Dual inhibition of 5-LOX and COX-2 suppresses esophageal squamous cell carcinoma

COX-2 and 5-LOX are up-regulated in ESCC. This study aims to determine the efficacy of COX-2 inhibitor, 5-LOX inhibitor and their combination on ESCC. Nimesulide can suppress cell growth and promote apoptosis, accompanied with a decrease of PGE(2) production. AA861 has the similar effect with a down-regulation of LTB(4). In animal experiment, the tumor volumes in drug-treated groups were significantly smaller with the lowest rates of Ki-67 positive cells. In conclusion, either COX-2 inhibitor or 5-LOX inhibitor can suppress ESCC. Dual inhibition of COX-2 and 5-LOX pathway may present a superior anticancer efficacy to either inhibition of COX-2 or 5-LOX alone.     

Significance of COX-2 expression in human esophageal squamous cell carcinoma

Cyclooxygenase-2 (COX-2) is well established to play an important role in the tumorigenesis of a variety of human cancers; however, the function of COX-2 in the development of esophageal squamous cell carcinoma (ESCC) remains less clear. Here, we determined, first, the pattern of COX-2 expression in normal esophageal mucosa, dysplasia, carcinoma in situ (CIS) and invasive SCC. Immunohistochemical analysis showed that, while COX-2 was weakly expressed, if at all, in normal squamous epithelium, strong COX-2 expression was detected as early as the stage of dysplasia and frequently in 20 of 26 (77%) CIS and 86 of 111 (77%) invasive SCC. Upregulation of COX-2 in ESCC was found to be significantly associated with tumor progression (R = 0.493, P < 0.01). Further, treatment of human ESCC cell lines (KYSE450 and KYSE510) with NS-398, a COX-2 specific chemical inhibitor, suppressed the production of prostaglandin E2 (PGE2) and induced cell growth inhibition, cell cycle arrest at the G1-S checkpoint, and the expression of cyclin-dependent kinase inhibitors p21waf1/cip1 and p27kip1. Finally, knockdown expression of COX-2 in KYSE450 cells by a specific COX-2 siRNA dramatically inhibited PGE2 production, cell growth and, more importantly, colony formation and tumorigenesis in nude mice. Together, this study suggested that COX-2 may be involved in an early stage of squamous cell carcinogenesis of the esophagus and has a non-redundant role in the regulation of cellular proliferation and tumorigenesis of esophageal epithelial cells.     

n-3 PUFAs reduce VEGF expression in human colon cancer cells modulating the COX-2/PGE2 induced ERK-1 and -2 and HIF-1alpha induction pathway

n-3 Polyunsaturated fatty acids (PUFAs) inhibit the development of microvessels in mammary tumors growing in mice. Human colorectal tumors produce vascular endothelial growth factor (VEGF) whose expression is up-regulated in tumor cells by both cyclooxygenase-2 (COX-2) and PGE(2) and directly correlated to neoangiogenesis and clinical outcome. The goal of this study was to examine the capability of n-3 PUFAs to regulate VEGF expression in HT-29 human colorectal cells in vitro and in vivo. Constitutive VEGF expression was augmented in cultured HT-29 cells by serum starvation and the effects of eicosapentaenoic (EPA) or docosahexaenoic acid (DHA) on VEGF, COX-2, phosphorylated extracellular signal-regulated kinase (ERK)-1 and -2 and hypoxia-inducible-factor 1-alpha (HIF-1alpha) expression and PGE(2) levels were assessed. Tumor growth, VEGF, COX and PGE(2) analysis were carried out in tumors derived from HT-29 cells transplanted in nude mice fed with either EPA or DHA. Both EPA and DHA reduced VEGF and COX-2 expression and PGE(2) levels in HT-29 cells cultured in vitro. Moreover, they inhibited ERK-1 and -2 phosphorylation and HIF-1alpha protein over-expression, critical steps in the PGE(2)-induced signaling pathway leading to the augmented expression of VEGF in colon cancer cells. EPA always showed higher efficacy than DHA in vitro. Both fatty acids decreased the growth of the tumors obtained by inoculating HT-29 cells in nude mice, microvessel formation and the levels of VEGF, COX-2 and PGE(2) in tumors. The data provide evidence that these n-3 PUFAs are able to inhibit VEGF expression in colon cancer cells and suggest that one possible mechanism involved may be the negative regulation of the COX-2/PGE(2) pathway. Their potential clinical application as anti-angiogenic compounds in colon cancer therapy is proposed.     

