VEGF基因表达抑制对胃腺癌细胞SGC-7901增殖的影响

目的:研究siRNA(small interfering RNA)对人胃腺癌细胞SGC-7901的VEGF基因表达的影响．方法:选择血管内皮生长因子(VEGF)基因为靶基因,设计两组针对VEGF mRNA的小干扰RNA,合成DNA寡核苷酸链,体外转录合成siRNA．以人胃腺癌细胞系SGC-7901为靶细胞,应用脂质体转染的方法,将siRNA导入细胞．采用Hoechst33258染色观察siRNA作用于SGC-7901细胞中出现凋亡小体的情况．流式细胞仪检测细胞周期的改变,RT-PCR法比较转染前后VEGF mRNA表达水平的变化, ELISA法检测细胞培养液中VEGF蛋白分泌量的变化．结果:两组siRNA转染后均能有效地抑制 SGC-7901细胞的生长,诱导细胞凋亡产生凋亡小体．siRNA作用于SGC-7901细胞．其细胞周期均发生了明显的变化,主要表现为G0／G1 期细胞增多,S期细胞减少,并使细胞周期阻滞于G0／G1期(siRNA1组,siRNA2组G0／G1期VS 对照组G0／G1期:75．04％,76．52％ vs 58．37％, P<0．01;siRNA1组,siRNA2组S期vs对照组S 期:17．82％,16．73％ vs 39．52％,P<0．01),而其他组则无明显变化．VEGF mRNA的表达量大幅度减少(siRNA1组,siRNA2组vs对照组: 0．638±0．078,0．656±0．085 vs 0．941±0．046, P<0．01),相对应的VEGF蛋白水平也显著降低(164．7±22．7,166．3±26．6 vs 414．0±61．5, P<0．01),而其他组siRNA转染后则无上述作用．结论:应用靶向VEGF基因RNA干扰技术可以有效抑制胃癌细胞SGC-7901的增殖．     

乙酰肝素酶反义寡核苷酸对人胃癌细胞株SGC 7901表达bFGF的抑制作用

目的利用人胃癌细胞株SGC7901细胞,探讨乙酰肝素酶反义寡核苷酸对人胃癌细胞株SGC7901中表达碱性成纤维细胞生长因子(bFGF)的影响。方法采用脂质体介导乙酰肝素酶反义寡核苷酸转染人胃癌细胞株SGC7901细胞,采用免疫细胞化学法观察细胞内bFGF的变化。结果脂质体介导转染乙酰肝素酶反义寡核苷酸后,SGC 7901胃癌细胞内乙酰肝素酶mRNA表达下降,bF-GF阳性表达率由转染前的72．23％降至40．25％。转染后细胞bFGF表达明显减少。结论转染乙酰肝素酶反义寡核苷酸可以有效抑制胃癌细胞bFGF的表达。     

CD14对胃癌细胞SGC-7901生物学性能的影响

目的 观察CD14对胃癌细胞SGC-7901生物学性能的影响,探讨其在胃癌发生发展中的作用.方法 用CD14蛋白受体胞壁酰二肽(MDP)刺激CD14稳定转染的胃癌SGC-7901细胞,CCK-8法以及平板克隆形成实验检测细胞的活性和增殖能力,流式细胞术检测CD14对细胞凋亡的影响,Transwell侵袭模型检测细胞的侵袭能力.结果 CD14稳定转染的胃癌SGC-7901细胞活性显著降低(P ＜0.05);CD14稳定转染的细胞克隆形成率为15.66％±5.94％,与空质粒转染细胞的19.28％ ±5.48％相比,P＜0.05;CD14稳定转染的胃癌细胞凋亡率为14.38％,与空质粒转染细胞的4.58％相比,P＜0.05;CD14稳定转染的胃癌SGC-7901细胞在24、48 h的侵袭细胞数分别为(69.40±6.73)、(108.20±9.68)个,与空质粒转染细胞的(81.40±7.80)、(133.20±12.87)个相比,P均＜0.05.结论 CD14能够促进胃癌SGC-7901细胞的凋亡,同时抑制其增殖及侵袭.     

