节律基因Per2对胶质瘤细胞增殖和凋亡的影响

目的探讨节律基因Per2对胶质瘤细胞的影响及其作用机制。方法将Per2表达质粒pcDNA3.1-Per2及空载对照质粒pcDNA3.1分别经阳离子脂质体介导转染CHG-5细胞,用G418筛选出Per2稳定表达细胞株;分别用MTT法、流式细胞仪、RT-PCR技术,检测CHG-5细胞增殖、细胞周期和凋亡,以及该细胞株中增殖、凋亡相关基因p53和c-myc表达。结果筛选到稳定表达Per2基因的细胞株CHG-5/Per2细胞,Per2有抑制肿瘤细胞增殖能力;与对照组（pcDNA 3.1-CHG-5）和未处理组（CHG-5）比较,转染组CHG-5/Per2细胞在G1期阻滞,细胞凋亡明显增加（P均〈0.05）;Per2可明显上调p53基因表达,抑制c-myc基因表达。结论节律基因Per2可促进胶质瘤细胞凋亡,抑制细胞增殖,是胶质瘤中的肿瘤抑制因子。     

p21WAF1/CIP1 基因转染对胃癌细胞生物学活性的影响

目的探讨p21^WAF1／CIP1基因(p21基因)对人胃癌细胞系(BGC)生物学活性的影响。方法应用分子克隆技术构建p21^WAF1／CIP1基因真核表达载体，然后用脂质体法将其导入到人胃癌细胞BGC中，经G418筛选获得可稳定表达p21^WAF1／CIP1的人胃癌细胞克隆，用中性红摄入法观察细胞生长速率，流式细胞仪(FcM)检测细胞周期变化。结果p21导入胃癌BGC细胞后，肿瘤细胞增值能力明显受到抑制，并出现细胞周期G1期阻滞。结论p21基因具有抑制胃癌细胞增殖的作用，可作为胃癌基因治疗的靶基因．     

重组核心蛋白聚糖转染对HepG2细胞周期、凋亡以及P21表达的影响

目的将已构建完成的分泌型核心蛋白聚糖（DCN）真核表达载体转染到HepG2中并检测其表达同时研究其抗肿瘤作用的机制。方法脂质体介导分泌型DCN真核表达载体转染HepG2细胞，经G418筛选建立稳定转染的细胞株，采用RT-PCR、免疫组化检测其表达。MTT检测细胞增殖活力，流式细胞仪分析细胞周期，RT-PCR方法检测P21^WAF1/CIP1mRNA表达情况。结果RT-PCR可见转染组细胞DCNmRNA表达明显增多，免疫组化可见转染组细胞DCN蛋白表达明显增高。细胞生长曲线显示转染组细胞生长缓慢；G1期细胞显著增多；P21^WAF1/CIP1mRNA表达增高。结论本研究成功建立稳定转染DCN的HepG2细胞株，证实DCN通过阻滞细胞周期、诱导细胞凋亡和提高P21^WAF1/CIP1蛋白抑制HepG2的生长。     

丝裂原活化蛋白激酶特异性小干扰RNA表达载体对结肠癌细胞周期和DNA甲基化的影响

目的 构建丝裂原活化蛋白激酶（MEK）基因的小干扰RNA（siRNA）表达载体，观察其静默效应及对结肠癌细胞SW1116生长周期和DNA甲基化的影响。方法 选择MEK不同靶点寡核苷酸片段，克隆到pGCsilencer真核表达载体中。脂质体转染SW1116细胞，荧光显微镜评估转染效率，G418筛选稳定表达siRNA的细胞。Western印迹法检测siRNA对MEK蛋白表达的静默效果。应用四甲基偶氮唑盐微量酶反应比色法检测细胞生长活力，流式细胞术分析细胞周期，甲基化特异性PCR和DNA测序检测p16^INK4A基因启动子甲基化状态。结果 构建2个靶点的MEK重组质粒，分别转染和联合转染SW1116细胞，转染效率约为72．1％，G418筛选培养2周得到稳定表达MEK siRNA的细胞，MEK蛋白抑制率分别为74．2％和69．1％和90．2％，下游分子ERK蛋白磷酸化水平随之降低；细胞增殖活力下降2～4倍和细胞周期阻滞于G1期，细胞周期负调控冈子p16^INK4A启动子区呈低甲基化状态。结论 MEK特异性siRNA表达载体对结肠癌细胞MEK蛋白表达有一定的静默效果，多靶点联合效果更好，阻滞细胞周期于G1期，促进p16^INK4A基因去甲基化。     