Growth stimulation of COX-2-negative pancreatic cancer by a selective COX-2 inhibitor

Cyclooxygenase 2 (COX-2) inhibitors are promising antiangiogenic agents in several preclinical models. The aim of the present study was to evaluate the effect of selective COX-2 inhibitors on vascular endothelial growth factor (VEGF) production in vitro and angiogenesis and growth of pancreatic cancer in vivo, focusing on putative differences between COX-2-negative and COX-2-positive tumors. VEGF production and angiogenesis in vitro were determined by ELISA and endothelial cell migration assay. To determine whether the effect of COX-2 inhibitors was mediated by peroxisome proliferator-activated receptor gamma (PPAR-gamma), we used a dominant-negative PPAR-gamma and a pharmacologic inhibitor. In vitro findings were validated in a pancreatic cancer animal model. Microvessel density was assessed by CD31 immunostaining. Intratumoral prostaglandin and VEGF levels were measured by mass spectroscopy and ELISA. Selective COX-2 inhibitors had a concentration-dependent effect on VEGF production in vitro. Higher concentrations increased VEGF levels and stimulated angiogenesis by activating PPAR-gamma. In vivo, nimesulide increased VEGF production by cancer cells in COX-2-positive and COX-2-negative pancreatic tumors. In COX-2-negative pancreatic cancer, this effect was associated with an increase in angiogenesis and growth. In COX-2-positive pancreatic cancer, the nimesulide-induced increase of VEGF production by the cancer cells was offset by a decrease in VEGF production by the nonmalignant cell types leading to reduced tumor angiogenesis and growth. Selective COX-2 inhibitors had opposite effects on growth and angiogenesis in pancreatic cancer depending on COX-2 expression. These findings imply that assessing the COX-2 profile of the pancreatic tumor is mandatory before initiating therapy with a selective COX-2 inhibitor.     

PGE2对胰腺癌PC-3细胞株血管内皮生长因子(VEGF)表达的影响

目的探讨PGE2对胰腺癌PC-3细胞株血管内皮生长因子(VEGF)表达的影响.方法应用逆转录-聚合酶链反应(RT-PCR)和酶联免疫吸附测定(ELISA)方法,在选择性环氧合酶(COX)-2抑制剂Celebres的干预的基础上,观测PGE2对胰腺癌PC-3细胞株VEGF表达的影响.结果 PGE2可上调胰腺癌PC-3细胞株VEGF的表达,且表现出一定的剂量依赖性关系.结论 PGE2可上调胰腺癌PC-3细胞株VEGF的分泌,其可能在COX-2参与胰腺癌新生血管生成的过程中起着重要的介导作用.     

Cyclooxygenase-2 pathway correlates with VEGF expression in head and neck cancer. Implications for tumor angiogenesis and metastasis

We evaluated the role of COX-2 pathway in 35 head and neck cancers (HNCs) by analyzing COX-2 expression and prostaglandin E2 (PGE2) production in relation to tumor angiogenesis and lymph node metastasis. COX-2 activity was also correlated to vascular endothelial growth factor (VEGF) mRNA and protein expression. COX-2 mRNA and protein expression was higher in tumor samples than in normal mucosa. PGE2 levels were higher in the tumor front zone in comparison with tumor core and normal mucosa (P<.0001). Specimens from patients with lymph node metastasis exhibited higher COX-2 protein expression (P=.0074), PGE2 levels (P=.0011) and microvessel density (P<.0001) than specimens from patients without metastasis. A significant correlation between COX-2 and tumor vascularization (r(s)=0.450, P=.007) as well as between COX-2 and microvessel density with VEGF expression in tumor tissues was found (r(s)=0.450, P=.007; r(s)=0.620, P=.0001, respectively). The induction of COX-2 mRNA and PGE2 synthesis by EGF and Escherichia coli lipopolysaccharide (LPS) in A-431 and SCC-9 cell lines, resulted in an increase in VEGF mRNA and protein production. Indomethacin and celecoxib reversed the EGF- and LPS-dependent COX-2, VEGF, and PGE2 increases. This study suggests a central role of COX-2 pathway in HNC angiogenesis by modulating VEGF production and indicates that COX-2 inhibitors may be useful in HNC treatment.     