SiRNA沉默livin基因表达促进胃癌细胞凋亡

目的:研究livin特异性小分子干扰RNA (siRNA)沉默胃癌SGC-7901细livin基因及对促胃癌细胞凋亡的影响。方法:设计针对人源livin基因的两条SiRNA:si-livin1和si-livin2,分别转染至对数生长期的胃癌SGC-7901细胞:逆转录酶链式反应(RT- PCR)检测转染前后胃癌SGC-7901细胞livin基因表达的变化,MTT法检测转染前后该细胞对5-FU、顺铂的半数抑制浓度(IC50)的变化以及检测转染前后细胞增殖能力的变化,PI染色后流式细胞仪检测转染前后细胞凋亡的变化。结果:livin特异性siRNA转染胃癌SGC-7901细胞48h后,si-livin1组livinαmRNA(灰度值表示)表达较空白对照组和阴性对照组显著减少(livinα:0.167±0.013 vs 0.403±0.036,0.389±0.053;livinβ:0.181±0.028 vs 0.413±0.041,0.404±0.029,均尸<0.01),而si-livin2组livin mRNA表达相比于空白对照组和阴性对照无显著差异;转染siRNA后,si-livin1组胃癌细胞生长缓慢,生长曲线较对照组平缓;si-livin1组细胞对5-FU和顺铂半数抑制浓度IC50较空白对照组和阴性对照组显著降低(5-FU:34.07±2.98 vs 74.39±4.91,69.85±4.57;顺铂:4.56±0.35 vs 9.07±0.44,7.96±0.64,均P<0.01);转染siRNA后,si-livin1组胃癌细胞自发凋亡率较空白对照组和阴性对照组增加(11.07±1.36 vs 3.54±2.89,6.72±1.77,P<0.01,P<0.05).5-FU和顺铂作用后,si-livin1组胃癌细胞凋亡率较空白对照组和阴性对照组显著增加(5-FU:34.90±1.76 vs 11.54±O.83,13.54±2.55;顺铂:48.14±2.70 vs 14.51±0.35,15.71±0_34,均P<0.01).结论:RNA干扰可有效沉,livin基因表达从而抑制胃癌SGC-7901细胞生长及增加该细胞凋亡敏感性,livin可能成为胃癌凋亡治疗途径的一个分子靶点。     

siRNA干扰galectin-3表达对人胃癌细胞株SGC-7901增殖、凋亡和化疗敏感性的影响

Galectin-3属于半乳凝素家族成员,参与细胞生长和凋亡、细胞黏附、新生血管形成、肿瘤浸润和转移等多种生理和病理过程,在多种恶性肿瘤细胞中呈高表达。目的:研究siRNA干扰galectin-3表达对人胃癌细胞株SGC-7901增殖、凋亡和化疗敏感性的影响。方法:合成靶向galectin-3的siRNA并转染SGC-7901细胞,以real time PCR和蛋白质印迹法检测干扰效果。CCK-8实验检测细胞增殖,流式细胞术检测细胞凋亡。结果:Galectin-3siRNA转染24 h后转染效率为83.8%,转染后SGC-7901细胞的galectin-3表达显著受抑,mRNA和蛋白表达量分别较空白对照组降低87.8%和90.4%(P0.01)。转染后24 h、48 h和72 h,galectin-3 siRNA组SGC-7901细胞增殖抑制率分别为15.57%±1.45%、32.90%±0.76%和57.35%±1.05%,转染后72 h该组细胞凋亡率为46.17%±2.39%,均显著高于同时间点空白对照组、空脂质体组和阴性对照siRNA组(P0.01)。Galectin-3 siRNA组SGC-7901细胞由化疗药物奥沙利铂诱导的增殖抑制亦较其余三组显著增加(P0.01)。结论:以siRNA干扰galectin-3表达后,SGC-7901细胞增殖减少、凋亡增加,对化疗药物的敏感性增强,表明galectin-3有望成为胃癌基因治疗的有效靶点。     

