Nimesulide诱导胰腺癌细胞凋亡机制的研究

目的：探讨选择性COX-2抑制剂Nimesulide对人胰腺癌PANC-1细胞增殖和凋亡的影响及其可能分子机制。方法：应用四甲基偶氮唑蓝（MTT）法观察不同浓度Nimesulide对PANC-1细胞增殖的影响;流式细胞术（FACS）及DNA梯状电泳（DNA ladder）检测PANC-1细胞凋亡的改变;Western blotting法检测Nimesulide不同浓度作用下PANC-1细胞COX-2蛋白水平的改变,RT-PCR法检测COX-2 mRNA水平的变化。结果：MTT、流式细胞术及DNA ladder显示Nimesulide呈剂量依赖性地抑制PANC-1细胞的增殖,并诱导其凋亡;Western blotting和RT-PCR法显示随着药物浓度的增加,COX-2蛋白及mRNA表达降低。结论：Nimesulide可能通过对COX-2表达的下调而诱导凋亡,从而抑制人胰腺癌PANC-1细胞生长。     

辛伐他汀对血小板源生长因子诱导的肺血管平滑肌细胞内粘着斑及肌动蛋白细胞骨架组装的影响及意义

目的观察辛伐他汀（simvastatin）对血小板源生长因子（platelet—derived growth factor—BB，PDGF—BB）诱导的增殖细胞内粘着斑（focal adhesion，FA）蛋白及肌动蛋白细胞骨架动态组装的影响，旨在探讨辛伐他汀抑制血管平滑肌细胞（vascular smooth muscle cell，VSMC）增殖和迁移与细胞骨架变化的关系。方法以体外培养的SD大鼠血管平滑肌细胞为基础，[^3H]—TdR掺入量测定DNA合成，透射电镜观察细胞的表型状态，采用免疫细胞化学和荧光细胞化学法，观察辛伐他汀对血小板源生长因子诱导的肺血管平滑肌细胞增殖细胞内粘着斑蛋白及肌动蛋白细胞骨架组装的影响。结果血小板源生长因子受刺激后（对照组），血管平滑肌细胞[^3H]-TdR掺入量明显增加，电镜示细胞超微结构出现表型变化，血管平滑肌细胞中增殖细胞内粘着斑蛋白中的桩蛋白（paxillin）体积增大、数量增加，血管平滑肌细胞内F—actin数量明显增加，呈纵向平行排列，α—SM—actin体积缩小、数量减少。辛伐他汀可明显抑制这些生物学效应（药物干预组）。结论辛伐他汀可以抑制血小板源生长因子介导的血管平滑肌细胞内增殖细胞内粘着斑蛋白中的桩蛋白，F—actin，α-SM-actin的动态组装，进而发挥抑制血管平滑肌细胞增殖和迁移的能力。     

微小RNA-152介导叶酸对体外血管平滑肌细胞增殖迁移的抑制作用

目的探究叶酸对(folic acid,FA)血小板源生长因子(PDGF-BB)诱导的血管平滑肌细胞(VSMCs)增殖迁移的影响及其机制。方法体外用PDGF-BB诱导大鼠血管平滑肌细胞系A7r5增殖迁移,分为对照组、PDGF组、PDGF+FA组、PDGF+FA+miRNA-152 inhibitor组、PDGF+FA+miRNA-152 NC组。采用实时定量聚合酶链反应(RT-PCR)检测各组VSMCs内miR-152的表达水平。采用CCK-8试剂盒检测各组VSMCs增殖水平。采用划痕实验检测各组VSMCs迁移水平。采用蛋白印迹法检测细胞增殖核抗原(PCNA)蛋白、基质金属蛋白酶9(MMP-9)的表达水平。结果 RT-PCR结果显示PDGF干预降低VSMCs miR-152表达水平,而PDGF+FA组VSMCs miR-152表达水平显著高于PDGF组(P0.05)。PDGF干预VSMCs的增殖迁移能力显著增强相对于对照组(P0.05),而PDGF+FA组的VSMCs增殖迁移能力低于PDGF组(P0.05),PDGF+FA+miR-152 inhibitor组的VSMCs增殖迁移能力强于PDGF+FA组(P0.05)。结论 miR-152参与介导FA抑制PDGF-BB诱导的VSMCs增殖迁移作用。[营养学报,2017,39(5):484-488]     

