prostaglandin-d2 and Neoplasm-Metastasis

Topics: Animals; Antineoplastic Agents; Blood Coagulation; Blood Platelets; Blood Vessels; Cell Adhesion; Cell Communication; Cells, Cultured; Cricetinae; Cysteine Endopeptidases; Disease Models, Animal; Endopeptidases; Epoprostenol; Humans; Killer Cells, Natural; Lung Neoplasms; Melanoma; Mice; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; Neoplasms, Experimental; Platelet Aggregation; Prostaglandin D2; Prostaglandins D; Rabbits; Rats; Thrombocytopenia; Thromboxane-A Synthase

The data presented suggest that F1 and F10 cells display an inverse relationship between their levels of metastasis and prostaglandin D2 production. Prostaglandin D2 was able to reduce in vitro aggregation of platelets from C57 black mice. Other prostaglandins that decreased platelet aggregation such as prostacyclin also reduced the metastatic rate. Prostaglandin D2 also reduced macrophage cytotoxicity for B16 target cells in vitro. Interferons stimulated prostaglandin D2 synthesis in F10 cells and reduced lung metastasis. F10 metastasis was not blocked by interferon to the same extent by in vivo treatment as it had been in vitro, suggesting that interferons and other modulators of cell function have broader activity in vivo than simply increasing the level of prostaglandins being produced by metastatic cells. Metastasis can therefore be viewed as being modulated in vivo by several mechanisms that may include platelet aggregation and elimination of metastasized cells by host defenses such as macrophages. Prostaglandins and other naturally occurring modulators of host resistance, such as interferons, appear to affect the metastatic rate of tumor cells. Although prostaglandin D2 is not a common major AA product of most cells and therefore may not operate in all cell systems, the B16 cells may provide a system to address the importance of these mediators and mechanisms in the metastatic process.

Topics: Animals; Cell Line; Cytotoxicity, Immunologic; Immunity, Innate; Indomethacin; Interferons; Killer Cells, Natural; Macrophages; Melanoma; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Neoplasm Transplantation; Platelet Aggregation; Prostaglandin D2; Prostaglandins D

Despite new therapeutic approaches, metastatic melanomas still have a poor prognosis. Statins reduce low-density lipoprotein cholesterol and exert anti-inflammatory and anti-proliferative actions. We have recently shown that simvastatin triggers an apoptotic burst in human metastatic melanoma cells by the synthesis of an autocrine factor.. The current in vitro study was performed in human metastatic melanoma cell lines (A375, 518a2) and primary human melanocytes and melanoma cells. The secretome of simvastatin-stressed cells was analysed with two-dimensional difference gel electrophoresis and MS. The signalling pathways involved were analysed at the protein and mRNA level using pharmacological approaches and siRNA technology.. Simvastatin was shown to activate a stress cascade, leading to the synthesis of 15-deoxy-12,14-PGJ2 (15d-PGJ2 ), in a p38- and COX-2-dependent manner. Significant concentrations of 15d-PGJ2 were reached in the medium of melanoma cells, which were sufficient to activate caspase 8 and the mitochondrial pathway of apoptosis. Inhibition of lipocalin-type PGD synthase, a key enzyme for 15d-PGJ2 synthesis, abolished the apoptotic effect of simvastatin. Moreover, 15d-PGJ2 was shown to bind to the fatty acid-binding protein 5 (FABP5), which was up-regulated and predominantly detected in the secretome of simvastatin-stressed cells. Knockdown of FABP5 abolished simvastatin-induced activation of PPAR-γ and amplified the apoptotic response.. We characterized simvastatin-induced activation of the 15d-PGJ2 /FABP5 signalling cascades, which triggered an apoptotic burst in melanoma cells but did not affect primary human melanocytes. These data support the rationale for the pharmacological targeting of 15d-PGJ2 in metastatic melanoma.

Topics: Apoptosis; Autocrine Communication; Caspase 8; Cell Line, Tumor; Cells, Cultured; Fatty Acid-Binding Proteins; Gene Knockdown Techniques; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Intramolecular Oxidoreductases; Lipocalins; Melanocytes; Melanoma; Neoplasm Metastasis; Prostaglandin D2; Simvastatin