p15INK4B和p21WAF1基因联合转染对人食管鳞癌细胞系EC109的协同抑制作用

目的:探讨p15INK4B和p21WAF1基因联合转染对人食管鳞癌细胞系EC109细胞增殖和凋亡的影响.方法:脂质体介导PcDNA3.1(+)-p15和pcDNA3.1(+)-p21转染EC109细胞,稳定筛选后用RT-PCR检测转染细胞p15与p21基因mRNA表达,Western blot检测转染细胞P15和P21蛋白的表达.用MTT法和透射电镜检测p15和p21基因分别及联合转染对EC109细胞增殖与凋亡的影响,流式细胞仪检测EC109细胞周期分布与凋亡率.结果:p15和p21转染组EC109细胞生长速度低于空载体组与未转染组,联合转染组与二者单独转染组相比.亦明显抑制EC109细胞体外生长速度.p15和p21转染组EC109细胞发生G1/S阻滞,G1期细胞比例显著高于空载体组和未转染组,S期则显著降低(G1期:60.52%±3.75%,63.12%±2.89% vs 42.17%±5.30%.41.38%±6.54%;S期:22.67%±1.25%,17.96%±2.03% vs 30.96%±3.33%,36.05%±1.78%,均P<0.01),并出现凋亡峰,透射电镜亦发现p15和p21转染组发生细胞凋亡,联合转染组发生更为明显的G1/S阻滞,G1期比例显著升高、S期比例明显降低(G1期:72.83%±2.31% vs60.52%±3.75%,63.12%±2.89%:S期:13.59%±2.59% vs 22.67%±1.25%,17.96%±2.03%.均P<0.05),凋亡率明显升高(21.21%±1.78%vs 4.32±1.74%,10.83%±2.40%,均P<0.01).结论:p15和p21基因联合转染在体外可以进一步增强对人食管鳞癌EC109细胞的抑制与诱导凋亡作用.     

丙戊酸钠对肝癌SMMC-7721细胞增殖和细胞周期的影响及机制

目的:探讨丙戊酸钠(VPA)对人肝癌SMMC-7721细胞增殖、细胞周期及对p21WAF1/CIP1mRNA表达的影响.方法:实验分为空白对照组、PBS组、VPA0.2mmol/L组、VPA1.0mmol/L组和VPA5.0mmol/L组.不同浓度VPA干预人肝癌SMMC-7721细胞24h、48h和72h,采用MTT法检测细胞存活率,流式细胞仪检测细胞周期;干预72h后,用Real-timePCR法检测VPA干预72h后p21WAF1/CIP1mRNA的表达情况.结果:与空白对照组及PBS组比较,不同浓度的VPA作用24h,48h及72h时组肝癌SMMC-7721细胞增殖均出现了不同程度抑制(请将具体数据列出来P<0.05),随着VPA药物浓度升高,细胞增殖抑制作用逐渐增强,随作用时间延长,抑制程度逐渐增强(P<0.05).随药物浓度升高,G1期细胞比例逐渐增多,S期细胞比例逐渐减少,细胞发生G0/G1期阻滞.VPA干预肝癌SMMC-7721细胞72h后,VPA组p21WAF/CIP1mRNA表达较空白对照组及PBS组表达明显升高(请将具体数据列出来P<0.01).结论:VPA可抑制人肝癌SMMC-7721细胞的增殖,且呈时间及剂量依赖性,并诱导出现G0/G1细胞周期阻滞,同时上调p21WAF1/CIP1mRNA的表达.     

survivin反义寡核苷酸对SMMC-7721细胞增殖和凋亡的影响

目的 观察survivin反义寡核苷酸(ASODN)对人肝癌细胞株SMMC-7721增殖和凋亡的影响.方法 人工合成survivin基因ASODN和正义ODN(SODN),并行硫代磷酸化修饰,通过脂质体途径转染SMMC-7721;分别用RT-PCR和Western blot检测survivin mRNA和蛋白表达;用MTT法检测ASODN对SMMC-7721增殖的影响;流式细胞仪检测细胞周期变化及细胞凋亡率;倒置显微镜观察细胞形态变化.结果 SMMC-7721可强表达survivin mRNA和蛋白;ASODN呈浓度依赖性抑制survivin mRNA和蛋白表达及SMMC-7721增殖,诱导细胞凋亡,使细胞阻滞于G2/M期.SODN对survivin mRNA和蛋白及SMMC-7721的增殖、细胞周期无明显抑制作用.结论 脂质体介导转染survivin ASODN可抑制细胞增殖、使细胞阻滞于G2/M期,从而促进细胞凋亡.     

