of this study is to reveal the biological function and direct target gene of miR-483 in colorectal cancer. The biological function of miR-483 on the proliferation and migration of colon cancer cells was then examined by Edu assay and transwell assay, respectively. Our findings revealed that miR-483 mimic could significantly inhibit cell proliferation and migration. The target gene of miR-483 was predicted by target scan software and identified by a dual fluorescence reporter system which showed that TRAF1 was a direct target gene of miR-483 in SW480 cell line. These data suggest that miR-483 is a colorectal cancer suppressor which could inhibit cell proliferation and migration, possibly via targeting TRAF1. The miR-483 could be a potential treatment target for colorectal cancer.     

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 （0-80 μmol/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-pNA as substrate. The levels of peroxisome PPARδ, 14-3-3ε and 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 10-80 μmol/L curcumin induced typical features of apoptosis and activated the caspase-3 in HT-29 cells. The expression of PPARδ, 14-3-3ε and 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, 14-3-3ε and VEGF in HT-29.     

肠复康对人结肠癌细胞HT-29增殖及浸润转移的影响

[目的] 探讨肠复康中药对人结肠癌细胞HT-29增殖及浸润转移影响的分子机制。[方法] 采用体外培养，应用免疫组化方法，检测其对核增殖抗原Ki-67、金属基质蛋白酶(MMP2)及其相应组织抑制物(TIMP2)表达的影响。[结果] 经中药血清处理过的HT-29细胞表现出增殖受抑，MMP2表达减少及TIMP2分泌增加，且其表达与中药血清浓度有量效关系，以30％血清组效果最明显。[结论] 中药肠复康通过抑制Ki-67的表达及影响MMP2、TIMP2的相互平衡来影响结肠癌细胞的增殖及浸润转移。     

表皮生长因子对HT-29细胞内游离Ca~(2 )和C-AMP的影响

本文应用荧光比色法和放射免疫法动态检测了表皮生长因子对大肠癌HT-29细胞内Ca~(2 )和C-AMP水平的影响。结果发表EGF可呈剂量依赖性升高Ca~(2 )水平,而EGF-R抗体则可阻断此作用;EGF可短时降低C-AMP水平,提示Ca2 和C-AMP参于EGF作用的信息传递。