Upregulation of vascular endothelial growth factor by cobalt chloride-simulated hypoxia is mediated by persistent induction of cyclooxygenase-2 in a metastatic human prostate cancer cell line

Upregulation of vascular endothelial growth factor (VEGF) expression induced by hypoxia is crucial event leading to neovascularization. Cyclooxygenase-2, an inducible enzyme that catalyzes the formation of prostaglandins (PGs) from arachidonic acid, has been demonstrated to be induced by hypoxia and play role in angiogenesis and metastasis. To investigate the potential effect of COX-2 on hypoxia-induced VEGF expression in prostate cancer. We examined the relationship between COX-2 expression and VEGF induction in response to cobalt chloride (CoCl₂)-simulated hypoxia in three human prostate cancer cell lines with differing biological phenotypes. Northern blotting and ELISA revealed that all three tested cell lines constitutively expressed VEGF mRNA, and secreted VEGF protein to different degrees (LNCaP > PC-3 > PC3ML). However, these cell lines differed in the ability to produce VEGF in the presence of CoCl₂-simulated hypoxia. CoCl₂ treatment resulted in 40% and 75% increases in VEGF mRNA, and 50% and 95% in protein secretion by LNCaP and PC-3 cell lines, respectively. In contrast, PC-3ML cell line, a PC-3 subline with highly invasive, metastatic phenotype, exhibits a dramatic upregulation of VEGF, 5.6-fold in mRNA and 6.3-fold in protein secretion after treatment with CoCl₂. The upregulation of VEGF in PC-3ML cells is accompanied by a persistent induction of COX-2 mRNA (6.5-fold) and protein (5-fold). Whereas COX-2 expression is only transiently induced in PC-3 cells and not affected by CoCl₂ in LNCaP cells. Moreover, the increases in VEGF mRNA and protein secretion induced by CoCl₂ in PC-3ML cells were significantly suppressed following exposure to NS398, a selective COX-2 inhibitor. Finally, the effect of COX-2 inhibition on CoCl₂-induced VEGF production was reversed by the treatment with exogenous PGE₂. Our data demonstrate that VEGF induction by cobalt chloride-simulated hypoxia is maintained by a concomitant, persistent induction of COX-2 expression and sustained elevation of PGE₂ synthesis in a human metastatic prostate cancer cell line, and suggest that COX-2 activity, reflected by PGE₂ production, is involved in hypoxia-induced VEGF expression, and thus, modulates prostatic tumor angiogenesis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Selective prostaglandin G/H synthase (PGHS)-2 inhibitors show greater inhibitory activities on human PGHS-2 than on murine PGHS-2 in intact cells

Excess eicosanoid formation during inflammation has been attributed to the expression of the gene coding for the inducible isoform of prostaglandin G/H synthase (PGHS-2). Human and murine PGHS-2 proteins differ in 73 out of the 604 amino acids. When comparing the inhibitory effects of a panel of PGHS-inhibitors in a whole cell human and murine PGHS-2 assay carried out under identical conditions, classical NSAIDs with the exception of aspirin and tenoxicam showed similar inhibitory effects on both human and murine PGHS-2 enzymes. However, the PGHS-2 selective inhibitors nimesulide, flosulide and NS398 showed a much greater inhibition of human PGHS-2. We suggest that these differences could be due to the genetic differences of human and murine PGHS-2. Formerly R&D Division of Hafslund Nycomed Pharma AG, Austria.     

NS-398诱导肝癌细胞凋亡的实验研究

目的 :研究选择性环氧化酶 2 (COX 2 )抑制剂NS 398对人肝癌细胞HepG2 凋亡的影响 ,及其相关蛋白Bcl 2在细胞凋亡中的作用。方法 :通过体外细胞培养 ,应用荧光显微镜、透射电镜、流式细胞仪观察NS 398对HepG2 的凋亡诱导作用 ,应用免疫细胞化学法观察Bcl 2在人肝癌细胞HepG2 凋亡中的表达。结果 :NS 398处理HepG2 细胞后 ,电镜下可见到细胞核固缩、染色质凝集成新月型紧靠核膜周边 ,核碎裂、染色质片断化等典型的细胞凋亡形态变化。荧光显微镜及流式细胞检测则未见凋亡征象。免疫细胞化学分析显示 ,NS 398处理后的HepG2 细胞 ,其Bcl 2表达较对照组明显下降。结论 :COX 2选择性抑制剂NS 398对人肝癌HepG2 细胞有显著的凋亡诱导作用 ;抗凋亡基因Bcl 2在NS 398诱导的HepG2 细胞凋亡中有重要的调控作用。     

选择性COX-2抑制剂NS-398的制备

目的制备选择性COX-2抑制剂NS-398。方法以2-氟硝基苯为起始原料,经4步反应化合成化合物NS-398。结果与结论用该方法可以在温和条件下合成出该药,最终产品纯度大于99%。     

选择性环氧合酶抑制剂NS398对子宫内膜癌细胞株的影响

目的探讨环氧合酶抑制剂NS398对子宫内膜癌细胞株的生物学行为的影响。方法2005年9月至2006年11月于华中科技大学同济医学院附属同济医院妇产科实验室用MTT、DNA梯度降解试验及流式细胞仪等方法,研究NS398体外对子宫内膜癌细胞系Ishikawa的抑制增殖、促进凋亡作用。结果NS398对Ishikawa细胞产生明显的生长抑制作用,且表现为剂量依赖性(F=36.598,P<0.01);DNA梯度降解试验、流式细胞仪分析NS398浓度依赖性地诱导了Ishikawa细胞凋亡(F=11.342,P<0.01),且凋亡与细胞周期受阻有关(F=22.445,P<0.01)、主要阻止在G1/S期即DNA合成期。结论NS398对Ishikawa细胞具有显著浓度依赖性的体外生长抑制、诱导凋亡、阻滞DNA合成作用。     

