Inhibition of cell cycle progression by hydroxytyrosol is associated with upregulation of cyclin-dependent protein kinase inhibitors p21(WAF1/Cip1) and p27(Kip1) and with induction of differentiation in HL60 cells

Recent evidence indicates that the cancer preventive activity of olive oil can be mediated by the presence of minor components, such as antioxidant phenolic compounds. However, their mechanisms of action remain largely unknown. In this study, we investigated the in vitro effects of one of the main olive oil phenols, hydroxytyrosol [3,4-dihydroxyphenylethanol (3,4-DHPEA)], on proliferation, cell cycle progression, apoptosis, and differentiation of HL60 human promyelocytic leukemia cells. 3,4-DHPEA showed a potent inhibitory activity on DNA synthesis, as evidenced by a 92% reduction of [3H]-thymidine incorporation at 100 micromol/L, and an induced apoptosis, as evidenced by the release of cytosolic nucleosomes and flow cytometry. This phenol, 3,4-DHPEA, was also able to inhibit the progression of the cell cycle in synchronized HL60 cells, which accumulated in the G0/G1 phase of the cell cycle after 25 h of treatment. Furthermore, 3,4-DHPEA induced differentiation on HL60 cells with a maximum effect (22% of cells) at 100 micromol/L after 72 h of treatment. Among the different proteins involved in the regulation of the cell cycle, 3,4-DHPEA reduced the level of cyclin-dependent kinase (CDK) 6 and increased that of cyclin D3. With regard to the CDK inhibitors, p15 was not altered by 3,4-DHPEA treatment, whereas the expression of p21(WAF1/Cip1) and p27(Kip1) was increased at both protein and mRNA levels. To our knowledge, these results provide the first evidence that 3,4-DHPEA may effect the expression of genes involved in the regulation of tumor cell proliferation and differentiation.     

Oxidative DNA damage is prevented by extracts of olive oil, hydroxytyrosol, and other olive phenolic compounds in human blood mononuclear cells and HL60 cells

Our aim in this study was to provide further support to the hypothesis that phenolic compounds may play an important role in the anticarcinogenic properties of olive oil. We measured the effect of olive oil phenols on hydrogen peroxide (H(2)O(2))-induced DNA damage in human peripheral blood mononuclear cells (PBMC) and promyelocytic leukemia cells (HL60) using single-cell gel electrophoresis (comet assay). Hydroxytyrosol [3,4-dyhydroxyphenyl-ethanol (3,4-DHPEA)] and a complex mixture of phenols extracted from both virgin olive oil (OO-PE) and olive mill wastewater (WW-PE) reduced the DNA damage at concentrations as low as 1 micromol/L when coincubated in the medium with H(2)O(2) (40 micromol/L). At 10 micromol/L 3,4-DHPEA, the protection was 93% in HL60 and 89% in PBMC. A similar protective activity was also shown by the dialdehydic form of elenoic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) on both kinds of cells. Other purified compounds such as isomer of oleuropein aglycon (3,4-DHPEA-EA), oleuropein, tyrosol, [p-hydroxyphenyl-ethanol (p-HPEA)] the dialdehydic form of elenoic acid linked to tyrosol, caffeic acid, and verbascoside also protected the cells against H(2)O(2)-induced DNA damage although with a lower efficacy (range of protection, 25-75%). On the other hand, when tested in a model system in which the oxidative stress was induced by phorbole 12-myristate 13-acetate-activated monocytes, p-HPEA was more effective than 3,4-DHPEA in preventing the oxidative DNA damage. Overall, these results suggest that OO-PE and WW-PE may efficiently prevent the initiation step of carcinogenesis in vivo, because the concentrations effective against the oxidative DNA damage could be easily reached with normal intake of olive oil.     

Synthesis and induction of G0-G1 phase arrest with apoptosis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazepin-4(3H)-one

The multistep synthesis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazepin-4(3H)-one 15 has been carried out. The compound showed antiproliferative and apoptotic effects against K562, K562-R (imatinib mesilate resistant), HL60 and multidrug resistant (MDR) HL60 cell lines. Compound 15 showed a pro-apoptotic activity against HL60 and K562 resistant cell lines markedly higher than etoposide and busulfan, respectively. Flow cytometry studies carried out on K562 cells allowed to establish that 15 induces G0-G1 phase arrest followed by apoptosis.     