澳洲茄胺盐酸盐对体外HeLa细胞培养生长抑制作用的研究

[目的]探索SBHL对体外培养HeLa细胞生长抑制影响,了解SBHL抗肿瘤活性. [方法]用细胞生长计数法观察SBHL对HeLa细胞生长抑制作用;MTT法测定SBHL抗肿瘤活性;流武细胞仪检测HeLa细胞DNA合成率和凋亡率. [结果]细胞生长计数法证实SBHL对HeLa细胞生长有抑制作用,且随药物浓度增加给药时间延长,其抑制作用增强;MTT法证实SBHL对HeLa细胞集落形成有抑制作用,并随SBHL浓度增加其抑制率也随之增强;流式细胞仪检测证实不同浓度SBHL对HeLa细胞DNA合成抑制率和凋亡率产生不同影响,且随药物浓度增加和给药时间延长,其抑制作用增强. [结论]SBHL能抑制HeLa细胞生长增殖作用,能抑制HeLa细胞DNA合成和诱导HeLa细胞凋亡.     

沉默信息调节因子1小干扰RNA诱导前列腺癌细胞PC3细胞凋亡

摘要:目的　观察沉默信息调节因子1（SIRT1）小干扰RNA（siRNA）对前列腺癌细胞PC3细胞生长增殖、DNA合成、细胞凋亡和Bcl-2和Bax蛋白的表达变化,探讨SIRT1在前列腺癌发生中的可能机制。方法　体外培养PC3细胞,分空白对照组（mock组）,转染阴性对照组（scramble siRNA组）和SIRT1 siRNA转染组;Western blot检测PC3细胞中SIRT1的干涉效能;MTT法测定PC3细胞的增殖率;BrdU掺入法测定DNA合成;流式细胞术检测细胞凋亡;Western blot检测PC3细胞中细胞凋亡关键调控因子Bcl-2和Bax的蛋白表达。结果　与对照组比较,SIRT1 siRNA组SIRT1蛋白表达降低（P＜0.01）,PC3细胞的增殖和DNA合成明显受抑制（P＜0.01）,细胞凋亡比例增加（P＜0.01）,Bcl-2蛋白表达减少,Bax的表达增加。结论　下调SIRT1的表达抑制细胞增殖和DNA合成,诱导前列腺癌PC3细胞发生凋亡,其机制可能与改变细胞凋亡关键调控因子Bcl-2和Bax的蛋白表达相关。     

三七皂苷R1对血管紧张素Ⅱ诱导的小鼠血管平滑肌细胞增殖及AT1R/MAPKs表达水平的影响

[目的]探讨三七皂苷R1(NR1)对血管紧张素Ⅱ(AngⅡ)诱导的小鼠主动脉血管平滑肌细胞(MOVAS细胞)增殖及血管紧张素Ⅱ1型受体(AT1R)/丝裂原活化蛋白激酶(MAPKs)信号通路的影响.[方法]体外培养MOVAS细胞,予以AngⅡ诱导后,采用BrdU法检测细胞增殖.通过Western blot法检测细胞中An...     

CD74小干扰RNA通过NF - κB途径诱导胃癌细胞凋亡的实验研究

目的 观察CD74小干扰RNA（siRNA）对胃癌细胞BGC - 823细胞生长增殖、DNA合成、细胞凋亡的影响,通过检测NF - κB信号通路家族成员P65及细胞凋亡关键调控因子Bcl - 2和Bax的表达变化,探讨CD74在胃癌发生发展中的可能机制。方法 选取胃癌细胞BGC - 823进行体外培养,选取对数生长期的细胞进行后续实验。实验分成3组:空白对照组（mock组）,转染对照组（control siRNA组）和CD74 siRNA转染组。western blotting检测细胞中CD74 siRNA对胃癌细胞BGC - 823中CD74的干涉效能;MTT法测定不同分组胃癌细胞BGC - 823的增殖率;BrdU掺入法测定BGC - 823细胞的DNA合成;流式细胞术检测各组细胞的细胞凋亡情况;western blotting检测细胞中P65蛋白、Bcl - 2和Bax的蛋白表达。结果 与2组对照组比较,CD74 siRNA组CD74蛋白表达降低,BGC823细胞的增殖和DNA合成明显受抑制,细胞凋亡比例增加,P65蛋白和Bcl - 2蛋白表达减少,Bax的表达增加。结论 下调CD74的表达抑制胃癌细胞BGC - 823增殖和DNA合成,诱导胃癌BGC823细胞发生凋亡,其作用机制可能与抑制NF - κB家族成员P56的表达,进而改变细胞凋亡关键调控因子Bcl - 2和Bax的表达相关。     