NS-398对宫颈癌细胞系的增殖抑制作用及对survivin基因表达的影响

目的:研究选择性环氧合酶-2(COX-2)抑制剂NS-398对宫颈癌HeLa,SiHa细胞系的增殖、凋亡作用及其对凋亡抑制基因survivin表达的影响。方法:体外培养宫颈癌HeLa,SiHa细胞系,用四甲基偶氮唑蓝(MTT)比色法分析不同浓度的NS-398分别作用于HeLa,SiHa细胞系24h、48h后对细胞增殖的作用;流式细胞仪(FCM)检测对细胞凋亡的作用;RT-PCR分析对凋亡抑制基因survivin表达的影响。结果:MTT检测显示,NS-398可抑制宫颈癌HeLa,SiHa细胞系增殖,并有浓度时间依赖性,与对照组相比差异有统计学意义(P<0.05)。FCM检测提示,NS-398可诱导HeLa,SiHa细胞系凋亡,有浓度依赖性,与对照组相比差异有统计学意义(P<0.05)。RT-PCR分析表明,NS-398可抑制HeLa,SiHa细胞系凋亡抑制基因survivinmRNA表达,与对照组的差异有统计学意义(P<0.05)。结论:NS-398可抑制宫颈癌HeLa,SiHa细胞增殖,诱导凋亡,其机制与抑制凋亡抑制基因survivin mRNA表达有关,为宫颈癌治疗提供了新的靶点和理论依据。     

选择性COX-2抑制剂NS398干预对HIBD新生鼠脑细胞凋亡的影响

目的研究新生大鼠缺氧缺血性脑损伤(HIBD)时应用选择性COX-2抑制剂NS398干预后不同时段脑原位细胞凋亡的变化。方法于制备新生大鼠左脑的HIBD模型前30min,腹腔注射NS39820mg/kg,同时设未注射组及假手术组对照,应用TUNEL染色方法及图像分析软件研究于HI后24h、7d脑皮层及海马TUNEL染色阳性细胞百分率变化。结果假手术组组脑组织中偶见TUNEL染色阳性细胞;未注射组缺氧缺血(HI)后24hTUNEL染色阳性细胞数较多,至HI后7d明显减少;NS398干预组染色阳性细胞数较未注射组明显减少。结论应用选择性COX-2抑制剂NS398于HIBD新生鼠,可以有效减少HI后凋亡细胞,提示NS398对发育期脑组织缺氧缺血损伤存在保护作用。     

非甾体类抗炎药NS398对胃癌细胞株SCG7901的影响

目的：探讨环氧合酶抑制剂NS398对胃癌细胞株SCG7901的生物学行为的影响。方法2014年6—12月于河北医科大学第二医院实验室,用MTT、DNA梯度降解试验及流式细胞仪等方法,研究NS398对胃癌细胞株SCG7901的抑制增殖、促进凋亡作用。结果 NS398对胃癌细胞株SCG7901产生明显的生长抑制作用,且表现为剂量依赖性(F=35.984,P<0.01);DNA梯度降解试验、流式细胞仪分析NS398浓度依赖性地诱导了胃癌细胞株SCG7901凋亡(F=12.414,P<0.01),且凋亡与细胞周期受阻有关(F=21.315,P<0.01),主要阻止在S/G2期。结论NS398对胃癌细胞株SCG7901具有显著浓度依赖性的体外生长抑制、诱导凋亡、阻滞DNA合成作用。     

Perfil lipoproteico avanzado en individuos con metabolismo glucémico normal y alterado

Introduction and objectivesSeveral types of lipoproteins beyond low-density lipoproteins (LDL) are causally related to cardiovascular disease. We aimed to analyze an advanced lipoprotein profile in individuals with normal and impaired glucose metabolism from different cohorts of a Mediterranean region.MethodsCross-sectional study in 929 participants (463 normoglycemia, 250 prediabetes, and 216 type 2 diabetes mellitus) with normal renal function, free from cardiovascular disease, and without lipid-lowering treatment. Conventional and advanced (nuclear magnetic resonance [NMR] spectroscopy) lipoprotein profiles were analyzed.ResultsCompared with men, normoglycemic women showed lower serum triglyceride and LDL cholesterol concentrations, lower total LDL particles (P) as well as their subclasses and their cholesterol and triglyceride content, higher high-density lipoproteins (HDL)-P and all HDL-related variables (P  ≤  .05 for all comparisons). Compared with normoglycemic participants, diabetic participants showed higher large and small very LDL-P concentrations (P < .05) and lower total HDL-P and medium HDL-P concentrations (P < .05). Waist circumference and Fatty Liver Index were positively associated with a proatherogenic profile.ConclusionsWomen had a better advanced lipoprotein profile than did men. Adiposity indexes related to insulin-resistance were positively associated with a proatherogenic lipid profile. NMR revealed altered lipoprotein particles other than LDL in participants with diabetes, frequently associated with an increased cardiovascular risk. Our findings support the usefulness of extended lipoprotein analysis by NMR spectroscopy to uncover new therapeutic targets to prevent cardiovascular events in at-risk participants.