leukotriene-b4 and Lung-Neoplasms

Besides smoking, lung cancer can be caused by other factors, including heavy metals such as cadmium, nickel, arsenic, beryllium and hexavalent chromium [Cr(VI)], which is used in multiple settings, resulting in widespread environmental and occupational exposures as well as heavy use. The mechanism by which Cr(VI) causes lung cancer is not completely understood. Currently, it is admitted chromosome instability is a key process in the mechanism of Cr(VI)-induced cancer, and previous studies have suggested Cr(VI) impacts the lung tissue in mice by triggering tissue damage and inflammation. However, the mechanism underlying Cr(VI)-induced inflammation and its exact role in lung cancer are unclear. Therefore, this review aimed to systematically examine previous studies assessing Cr(VI)-induced inflammation and to summarize the major inflammatory pathways involved in Cr(VI)-induced inflammation. In cell culture studies, COX2, VEGF, JAK-STAT, leukotriene B4 (LTB4), MAPK, NF-ҡB and Nrf2 signaling pathways were consistently upregulated by Cr(VI), clearly demonstrating that these pathways are involved in Cr(VI)-induced inflammation. In addition, Akt signaling was also shown to contribute to Cr(VI)-induced inflammation, although discrepant findings were reported. Few mechanistic studies were performed in animal models, in which Cr(VI) upregulated oxidative pathways, NF-kB signaling and the MAPK pathway in the lung tissue. Similar to cell culture studies, opposite effects of Cr(VI) on Akt signaling were reported. This work provides insights into the mechanisms by which Cr(VI) induces lung inflammation. However, discrepant findings and other major issues in study design, both in cell and animal models, suggest that further studies are required to unveil the mechanism of Cr(VI)-induced inflammation and its role in lung cancer.

Topics: Animals; Arsenic; Beryllium; Cadmium; Chromium; Cyclooxygenase 2; Inflammation; Leukotriene B4; Lung; Lung Neoplasms; Mice; NF-E2-Related Factor 2; NF-kappa B; Nickel; Proto-Oncogene Proteins c-akt; Vascular Endothelial Growth Factor A

In this phase II study, patients with stage IIIB/IV non-small-cell lung cancer were randomly assigned (1:1:1) to receive LY293111 (200 mg twice daily [200 LY293111] or 600 mg twice daily [600 LY293111]) or placebo for 7 days, followed by concurrent cisplatin (75 mg/m2; day 1) and gemcitabine (1250 mg/m2; days 1 and 8), every 21 days.The primary endpoint was progression-free survival, (PFS), with 75% power to detect 33% improvement compared with placebo (5 months).. Of 200 randomized patients, 195 were treated. Demographics were well balanced across treatment arms: 65% of the patients were men; median age was 62 years; 85% had stage IV disease; and patients had an Eastern Cooperative Oncology Group performance status of 0 (36%) or 1 (64%).. The most frequent study drug-related toxicities were nausea, vomiting, and fatigue. Response rates were similar across treatment arms (200 LY293111: 20%; 600 LY293111: 25%; placebo: 31%).. Median PFS (95% confidence interval) was not significantly different across treatment arms (200 LY293111: 4.6 months [3.2-5.0]; 600 LY293111: 5.6 months [4.1-6.8]; placebo: 6.0 months [5.2-7.5]). LY293111 combined with gemcitabine-cisplatin did not increase median PFS compared with placebo plus gemcitabine-cisplatin in patients with non-small-cell lung cancer.

Topics: Adiponectin; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzoates; Carcinoma, Non-Small-Cell Lung; Cisplatin; Deoxycytidine; Double-Blind Method; Female; Gemcitabine; Humans; Leukotriene B4; Lung Neoplasms; Male; Middle Aged

Macrophages in lungs can be classified into two subpopulations, alveolar macrophages (AMs) and interstitial macrophages (IMs), which reside in the alveolar and interstitial spaces, respectively. Accumulating evidence indicates the involvement of IMs in lung metastasis, but the roles of AMs in lung metastasis still remain elusive. An i.v. injection of a mouse hepatocellular carcinoma (HCC) cell line, BNL, caused lung metastasis foci with infiltration of AMs and IMs. Comprehensive determination of arachidonic acid metabolite levels revealed increases in leukotrienes and PGs in lungs in this metastasis model. A 5-lipoxygenase (LOX) inhibitor but not a cyclooxygenase inhibitor reduced the numbers of metastatic foci, particularly those of a larger size. A major 5-LOX metabolite, LTB