Absorption and metabolism of olive oil secoiridoids in the small intestine

The secoiridoids 3,4-dihydroxyphenylethanol-elenolic acid (3,4-DHPEA-EA) and 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA) account for approximately 55 % of the phenolic content of olive oil and may be partly responsible for its reported human health benefits. We have investigated the absorption and metabolism of these secoiridoids in the upper gastrointestinal tract. Both 3,4-DHPEA-EDA and 3,4-DHPEA-EA were relatively stable under gastric conditions, only undergoing limited hydrolysis. Both secoiridoids were transferred across a human cellular model of the small intestine (Caco-2 cells). However, no glucuronide conjugation was observed for either secoiridoid during transfer, although some hydroxytyrosol and homovanillic alcohol were formed. As Caco-2 cells are known to express only limited metabolic activity, we also investigated the absorption and metabolism of secoiridoids in isolated, perfused segments of the jejunum and ileum. Here, both secoiridoids underwent extensive metabolism, most notably a two-electron reduction and glucuronidation during the transfer across both the ileum and jejunum. Unlike Caco-2 cells, the intact small-intestinal segments contain NADPH-dependent aldo-keto reductases, which reduce the aldehyde carbonyl group of 3,4-DHPEA-EA and one of the two aldeydic carbonyl groups present on 3,4-DHPEA-EDA. These reduced forms are then glucuronidated and represent the major in vivo small-intestinal metabolites of the secoiridoids. In agreement with the cell studies, perfusion of the jejunum and ileum also yielded hydroxytyrosol and homovanillic alcohol and their respective glucuronides. We suggest that the reduced and glucuronidated forms represent novel physiological metabolites of the secoiridoids that should be pursued in vivo and investigated for their biological activity.     

二十碳五烯酸联合视黄酸对HL-60细胞株N-ras基因表达的影响

目的 :　研究二十碳五烯酸 (Eicosapentaenoicacid,EPA )是否协同视黄酸 (retinoicacid,RA)影响 HL-60细胞的增殖与分化功能及相应分子机制。方法 :　流式细胞仪 (FCM)测定细胞增殖功能 ;NBT还原实验鉴定 HL-60细胞分化 ;Western blot法分析 p2 1 N- ras表达。结果 :　EPA和 RA联合应用能增强 HL-60细胞的增殖抑制和分化效应 ,同时细胞内 p2 1 N- ras表达降低。结论 :　 EPA和 RA可能通过下调节 N-ras基因的蛋白质表达 ,发挥它们对 HL-60细胞增殖与分化功能的联合效应     

The effects of fish oil,olive oil,oleic acid and linoleic acid on colorectal neoplastic processes

BACKGROUND AND AIMS: Several nutrients play a significant role in colorectal cancer development, and fats could be among the most determinant. While several studies have shown that the n-3 fatty acids eicosapentaenoic and docosahexaenoic and its main dietary source, fish oil could exert important antineoplastic effects, much less is known about the effects of olive oil and its main fatty acid, oleic acid, and linoleic acid. The aim of these studies is to assess the role of these nutrients in crucial processes involved in colorectal carcinogenesis. METHODS: Caco-2 and HT-29 colorectal cancer cells were supplemented with different fats and their role in apoptosis induction, cell proliferation, and differentiation was studied. COX-2 and Bcl-2 expressions were also assessed. RESULTS: Supplementation with fish oil or olive oil results in an induction of apoptosis and cell differentiation. The latest effect was also induced by oleic and linoleic acid. Fish oil diminishes significantly cell proliferation. Supplementation with fish oil and olive oil results in an early downregulation of COX-2 followed by a decrease in Bcl-2 expression. CONCLUSIONS: Fish oil and olive oil are capable of influencing crucial processes responsible for colorectal cancer development. COX-2 and Bcl-2 may be important mediators of some of these effects.     