ERK1/2在氧化型低密度脂蛋白诱导血管平滑肌细胞增殖中的作用

目的研究细胞外信号调节蛋白激酶(extracellular signal-regulated kinase 1 and 2,ERK1/2或p42-44MARK)信号通路在氧化型低密度脂蛋白(oxidized low density lipoprotein,Ox-LDL)诱导血管平滑肌细胞增殖中的作用.方法采用3个时间水平(24h、48h、72h),4个剂量水平(0,50,100,200μg/ml)的两因素析因设计观察Ox-LDL对兔主动脉血管平滑肌细胞(vascular smooth muscle cels,VSMCs)增殖影响的时间、剂量效应关系;Ox-LDL对兔主动脉血管平滑肌细胞ERK1/2活性影响;ERK1/2的特异断剂U0126对Ox-LDL诱导兔主动脉血管平滑肌细胞增殖的影响.结果Ox-LDL在剂量为50,100μg/ml时,可诱导血管平滑肌细胞增殖,当Ox-LDL剂量达到200μg/m1时,细胞增殖能力迅速降低,并与其作用时间和剂量显著相关(P值均＜0.01);Ox-LDL可引起血管平滑肌细胞ERK1/2活性的改变;ERK1/2的特异阻断剂U0126可完全抑制Ox-LDL诱导的VSMCs增殖.结论Ox-LDL诱导血管平滑肌细胞增殖与其作用浓度、时间相关;ERK1/2信号通路可能在Ox-LDL诱导的血管平滑肌细胞增殖过程中起着关键的信号转导作用.     

Pkd2基因低表达调控ERK1/2途径诱导血管平滑肌细胞表型转化

目的探讨ERK1/2途径是否参与Pkd2基因低表达诱导主动脉血管平滑肌细胞(VSMCs)表型转化及可能分子机制。方法原代培养小鼠主动脉VSMCs,转染Pkd2+/-突变载体,构建Pkd2基因低表达细胞模型。实验共分为空白对照的Control组、Pkd2+/-组、空病毒组、Ets1组(Pkd2促进剂)、PD98059组(ERK抑制剂)、EGF组(ERK激动剂)。Western blot检测多囊蛋白2(PC2,Pkd2编码蛋白)、a-SMA(VSMCs收缩型标志蛋白)、骨桥蛋白(OPN,VSMCs增殖型标志蛋白)、ERK1/2、ERK磷酸化蛋白(P-ERK1/2)表达水平;RT-PCR检测PC2、a-SMA、OPN、ERK1、ERK2 mRNA表达水平;MTT法检测细胞增殖。结果 (1)Pkd2+/-组中PC2蛋白及mRNA表达明显下调,Pkd2基因低表达模型构建成功。(2)Pkd2+/-组中a-SMA表达下调、OPN表达升高,VSMCs细胞增殖明显,细胞发生了表型转化;加入Ets1后被明显抑制(P0.05)。(3)Pkd2+/-组中ERK1/2及P-ERK1/2表达明显升高,加入PD98059后表达被抑制,但PC2表达无变化(P0.05)。(4)Pkd2+/-组中加入PD98059后,a-SMA表达升高、OPN表达下调,VSMCs细胞增殖被抑制,细胞表型转化被抑制。结论 Pkd2基因低表达可以诱导小鼠主动脉VSMCs表型转化,这一过程可能与ERK1/2异常活化有关。     

大肠癌微血管和PCNA的形态计量学分析

肿瘤生长、侵袭及转移依赖新生血管生成，细胞增殖加快是癌细胞的基本特征，增殖细胞核抗原(PCNA)是一种细胞内与DNA转录、合成、修复有关的蛋白，常用于检测细胞的增殖活性。本研究采用免疫组化和病理图像分析技术对大肠癌微血管、PCNA进行检测以探讨其与临床病理因素的关系。     