Topics: Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acid; Bronchoalveolar Lavage Fluid; Carcinoma, Hepatocellular; Cell Line; Cell Line, Tumor; Cyclooxygenase Inhibitors; Humans; Leukotriene B4; Leukotrienes; Liver Neoplasms; Lung; Lung Neoplasms; Macrophages; Macrophages, Alveolar; Male; Mice; Mice, Inbred BALB C

Chronic exposure to crystalline silica (CS) causes silicosis, an irreversible lung inflammatory disease that may eventually lead to lung cancer. In this study, we demonstrate that in K-ras(LA1) mice, CS exposure markedly enhances the lung tumour burden and genetic deletion of leukotriene B4 receptor-1 (BLT1(-/-)) attenuates this increase. Pulmonary neutrophilic inflammation induced by CS is significantly reduced in BLT1(-/-)K-ras(LA1) mice. CS exposure induces LTB4 production by mast cells and macrophages independent of inflammasome activation. In an air-pouch model, CS-induced neutrophil recruitment is dependent on LTB4 production by mast cells and BLT1 expression on neutrophils. In an implantable lung tumour model, CS exposure results in rapid tumour growth and decreased survival that is attenuated in the absence of BLT1. These results suggest that the LTB4/BLT1 axis sets the pace of CS-induced sterile inflammation that promotes lung cancer progression. This knowledge may facilitate development of immunotherapeutic strategies to fight silicosis and lung cancer.

Topics: Animals; Cell Proliferation; Chemokines; Chemotactic Factors; Crystallization; Disease Progression; Inflammation; Inflammation Mediators; Interleukin-1beta; Leukotriene B4; Lung Neoplasms; Mice, Inbred C57BL; Mice, Transgenic; Models, Biological; Neutrophil Infiltration; Proto-Oncogene Proteins p21(ras); Receptors, Leukotriene B4; Silicon Dioxide

Recent advances in lung cancer biology presuppose its inflammatory origin. In this regard, LTB-4 and IL-8 are recognized to play a crucial role in neutrophil recruitment into airways during lung cancer.Notwithstanding the intriguing hypothesis, the exact role of neutrophilic inflammation in tumour biology remains complex and not completely known.The aim of this study was to give our contribution in this field by investigating LTB-4 and IL-8 in the breath condensate of NSCLC patients and verifying their role in cancer development and progression.. We enrolled 50 NSCLC patients and 35 controls. LTB-4 and IL-8 concentrations were measured in the breath condensate and the blood of all the subjects under study using EIA kits. Thirty NSCLC patients and ten controls underwent induced sputum collection and analysis.. LTB-4 and IL-8 resulted higher in breath condensate and the blood of NSCLC patients compared to controls. Significantly higher concentrations were found as the cancer stages progressed. A positive correlation was observed between exhaled IL-8 and LTB-4 and the percentage of neutrophils in the induced sputum.. The high concentrations of exhaled LTB-4 and IL-8 showed the presence of a neutrophilic inflammation in the airways of NSCLC patients and gave a further support to the inflammatory signalling in lung cancer. These exhaled proteins could represent a suitable non-invasive marker in the diagnosis and monitoring of lung cancer.

Topics: Aged; Breath Tests; Carcinoma, Non-Small-Cell Lung; Case-Control Studies; Exhalation; Female; Humans; Inflammation; Interleukin-8; Leukotriene B4; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Neutrophil Infiltration; Sputum