Lycopene and 1,25-dihydroxyvitamin D3 cooperate in the inhibition of cell cycle progression and induction of differentiation in HL-60 leukemic cells

Lycopene, the major tomato carotenoid, has been found to inhibit proliferation of several types of cancer cells, including those of breast, lung, and endometrium. By extending the work to the HL-60 promyelocytic leukemia cell line, we aimed to evaluate some mechanistic aspects of this effect. Particularly, the possibility was examined that the antiproliferative action of the carotenoid is associated with induction of cell differentiation. Lycopene treatment resulted in a concentration-dependent reduction in HL-60 cell growth as measured by [3H]thymidine incorporation and cell counting. This effect was accompanied by inhibition of cell cycle progression in the G0/G1 phase as measured by flow cytometry. Lycopene alone induced cell differentiation as measured by phorbol ester-dependent reduction of nitro blue tetrazolium and expression of the cell surface antigen CD14. Results of several recent intervention studies with beta-carotene, which have revealed no beneficial effects of this carotenoid, suggest that a single dietary component cannot explain the anticancer effect of diets rich in vegetables and fruits. Thus another goal of our study was to examine whether lycopene has the ability to synergize with other natural anticancer compounds, such as 1,25-dihydroxyvitamin D3, which when used alone are therapeutically active only at high and toxic concentrations. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibited a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression. Such synergistic antiproliferative and differentiating effects of lycopene and other compounds found in the diet and in plasma may suggest the inclusion of the carotenoid in the diet as a cancer-preventive measure.     

舒林酸抑制结肠癌细胞株增殖及其转移机制的研究

目的 研究非选择性COX抑制荆舒林酸对结肠癌细胞株HT-29生长的影响及其参与引起细胞死亡的可能机制.方法 采用四甲基偶氮唑蓝(MTT)比色法检测舒林酸对结肠癌细胞增殖的抑制,激光共聚焦显微镜(LSM)及荧光显微镜观察细胞凋亡,流式细胞仪(FCM)分析其对细胞凋亡及细胞周期的影响.结果 MTT显示舒林酸能呈剂量和浓度依赖性抑制HT-29的增殖.TUNEL染色荧光显微镜下观察凋亡细胞呈棕褐色,AnnexinV/PI染色后LSM观察凋亡细胞胞膜绿染,胞核红染或呈桔黄色,FCM显示此药促进细胞的凋亡,使处于G0/G1期的细胞比例显著降低.结论 舒林酸可抑制结肠癌细胞株HT-29生长,促进其凋亡,其机制可能与其阻止细胞周期的进展有关.     

ω-3PUFA及其诱导的外源性跨膜型TNFα对肿瘤细胞生长的影响

目的:探讨ω-3多不饱和脂肪酸(ω-3PUFA)及其诱导的外源性跨膜型TNFα对肿瘤细胞增殖和凋亡的影响。方法:将ω-3PUFA可调控的跨膜型TNFα真核表达载体转导入HL-60和MCF-7细胞,免疫荧光细胞化学方法检测ω-3PUFA对转染细胞外源基因表达的调控,生长曲线、流式细胞和DNA梯形带分析检测ω-3PUFA对转染细胞增殖能力和凋亡的影响。结果:在6.0×10-5mol/Lω-3PUFA诱导下转染细胞外源性跨膜型TNFα表达增加。HL-60和MCF-7细胞经6.0×10-5mol/Lω-3PUFA处理后增殖能力减弱,但只有HL-60细胞周期阻滞于G0/G1期及形成DNA梯形带。经ω-3PUFA处理后,以上变化在HL-60和MCF-7转染细胞中均更为显著。结论:ω-3PUFA诱导的外源性跨膜型TNFα基因产物可以增强ω-3多不饱和脂肪酸的抗肿瘤能力,而诱导细胞凋亡可能是其中重要机制之一。     