硒和锌对人食管癌细胞株Eca109生长增殖影响的血清生理学研究

目的观察不同剂量硒、锌灌胃大鼠血清对人食管癌细胞株Eca109生长增殖的影响。方法将SD大鼠随机分为7组(基础饲料组、低硒组、高硒组、低锌组、高锌组、低硒低锌组、高硒高锌组),每组8只。喂养30天后取大鼠血清培养人食管癌细胞株Eca109和人正常肝上皮细胞株HL7702。用AAS法分别测定各组大鼠血清硒、锌;采用MTT法、3H-TDR掺入实验研究不同浓度硒、锌灌胃大鼠血清对两株细胞生长增殖的影响。结果 (1)基础饲料组血清硒、锌水平最低,高锌组血清锌最高;高硒高锌灌胃组大鼠血清硒水平最高,低硒低锌灌胃组血清硒水平次之,均明显高于基础饲料组;而此两组大鼠血清锌与基础饲料喂饲组大鼠血清锌水平差异无统计学意义(P>0.05);(2)与小牛血清对照组相比,只有高硒高锌灌胃组大鼠血清从第72h起抑制癌细胞生长(P<0.05),其余各组均促进食管癌细胞的生长;且该组大鼠血清也抑制肝细胞生长(P<0.05);(3)高硒高锌灌胃组大鼠血清明显抑制食管癌细胞DNA合成(P<0.05),其余各组与对照组作用相近,但该组对肝细胞DNA合成的抑制作用也最强。结论硒、锌在吸收、代谢等方面可能存在相互抑制作用;血清硒、锌含量较低会促进人食管癌细胞的增殖,而增加硒、锌的摄入可提高血清硒、锌的含量且可能抑制癌细胞的增殖。     

Injury to cultured human vascular endothelial cells by copper (CuSO4).

The effect of copper sulfate (CuSO4) on cultured human vascular endothelial (HVE) cells and cultured human fibroblasts (HAIN-55) was investigated. HVE cells were collected from umbilical veins by enzymatic digestion with collagenase. The viability, subsequent growth and DNA synthesis of both cell types were inhibited concentration-dependently by the addition of copper. The cytotoxic effect of copper on the morphology of these cells was also concentration-dependent. However, the cytotoxic effect of copper on the viability, subsequent growth and DNA synthesis was greater in HVE cells than in HAIN-55 cells. These results suggest that HVE cells are more susceptible to concentration-dependent copper cytotoxicity than HAIN-55 cells are, and that copper could induce vascular endothelial injury, which may be involved in the pathogenesis of cardiovascular disease.     

胆碱与叶酸组合对人成淋巴细胞株DNA损伤效应

目的探讨叶酸充足时胆碱缺乏对人成淋巴细胞株的遗传损伤效应。方法在甲硫氨酸(Met)浓度为50μmol/L条件下,设置0～21.5μmol/L的胆碱与30、60、120、240nmol/L的叶酸(folic acid,FA)组成不同浓度组合,培养人成淋巴细胞株9d后,利用胞质阻断微核细胞组分析(CBMNCyt),评价上述组分缺乏诱发的微核化双核细胞(MNedBNC)、核质桥(NPB)及核芽(NBUD)千分率。结果各叶酸浓度下,低浓度胆碱组(0、3、6μmol/L)与高浓度胆碱组(12、18、21.5μmol/L)之间的MNedBNC及NBUD千分率差异有统计学意义(P0.001);低叶酸情况下(30、60nmol/L),12μmol/L胆碱以上的NPB千分率显著降低(P0.001),而高叶酸情况下(120、240nmol/L)各胆碱浓度之间的NPB率无显著差异。胆碱和叶酸对MNedBNC、NPB及NBUD变异的贡献率均达到了极显著(P0.001)。结论胆碱不足对人成淋巴细胞株造成遗传损伤,该细胞株基因组的稳定需要叶酸和胆碱浓度分别维持在120nmol/L和12μmol/L以上。     

Beef conjugated linoleic acid isomers reduce human cancer cell growth even when associated with other beef fatty acids

Although many data are available concerning anticarcinogenic effects of industrial conjugated linoleic acid (CLA), few studies have reported the antitumour properties of CLA mixtures originating from ruminant products. The aim of the present study was to investigate the in vitro antiproliferative effects of beef CLA mixtures on breast, lung, colon, melanoma and ovarian human cancer cell lines. For this purpose, four fatty acid (FA) extracts prepared from beef lipid and varying in their CLA composition, their corresponding purified CLA-enriched fractions, and mixtures of pure synthetic CLA, the composition of which reproduced that of the four selected beef samples, were tested on cancer cell lines. Cancer cells were exposed for 48 h to medium containing 100 microm-FA and their proliferation was determined by quantifying cellular DNA content (Hoechst 33342 dye). Compared with cells incubated without FA, the number of cancer cells was reduced from 25 to 67 % (P<0.0001) following FA treatment. Antiproliferative effects of CLA mixtures varied in magnitude according to the source of FA, the CLA composition and the cell lines. CLA mixtures naturally present in beef inhibited the proliferation of human cancer cell lines, a high content in cis-trans isomers allowing the most important antiproliferative effect. Beef total FA exhibited a greater growth-inhibitory activity than their corresponding CLA-enriched fractions. These results suggested that either beef FA other than beef CLA could possess antiproliferative properties and/or the existence of complementary effects of non-conjugated FA and CLA, which could favour the antiproliferative properties of beef total FA.     

