胰腺癌MiR-224的表达与细胞增殖和凋亡

目的:分析miR-224在胰腺癌组织中的表达,探讨其在胰腺癌细胞增殖、细胞周期及凋亡中的意义.方法:采用TagMan MGB探针法定量分析40例原发性胰腺癌及对应的癌旁组织MiR-224的表达;利用反义技术降低胰腺癌细胞(Aspc-1和Bxpc-3)中miR-224的表达;采用MTT比色法检测细胞增殖的改变,利用流式细胞技术检测胰腺癌细胞周期和凋亡情况.结果:在40例胰腺癌病例中,43%(17/40)的胰腺癌组织miR-224表达明显高于癌旁组织(P<0.05);反义miR-224转染胰腺癌细胞Aspc-1和Bxpc-3后,miR-224的表达明显降低,Aspc-1和Bxpc-3胰腺癌细胞生长受到明显抑制,其生长主要停滞在G0/G1期,而S期和G2/M期细胞的比例下降;另外降低miR-224的表达,Aspc-1和Bxpc-3胰腺癌细胞早期凋亡明显增加.结论:miR-224在胰腺癌组织中表达上调,降低其表达能明显抑制Aspc-1和Bxpc-3细胞的生长和诱导细胞早期凋亡增加,miR-224有可能成为胰腺癌基因表达调控的新靶点.     

微小RNA-221对HepG2细胞增殖及其凋亡的影响

目的 探讨微小RNA-221(miR-221)对肝癌细胞株HepG2细胞增殖与凋亡的影响.方法 将miR-221阻遏物及模拟物转染至HepG2后,用实时荧光定量RT-PCR检测miR-221的表达水平;用细胞增殖试剂盒、Hoechst 33342及碘化丙啶(PI)双重染色、流式细胞仪及caspase3/7活性试剂盒检测HepG2细胞增殖与凋亡情况.对数据进行多样本的单因素方差分析,两两比较采用LSD法;相关性比较用Pearson检验.结果 RT-PCR结果显示,转染miR-221阻遏物后其表达受到抑制,而转染miR-221模拟物可促进其表达.细胞增殖试剂盒及Hoechst 33342/PI染色结果显示,48 h后miR-221阻遏物明显抑制HepG2细胞增殖(P＜0.05),而miR-221模拟物促进HepG2细胞增殖(P＜0.05),两种方法结果呈正相关(r=0.993,P＜0.01).流式细胞仪检测细胞周期显示,miR-221模拟物组G1期细胞比例(47.6%±1.53%)明显低于空白对照组(59.00%±1.00%)及阴性对照组(58.00%±1.00%,F=81.77,P＜0.01); S期细胞比例(20.33%±1.15%)明显高于空白对照组(11.00%±1.00%)及阴性对照组(12.00%±1.00%,F=70.90,P＜0.01).Hoechst 33342/PI染色、流式细胞仪膜联蛋白V凋亡试剂盒检测均显示,转染miR-221阻遏物48 h后,细胞凋亡和坏死增加(P＜0.05),差异有统计学意义.Caspase-3/7试剂盒检测caspase-3/7活性变化结果显示,转染miR-221阻遏物24 h后,细胞caspase3/7活性明显增高(P＜0.05),差异有统计学意义.结论 miR-221可促进肝癌细胞生长增殖,抑制miR-221表达可诱导细胞凋亡.miR-221有望成为治疗肝癌新的分子靶点之一.     