硒和锌对氟致大鼠肾脏细胞凋亡及增殖周期变化的影响

目的 研究一定剂量的硒和锌对氟引起的大鼠肾脏细胞凋亡和细胞增殖周期变化的作用。方法 给Wstar大鼠饮用含50mg／L氟化钠的高氟水,同时通过灌胃方式给予不同剂的硒和锌制剂。6个月后,用TUNEL法和流式细胞术检测大鼠肾脏细胞凋亡和细胞增殖周期的变化。结果 氟能明显诱导大鼠肾脏细胞凋亡,并使G2／M期细胞明显下降,DNA相对含量（DNARC）也显著下降。一定剂量的硒和锌制剂对氟诱导拓大鼠肾脏细胞凋亡具有明显的拮抗作用,而且能明显抑制氟引起的G2／M期细胞减少,但对氟引起的DNARC下降却无明显拮抗作用。结论 氟可诱导大鼠肾脏细胞凋亡并可使细胞增殖周期改变;硒和锌制剂对氟诱导的大鼠肾脏细胞凋亡和细胞增殖周期的变化具有一定的拮抗作用。     

甲基丙烯酸环氧丙酯对人支气管上皮细胞周期及凋亡影响的研究

目的探讨甲基丙烯酸环氧丙酯(GMA)对人支气管上皮细胞周期及凋亡的影响。方法人支气管上皮细胞(16HBE)经1~16μg/ml剂量的GMA染毒不同次数后,应用流式细胞仪(FCM)检测细胞周期及凋亡率的改变,同时测定细胞分裂指数(MI)。结果经1次染毒处理后,随着染毒剂量的增加,G0/G1期细胞显著减少(P<0.01),S期和G2/M期细胞显著增加,凋亡细胞数增多,细胞分裂指数下降;随着染毒次数的增加,各剂量组细胞周期均明显阻滞于G0/G1期,但高剂量组细胞仍表现出S期和G2/M期增多现象;经3次染毒后,高剂量组细胞出现凋亡率下降、分裂指数升高现象。结论经GMA染毒处理后,16HBE细胞周期由G0/G1期向S期和G2/M期移动而呈现增殖性改变。     

β-胡萝卜素对白血病HL-60细胞凋亡及细胞周期分布的影响

目的：　探讨β－胡萝卜素抑制白血病细胞增殖的机制。方法：　体外培养白血病细胞株ＨＬ－６０,培养时添加１０μｍ ｏｌ／Ｌ、５０μｍ ｏｌ／Ｌ、１００μｍ ｏｌ／Ｌβ－胡萝卜素作用２４ｈ、４８ｈ、７２ｈ 后,用台盼蓝拒染法进行活细胞计数,绘制细胞生长曲线;应用流式细胞术分析细胞周期分布,同时利用流式细胞术结合ＤＮＡ 凝胶电泳检测白血病细胞凋亡。结果：　细胞生长曲线显示１０～１００μｍ ｏｌ／Ｌ的β－胡萝卜素均对白血病细胞株ＨＬ－６０ 有显著性抑制作用,且呈剂量效应关系。流式细胞术结果显示５０μｍ ｏｌ／Ｌ的β－胡萝卜素处理ＨＬ－６０ 细胞２４ｈ 后,出现Ｓ期阻滞,并诱导５．５９％ 的细胞凋亡。ＤＮＡ 凝胶电泳结果同样显示β－胡萝卜素能够诱导白血病ＨＬ－６０ 细胞凋亡。结论：　β－胡萝卜素对于髓系白血病细胞株ＨＬ－６０ 细胞的增殖具有显著性抑制作用,其机制可能是干扰的白血病细胞ＤＮＡ代谢;β－胡萝卜素诱导白血病细胞凋亡也是其抑制白血病的重要途径之一。     