The present study investigated the effects of a preparation of a gamma-tocopherol-rich mixture of tocopherols (gamma-TmT) on chemically induced lung tumorigenesis in female A/J mice and the growth of H1299 human lung cancer cell xenograft tumors. In the A/J mouse model, the lung tumors were induced by either 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK; intraperitoneal injections with 100 and 75 mg/kg on Week 1 and 2, respectively) or NNK plus benzo[a]pyrene (B[a]P) (8 weekly gavages of 2 mumole each from Week 1 to 8). The NNK plus B[a]P treatment induced 21 tumors per lung on Week 19; dietary 0.3% gamma-TmT treatment during the entire experimental period significantly lowered tumor multiplicity, tumor volume and tumor burden (by 30, 50 and 55%, respectively; P < 0.05). For three groups of mice treated with NNK alone, the gamma-TmT diet was given during the initiation stage (Week 0 to 3), post-initiation stage (Week 3 to 19) or the entire experimental period, and the tumor multiplicity was reduced by 17.8, 19.7 or 29.3%, respectively (P < 0.05). gamma-TmT treatment during the tumor initiation stage or throughout the entire period of the experiment also significantly reduced tumor burden (by 36 or 43%, respectively). In the xenograft tumor model of human lung cancer H1299 cells in NCr-nu/nu mice, 0.3% dietary gamma-TmT treatment significantly reduced tumor volume and tumor weight by 56 and 47%, respectively (P < 0.05). In both the carcinogenesis and tumor growth models, the inhibitory action of gamma-TmT was associated with enhanced apoptosis and lowered levels of 8-hydroxydeoxyguanine, gamma-H2AX and nitrotyrosine in the tumors of the gamma-TmT-treated mice. In cell culture, the growth of H1299 cells was inhibited by tocopherols with their effectiveness following the order of delta-T > gamma-TmT > gamma-T, whereas alpha-T was not effective. These results demonstrate the inhibitory effect of gamma-TmT against lung tumorigenesis and the growth of xenograft tumors of human lung cancer cells. The inhibitory activity may be due mainly to the actions of delta-T and gamma-T.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Apoptosis; Benzo(a)pyrene; Cell Line, Tumor; Cell Proliferation; Deoxyguanosine; Dinoprostone; Female; gamma-Tocopherol; Histones; Leukotriene B4; Lung Neoplasms; Mice; Neovascularization, Pathologic; Nitrosamines; Tyrosine; Xenograft Model Antitumor Assays

Aggressive bladder cancer is a major cause of morbidity and mortality. Despite the fact that metastatic disease results in death in the majority of bladder cancer cases, the molecular events regulating the invasive phenotype of aggressive bladder cancer are not well understood. In this study, immunohistochemical examination showed that the leukotriene B(4) receptor BLT2 is overexpressed in advanced malignant bladder cancers (human transitional cell carcinomas) in proportion to advancing stages, with high prognostic significance (p<0.001). Blockade of BLT2 with the specific antagonist LY255283 or siRNA knockdown significantly suppressed the invasiveness of highly aggressive 253J-BV bladder cancer cells. Moreover, our results demonstrated that BLT2 mediates invasiveness through a signaling pathway dependent on NAD(P)H oxidase (Nox) 1- and Nox4-induced generation of reactive oxygen species (ROS) and subsequent NF-kappaB stimulation. Metastasis of 253J-BV cells in mice was also dramatically suppressed by inhibition of BLT2 or its signaling. These findings suggest that a BLT2-Nox-ROS-NF-kappaB cascade plays a critical role in bladder cancer invasion and metastasis.

Topics: Animals; Carcinoma; Cell Line, Tumor; Humans; Leukotriene B4; Lung Neoplasms; Mice; Mice, Nude; NADPH Oxidase 1; NADPH Oxidase 4; NADPH Oxidases; Neoplasm Invasiveness; Neoplasm Staging; Neoplasm Transplantation; NF-kappa B; Prognosis; Reactive Oxygen Species; Receptors, Leukotriene B4; RNA, Small Interfering; Signal Transduction; Tetrazoles; Transcriptional Activation; Urinary Bladder Neoplasms