下调MiR-221对胃癌顺铂耐药细胞增殖及顺铂敏感性的影响及其相关机制

背景晚期胃癌(gastric cancer, GC)患者通常接受化疗作为主要治疗方法.然而,化疗的有效性受到GC细胞耐药性的限制.本研究旨在探讨microRNA-221(miR-221)在顺铂(cisplatin, DDP)耐药GC细胞中的生物学作用和潜在机制,以期为临床治疗提供参考.目的研究下调Mi R-221对GC DDP耐药细胞增殖及DDP敏感性的影响及相关机制.方法采用AGS和MGC-803细胞构建出DDP耐药AGS/DDP和MGC-803/DDP细胞. RT-qPCR检测GC及癌旁组织、DDP化疗敏感组织、DDP化疗耐药组织、GC细胞和GC DDP耐药细胞的miR-221表达水平;用LVmiR-221-shRNA慢病毒转染AGS/DDP和MGC-803/DDP细胞后,MTT检测细胞增殖以及对DDP的化学敏感性; Annexin V-FITC/PI染色检测细胞凋亡;进行生物信息学分析以寻找miR-221的潜在靶基因,应用RT-qPCR和Western blotting检测细胞中CCND1的m RNA和蛋白表达.结果在GC组织和GC细胞细中miR-221明显上调,且DDP耐药组织和DDP耐药细胞中miR-221表达更高.下调miR-221抑制了AGS/DDP和MGC-803/DDP细胞增殖,促进了细胞凋亡和细胞对DDP的化学敏感性;CCND1是miR-221的直接靶基因,转染LV-miR-221-sh RNA抑制CCND1 mRNA和蛋白表达水平.结论下调miR-221可以抑制GC DDP耐药细胞增殖,促进其对DDP的化学敏感性,这一作用可能通过抑制靶基因CCND1表达来实现的.     

TFPI-2基因体外诱导胰腺癌Panc-1细胞的凋亡

目的: 将TFPI-2基因转染胰腺癌细胞系Panc-1细胞, 研究其对胰腺癌细胞凋亡的影响.方法:将重组质粒pEGFP-C1-TFPI-2通过脂质体介导转染胰腺癌细胞系Panc-1细胞, G418筛选获得阳性细胞克隆后, 用逆转录-聚合酶链反应(RT-PCR)和免疫印迹(Western blot)技术分别检测转染细胞中TFPI-2 mRNA及相应蛋白的表达, 同时测定转染细胞的生长曲线和凋亡情况. 结果: 同转染空载体及未转染细胞相比, 转染成功的Panc-1细胞可以检测到TFPI-2 mRNA和相应蛋白的表达, 细胞生长受到抑制(n = 9, P = 0.02), DNA琼脂糖凝胶电泳显示凋亡细胞特有的"梯状"条带.结论:外源性TFPI-2基因能够抑制胰腺癌细胞生长增殖、诱导胰腺癌细胞凋亡.     

miR-221/222在肝癌细胞抵抗内质网应激凋亡中的作用

目的 研究内质网应激对miR-221/222的调控及其在肝癌细胞抵抗内质网应激诱导细胞凋亡中作用.方法 采用miR-221/222抑制物和miR-221/222类似物分别阻断或模拟内源性miR221/222的功能,并利用Western blot和流式细胞技术分析内质网应激条件下miR-221/222对肝癌细胞周期和凋亡的调控作用.结果 内质网应激诱导miR-221/222表达下调,miR-221/222类似物和抑制物分别抑制和促进内质网应激诱导的p27Kip1表达上调,干扰p27Kip1不仅抑制了内质网应激诱导的肝癌细胞G0/G1期阻滞,也促进了内质网应激介导的肝癌细胞凋亡.结论 内质网应激诱导miR-221/222下调能够通过促进p27Kipl表达对内质网应激条件下肝癌细胞周期和凋亡起重要调控作用.

Abstract：

Objective To investigate the role of miR-221/222 in inhibiting endoplasmic reticulum stress-induced human hepatocarcinoma cells apoptosis. Method miR-221/222 mimics and inhibitors were used to mimic or block the function of endogenous miR-221/222 respectively. Western blot and flow cytometry were used to test the effects of miR-221/222 on cell cycle and apoptosis under endoplasmic reticulum stress in human hepatocellular carcinoma cells. Results Endoplasmic reticulum stress resulted in miR-221/222down-regulation in human hepatocellular carcinoma cells. miR-221/222 mimics and inhibitors inhibited and promoted respectively endoplasmic reticulum stress-mediated p27Kip1 induction. Moreover, p27Kip1 suppression not only resulted in reduction in the fraction of G1 phase cells, but also promoted the endoplasmic reticulum stress-mediated apoptosis in human hepatocellular carcinoma cells. Conclusions miR-221/222 were downregulated by endoplasmic reticulum stress in human hepatocellular carcinoma cells, which subsequently protected human hepatocellular carcinoma cells against endoplasmic reticulum stress-induced apoptosis through p27KiP1 regulation.     