人生长激素对结肠癌细胞株细胞周期动力学的影响

目的：了解人生长激素（ｈＧＨ）对于结肠癌细胞有无促增殖和分化作用。方法：取对数生长期的人结肠癌细胞株ＬＯＶＯ,以顺铂和（或）不同浓度的ｈＧＨ体外培养,２４ｈ后以流式细胞增殖周期及细胞凋亡等指标。结果：同时加顺铂和ｈＧＨ培养细胞,癌细胞群在Ｇ２－Ｍ期发生阻滞,细胞凋亡率增加,Ｓ期细胞数率非常显著地降低;加ｈＧＨ１００ｎｇ／ｍｌ组Ｇ０－Ｇ１期九率降低,Ｓ期百分率增高。结论：ＬＯＶＯ细胞表面可能有ｈＧＨ     

洛伐他汀对人粒系白血病细胞生长的影响

目的观察洛伐他汀(Lovastatin)对体外培养的人粒系白血病细胞株HL-60生长的影响。方法采用四甲基偶氮唑蓝(MTT)检测、流式细胞仪分析等技术。结果洛伐他汀可显著抑制HL-60细胞的增殖．且呈剂量一效应关系。流式细胞仪分析结果显示：洛伐他汀不仅能影响该细胞周期进程而且可诱导该细胞凋亡。结论洛伐他汀可能通过影响细胞的生长周期和诱导细胞凋亡来抑制HL-60细胞的增殖。     

Wortmannin抑制PI3K途径对bcr/abl基因介导的白血病细胞增殖和凋亡抗性影响的研究

目的探讨磷酰肌醇-3激酶(PI3K)途径在K562、NB4和HL60细胞增殖和凋亡抗性中的不同作用。方法用磷酰肌醇-3激酶(PI3K)特异抑制剂Wortmannin(WT)抑制PI3K活性,经细胞生长曲线测定、半固体集落形成实验、流式细胞膜联蛋白V(Annexin-V-Flous)标记技术检测细胞凋亡百分比和凋亡指数。观察K562、NB4和HL60细胞增殖能力及凋亡抗性的变化。结果K562、NB4和HL60细胞在24、48、72h的增殖抑制率分别为41.33%、57.46%、65.85%和26.29%、5.51%、2.10%及32.14%、17.14%、13.14%。生长曲线显示WT抑制PI3K途径可显著抑制K562细胞的增殖,对NB4和HL60细胞增殖无明显影响。K562、NB4和HL60细胞加和不加WT,培养14d后的集落形成率分别为16.15%和7.60%,5.90%和6.10%,6.60%和6.40%。集落形成抑制率为52.94%、3.39%和3.03%。K562、NB4和HL60细胞加WT、AraC、WT+AraC作用24h后的凋亡细胞百分比分别为(17.27±1.94)%、(23.25±14.12)%、(17.60±1.27)%;(17.00±3.36)%、(20.55±8.57)%、(22.07±5.62)%;(27.60±4.36)%、(17.56±9.28)%、(20.50±7.97)%。凋亡指数分别为(6.88±2.66)、(7.79±2.75)、(3.03±0.56);(8.91±3.86)、(9.35±4.19)、(3.79±0.93);(13.39±4.49)、(7.61±6.35)、(5.27±2.69)。结论WT可以通过抑制PI3K通     

三羟异黄酮对人乳腺癌细胞增殖和细胞周期的影响

目的 观察三羟异黄酮对体外培养的人乳腺癌细胞MDA—MB—435S细胞存活率、细胞周期和凋亡的影响。方法 用噻唑蓝(MTT)法观察三羟异黄酮对MDA—MB—435S细胞生长的影响；流式细胞仪观察三羟异黄酮处理人乳腺癌细胞后细胞周期改变的剂量效应和时间效应；吖啶橙／溴乙锭染色法在荧光显微镜下观察三羟异黄酮对MDA—MB—435S细胞的凋亡作用。结果 随剂量增大和作用时间延长，三羟异黄酮对细胞增殖的抑制作用逐渐增强。同时可以阻滞细胞周期于G2—M期，而且随剂量的增大，作用时间的延长，阻滞作用也增强。经吖啶橙染色法于荧光显微镜下可见，随三羟异黄酮剂量增大，细胞凋亡也逐渐明显。结论 三羟异黄酮可抑制人乳腺癌细胞的增殖，其作用机制可能包括诱导细胞凋亡和G2—M期阻滞。     