IL-6与VEGF在食管鳞状细胞癌中的表达及其临床意义

目的：检测食管鳞状细胞癌（esophageal squamous cell cancer,ESCC）患者血清中白细胞介素-6（interleukin-6,IL-6）和ESCC组织中血管内皮生长因子（vascular endothelial growth factor,VEGF）的表达及其两者关系,并研究两者表达对ESCC的临床意义。方法：收集河北医科大学第四医院胸外科于2014年1月至2015年1月期间行ESCC切除术的患者52例,每例患者均取原发灶组织和癌旁组织标本;同时在术前抽取患者外周血5 ml,再取52例健康体检者外周血5 ml为血清对照。应用ELISA法测定ESCC患者血清中IL-6的水平,免疫组化技术检测VEGF在ESCC组织中的表达,RT-PCR法检测肿瘤组织中IL-6和VEGF mRNA的表达情况。结果：ESCC患者血清IL-6表达水平为（116.71±25.98）pg/ml,明显高于健康对照组的\[（78.43±9.36）pg/ml\]（P＜0.05）,血清中IL-6的表达水平与患者肿瘤分化程度、TNM分期、肿瘤浸润深度和淋巴结转移相关（P＜0.05）。肿瘤组织VEGF蛋白阳性表达率明显高于癌旁组织（67.31% vs 32.69%,P<0.01),且与患者肿瘤分化程度、TNM分期、肿瘤浸润深度和淋巴结转移相关（P＜0.05）。肿瘤组织中IL-6 mRNA的表达与VEGF mRNA的表达呈显著正相关（r=7.113,P＜0.05）。结论：ESCC患者肿瘤组织中IL-6和VEGF均呈高表达且两者呈正相关,两者可能在ESCC侵袭和转移中发挥重要作用。     

尼美舒利对不同COX-2表达水平的食管鳞癌细胞的抑制作用

目的:比较选择性环氧合酶-2(COX-2)抑制剂尼美舒利对不同COX-2表达水平的食管鳞癌细胞的抑制作用。方法:选取食管鳞癌细胞株EC 109、KYSE 150和TE-1,采用Western blot方法测定COX-2蛋白表达、MTT法检测细胞增殖抑制,流式细胞术检测细胞周期和细胞凋亡,观察尼美舒利对各组细胞的增殖抑制和促凋亡作用。结果:COX-2蛋白在EC 109细胞中呈高表达,KYSE 150细胞中呈中等度表达,TE-1细胞不表达COX-2蛋白。尼美舒利在50μmol/L-400μmol/L浓度区间可抑制EC 109、KYSE 150细胞的增殖(P<0.05),并呈剂量依赖性,在400μmol/L时对TE-1细胞有抑制作用。EC 109细胞尼美舒利的IC50值最低,KYSE150次之,TE-1最高。尼美舒利可使EC 109和KYSE 150的细胞周期阻滞于G0/G1期,并诱导细胞凋亡,但对TE-1细胞无上述作用。结论:尼美舒利对表达COX-2的食管鳞癌细胞有较好的增殖抑制和促凋亡作用。     

Bile acids induce cyclooxygenase-2 expression in human pancreatic cancer cell lines

