大鼠血管平滑肌细胞中以COX-2/JAK2/STAT3为靶向的信号转导分子调控机制的研究

目的:研究转录信号转导子和激活子3(STAT3)信号转导通路与选择性环氧化酶2(COX-2)抑制剂调控血管平滑肌细胞(VSMC)增殖凋亡的关系,明确COX-2抑制剂作用的细胞内信号转导机制。方法:将选择性COX-2抑制剂NS-398,作用于鼠VSMCs,运用MTT法检测细胞增殖状态;流式细胞仪观察NS-398对细胞凋亡的影响,进一步用RT-PCR检测药物作用前后VSMCs中COX-2mRNA表达;Westernblot检测药物作用前后STAT3通路相关蛋白JAK2、STAT3、CyclinD1、Bcl-2的表达及磷酸化活性。结果:鼠VSMCs中COX-2mRNA呈高表达,NS-398呈时间、剂量依赖性方式抑制VSMCs细胞增殖,促进其凋亡。加入NS-398的VSMCs中COX-2mRNA表达水平显著下降(P<0·01)。同时P-JAK2、P-STAT3、CyclinD1、Bcl-2表达水平随作用时间延长而下降(P<0·01)。结论:选择性COX-2抑制剂NS-398对VSMCs作用与COX-2mRNA水平相关,癌基因Stat3信号转导通路调控了NS-398对VSMCs作用的细胞内信号转导机制,最终通过其下游靶基因CyclinD1、Bcl-2影响VSMCs的增殖与凋亡。     

环氧合酶-2抑制剂对结肠癌细胞株的体外研究

目的 观察选择性环氧合酶-2（COX-2）抑制剂对COX-2高表达的结肠癌细胞株HT-29增殖和凋亡的影响，明确以COX2为靶点治疗结肠癌的作用途径以及与COX-2活性、表达水平的相关关系。方法 将选择性COX-2抑制剂NS-398作用于结肠癌细胞系HT29，运用MTT法检测细胞增殖状态。流式细胞仪观察NS-398对细胞凋亡的影响。进一步用逆转录聚合酶链式反应（RT-PCR）检测药物作用前后HT-29中COX-2mRNA表达。ELISA法测定前列腺素E2（PGE2）水平。Western blot检测药物作用前后细胞周期素D1、Bcl-2的表达。结果 结肠癌细胞系HT-29中COX-2 mRNA高表达，NS-398呈时间和剂量依赖性抑制HT-29细胞增殖，促进其凋亡。加入NS-398的HT-29细胞中COX-2mRNA表达水平无明显变化（P〉0．05），PGE2却显著下降（P〈0．01）。72h时空白组与NS-398（75μmol／L）处理组细胞周期素D1、Bcl-2表达水平比值分别为2．21和3．25（P〈0．01），两者表达水平随作用时间延长而下降。结论 选择性COX-2抑制剂NS-398不影响结肠癌细胞COX-2 mRNA表达水平，而与其活性相关（PGE2水平）．可能通过细胞周期素D1、Bcl-2影响结肠癌细胞系HT-29的增殖与凋亡，揭示了COX-2为靶点治疗结肠癌的分子机制。     

肝细胞生长因子受体在血管平滑肌细胞增殖凋亡中的表达

目的研究球囊扩张术后血管平滑肌细胞(VSMCs)中肝细胞生长因子(HGF)及其受体(c-Met)mRNA表达的变化,明确HGF受体与VSMCs增殖凋亡分子机制的相关性。方法用逆转录聚合酶链式反应检测36只兔腹主动脉球囊损伤前后不同时间点VSMCs中c-Met的mRNA表达水平;体外实验将选择性c-Met蛋白抑制剂NK-4作用于免VSMCs,运用MTF分别于0、24、48及72h检测细胞增殖状态;流式细胞仪观察NK-4对细胞凋亡的影响,进一步采用Western blot检测药物作用前后细胞周期蛋白(Cyclin D1)、凋亡蛋白(Bcl-2)的表达。结果球囊损伤后VSMCs c-Met mRNA的表达水平明显高于正常VSMCs(P＜0．01),平均为对照组2．42倍;对照组S及G_2/M期DNA百分含量与处理组比值分别为1．31,1．62(P＜0．01),NK-4呈时间、剂量依赖性方式抑制VSMCs增殖,促进其凋亡。72h时对照组与NK-4(1．0mg/L)处理组Cyclin D1、Bcl-2表达水平比值分别为2．37和3．81(P＜0．01),故两者表达水平随NK-4作用时间延长而下降。结论c-Met在球囊扩张术后血管平滑肌细胞中高表达可能在VSMCs过度增殖、凋亡受阻中起重要作用。选择性c-Met蛋白抑制剂NK-4可能通过Cyclin D1,Bcl-2影响VSMCs的增殖与凋亡,提示c-Met抑制剂可作为预防血管成形术后再狭窄新的候选药物。     