Leukotrienes have been implicated to play a prominent inductive role in carcinogenesis. We previously reported that bronchoalveolar lavage (BAL) cells from smokers manifested higher levels of leukotriene B4 (LTB4) production than ex-smokers. This study aims to elucidate the underlying mechanism(s). BAL cells from current and former smokers were exposed to lipopolysaccharide (LPS) for up to 7 days. LPS induced the release of LTB4 from BAL cells and down-regulated 5-lipoxygenase (5-LOX) mRNA expression in a dose-dependent manner, followed by a decrease in 5-LOX protein production and normalization of LTB4 levels. Exogenous LTB4 inhibited LPS-induced 5-LOX activity and accentuated the down-regulation of 5-LOX mRNA, whereas suppression of 5-LOX abrogated the LPS-induced changes, suggesting a negative feedback mechanism. LPS concomitantly induced expression and activity of the LTB4 metabolizing enzyme LTB4 omega-hydroxylase (LTB4OH) in ex-smokers' BAL cells, but not in smokers' BAL cells. In vitro smoke exposure of ex-smokers' BAL cells also abrogated the LPS-induced up-regulation of LTB4OH mRNA expression. Furthermore, ex-smokers' BAL cells expressed significantly higher LTB4OH mRNA levels than smokers' BAL cells. Such differential modulation of LTB4 synthesis and degradation by LPS in the setting of tobacco smoke exposure suggests that mechanisms responsible for sustained elevation of LTB4 levels in the lung microenvironment may contribute to the pathogenesis of tobacco-related respiratory diseases such as lung cancer. By regulating the balance of LTB4 in the lung, LTB4OH may function as a suppressor of lung carcinogenesis.

Topics: Aged; Aged, 80 and over; Arachidonate 5-Lipoxygenase; Bronchoalveolar Lavage Fluid; Carcinoma; Cells, Cultured; Cytochrome P-450 Enzyme System; Cytochrome P450 Family 4; Dose-Response Relationship, Drug; Gene Expression Regulation, Enzymologic; Humans; Leukotriene B4; Lipopolysaccharides; Lung; Lung Neoplasms; Middle Aged; RNA, Messenger; Smoking

The arachidonic acid-metabolizing enzymes cyclooxygenase-2 (COX-2) or 5-lipoxygenase (5-LOX) are overexpressed during lung carcinogenesis and their end products (e.g.; PGE2, 5-HETE, and LTB4) have been implicated in tumor development. Recently, COX-2 inhibitors (e.g.; celecoxib) and 5-LOX inhibitors (e.g.; MK886 and REV5901) used as single agents have shown promising activities in the treatment and chemoprevention of cancer. However, little is known about the effects of combinations of these inhibitors. We found that simultaneous treatment of premalignant and malignant human lung cell lines with celecoxib, MK886, and REV5901 is more potent in growth suppression and induction of cell death than single or dual combination of these agents. However, their sensitivity to the inhibitors was not directly associated with the expression of COX-2, 5-LOX, or 5-LOX-activating protein (FLAP), but correlated with the production of corresponding metabolites. Furthermore, partial protection of cell death was observed when PGE2 and/or 5-HETE was added to cell cultures treated with celecoxib, MK886, and REV5901 simultaneously. Our data indicate that a triple drug combination of distinct inhibitors of the eicosanoid metabolism at clinically feasible concentrations were more effective than each agent alone suggesting further investigations.

Topics: 5-Lipoxygenase-Activating Proteins; Apoptosis; Blotting, Western; Carrier Proteins; Celecoxib; Cell Cycle; Cell Death; Cell Division; Cell Line, Tumor; Cyclooxygenase 2 Inhibitors; Dinoprostone; Humans; Hydroxyeicosatetraenoic Acids; Indoles; Leukotriene B4; Lipoxygenase Inhibitors; Lung Neoplasms; Membrane Proteins; Pyrazoles; Quinolines; Spectrometry, Mass, Electrospray Ionization; Sulfonamides

Topics: Animals; Cell Line; Chromatography, High Pressure Liquid; Deuterium; Leukotriene B4; Lung Neoplasms; Mass Spectrometry; Swine; Tumor Cells, Cultured

The addition of glucose to the culture medium of HepG2 or A549 cells for 22 h caused a dose-dependent increase in leukotriene B(4) omega-hydroxylation activity in the homogenate. The addition of genistein to the culture medium of HepG2 or A549 cells for 22 h caused a dose-dependent decrease in the activity, although the number of living cells was not influenced by the addition of genistein. The inhibition by genistein was reversed by removal of genistein from the culture medium in 22 h. The specific leukotriene B(4) omega-hydroxylation activity was high in the nuclear envelope fraction of HepG2 or A549 cells, and a large portion of the activity was concentrated in the nuclear envelope fraction. In the nuclear envelope fraction, leukotriene B(4) omega-hydroxylation activity was accompanied by high polyunsaturated fatty acid omega-hydroxylation activity. The apparent K(m) values for arachidonic acid and leukotriene B(4) in the fractions of HepG2 or A549 cells were 25 and 50 microM, or 22 and 66 microM, respectively. The V(max) values were 222 and 104 pmol/min/mg protein, or 175 and 370 pmol/min/mg protein, respectively. NADPH-dependent omega-hydroxylation of LTB(4) in the nuclear envelope fraction of HepG2 or A549 cells was strongly inhibited by metyrapone and CO. The expression of cytochrome P450 4F2 mRNAs was detected in HepG2 and A549 cells, and thus the arachidonic acid and leukotriene B(4) omega-hydroxylation activities in the nuclear envelope fractions of HepG2 and A549 cells are likely due to cytochrome P450 4F2.