β-紫罗兰酮对人乳腺癌细胞抑制作用

目的　研究 β 紫罗兰酮对人乳腺癌细胞 (MCF 7)生长的影响。 方法　采用细胞核分裂 ,生长曲线 ,集落形成和DNA合成实验 ,观察了用不同浓度 β 紫罗兰酮 (2 5、5 0、10 0和2 0 0 μmol L)对MCF 7细胞生长作用。 结果　β 紫罗兰酮可明显抑制MCF 7细胞增殖、细胞核分裂、集落形成和细胞DNA的合成 ,随着剂量的增加 ,抑制作用增强 ,IC50 值为 10 4 μmol L。细胞核分裂的抑制率分别为 2 4h 12 88%～ 6 8 6 7%。 4 8h 2 0 79%～ 87 79% ;集落形成抑制率分别为 2 4h 14 11%～ 6 5 18% ,4 8h 6 5 8%～ 72 4 8% ;DNA合成实验抑制率为 2 4h 16 75 %～6 5 33% ,4 8h 35 10 %～ 81 89%。结论　β 紫罗兰酮可抑制MCF 7细胞的生长 ,其机制需要进一步探讨。     

Soybean isoflavones, genistein and genistin, inhibit rat myoblast proliferation, fusion and myotube protein synthesis.

The isoflavones, genistein and genistin, are cytotoxic in vitro (e.g. , inhibition of cell proliferation), due in part to inhibition of protein tyrosine kinase and DNA topoisomerase activities. Normal cell functions associated with these enzymatic activities could potentially be impaired in animals through ingestion of soybean products. In this study, cultured rat myogenic cells (L8) were used to determine whether genistein or genistin influences myoblast proliferation and fusion, and myotube protein synthesis and degradation. Genistein or genistin was dissolved in dimethylsulfoxide and included in the culture medium at 0, 1, 10 or 100 micromol/L. Myoblast proliferation was measured by methyl-3H-thymidine incorporation over 48 h. Myoblast differentiation was evaluated by the number of nuclei in multinucleated myotubes. Myotube protein synthesis was measured by 2-h 3H-amino acid incorporation into the myosin and total protein pools after acute (2 h) or chronic (24 h) exposure to similar treatments; protein degradation was measured by measuring radioactivity in protein pools following a time course of protein breakdown after myotube proteins were prelabeled with 3H-amino acids. Genistein or genistin strongly inhibited in vitro myoblast proliferation (P < 0.001) and fusion (P < 0.001) in a dose-dependent manner with effective genistein concentration as low as 1 micromol/L. Genistein or genistin inhibited protein accretion in myotubes (P < 0.001). Decreased protein accretion is largely a result of inhibition on cellular (myofibrillar) protein synthesis rate. No adverse effect on protein degradation was observed. Results suggest that if sufficient circulating concentrations are reached in tissues of animals consuming soy products, genistein/genistin can potentially affect normal muscle growth and development.     

共轭亚油酸对人胃腺癌细胞的抑制作用

采用体外细胞培养方法，研究共轭亚油酸（ＣＬＡ）对人胃腺癌细胞（ＳＧＣ－７９０１）生长的影响。ＣＬＡ的剂量分别为２５、５０、１００和２００μｍ ｏｌ／Ｌ，以乙醇为溶剂对照。结果表明：ＣＬＡ 能抑制ＳＧＣ－７９０１细胞的增殖、细胞核分裂、集落形成和细胞ＤＮＡ的合成，并诱导ＳＧＣ－７９０１细胞的分化     

Mulberry Leaf and Neochlorogenic Acid Alleviates Glucolipotoxicity-Induced Oxidative Stress and Inhibits Proliferation/Migration via Downregulating Ras and FAK Signaling Pathway in Vascular Smooth Muscle Cell