COX-2抑制剂NS398调控PPARs信号转导通路抑制结肠癌细胞增殖的分子机制

目的:观察选择性COX-2抑制剂NS-398对结肠癌细胞系SW480中PPARs信号转导通路的影响,以期初步阐明选择性COX-2抑制剂抗结直肠癌非COX-2依赖性途径的作用机制．方法:应用RT-PCR检测结肠癌细胞系SW480中COX-2 mRNA表达水平,用选择性COX-2抑制剂NS-398处理结肠癌细胞系SW480．Western blot检测PPARs信号转导通路成员表达,四甲基偶氮唑盐(MTT)法检测细胞增殖状态,流式细胞技术检测细胞周期与凋亡情况．结果:结肠癌细胞系SW480中未检测到COX-2 mRNA表达,NS-398(75μmol／L)作用于SW480细胞72 h后,G1期细胞比率由31．2％上升至40．6％,S期细胞比率由52．8％下降至41．2％,细胞增殖受抑制．PPARα,PPARδ,PPARγ,cyclin D1与Bcl-xl表达水平随NS-398作用时间延长而下降．结论:选择性COX-2抑制剂NS-398可能通过非COX-2依赖途径影响结肠癌细胞的增殖．     

选择性环氧合酶-2抑制剂NS-398抑制胃癌细胞P-糖蛋白表达

目的 探讨选择性环氧合酶-2（COX-2）抑制剂NS-398对胃癌细胞株SGC-7901 P-糖蛋白（P-gp）表达的影响。方法 胃癌细胞株SGC-7901经浓度分别为0、10、100μmol／L的NS-398处理后，酶联免疫吸附试验检测NS-398对胃癌细胞前列腺素E2（PGF2）分泌的影响，24、48h后用RT-PCR检测多药耐药（mdr）1 mRNA表达，48h后用免疫细胞化学染色法检测P-gp表达。结果 NS-398可显著抑制胃癌细胞株SGC-7901 PGE2分泌，并呈浓度依赖性（P〈0．05）。不同浓度NS-398作用于细胞后，胃癌细胞株SGC-7901的mdr1／P-gp表达受不同程度抑制，100μmol／L的NS-398对mdr1 mRNA表达抑制作用强于10μmol／L（P〈0．01）。不同浓度药物与测量时间为交互作用．作用48h与24h相比，NS-398对mdr1 mRNA表达的抑制作用更强（P〈0．01）。结论 NS-398可抑制SGC-7901的mdr1／Pgp表达，且呈剂量效应关系。NS-398可能通过抑制COX-2活性，抑制COX-2下游产物PGE2表达，从而抑制P-gp表达。选择性COX-2抑制削可能有助于减轻肿瘤细胞对化疗药物的耐药性。     

环氧化酶-2选择性抑制剂抑制人食管癌细胞的生长及其诱导凋亡

目的:探讨NS-398对食管癌细胞的生物学效应及可能的作用机制.方法:常规方法培养食管癌Eca-109和TE-13细胞,以不同浓度NS-398(5,10,20,40,80 μmol/L)处理24,48,72 h.采用四甲基唑蓝法(MTT)检测NS-398对Eca-109和TE-13细胞生长的抑制作用;流式细胞仪(FCM)检测细胞凋亡及COX-2,Bcl-2,Bax蛋白的表达;TUNEL法检测2种细胞凋亡情况;用放射免疫分析(RIA)检测培养液上清中前列腺素E2(PGE2)含量.结果:NS-398可抑制2种细胞的生长,并随药物浓度的增高及作用时间的延长抑制率逐渐增高,并使2种细胞产生的PGE2明显降低.NS-398使2种细胞G0/G1期细胞显著增多,S期细胞显著减少(Eca-109:F=22.39,P＜0.01;TE-13:F=46.99,P＜0.01),并引起了明显的细胞凋亡.NS-398使2种细胞COX-2和Bcl-2表达显著减少,而Bax表达显著增高.COX-2和Bcl-2的表达呈显著正相关(Eca-109:r=0.925,P＜0.01;TE-13:r=0.925,P＜0.01),COX-2和Bax表达呈显著负相关(Eca-109:r=-0.937,P＜0.01;TE-13:r=-0.703,P＜0.01)、Bax和bcl-2表达呈显著负相关(Eca-109:r=-0.926,P＜0.01;TE-13:r=-0.753,P＜0.01).结论:NS-398可抑制食管癌细胞的增殖并可诱导其凋亡,应用COX-2选择性抑制剂对食管癌进行化学预防或辅助治疗具有可能性.     