Topics: Adenocarcinoma; Culture Media; Fatty Acids, Unsaturated; Genistein; Hepatoblastoma; Humans; Hydroxylation; Kinetics; Leukotriene B4; Lung Neoplasms; Tumor Cells, Cultured; Vanadates

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adenocarcinoma; Calcimycin; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Communication; Cell Line; Coculture Techniques; Erythrocytes; Humans; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lung Neoplasms; Models, Biological; Neutrophils; Phospholipases A; Phospholipases A2; Tumor Cells, Cultured

The 190-kDa multidrug resistance protein (MRP) has recently been associated with the transport of cysteinyl leukotrienes and several glutathione (GSH) S-conjugates. In the present study, we have examined the transport of leukotriene C4 (LTC4) in membrane vesicles from MRP-transfected HeLa cells (T14), as well as drug-selected H69AR lung cancer cells which express high levels of MRP. V(max) and K(m) values for LTC4 transport by membrane vesicles from T14 cells were 529 +/- 176 pmol mg(-1) min(-1) and 105 +/- 31 nM, respectively. At 50 nM LTC4, the K(m) (ATP) was 70 micron. Transport in T14 vesicles was osmotically-sensitive and was supported by various nucleoside triphosphates but not by non- or slowly-hydrolyzable ATP analogs. LTC4 transport rates in membrane vesicles derived from H69AR cells and their parental and revertant variants were consistent with their relative levels of MRP expression. A 190-kDa protein in T14 membrane vesicles was photolabeled by [3H]LTC4 and immunoprecipitation with MRP-specific monoclonal antibodies (mAbs) confirmed that this protein was MRP. LTC4 transport was inhibited by an MRP-specific mAb (QCRL-3) directed against an intracellular conformational epitope of MRP, but not by a mAb (QCRL-1) which recognizes a linear epitope. Photolabeling with [3H]LTC4 was also inhibitable by mAb QCRL-3 but not mAb QCRL-1. GSH did not inhibit LTC4 transport. However, the ability of alkylated GSH derivatives to inhibit transport increased markedly with the length of the alkyl group. S-Decylglutathione was a potent competitive inhibitor of [3H]LTC4 transport (K(i(app)) 116 nM), suggesting that the two compounds bind to the same, or closely related, site(s) on MRP. Chemotherapeutic agents including colchicine, doxorubicin, and daunorubicin were poor inhibitors of [3H]LTC4 transport. Taxol, VP-16, vincristine, and vinblastine were also poor inhibitors of LTC4 transport but inhibition by these compounds was enhanced by GSH. Uptake of [3H]vincristine into T14 membrane vesicles in the absence of GSH was low and not dependent on ATP. However, in the presence of GSH, ATP-dependent vincristine transport was observed. Levels of transport increased with concentrations of GSH up to 5 mM. The identification of an MRP-specific mAb that inhibits LTC4 transport and prevents photolabeling of MRP by LTC4, provides conclusive evidence of the ability of MRP to transport cysteinyl leukotrienes. Our studies also demonstrate that MRP is capable of mediating ATP-depe

Topics: Adenosine Triphosphate; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biological Transport; Carcinoma, Small Cell; Cations, Divalent; Cell Line; Cell Membrane; Glutathione; HeLa Cells; Humans; Kinetics; Leukotriene B4; Leukotriene C4; Lung Neoplasms; Membrane Proteins; Osmolar Concentration; Recombinant Proteins; Sucrose; Transfection; Tumor Cells, Cultured; Vinblastine; Vincristine