To investigate a possible link between bile acids and the pathogenesis of pancreatic cancer, we determined whether conjugated or unconjugated bile acids induced cyclooxygenase-2 (COX-2) in two human pancreatic cancer cell lines, BxPC-3 and SU 86.86. Bile acids are known promoters of gastric and colon cancer. We demonstrated previously that COX-2, an enzyme that catalyzes the synthesis of prostaglandins, is over-expressed in human pancreatic adenocarcinoma. Both human pancreatic cell lines were treated with conjugated and unconjugated bile acids. COX-2 mRNA and protein were determined. In addition, prostaglandin E2 (PGE2) synthesis was measured. Treatment with conjugated or unconjugated bile acids for 3 h up-regulated COX-2 mRNA. Chenodeoxycholate (CD) or deoxycholate at concentrations ranging from 12.5 to 100 micro M caused a dose-dependent induction of COX-2 protein with a maximal effect at 100 micro M. Induction of COX-2 protein by CD and deoxycholate was detected after treatment for 6 h with maximal induction at 12 h. Taurochenodeoxycholate, a conjugated bile acid, also caused dose-dependent induction of COX-2 but higher concentrations of bile acid (200-1200 micro M) were required. Levels of cyclooxygenase-1 were unaffected by bile acid treatment. Unconjugated and conjugated bile acids caused 7- and 4-fold increases in PGE2 production, respectively. Taken together, these findings suggest a possible role for bile acids in the pathogenesis of pancreatic cancer.     

COX-2和VEGF在食管鳞癌中的表达及其与淋巴结转移的关系

目的:探讨血管内皮生长因子(VEGF)和环氧化酶-2(COX-2)蛋白在食管鳞癌(ESCC)中的表达情况及其与淋巴结转移的关系。方法:应用SP法对60例ESCC手术病理标本进行COX-2和VEGF蛋白表达检测。结果:COX-2和VEGF在ESCC中的表达率分别为85.0%(51/60)和53.3%(32/60)。有淋巴结转移组COX-2和VEGF的表达水平均高于未转移组。COX-2和VEGF蛋白的表达呈明显的正相关,r=0·5202,P<0·01。结论:ESCC中COX-2和VEGF的高表达与ESCC的发生、发展及淋巴结转移有重要关系。     

Id-1 promotes proliferation of p53-deficient esophageal cancer cells

The helix-loop-helix protein inhibitor of differentiation and DNA binding (Id-1) is known to promote cellular proliferation in several types of human cancer. Although it has been reported that Id-1 is over-expressed in esophageal squamous cell carcinoma (ESCC), its function and signaling pathways in esophageal cancer are unknown. In our study, we investigated the direct effects of Id-1 on esophageal cancer cell growth by transfecting an Id-1 expression vector into an ESCC cell line (HKESC-3), which showed serum-dependent Id-1 expression. Ectopic Id-1 expression resulted in increased serum-independent cell growth and G1-S phase transition, as well as up-regulation of mouse double minute 2 (MDM2) and down-regulation of p21Waf1/Cip1 protein expressions in the transfectant clones in a p53-independent manner. However, overexpression of Id-1 had no effect on the pRB, CDK4 and p16INK4A expressions. Stable transfection of Id-1 antisense expression vector to inhibit the expression of endogenous Id-1 in another ESCC cell line (HKESC-1) reversed the effects on MDM2 and p21Waf1/Cip1. In addition, Id-1 expression protected ESCC cells from Tumor Necrosis Factor (TNF)-alpha-induced apoptosis by up-regulating and activating Bcl-2. In conclusion, our study provides evidence for the first time that Id-1 plays a role in both proliferation and survival of esophageal cancer cells. Our findings also suggest that unlike prostate, hepatocellular and nasopharyngeal carcinomas in which Id-1 induces cell proliferation through inactivation of p16INK4A/RB pathway, the increased cell proliferation observed in ESCC cells may be mediated through a different mechanism.     

Aspirin induction of apoptosis in esophageal cancer: a potential for chemoprevention.