NS-398对人胃癌细胞株增殖及COX-2表达的影响

目的 体外观察选择性环氧化酶2(COX-2)抑制剂NS-398对人胃癌细胞株SGC7901细胞增殖及COX-2表达的影响。方法 采用噻唑蓝(MTT)法观察NS-398对SGC7901细胞增殖的影响，流式细胞仪(FCM)研究NS-398对SGC790l细胞凋亡的作用．免疫细胞化学观察COX-2蛋白的表达。结果 体外NS-398能减少SGC790l细胞株COX-2的表达．对SGC7901有细胞毒作用．可增加细胞凋亡率。结论 体外NS-398对SGC7901细胞增殖有抑制作用。可能与抑制COX-2表达及诱导细胞凋亡有关。     

NS-398对HGF诱导的肝癌细胞株MMP-7,MMP-9,TIMP-1表达的影响

目的:研究选择性COX-2抑制剂NS-398对肝癌细胞株MMP和TIMP表达的影响,探讨选择性COX-2抑制剂降低肿瘤细胞侵袭力的机制．方法:以不同浓度的NS-398(0,20,40,60, 80μmol/L)作用于HGF诱导的HepG2细胞,免疫组化法观察细胞中MMP-7,MMP-9,TIMP-1的蛋白质表达,ELISA法检测细胞外培养液中MMP-7,MMP-9,TIMP-1的含量,RT-PCR法分析3种蛋白酶的mRNA转录水平．结果:NS-398作用细胞48 h后,发现MMP-7, MMP-9,TIMP-1的蛋白质表达程度均下降, NS-398作用于HepG2细胞后,MMP-7在培养液中的含量和其在细胞内的mRNA相对水平分别为8．2±0．6,5．8±0．8,4．3±0．8,2．7±0．4, 1．7±0．4μg／L和0．58±0．06,0．42±0．03,0.37±0．01,0．36±0．01,0．33±0．01:MMP-9在培养液中未检出,其细胞内mRNA相对水平分别为0．32±0．02,0．23±0．02,0．21±0．01,0．17±0．01,0．13±0．01;TIMP-1在培养液中的含量和其在细胞内的mRNA相对水平分别为39．0±0．9,29．5±2．8,25．0±0．9,16．8±0．4,11．8±0．3μg/L和0．19±0．02,0．17±0．02,0．16±0．01, 0．13±0．01．0．结论:选择性COX-2抑制剂能够抑制MMP和TIMP基因转录,使TIMP/MMP比例失衡,这可能是其降低肿瘤细胞侵袭力的机制之一．     

选择性环氧合酶-2抑制剂与COX-2/5-脂氧合酶双酶抑制剂对食管鳞状细胞癌细胞增殖的影响

目的比较选择性环氧合酶-2（COX-2）抑制剂与COX-2/5-脂氧合酶（5-LOX）双酶抑制剂对食管鳞状细胞癌（ESCC）细胞增殖的影响,探讨单一抑制COX-2对抑制ESCC细胞增殖可能存在的局限性。方法 COX-2/5-LOX双抑制剂licofelone和选择性COX-2抑制剂NS-398分别作用于ESCC细胞株TE-1,设药物处理组、溶媒（DMSO）对照及空白对照组。两种药物分别以25μmol/L、50μmol/L、75μmol/L和100μmol/L浓度作用24 h及48 h。四唑单钠盐（CCK-8）法检测细胞增殖;RT-PCR和W esternb lot检测mRNA及蛋白表达;ELISA法检测PGE2和LTB4含量;流式细胞术检测细胞周期。结果 TE-1细胞的浓度及时间依赖性增殖抑制只出现于licofelone处理组。licofelone及NS-398对COX-2 mRNA、蛋白及下游产物PGE2表达均有时间、浓度依赖性抑制作用（P〈0.05）,但仅licofelone处理组出现5-LOX mRNA、蛋白及下游产物LTB4的时间、浓度依赖性表达抑制。100μmol/L licofe-lone及50μmol/L NS-398作用24 h后TE-1细胞分别有67.1%、63.8%处于G0/G1期,显著高于对照组（P〈0.05）。结论单一抑制COX-2并不能稳定抑制TE-1细胞的增殖。较高浓度NS-398可增加5-LOX分流,减弱COX-2抑制对细胞增殖的负性影响。     