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder characterized by inflammation, fibroblast proliferation, and accumulation of extracellular matrix proteins. Leukotrienes (LTs) are pro-inflammatory and pro-fibrogenic mediators derived from the 5-lipoxygenase (5-LO) pathway of arachidonic acid metabolism. They are thought to play a role in a number of disease processes, but have received relatively little attention in investigations into the pathogenesis of IPF. In this study, we measured the levels of immunoreactive LTs B(4) and C(4) in homogenates of lung tissue obtained from patients with newly diagnosed, untreated IPF, as compared to levels measured in homogenates of uninvolved nonfibrotic lung tissue from patients undergoing resectional surgery for bronchogenic carcinoma. Compared to homogenates on nonfibrotic control lung, homogenates from IPF patients contained 15-fold more LTB(4) and 5-fold more LTC(4). IPF homogenate levels of LTB(4) were significantly correlated with histologic indices of both inflammation (r=0.861) and fibrosis (r=0.926). Activation of 5-LO is known from in vitro studies to be associated with localization of the enzyme at the nuclear membrane. Immunohistochemical staining for 5-LO protein in alveolar macrophages (AMs) demonstrated that such an "activated" localization pattern was significantly more frequent in IPF lung (19.2+/-3.3% of cells) than in control lung (9.3+/-0.9%); this localization pattern was rarely seen (3.2%) in sections from a truly normal transplant donor lung. Consistent with these data, AMs obtained from IPF patients by bronchoalveolar lavage, purified by adherence, and cultured in the absence of a stimulus for 16 h elaborated significantly greater amounts of LTB(4) and LTC(4) than did control AMs obtained from normal volunteers. These data indicate that the 5-LO pathway is constitutively activated in the lungs of patients with IPF, and the AM represents at least one cellular source of LT overproduction in this disorder. We speculate that LTs participate in the pathogenesis of IPF, and their overproduction in this disorder may be amenable to specific pharmacotherapy.

Topics: Adult; Aged; Arachidonate 5-Lipoxygenase; Cells, Cultured; Enzyme Activation; Female; Humans; Immunohistochemistry; Inflammation; Leukotriene B4; Leukotriene C4; Lung; Lung Neoplasms; Macrophages, Alveolar; Male; Middle Aged; Pulmonary Fibrosis; Smoking

We studied cellular interactions between human polymorphonuclear leukocytes (PMN) and lung cancer cell lines by investigating the influence of cancer cells on the production of leukotriene B4 (LTB4) and superoxide anion (O2-) by stimulated PMN. Of the nine cancer cell lines established from human lung cancers that we examined, H23 cells showed the highest LTA4 hydrolase activity. When PMN were stimulated by the calcium ionophore A23187 in the presence of H23 cells, the production of LTB4, 5(S)-hydroxyeicosatetraenoic acid (5-HETE), and 12(S)-hydroxyeicosatetraenoic acid (12-HETE) decreased in a dose-dependent manner. On the contrary, H23 did not inhibit O2- production by PMN. Two other cell lines (N417 and Q9) caused similar inhibition of LTB4 production by PMN. These three cancer cell lines alone did not generate any metabolites of the arachidonic acid (AA) lipoxygenase pathway or any O2- upon stimulation with A23187 alone. The addition of AA dose-dependently reversed the H23-induced inhibition of LTB4, 5-HETE, and 12-HETE production by PMN, suggesting inhibition at the phospholipase A2 (PLA2) level. Furthermore, addition of the cancer cell line Q9 inhibited 14C release from [14C]AA prelabeled PMN in a cell number-dependent manner in the buffer, with and without albumin. The supernatant of H23 cells also inhibited the production of LTB4 by PMN stimulated by A23187, as did the addition of H23 lysate or its 10(4) x g centrifugation supernatant. While neither the 10(5) x g supernatant (cytosol) nor the pellet (microsome) exhibited inhibitory activity, the combination of the separated cytosol and microsomal fractions restored the inhibitory activity. Furthermore, addition of the 10(4) x g supernatant of Q9 lysate to partially purified human cytosolic PLA2 inhibited PLA2 activity in a dose-dependent manner. Our results indicate that the lung cancer cell lines used in our study inhibit LTB4 production by human PMN through inhibition of phospholipase A2 activity, which may contribute to a predisposition to pulmonary infections in patients with lung cancer.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acid; Calcimycin; Calcium; Coculture Techniques; Cyclooxygenase Inhibitors; Dinoprostone; Erythrocytes; Humans; Hydroxyeicosatetraenoic Acids; Indomethacin; Ionophores; Leukotriene B4; Lipoxygenase; Lung Neoplasms; Neutrophils; Phospholipases A; Phospholipases A2; Subcellular Fractions; Superoxides; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