Mulberry leaf (Morus alba L.) has been used as a health food and in traditional medicine to treat several metabolic diseases, including diabetes, hypertension, and hyperlipidemia. However, the mechanism by which mulberry leaf and its functional components mediate atherosclerosis remains unclear. This study aimed to determine the effect of mulberry leaf extract (MLE) and its major component, neochlorogenic acid (nCGA), on the proliferation and migration of rat aortic vascular smooth muscle cells (VSMCs, A7r5 cell line) under diabetic cultured conditions (oleic acid and high glucose, OH). Our findings showed that MLE and nCGA significantly inhibited cell proliferation and migration in A7r5 cells as determined by a scratch wound assay and a Transwell assay. Furthermore, we observed MLE and nCGA inhibited cell proliferation and migration, such as reducing the phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt), focal adhesion kinase (FAK), and small GTPase proteins using Western blot analysis. In conclusion, we confirmed the anti-atherosclerotic effects of MLE and nCGA in reducing vascular smooth muscle cell (VSMC) migration and proliferation under diabetic cultured conditions via inhibition of FAK/small GTPase proteins, PI3K/Akt, and Ras-related signaling.     

Effect of vitamin E on oxysterol- and fatty acid hydroperoxide-induced changes of repair and permeability properties of cultured endothelial cell monolayers

Oxidation products of fatty acids (fatty acid hydroperoxides) or of cholesterol (oxysterols) may be atherogenic by being injurious to the vascular endothelium. Vitamin E may protect cells against such injury by acting as an antioxidant and by regulating cell growth and/or repair. As indices of proliferation and growth/repair, synthesis of DNA [3H]thymidine incorporation) and protein ([3H]leucine incorporation), as affected by exposure to linoleic acid hydroperoxide (18:2-OOH), cholestan-3 beta, 5 alpha, 6 beta-triol (Triol), and/or alpha-tocopherol, was determined in confluent vascular endothelial cell cultures. Cell injury was assessed by measuring the passage of albumin through a cultured endothelial monolayer. Exposure to either Triol or 18:2-OOH significantly increased the rate of albumin transfer across endothelial monolayers. Prior enrichment with vitamin E protected endothelial cells from injury by 18:2-OOH but not Triol. Cell exposure to 25 microM vitamin E increased DNA synthesis compared with control cultures. DNA synthesis was also elevated in 18:2-OOH exposed cells, whereas Triol had no effect on cell replication. Prior cell exposure to vitamin E prevented the marked increase in DNA synthesis seen with 18:2-OOH. Protein synthesis was increased by 18:2-OOH, but not by Triol or vitamin E treatment. These results show that 1) both Triol and 18:2-OOH are cytotoxic, 2) vitamin E stimulates cell proliferation, 3) vitamin E protects cells against 18:2-OOH- but not Triol-induced cell injury (i.e., increased permeability to albumin), and 4) endothelial cell damage initiated by 18:2-OOH, but not Triol, stimulates synthesis of DNA and protein in an attempt to divide and repair the injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

Folates Induce Colorectal Carcinoma HT29 Cell Line Proliferation Through Notch1 Signaling

Folic acid (FA) consumption at high levels has been associated with colon cancer risk. Several mechanisms have been proposed to explain this association. The Notch signal pathway has been implicated in the regulation of cellular proliferation. Our aim was to demonstrate that high concentrations of FA or its reduced form, 5-methyltetrahydrofolic acid (5-MTHF), increase colorectal carcinoma HT29 cell proliferation through an increase of Notch1 activation and to prove if the inhibition of Notch1 activation by gamma secretase inhibitor, reduce the effect of folic acid. HT29 cells were cultured in high (400 nM), low (20 nM), or 0 nM FA or 5-MTHF concentrations during 96 h with or without DAPT (gamma secretase inhibitor). Cell proliferation was determined by the methylthiazole tetrazolium method, and Notch1-intracellular domain (NICD) was analyzed by flow cytometry. HT29 cells exposed to 400 nM FA or 5-MTHF showed higher proliferation rate than those exposed to 20 nM of FA or 5-MTHF (P < 0.01) during 96 h. NICD expression increased at higher FA or 5-MTHF concentrations compared with lower concentrations (P < 0.01). This effect on proliferation was partially reversible when we blocked Notch1 activation with the inhibitor of γ-secretase (P < 0.05).These data suggest that high concentration of FA and 5-MTHF induce HT29 cell proliferation activating Notch1 pathway.