西咪替丁对胃癌细胞SGC-7901增殖及凋亡的影响

目的:观察西咪替丁对人胃癌SGC-7901细胞增殖、细胞周期分布及凋亡的影响,并初步探讨其作用机制.方法:培养人胃癌SGC-7901细胞,以不同浓度的西咪替丁处理后用MTT法检测SGC-7901细胞的增殖情况;流式细胞术检测癌细胞周期和凋亡;Hoechst33258染色后荧光显微镜观察药物作用后癌细胞的形态变化;透射电镜观察用药后细胞超微结构的改变;Western印记法检测Bcl-2和Bax蛋白表达.结果:以不同浓度的西咪替丁分别处理人胃癌SGC-7901细胞24h和48 h,结果发现,在0.5,1,2.5,5,10 mmol/L时对SGC-7901细胞的增殖具有显著的抑制作用,与对照组相比差异显著(24 h:0.705±0.018,0.560±0.038,0.408±0.029,0.276±0.042,0.205±0.031 vs 0.803±0.012,P<0.05;48 h:0.902±0.024,0.671±0.015,0.420±0.030,0.180±0.037,0.0117±0.021 vs 1.079±0.040,P<0.05),并呈时间和剂量依懒性,而在0.25 mmol/L以下浓度对SGC-7901细胞未见明显细胞毒作用;0.5-10 mmol/L西咪替丁作用后,可观察到典型的细胞凋亡形态学改变;流式细胞仪检测可见凋亡峰,G0/G1期细胞明显增多(60.83±2.27,67.21±1.18,75.15±4.01,81.88±3.10,86.99±1.43 vs 50.28±1.97,P<0.05);西咪替丁还可下调SGC-7901细胞中的Bcl-2蛋白表达,上调Bax蛋白表达.结论:西咪替丁可改变细胞周期分布,并能通过下调Bcl-2、上调Bax蛋白表达,诱导SGC-7901细胞凋亡,从而抑制细胞增殖.     

Ss-A/Ro核蛋白60 ku亚单位反义核酸逆转胃癌细胞多药耐药

目的:对Ro 60反义核酸在逆转胃癌细胞多药耐药中作用进行研究．方法:克隆Ro 60编码基因,构建Ro 60编码基因的反义真核表达载体,将其转导入SGC7901细胞,应用半定量RT-PCR技术,对基因转染细胞进行鉴定,通过MTT法进行体外药物敏感性分析,借助流式细胞仪检测细胞内蓄积的阿霉素．结果:成功构建了Ro 60反义真核表达载体,应用脂质体介导法将其转导入SGC7901-VCR, Ro 60反义真核表达载体转染SGC7901-VCR细胞后,Ro 60的表达量明显下降,体外药物敏感性实验提示其对长春新碱、丝裂霉素、顺铂、阿霉素的敏感性增加,转染反义表达载体的SGC7901-VCR细胞与未转染和转染空载体的细胞相比,IC50值(mg/L)有显著的下降(7．66±0．45 vs 19．56±0．38,17．48±0．85;0．84±0．03 vs 1．62±0．06．1．80±0．03;0．51±0．03 vs 0．87±0．03．0．88±0．03;0．22±0．01 vs 0．52±0．02,0．43±0．03,均P<0．01),细胞内阿霉素蓄积有显著的增加(51．94±1．26 mg／L vs 36．27±0．98,37．01±0．91 mg／L,P<0．01)．结论:Ro 60反义真核表达载体转染SGC7901后能够抑制胃癌细胞的多药耐药表型．     