Like many clinical non-small-cell lung cancers, the Lewis lung carcinoma produces prostaglandins. The Lewis lung carcinoma was used as a model of both primary and metastatic disease to assess the ability of cyclooxygenase inhibitors (mefenamic acid, diflunisal, sulindac, and indomethacin), the collagenase inhibitor minocycline, and the lipoxygenase inhibitor phenidone to act as modulators of cytotoxic cancer therapies. Although none of the single modulators given i.p. daily on days 4-18 altered tumor growth or the number of metastases found on day 20, modulator combinations consisting of minocycline/a cyclooxygenase inhibitor and, especially, of phenidone/a cyclooxygenase inhibitor resulted in modest tumor growth delay and a decreased number of lung metastases on day 20. The most effective modulators of cisplatin (CDDP) were phenidone/sulindac and phenidone/indomethacin, which led to 2.4- to 2.5-fold increases in the tumor growth delay produced by CDDP. The most effective modulations of cyclophosphamide resulted from administration of minocycline, minocycline/sulindac, or phenidone/sulindac and led to 2.0- to 2.1-fold increases in tumor growth delay by cyclophosphamide. The most effective modulators of melphalan produced 4.5- to 4.7-fold increases in tumor growth delay by the drug and were minocycline/sulindac, minocycline/mefenamic acid, and phenidone/sulindac. The most effective modulation of carmustine (BCNU) was obtained with minocycline/sulindac and minocycline/diflunisal leading to 2.8- to 3.1-fold increases in tumor growth delay by BCNU. Finally, the most effective modulation of radiation was obtained with minocycline/sulindac and phenidone/sulindac and resulted in 2.8- to 3.3-fold increases in tumor growth delay by radiation. The modulator combination that along with the cytotoxic therapies was most effective against metastatic disease was phenidone/mefenamic acid. There was no clear relationship between effective modulation of the cancer therapies and the degree of reduction in serum levels of prostaglandin E2 and leukotriene B4 by the agents in Lewis lung tumor bearing mice.

Topics: Animals; Antineoplastic Agents; Cyclooxygenase Inhibitors; Dinoprostone; Drug Synergism; Leukotriene B4; Lipoxygenase Inhibitors; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Minocycline; Neoplasm Transplantation; Pyrazoles; Tumor Cells, Cultured

To enhance monoclonal antibody uptake in tumors, seven novel vasoactive immunoconjugates were developed that selectively alter the vascular permeability and/or blood volume of tumors in vivo. These immunoconjugates, composed of IL-1 beta, IL-2, TNF-alpha, physalaemin, leukotriene B4, histamine, and bradykinin chemically linked to TNT-1, a murine monoclonal antibody that binds necrotic regions in tumors, have been tested for their effects on antibody uptake in vivo.. Groups of four mice, each bearing the ME-180 human cervical carcinoma, were pretreated either 3 or 24 hours before the administration of I-125 labeled TNT-1 F(ab')2 fragment. Three-day biodistribution studies then were performed to determine the amount of radiolabeled antibody in the tumors and normal organs of the mice. In addition, mechanism of action studies were performed to determine if the vasoactive immunoconjugate affected the vascular permeability or blood volume of the tumor vessels.. TNT-1/IL-2 gave the highest percent injected dose/g in tumor (4.80), compared with TNT-1/TNF (4.00), TNT-1/IL-1 (3.83), TNT-1/leukotriene-B4 (2.84), TNT-1/histamine (2.80), TNT-1/physalaemin (2.19), TNT-1/bradykinin (1.57), or TNT-1 alone (1.28). All of these immunoconjugates showed specific enhancement of monoclonal antibody uptake in tumor with no changes seen in normal tissues. Quantitative studies that demonstrated the mechanism of action of these immunoconjugates showed that TNT-1/IL-2 and TNT-1/histamine produced a marked change in the vasopermeability of tumor vessels but had no effect on tumor blood volume. In contrast, TNT-1/IL-1 and TNT-1/TNF produced a combination of effects, and TNT-1/leukotriene B4, TNT-1/bradykinin, and TNT-1/physalaemin affected only tumor blood volume.. These studies indicate that pretreatment with vasoactive immunoconjugates may improve monoclonal antibody uptake in tumors significantly and thereby increase the therapeutic index of monoclonal antibody-directed immunotherapy.