环氧合酶-2选择性抑制剂NS-398诱导食管癌细胞EC 9706凋亡及其机制的探讨

目的 观察环氧合酶-2(COX-2)选择性抑制剂NS一398对食管癌细胞株EC 9706增殖及凋亡的影响,砌究其对凋亡抑制蛋白Survivin和Caspase-3表达的影响,探讨NS-398诱导Ec 9706细胞凋亡的作用机制.方法 NS-398作用EC 9706细胞后,MTT法测定NS-398对人食管癌EC 9706细胞增殖的抑制率;DNA片段分析法和流式细胞仪检测细胞凋亡;免疫细胞化学检测Survivin和Caspase-3蛋白表达变化.结果 NS-398(10～100μmol/L)对EC 9706细胞生长有抑制作用,随浓度升高、时间延长抑制作用增强,并诱导EC 9706细胞凋亡,呈剂量-时间效应关系;NS-398可降佴Survivin蛋白表达,增加Caspase-3蛋白表达.结论 NS-398可诱导人食管癌细胞株EC 9706凋亡,其机制可能与下调Survivin表达及激活Capase-3表达有关.     

Cyclooxygenase-2 in cancer and angiogenesis

Tumor angiogenesis is a process where new blood vessels are formed from preexisting ones, resulting in several pathologies. Solid tumors induce angiogenesis to obtain the required nutrients and oxygen. Otherwise, tumors do not grow beyond 2 to 3 mm in diameter. Cyclooxygenase-2, an inducible enzyme important in inflammation, catalyzes the production of prostanoids from arachidonic acid. Cyclooxygenase-2 plays an important role in several cancer types, including colorectal, gastric, prostate, breast, lung, and endometrial cancer. Besides, cyclooxygenase-2 has been implicated in the progression and angiogenesis of cancers. Cyclooxygenase-2 inhibitors have been used to block angiogenesis and tumor proliferation. In this review, the recent studies related to the role of cyclooxygenase-2 in several cancer types and tumor-induced angiogenesis were compiled.     

环氧化酶-2与肺癌

环氧化酶-2（COX-2）在肺癌细胞呈过表达,并且促进肿瘤增殖、侵袭、血管生成和抗凋亡。COX-2抑制剂在动物实验中可抑制肿瘤生长。进一步了解COX-2介导的肿瘤生成及其与其它分子的相互作用机制可能为肺癌的治疗提供新的途径。     

环氧化酶-2与肺癌

环氧化酶-2（ cyclooxygenase-2, COX-2 ）是环氧化酶的诱导型,在肺癌及其转移灶中高表达,以多环节参与肺癌的发生发展,且与肺癌患者的预后有关。COX-2抑制剂的临床应用有预防和抑制肺癌的作用。     

环氧化酶-2与糖尿病

糖尿病通常伴有慢性低水平的炎性反应.目前研究证实环氧化酶2(COX-2)在糖尿病及其并发症的发病中起重要作用.启动子的激活、高糖刺激、炎性因子、自由基、十二脂氧化酶、前列腺素E等多种因素的作用下,COX-2表达显著上调.随着对COX-2的进一步研究,为糖尿病的预防、诊断以及治疗提供了新的思路.     

环氧化酶-2与帕金森病

环氧化酶是花生四烯酸代谢产生前列腺素过程中的主要限速酶。住体内环氧化酶至少存在结构酶和历导酶两种同源异构体。在帕金森病患者尸检及帕金森病动物模型中均发现黑质Ⅸ诱导型同工酶环氧化酶-2的表达增高,环氧化酶-2在帕金森病发病机制中的作用倍受关注,选择性环氧化酶-2抑制剂可能成为帕金森病治疗的新药物。     