Recently, a number of steps in the progression of metastatic disease have been shown to be regulated by redox signalling. Electrophilic lipids affect redox signalling through the post-translational modification of critical cysteine residues in proteins. However, the therapeutic potential as well as the precise mechanisms of action of electrophilic lipids in cancer cells is poorly understood. In the present study, we investigate the effect of the electrophilic prostaglandin 15d-PGJ2 (15-deoxy-Delta12,14-prostaglandin J2) on metastatic properties of breast cancer cells. 15d-PGJ2 was shown to decrease migration, stimulate focal-adhesion disassembly and cause extensive F-actin (filamentous actin) reorganization at low concentrations (0.03-0.3 microM). Importantly, these effects seem to be independent of PPARgamma (peroxisome-proliferator-activated receptor gamma) and modification of actin or Keap1 (Kelch-like ECH-associated protein 1), which are known protein targets of 15d-PGJ2 at higher concentrations. Interestingly, the p38 inhibitor SB203580 was able to prevent both 15d-PGJ2-induced F-actin reorganization and focal-adhesion disassembly. Taken together, the results of the present study suggest that electrophiles such as 15d-PGJ2 are potential anti-metastatic agents which exhibit specificity for migration and adhesion pathways at low concentrations where there are no observed effects on Keap1 or cytotoxicity.

Topics: Actins; Adaptor Proteins, Signal Transducing; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Survival; Cytoskeletal Proteins; Focal Adhesion Kinase 1; Focal Adhesions; Kelch-Like ECH-Associated Protein 1; Mice; Neoplasm Metastasis; p38 Mitogen-Activated Protein Kinases; Prostaglandin D2; Signal Transduction

Arachidonic acid metabolites known to affect platelet function also interfere with tumor growth and metastases. The purpose of this study was to evaluate the anti-metastatic potential of ketoconazole, a thromboxane synthetase and 5-lipoxygenase inhibitor, on hepatic metastasis from a human pancreatic adenocarcinoma in nude mice and its effect on serum prostaglandin levels.. The human pancreatic tumor cells (RWP-2) were injected intrasplenically in nude mice grouped into control, ketoconazole (270 microg), ketoconazole (360 microg), and ketoconazole (540 microg). The agent was administered intraperitoneally 30 min before and every 24 h after the tumor cell inoculation for 8 days. In a separate experiment thromboxane B2 (TxB2), prostaglandin D2 (PGD2), prostaglandin E2 (PGE2) and 6-Keto-F1a (stable prostacyclin derivative) were measured on blood from controls, tumor bearing animals and animals bearing tumors treated with 270 microg of ketoconazole.. Statistically significant differences were observed between the control and three-treatment groups on the reduction of liver tumor nodules (p < 0.001), and in the liver surface areas occupied by tumor (p < 0.001). The TxB2 levels decreased from 150.6 ng/mL in the tumor bearing to 104.8 ng/mL in the ketoconazole treated animals (p < 0.05). PGD2, PGE2 and 6-keto-F1a levels increased to 7.1 ng/mL, 8.3 ng/mL, and 13.6 ng/mL from 3 ng/mL, 5.8 ng/mL, and 0.02 ng/mL respectively (p < 0.001).. These results indicate that ketoconazole significantly reduced hepatic metastases from the human pancreatic carcinoma RWP-2 in the nude mouse model, and inhibited thromboxane B2 formation, potentiating a concomitant redirection of platelet endoperoxide metabolism into PGD2, PGE2, and 6-keto-F1a. It is hypothesized that the changes in the arachidonic acid metabolism mediate the ameliorating effect of ketoconazole on experimental hepatic metastasis.

Topics: 6-Ketoprostaglandin F1 alpha; Adenocarcinoma; Animals; Antineoplastic Agents; Dinoprostone; Humans; Injections, Intraperitoneal; Ketoconazole; Liver Neoplasms; Mice; Mice, Nude; Neoplasm Metastasis; Pancreatic Neoplasms; Prostaglandin Antagonists; Prostaglandin D2; Prostaglandins; Thromboxane B2; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The metastatic murine mammary tumor cell line 410.4 and its nonmetastatic counterpart tumor line 410 were examined for the presence of prostaglandin E2 (PGE2) binding using a 3H-PGE2 ligand binding assay. Inhibition of endogenous prostaglandin synthesis with indomethacin was shown to increase markedly binding of 3H-PGE2. Equilibrium binding data for tumor 410.4 show that specific binding is saturable, reversible by unlabeled PGE2, temperature-dependent and specific. PGE1, PGE2 or 16-16-dimethyl PGE2 compete well with 3H-PGE2 for binding. PGD2 partially inhibits 3H-PGE2 binding, whereas PGA2 does not compete. Scatchard analysis of equilibrium binding data reveals a high affinity (Kd = 3.9 X 10(-9) M) and an average of 33,785 binding sites/cell. In contrast, binding of 3H-PGE2 to nonmetastatic line 410 has a slightly lower affinity (Kd = 8.8 X 10(-9) M) and an average of 368,857 binding sites/cell. 3H-PGE binding to line 410 cells is comparatively nonspecific as PGD2 is nearly as effective as PGE1, PGE2 and an analogue of PGE2 in competing with 3H-PGE2 and PGA2 also inhibits 3H-PGE2 binding.