Topics: Animals; Antibodies, Monoclonal; Blood Vessels; Capillary Permeability; Female; Humans; Leukotriene B4; Lung Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Tissue Distribution; Transplantation, Heterologous; Uterine Cervical Neoplasms

Eicosanoid synthesis by alveolar macrophages (AM), harvested from tumor bearing animals, was measured after tumor inoculation in rats treated with or without carrageenan (carra), an immunomodulating agent. After incubation of the cells with [14]C-arachidonic acid and the Ca-ionophore A23187, samples were measured by high pressure liquid chromatography (HPLC). From the HPLC profiles the lypoxygenase products, 12-hydroxyeicosatetraenoic acid (12-HETE), 15-HETE, and leukotriene-B4 (LTB4) were determined as well as the cyclooxygenase products, prostaglandin (PG)E2, PGF2 alpha and TXB2. After tumor inoculation AM-synthesis of lipoxygenase products tended to increase to values twice those of the base line values, whereas cyclooxygenase products showed subnormal values. In the non treated animals, 10 days after tumor inoculation, statistically significant increases in 12- and 15-HETE, LTB4 and PGE2 were observed when compared with carra treated animals. Later measurements did not show these differences in AM metabolism. AM metabolism was (negatively) correlated with the number of macrophages, which was particularly evident in the correlation with 12-HETE synthesis.

Topics: Animals; Arachidonic Acids; Carrageenan; Chromatography, High Pressure Liquid; Dinoprost; Dinoprostone; Drug Implants; Female; Hydroxyeicosatetraenoic Acids; Leukotriene B4; Lung Neoplasms; Macrophages; Mammary Neoplasms, Experimental; Prostaglandins; Pulmonary Alveoli; Rats; Rats, Inbred BN; Thromboxane B2; Time Factors

We studied the generation and metabolism of leukotrienes (LTs) in human lung macrophages obtained from lung tissue of patients with central bronchial carcinoma. By counterflow centrifugation macrophages were enriched with a purity of more than 95-100%. A time and dose dependent generation of LTB4 and LTC4 was determined by specific radioimmunoassays after stimulation with the Ca-ionophore and anti-IgE. The amount of LTB4 exceeded the amount of LTC4. The concentrations of leukotrienes in the macrophage fraction amounted to 4.3 +/- 2.2 ng LTB4 and 0.6 +/- 0.05 ng LTC4/1 x 10(7) cells after 5 min of incubation with the Ca-ionophore. The LTB4 levels decreased to 3.0 +/- 0.6 ng after 60 min indicating the metabolism of the generated LTB4 by human lung macrophages. This was confirmed by incubation of the cells with exogenously added [3H]LTB4. LTB4 was converted into unpolar products as was identified by thin-layer chromatography and high-performance liquid chromatography; a comparison with the fibroblast cell line L929 which is known to convert LTB4 into the dihydro-LTB4 metabolite (5,12-dihydroxyeicosatrienoic acid) indicates that human lung macrophages use the same pathway of metabolization. Biological inactivation as determined by chemotaxis and cross-reaction with the LTB4 antiserum correlates with the degree of LTB4 metabolism. Moreover, the macrophages convert LTC4 into LTD4 and LTE4 by the enzymatic activity of the gamma-glutamyltranspeptidase and dipeptidase. Our data emphasize that the human alveolar macrophage not only produces arachidonic acid metabolites but modulates the local inflammatory potential by its metabolizing capacity for leukotrienes.

Topics: Antibodies, Anti-Idiotypic; Calcimycin; Carcinoma, Bronchogenic; Cells, Cultured; Humans; Immunoglobulin E; Leukotriene B4; Lung; Lung Neoplasms; Macrophages; SRS-A