Cyclooxygenase-2 and prostaglandins in articular tissues

OBJECTIVES: To provide an overview on: 1) the expression of cyclooxygenase (COX)-2 in articular tissues; 2) the role of prostaglandin E2 (PGE2) in these tissue functions; and 3) clinical trials with COX-2-selective nonsteroidal anti-inflammatory drugs (NSAIDs) (coxibs). METHODS: MEDLINE search was performed using the key words "cyclooxygenase," "prostaglandin," "osteoarthritis" (OA), and "rheumatoid arthritis" (RA). Selected publications related to clinical trials with coxibs also are included. RESULTS: COX-2 is upregulated in inflamed joint tissues and is responsible for elevated PGE2 production. The overexpression of COX-2 is likely induced by proinflammatory mediators such as interleukin-1beta (IL-1beta) and tumor necrosis factor (TNF) alpha. However, the exact molecular mechanisms through which the expression of COX-2 is regulated remain to be elucidated. Several studies suggest that PGE2 is involved in inflammation, apoptosis, angiogenesis, and possibly structural changes that characterize arthritic diseases. NSAIDs are prescribed for the treatment of OA and RA and provide effective relief from symptoms; however, serious gastrointestinal complications occur with their use. The clinical efficacy of NSAIDs is primarily related to the inhibition of COX-2, whereas much of the toxicity is related to COX-1 inhibition. Selective COX-2 inhibitors (coxibs) that spare COX-1 at therapeutic doses are more effective than placebo and as effective as other NSAIDs for relief of symptoms of OA and RA, and have significantly improved gastrointestinal safety and tolerability. However, some studies showed that COX-2-selective inhibitors still have classic NSAID complications. CONCLUSIONS: Overexpression of COX-2 protein in articular tissues is a characteristic feature of arthritic diseases. However, the molecular mechanisms involved in the regulation of COX-2 expression and activity are still unclear. Elucidating the mechanisms of COX-2 expression and PGE2 production and action will help identify novel and more selective potential drug targets in the treatment of arthritic diseases.     

Cyclooxygenase-2 expression and inhibition in atherothrombosis

Arachidonic acid metabolism plays an important role in acute ischemic syndromes affecting the coronary or cerebrovascular territory, as reflected by biochemical measurements of eicosanoid biosynthesis and the results of inhibitor trials in these settings. Two cyclooxygenase (COX)-isozymes have been characterized, COX-1 and COX-2, that differ in terms of regulatory mechanisms of expression, tissue distribution, substrate specificity, preferential coupling to upstream and downstream enzymes, and susceptibility to inhibition by the extremely heterogeneous class of COX-inhibitors. Although the role of platelet COX-1 in acute coronary syndromes and ischemic stroke is firmly established through approximately 20 years of thromboxane metabolite measurements and aspirin trials, the role of COX-2 expression and inhibition in atherothrombosis is substantially uncertain, because the enzyme was first characterized in 1991 and selective COX-2 inhibitors became commercially available only in 1998. In this review, we discuss the pattern of expression of COX-2 in the cellular players of atherothrombosis, its role as a determinant of plaque "vulnerability," and the clinical consequences of COX-2 inhibition. Recent studies from our group suggest that variable expression of upstream and downstream enzymes in the prostanoid biosynthetic cascade may represent important determinants of the functional consequences of COX-2 expression and inhibition in different clinical settings.     

环氧合酶-2与非酒精性脂肪性肝炎关系的研究进展

非酒精性脂肪性肝炎( NASH)呈慢性肝脏脂毒性炎症表现,是非酒精性脂肪性肝病(NAFLD)的重要转折点,存在肝病重症化趋势.环氧合酶-2(COX -2)作为启动炎症反应的关键酶同样涉及到NASH的形成及进展.本文就COX -2及其抑制剂与NASH关系的研究予以综述.     

Cyclooxygenase-2 Expression in Barrett's Esophagus

Barrett's epithelium is a recognized premalignant condition for esophageal adenocarcinoma. Nonsteroidal antiinflammatory drugs (NSAIDs) decrease the relative risk of colon cancer in humans and the esophageal tumor load in carcinogen-treated mice. Previous studies provided conflicting results for COX-2 activity in Barrett's mucosa. Pinch mucosal biopsies were collected from Barrett's and adjacent normal esophageal mucosa from 17 patients with Barrett's esophagus. Low-grade dysplasia was found in seven patients. COX-2 protein was undetectable in normal esophageal mucosa. COX-1 protein expression did not vary between normal and Barrett's epithelium. Increased COX-2 protein was detected in Barrett's epithelium in seven patients (41%) but did not differ with or without dysplasia (43% vs 40%). In conclusion, COX-2 protein is increased in 41% of patients with Barrett's epithelium compared to normal esophageal mucosa but did not differ with or without dysplasia. COX-2 induction may be an early event in the development of Barrett's esophagus.