佛波酯对BALB/c 3T3细胞转化早期基因表达的影响

目的 探讨佛波酯(12-O-tetradecanoylphorbol-13-acetate,TPA)促进细胞转化早期基因表达谱的变化。方法 以N-甲基-N’-硝基-N-亚硝基胍(N-methyl-N’-nitro-N-nitrosoguanidine,MNNG)为启动剂,TPA为促癌剂,建立BALB／c3T3细胞转化模型。采用锥虫蓝染色法检测细胞生长情况,流式细胞仪检测细胞周期变化。采用cDNA微阵列检测TPA处理早期的基因表达谱变化。结果 TPA处理早期可抑制细胞增殖,阻滞细胞于G1期与S期。TPA处理4h和24h后,在检测的1152个基因中筛选出19个差异表达基因,其中9个基因表达上调,10个基因表达下调。许多差异表达基因的功能与细胞增殖、凋亡和周期调控相关,主要涉及ras和p53基因信号传导通路。结论 TPA在促进BALB／c3T3细胞转化的早期阶段,可影响某些调节细胞周期进展基因的转录表达,从而导致细胞生长阻滞。     

氟中毒对大鼠肾脏脂质过氧化、细胞坏死、凋亡及增殖周期的影响

目的：研究氟中毒对大鼠肾脏细胞凋亡和对肾脏细胞增殖周期的作用,并研究氟中毒对肾脏氧化应激和肾脏损伤的影响。方法：给Wistar大鼠饮用含50mg/L氟化钠的高氟水,6个月后用TUNEL法和流式细胞术检测大鼠肾脏细胞凋亡和细胞增殖周期的变化。结果：氟中毒能诱导大鼠肾脏TUNEL阳性细胞,且凋亡细胞率较对照组明显增高,并使G2／M期细胞明显下降,DNA相对含量（DNARC）也显著下降。且氟中毒能引起大鼠肾脏氧化应激和组织损伤。结论：本研究提示氟中毒可诱导大鼠肾脏细胞凋亡并可使细胞增殖周期改变。     

大豆苷原对体外培养人胃癌细胞增殖和细胞周期的影响

目的:了解二羟异黄酮对胃癌细胞有无促增殖与诱导凋亡作用。方法:以不同浓度的二羟异黄酮处理人胃癌细胞系MGC-803细胞。然后分别用MTT法测定细胞增殖情况、流式细胞仪和琼脂糖凝胶电泳测定细胞周期和细胞凋亡等。结果:MTT 结果显示:二羟异黄酮对胃癌细胞具有促进和抑制增殖的双相作用-在低浓度(0.1-1 μmol/L)时促进细胞生长,在较高浓度(10-100 μmol/L)时对细胞生长则有抑制作用。流式细胞术结果显示:癌细胞群阻滞在G1期,没有明显凋亡峰的出现;凝胶电泳也末检测到明显的DNA阶梯状条带。结论:二羟异黄酮对体外培养的胃癌细胞的生长有双相作用,较高浓度可抑制胃癌细胞的生长并使细胞阻滞在G1期,而无诱导细胞凋亡的作用。     

1，25-二羟基维生素D3对K562细胞周期及凋亡的影响

目的观察1，25-二羟基维生素D3[1，25（OH）2D3]对白血病细胞株K562细胞周期及细胞凋亡的作用。方法Western印迹检测维生素D受体（VDR）在K562细胞的表达；四噻唑蓝法（MTT）、AO／EB、流式细胞仪分析细胞生长抑制率、细胞凋亡率及细胞周期。结果（1）K562细胞核阳性表达VDR；（2）0-10^-6mol／L浓度的1，25（OH）2D3呈浓度依赖性抑制K562细胞增殖，10^-8mol／L 1，25（OH）2D3明显抑制K562细胞增殖，促进凋亡，细胞周期阻滞主要发生在G2期或M早期，凋亡率从4．1％（对照组）增至26．5％（P〈0．01）。结论1，25（OH）2D3可明显抑制K562细胞增殖，促进细胞凋亡。