鼠源性血管抑素基因转染对人肝癌细胞体内致瘤力的影响及新血管抑制作用

目的 研究血管抑素血管他丁（angiostatin）基因转染人肝癌细胞系HCC7721,对肿瘤细胞体外生长、周期分布、形态以及体内致瘤力的影响。探讨血管抑素的作用机制。方法 应用定向克隆技术构建鼠源性血管抑素血cDNA基因真核表达载体pcDNA3.1( )-angio,酶切鉴定和测序。采用脂质体基因转染技术将真核表达载体导入人肝癌细胞系HCC7721,新霉素G418筛选抗性克隆,设置转染空载体细胞为阴性对照和未转染细胞为空白对照。通过RNA点杂交和流式细胞荧光免疫检测血管抑素的表达,测定细胞生长曲线,计算细胞倍增时间,流式细胞仪检测细胞周期分布。建立动物模型,观察转染前后肿瘤细胞致瘤力的改变。免疫组化检测肿瘤组织微血管密度（MVD）和血管抑素体内表达。结果 成功构建带有碱基序列正确的血管抑素基因片段的重组真核表达载体pcDNA3.1（ ）-angio。分别转染脂质体/pcDNA3.1( ）-angio和脂质体/pcDNA3.1( ）的实验组,HCC7721肝癌细胞作阴性对照组经G418筛选,30d后均得到稳定的抗性细胞克隆,空白对照组在筛选1周后全部死亡。实验组HCC7721细胞在体内和体外均表达目的蛋白,而对照组细胞中无表达。与对照组相比,虽然实验细胞在体外的生长速度和细胞周期分布未发生明显改变。但在体内的致瘤力显著降低,瘤体增长缓慢,平均抑瘤率达47%。肿瘤MVD计数显示,实验组肝癌细胞形成的瘤体组织中MVD明显低于阴性对照组。结论 血管抑素不直接影响肝癌细胞HCC7721在体外的生物学特笥,但可强烈抑制体内肿瘤的形成,其机制可能是通过抑制肿瘤的新血管生成,间接发挥抑制肿瘤作用。     

pEGFP—P21真核表达载体构建及在AGS细胞的表达定位

目的：构建人细胞周期蛋白依赖性激酶抑制蛋白（cyclin2dependent kinase inhibitor）P21^WAF基因的真核表达载体pEGFP—P21，建立稳定表达P21蛋白与pEGFP 融合蛋白的AGS细胞系，，为进一步研究P21对下游基因的调节作用提供实验基础。方法：用PCR法在pCDNA3-P21质粒中定向插入EcoR1、BarnH1酶切位点，扩增P21 cDNA；采用亚克隆技术构建绿色荧光蛋白pEGFP—C2-P21融合基因表达载体；PCR法、双酶切及测序鉴定。脂质体转染试剂将重组载体转染人胃癌AGS细胞系，G418筛选20天挑取表达pEGFP-P21的抗性克隆扩大培养、传代。荧光显微镜直接观察pEGFP—p21在细胞中的分布和定位，流式细胞术分析细胞周期。结果：鉴定结果表明重构载体pEGFP-P21序列和方向正确，借助绿色荧光蛋白直观观察P21定位于AGS细胞核。细胞周期分析细胞阻滞与G1／S期。结论：成功建立稳定表达pEGFP—P21的AGS细胞株，P21在细胞核内发挥周期阻滞的作用，P21对细胞周期的影响可能为其调节其他因子是始动因素，为进一步研究P21基因的功能奠定了实验基础。     

MicroRNA-30a-5p对肝癌细胞株SMMC-7721增殖凋亡及侵袭转移的影响

目的 探讨转染miRNA-30a-5p对肝癌细胞生物学行为的影响. 方法 将miRNA-30a-5p模拟物、miRNA-30a-5p抑制物瞬时转染入肝细胞肝癌细胞株SMCC-7721,应用实时荧光定量PCR检测正常肝细胞株L02及肝癌细胞株SMCC-7721转染后的miR-30a-5p的mRNA表达情况,CCK-8法检测细胞增殖能力,克隆形成实验检测集落形成情况,流式细胞术检测细胞凋亡及各组细胞周期分布的差异,Transwell小室检测各组细胞体外侵袭转移能力,建立BALB/c-nu裸小鼠肝癌模型并观察miRNA-30a-5p对肿瘤生长的影响. 结果 实时荧光定量PCR显示,与未转染组及正常肝细胞株L02相比,肝癌细胞株SMCC-7721在转染miRNA-30a-5p模拟物后,mRNA表达明显上调(P＜0.01),而转染miRNA-30a-5p抑制物的mRNA表达明显受抑(P＜0.01),差异有统计学意义.肝细胞肝癌细胞株SMCC-7721在转染miRNA-30a-5p模拟物后,细胞活性、克隆形成能力、迁移和侵袭能力与miRNA-30a-5p抑制物转染组、未转染组及正常肝细胞株L02相比,相对减弱(P＜0.05),miRNA-30a-5p模拟物转染组凋亡率,高于miRNA-30a-5p抑制物转染组、未转染组及正常肝细胞株L02 (P＜0.05),细胞周期出现S期阻滞.裸鼠肝癌模型中,实验组裸鼠瘤体质量及体积明显小于空载体对照组和空白对照组(P＜ 0.05).结论 上调miR-30a-5p表达可明显抑制肝细胞肝癌细胞株SMCC-7721的增殖,促进其凋亡,抑制其迁移、侵袭能力,并且抑制裸小鼠肝癌模型肿瘤的生长.     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.