miR-20a-5p在胰腺癌中的表达及作用机制研究

目的检测并分析胰腺癌组织和胰腺癌细胞株中miR-20a-5p的表达情况及对胰腺癌细胞发生、发展的影响。方法收集16对手术切除胰腺癌患者的癌组织及对应癌旁组织、5种胰腺癌细胞株及1株正常胰腺导管上皮细胞,通过实时荧光定量聚合酶链反应(quantitative realtime polymerase chain reaction,qRT-PCR)检测临床标本及胰腺癌细胞株中miR-20a-5p的表达水平;通过转染miR-20a-5p mimics及miR-20a-5p inhibitor分别上调及下调胰腺癌细胞(AsPC-1、BxPC-3)中miR-20a-5p的表达水平,采用CCK-8、EdU及流式凋亡实验检测过表达及敲低miR-20a-5p后对胰腺癌细胞活力、增殖及凋亡能力的影响。结果胰腺癌组织中miR-20a-5p的表达量显著高于癌旁组织(P0.01),5种胰腺癌细胞系中miR-20a-5p的表达量较正常胰腺细胞也明显升高(P0.05)。CCK-8及EdU实验结果显示,过表达miR-20a-5p促进胰腺癌细胞增殖能力,反之,干扰miR-20a-5p抑制胰腺癌细胞增殖。凋亡检测结果显示,过表达miR-20a-5p抑制胰腺癌细胞凋亡能力,反之,干扰miR-20a-5p促进胰腺癌细胞凋亡。结论胰腺癌组织和胰腺癌细胞系均高表达miR-20a-5p,上调miR-20a-5p能促进胰腺癌细胞增殖及抗凋亡能力。     

miR-1908对人内脏前体脂肪细胞增殖、细胞凋亡和细胞周期的影响

目的研究miR-1908对人内脏前体脂肪细胞（HPA-v）增殖、细胞凋亡和细胞周期的影响。 方法体外培养HPA-v脂肪细胞,并根据实验分为抑制剂组（转染经化学修饰的miR-1908-5p抑制剂）、空载体组（转染空载体）、对照组（未进行任何处理），CCK8（Cell Counting Kit-8）法用于检测细胞的增殖情况，流式细胞仪检测细胞周期、Tunnel法检测细胞凋亡情况。 结果CCK8结果显示miR-1908抑制剂组的吸光度（OD）值（0.61±0.07）明显低于对照组（1.01±0.05）（P<0.05），抑制miR-1908具有抑制HPA-v脂肪细胞增殖的作用；Tunel结果表示miR1908抑制剂组凋亡率（0.27±0.03）%明显大于对照组（0.13±0.05）%（P<0.05）；流式细胞测定的结果为G0/G1期细胞增加（与对照组相比，P<0.05），表明抑制miR-1908表达可能通过诱导HPA-v脂肪细胞G0/G1期阻滞抑制HPA-v脂肪细胞增殖。 结论下调miR-1908表达能明显抑制人内脏前体脂肪细胞增殖，诱导细胞凋亡及改变细胞周期分布。     

吉西他滨对Beclinl基因沉默的人胰腺癌MiaPaCa-2细胞的周期及凋亡的影响

目的 探讨吉西他滨对Beclinl基因沉默的人胰腺癌MiaPaCa-2细胞周期及凋亡的影响.方法 构建靶向Beclinl的siRNA,插入表达质粒,转染MiaPaCa-2细胞.采用RT-PCR法和蛋白质印迹法检测细胞Beclinl mRNA及蛋白的表达,应用吉西他滨处理Beclinl基因沉默的MiaPaCa-2细胞,应用流式细胞仪检测细胞周期及细胞凋亡状况.结果 成功获得Beclin1基因沉默的MiaPaCa-2细胞,转染后细胞的Beclin1 mRNA表达量从对照组的1.0下降到0.295;S、G2期细胞数减少,而G1期细胞增多;细胞凋亡未受影响.应用吉西他滨处理后,Beclin1基因沉默的MiaPaCa-2细胞的S期细胞数进一步减少,而G1、G2期细胞增多,细胞凋亡被抑制.结论 Beclinl表达沉默使人胰腺癌细胞系MiaPaCa-2细胞周期发生改变,并影响吉西他滨对细胞周期及凋亡的作用.     