Topics: Animals; Binding, Competitive; Dinoprostone; Indomethacin; Kinetics; Mammary Neoplasms, Experimental; Neoplasm Metastasis; Prostaglandin D2; Prostaglandins A; Prostaglandins D; Prostaglandins E; Tumor Cells, Cultured

The five stable metabolites [prostaglandin F2 alpha (PGF2 alpha), prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha)] of arachidonic acid (AA) via the cyclooxygenase pathway were measured by high-resolution gas chromatography-mass spectrometry in M5076 ovarian reticulosarcoma (M5) homogenates at various times after tumor implantation (Days 15, 18, 21, and 24). Vegetating tumor showed an active AA overall metabolism, which significantly increased during tumor growth. Synthesis of selected products (TXB2, PGD2, and PGE2) increased markedly over time (up to 10.6, 3.5, and 0.9 micrograms/g, respectively). The overall metabolic profile was TXB2 much greater than PGD2 greater than PGF2 alpha greater than 6-keto-PGF1 alpha greater than PGE2 on Day 15 and TXB2 much greater than PGD2 much greater than PGF2 alpha greater than 6-keto-PGF1 alpha on Day 24. TXB2 was also by far the most abundant product of in vitro-cultured M5 cells. Chronic treatment of M5-bearing mice with dazmegrel (UK-38,485), a selective thromboxane synthetase inhibitor (100 mg/kg p.o. daily, from Day 7 to killing), resulted in incomplete TXB2 synthesis inhibition, AA metabolism diversion toward the other prostaglandins, and no effects of tumor growth and metastasis. More frequent dazmegrel treatment (100 mg/kg p.o. every 8 h from Day 1 to killing) resulted in complete TXB2 synthetase inhibition, AA metabolism diversion, and increased tumor growth and metastasis. These data do not support the hypothesis of thromboxane synthetase inhibitors reducing tumor growth. However, since TXB2 suppression was accompanied by the production of other products possibly interfering in tumor growth, no conclusions on the effective role of TXA2 in malignancy can be drawn.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Dinoprostone; Female; Gas Chromatography-Mass Spectrometry; Imidazoles; Lymphoma, Non-Hodgkin; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Ovarian Neoplasms; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Thromboxane B2; Thromboxane-A Synthase; Thromboxanes

Combination of dibutyryl adenosine 3', 5'-cyclic monophosphate or prostaglandin E1 (PGE1) and papaverine effectively induced differentiation of neuroblastoma in mice. Two cases of human neuroblastoma with stage III and IV were administered intraaortic PGE1 infusion combined with oral papaverine and conventional chemotherapy. There were no noticeable side effects and the treatment was effective in decreasing tumor size and promoting tumor maturation in the infused area. However, distant osseous metastases were developed in both cases, during and after the PGE1 administration. They survived 30 and 17 months, respectively, from the initiation of therapy. (Jpn J Cancer Chemother 10(9): 1936-1943, 1983) These results prompted us to study the metastatic potentials of neuroblastoma. In vitro studies demonstrated that cultured human neuroblastoma cells (NB-1, GOTO, SK-N-DZ, SJ-N-KP, SJ-N-CG and SK-N-FI) aggregate human platelets with maximum aggregation ranging from 28% to 51%. Addition of PGE1 or PGD2 to PRP effectively inhibited the tumor-cell-platelet interaction, with IC50 approximately 100 nM for PGE1 and 10 nM for PGD2, respectively. In addition, 50 microM PGE1 or PGD2, 5 microM PGI2 reversed neuroblastoma-induced platelet aggregation in 4 out of 5 cell lines were studied. These findings indicate a the possible role of PGs in effective inhibition of neuroblastoma metastases in vivo. However, two cell lines (SK-N-DZ and SJ-N-CG), which had been exposed to 8.5 microM PGE1 or PGD2 for 90 min and 72 hr, respectively, retained the platelet aggregating activity which was not significantly different from that of untreated cells. We conclude that clinical application of intraaortic PGE1 in the treatment of advanced neuroblastoma has advantage in potentiation of tumor cell kill and in inducing maturation. Administered PGE1 may exert its action in two ways: in preventing tumor metastasis or possibly in enhancing the metastatic potential of neuroblastoma cells. Further refinement of these modalities including other PGs such as PGD2 or PGI2 and more detailed studies on optimal PG administration to prevent metastasis should be evaluated in future.

Topics: Alprostadil; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Humans; Infusions, Intra-Arterial; Neoplasm Metastasis; Neuroblastoma; Platelet Aggregation; Prostaglandin D2; Prostaglandins D; Prostaglandins E