The potential use of non-steroidal anti-inflammatory drugs (NSAIDs) in the prevention of gastrointestinal cancers has been highlighted recently. However, it is not known whether NSAIDs could also be useful for preventing esophageal cancer, although regular users of these drugs appear to have a decreased incidence of esophageal cancer. Therefore, we examined the effect of aspirin on growth and apoptosis in 10 esophageal cancer cell lines as well as the expression and modulation of its target enzymes, cyclooxygenases (COXs), and their product prostaglandin E2. Growth inhibition of these cells by aspirin was dose- and time-dependent and associated with the induction of apoptosis. COX-1 and COX-2 were expressed in 7 of the 10 cell lines. Bile acids could induce COX-2 expression in six of eight cell lines tested, which was correlated with prostaglandin E2 production, and aspirin could inhibit COX-2 enzymatic activity even after bile acid stimulation but was unable to change the COX-2 protein level in these cell lines. Down-regulation of bcl-2 by aspirin was found in the two cell lines tested. These results suggest that induction of apoptosis by aspirin may be a mechanism by which it can intervene in esophageal carcinogenesis and may be indicative of the potential of NSAIDs as chemopreventive agents in esophageal cancer.     

食管鳞癌中血管内皮生长因子－C 的表达及与淋巴管生成的关系

目的：探讨血管内皮生长因子－C（VEGF －C）在食管鳞癌中的表达及其与淋巴管生成、淋巴结转移的关系。方法：收集2013年3月至2014年1月遂宁市中心医院胸心外科的107例食管鳞癌手术切除病例及56例正常食管组织的石蜡包埋组织样本,采用免疫组化检测 VEGF －C 在食管鳞癌中的表达,并应用 D2－40抗体标记组织中的微淋巴管内皮细胞,计数微淋巴管密度（LVD）。同时对其与临床病理参数的关系进行分析。结果：食管鳞癌中 VEGF －C 蛋白的高表达率明显高于正常食管组织,且在食管鳞癌不同 TNM分期中有差异（P ＜0．05）;淋巴结转移组中 VEGF －C 蛋白的高表达率为68．3％,高于无淋巴结转移组（P ＜0．05）。T3／T4期组中 VEGF －C 蛋白的高表达率高于 T1／T2期组（P ＜0．05）。VEGF －C 蛋白的高表达率与食管鳞癌患者的年龄、性别、分化程度、肿瘤大小等均无明显相关性（P ＞0．05）。食管鳞癌中 LVD 在 VEGF －C 不同表达强度组中有差异,差异有统计学意义（P ＜0．05）。食管鳞癌淋巴结转移组 LVD 高于无淋巴结转移组,差异均有统计学意义（P ＜0．05）。结论：VEGF －C 基因可能促进食管鳞癌的淋巴管生成及淋巴结转移,有可能成为预测食管鳞癌预后的实验室指标。     

ＣＯＸ-２和ＶＥＧＦ在食管癌中的表达及其与放射敏感性的关系

目的　探讨环氧合酶-２（ＣＯＸ-２）和血管内皮生长因子（ＶＥＧＦ）在食管癌中的表达及其与放射敏感性的关系。方法　应用免疫组化方法检测６０例食管癌组织放疗前ＣＯＸ ２和ＶＥＧＦ的表达情况,并分析ＣＯＸ-２、ＶＥＧＦ及二者联合表达与放射敏感性的关系。结果　６０例食管癌组织ＣＯＸ-２和ＶＥＧＦ阳性表达率分别为６８-３％（４１／６０）和７６-７％（４６／６０）,二者表达呈显著正相关（ｒ＝０.５２６,Ｐ＜０.０１）。ＣＯＸ-２或ＶＥＧＦ阳性表达患者的放疗疗效低,且二者均阳性表达者较均阴性表达者的放疗疗效亦低。结论　ＣＯＸ-２和ＶＥＧＦ在食管癌中的表达显著正相关,二者可作为食管癌放射敏感性和预测食管癌近期疗效的重要指标。     

VEGF、COX-2 mRNA在食管癌中的表达及其意义

目的 探讨血管内皮生长因子(VEGF)剪接变异体、环氧合酶-2(COX-2)与食管癌发生的关系.方法 应用RT-PCR方法对40例食管癌组织及其相应癌旁组织中VEGF、COX-2 mRNA的表达进行了研究.结果 VEGF121mRNA在癌组织中及相应癌旁组织中均有表达,两组差异无统计学意义.40例癌组织中,VEGF165高表达25例,占62.5%;COX-2高表达28例,占70%;40例癌旁组织中,VEGF165高表达6例(15.0%);COX2高表达5例(12.5%).结论 VEGF165、COX-2与食管癌的发生密切相关.     