生存素siRNA表达质粒对MGC-803细胞增殖的影响

目的:应用siRNA表达载体介导的RNAi技术,观察 RNA干扰沉默生存素基因对胃癌MGC-803细胞增殖的影响．方法:用脂质体介导将生存素siRNA表达质粒转染 MGC-803细胞,通过倒置显微镜观察转染后细胞形态学的变化,四甲基偶氮唑蓝(MTT)法检测细胞增殖活性,流式细胞术分析细胞周期的变化,逆转录聚合酶链式反应(RT-PCR)方法检测生存素mRNA的表达水平．结果:生存素siRNA表达质粒转染组MGC-803细胞变圆、浮起,生存素siRNA表达质粒明显下调MGC-803 细胞内生存素mRNA的表达,与空白对照组相比降低了48．2％,阻断细胞周期在G1期(77．4％),显著抑制细胞增殖,siRNA转染组细胞吸光度比空白组显著降低 (24 h:0．272±0．048 vs 0．576±0．018;48 h:0．270±0．060 vs 0．809±0．027;72 h:0．143±0．046 vs 1．015±0．075;均 P<0．01)．转染24,48和72 h后的抑制率分别为53．4％, 66．7％和86.3％．结论:应用siRNA表达载体介导的RNAi技术,可有效下调生存素在MGC-803细胞中的表达,并在体外抑制细胞的增殖．     

幽门螺杆菌致胃上皮细胞株GES-1和胃癌细胞株SGC-7901的氧化性损伤

目的: 探讨H pylori对人正常胃黏膜上皮细胞永生细胞株GES-1和人淋巴结转移胃腺癌细胞株SGC-7901的氧化性DNA损伤作用.方法: 采用细菌-细胞共培养的方法, 比较H pylori作用前后GES-1和SGC-7901细胞株的形态学变化;采用激光扫描共聚焦显微镜方法, 比较H pylori作用前后GES-1和SGC-7901细胞株8-羟基脱氧鸟苷(8-OhdG)的表达.结果: H pylori对GES-1和SGC-7901细胞株均具有损伤作用;8-OHdG表达升高, 加菌组与对照组相比差别具有统计学意义(64.9396±17.8142 vs 32.3010±7.3620;102.8344±30.2632 vs 77.1336±32.3223, 均P = 0.000);而且8-OHdG表达的变化程度GES-1细胞显著高于SGC-7901细胞.结论: H pylori能够诱导GES-1和SGC-7901细胞DNA氧化性损伤显著增加;在H pylori氧化损伤的相关研究中, 更适宜选择对损伤作用敏感的GES-1细胞株作为研究对象.     

生存素反义寡核苷酸诱导结肠癌细胞株凋亡的实验研究

背景:生存素(survivin)是凋亡抑制蛋白家族的成员之一,在肿瘤组织和人类胚胎组织中有高水平表达,在分化成熟的组织中不表达或低水平表达。有研究显示,64.5%～85%的结肠癌组织中存在生存素基因表达,其表达与结肠癌患者的不良预后有关。目的:观察生存素反义寡核苷酸对结肠癌细胞株凋亡的影响。方法:通过基因工程技术构建生存素反义寡核苷酸质粒pcDNA3鄄sur鄄As,以脂质体转染的方法将质粒DNA转入结肠癌细胞株。应用逆转录聚合酶链反应(RT鄄PCR)和蛋白质印迹法(Westernblot)检测结肠癌细胞株中生存素mRNA和蛋白的表达,流式细胞仪和碘化丙啶(PI)染色检测细胞凋亡,比色测定检测caspase鄄3活性的变化。结果:SW1116、COLO205、HT鄄29和SW1417四株结肠癌细胞株中均有生存素mRNA和蛋白表达。瞬时转染生存素反义寡核苷酸后,4株结肠癌细胞株的细胞凋亡率均明显增加,并呈剂量依赖性(P<0.01);结肠癌细胞株SW1116在荧光显微镜下呈现典型的凋亡细胞形态,细胞中生存素蛋白表达水平明显降低,caspase鄄3活性显著增加(P<0.01)。结论:应用生存素反义寡核苷酸抑制生存素基因的表达能诱导结肠癌细胞株凋亡,以生存素为靶基因的治疗方案可能有助于结肠癌患者的治疗。     

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.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

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.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.