miR-151a-3p对胰腺癌细胞增殖、迁移、侵袭及凋亡的影响

目的探讨miR-151a-3p在胰腺癌细胞中的表达及miR-151a-3p表达对胰腺癌细胞增殖、迁移、侵袭及凋亡的影响。方法采用实时荧光定量聚合酶链反应(qRT-PCR)检测miR-151a-3p在三种胰腺癌细胞系的表达情况;利用脂质体转染技术将miR-151a-3p mimic和mimic NC转染至胰腺癌BxPC-3细胞中,qRT-PCR检测转染后miR-151a-3p在BxPC-3细胞中的表达水平;CCK-8法检测转染后BxPC-3细胞的增殖能力;Transwell实验检测转染后BxPC-3细胞的迁移及侵袭能力;流式细胞术检测转染BxPC-3细胞的凋亡能力。结果 qRT-PCR结果显示,3种胰腺癌细胞系中miR-151a-3p表达水平均显著升高(P0.01),其中,BxPC-3细胞中miR-151a-3p表达水平最高;转染miR-151a-3p mimic的BxPC-3细胞中miR-151a-3p表达水平显著高于mimic NC和空白组(P0.001);CCK-8实验结果显示,转染miR-151a-3p mimic的BxPC-3细胞增殖能力显著高于mimic NC和空白对照组(P0.01);Transwell实验结果显示,转染miR-151a-3p mimic的BxPC-3细胞迁移及侵袭能力显著高于mimic NC和空白对照组(P0.01);流式细胞术结果显示,转染miR-151a-3p mimic的BxPC-3细胞凋亡率显著低于mimic NC和空白对照组(P0.001)。结论 miR-151a-3p在胰腺癌细胞中高表达,过表达miR-151a-3p促进胰腺癌细胞增殖、迁移及侵袭,抑制细胞凋亡。     

miR-221通过细胞周期蛋白D1介导同型半胱氨酸诱导人冠状动脉内皮细胞损伤

目的研究miR-221通过细胞周期蛋白D1介导同型半胱氨酸(Hcy)诱导人冠状动脉内皮细胞(HCAEC)损伤。方法培养HCAEC并分为4组,对照组用无血清培养基处理,Hcy组用含有1 mmol/L Hcy的培养基处理,Hcy+NC(阴性对照)组转染NC抑制物后用含有1 mmol/L的培养基处理,Hcy+miR-221组转染miR-221抑制物后用含有1 mmol/L的培养基处理。采用荧光定量PCR检测miR-221的表达水平,Western blot检测细胞周期蛋白D1的表达水平,MTS检测细胞活力OD_(490 nm)水平,流式细胞术检测细胞周期,双荧光素酶报告基因实验验证miR-221靶向细胞周期蛋白D1。结果与对照组比较,Hcy组HCAEC的miR-221表达水平、细胞G0/G1期比例明显增加,OD_(490 nm)水平、S期及G2/M期比例、细胞周期蛋白D1表达水平明显降低。与Hcy组及Hcy+NC组比较,Hcy+miR-221组的miR-221表达水平、G0/G1期比例明显降低,OD_(490 nm)水平、S期及G2/M期比例、细胞周期蛋白D1表达水平明显增加。细胞周期蛋白D1基因mRNA 3′UTR第1224-1231碱基是miR-221的结合位点,miR-221能够降低野生型细胞周期蛋白D1双荧光素酶报告基因的荧光活力。结论 miR-221在Hcy诱导HCAEC损伤过程中表达增加,抑制miR-221表达能够减轻Hcy诱导的HCAEC损伤,靶向细胞周期蛋白D1是可能的分子机制。     

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.