Hepatocyte growth factor promotes cancer cell migration and angiogenic factors expression: a prognostic marker of human esophageal squamous cell carcinomas.

PURPOSE: Hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, c-Met, play important roles in tumor development and progression. In this study, we measured the serum HGF levels in patients with esophageal squamous cell carcinoma (ESCC) to evaluate its relationships with clinicopathologic features and the role of HGF in ESCC. EXPERIMENTAL DESIGN: One hundred and forty-nine patients with ESCC were studied. Pretherapy serum was collected and ELISA was used to detect the concentrations of HGF, vascular endothelial growth factor (VEGF), and interleukin 8 (IL-8). The function of HGF was shown by invasion chamber assay. RESULTS: Pretherapy serum HGF was found to be significantly higher in patients with ESCC than in control subjects. The levels of HGF correlated significantly with advanced tumor metastasis stage and survival. Multivariate analyses showed that serum HGF level in cell migration was an independent prognostic factor. Increased HGF serum levels correlated positively with serum levels of VEGF and IL-8. Our results also showed that HGF was overexpressed in ESCC tissues and cell lines. In vitro study showed that HGF could stimulate ESCC cell to express VEGF and IL-8 and markedly enhance invasion and migration of ESCC cells. Furthermore, HGF-induced IL-8 and VEGF expression was dependent on extracellular signal-regulated kinase signaling pathways. The inhibition of extracellular signal-regulated kinase activation reduced HGF-mediated IL-8 and VEGF expression. CONCLUSIONS: Our results suggest that serum HGF may be a useful biomarker of tumor progression and a valuable independent prognostic factor in patients with ESCC. HGF may be involved in the progression of ESCC as an autocrine/paracrine factor via enhancing angiogenesis and tumor cell invasion and migration.     

Cyclooxygenase-2 activation mediates the proangiogenic effect of nitric oxide in colorectal cancer.

PURPOSE: Up-regulation of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) enzymes has been reported in colorectal cancer. We aimed at evaluating the possible interaction between the nitric oxide and COX-2 pathways, and its effect on promoting tumor angiogenesis. EXPERIMENTAL DESIGN: Expression of iNOS, COX-2, vascular endothelial growth factor (VEGF), and CD31 was analyzed in tumor samples and corresponding normal mucosa obtained from 46 surgical specimens. We also evaluated iNOS activity, prostaglandin E(2) (PGE(2)), cyclic GMP and cyclic AMP production in the same specimens. Nitrite/nitrate levels, and PGE(2) and VEGF production were assessed in HCT116 and HT29 colon cancer cell lines after induction and selective inhibition of the two enzyme pathways. RESULTS: A significant correlation was found between iNOS and COX-2 immunohistochemical expression. PGE(2) production significantly correlated with iNOS activity and cGMP levels. A significant correlation was also found among PGE(2) production, microvessel density, and VEGF expression. Coinduction of both iNOS and COX-2 activities occurred after lipopolysaccharide (LPS) and epidermal growth factor (EGF) treatment in HCT116 and HT29 cells. Inhibition of iNOS by 1400W significantly reduced both LPS- and EGF-induced PGE(2) production. Treatment with LPS, EGF, and arachidonic acid significantly increased VEGF production in the iNOS-negative/COX-2-positive HT29 cells. This effect was completely reversed by treatment with the selective COX-2 inhibitor celecoxib. CONCLUSIONS: Our data showed a prominent role of nitric oxide in stimulating COX-2 activity in colorectal cancer. This interaction is likely to produce a cooperative effect in promoting angiogenesis through PGE(2)-mediated increase in VEGF production.