d-609 and Lung-Neoplasms

Transforming growth factor-beta (TGF-beta) is a potent inducer of numerous extracellular matrix components, largely through a transcriptional mechanism. To define the postreceptor signaling pathways used by TGF-beta in the induction of extracellular matrix gene expression, we have utilized the human lung carcinoma cell line, A549, in transfection experiments with the TGF-beta inducible reporter construct, p3TP-Lux. Previous work from this laboratory using pharmacologic agents suggested that a phosphatidylcholine-specific phospholipase C and protein kinase C may be involved in early aspects of TGF-beta signaling. Here we provide evidence that TGF-beta induces a rapid and transient increase in diacylglycerol (DAG) production. When cells transfected with the p3TP-Lux reporter plasmid are simultaneously treated with TGF-beta and a DAG kinase inhibitor, we observed a higher level of luciferase than with TGF-beta alone. We also find elevated levels of phosphocholine in cells following TGF-beta treatment. Further, exogenously added bacterial phosphatidylcholine phospholipase C (PC-PLC) is capable of inducing expression of the p3TP-Lux reporter to the same extent as TGF-beta indicating that the bacterial PC-PLC can mimic the TGF-beta effect. In contrast, neither hexanoyl sphingosine (a ceramide analogue) nor arachadonic acid induce expression of the p3TP-Lux reporter. Measurements with the fluorescent, calcium-sensitive dye, FURA2, indicated that there was no change in intracellular calcium in response to TGF-beta. Furthermore, buffering intracellular calcium with the calcium chelating agent BAPTA/AM failed to block TGF-beta induction of the p3TP-Lux reporter. Thus the TGF-beta signaling pathway appears to involve the production of diacylglycerol but is independent of calcium.

Topics: Acetophenones; Arachidonic Acid; Bridged-Ring Compounds; Calcium; Chelating Agents; Chromatography, Thin Layer; Diglycerides; Dose-Response Relationship, Drug; Egtazic Acid; Enzyme Inhibitors; Extracellular Matrix; Humans; Hydrolysis; Lipids; Lung Neoplasms; Norbornanes; Phosphatidylcholines; Phosphodiesterase Inhibitors; Plasmids; Protein Isoforms; Second Messenger Systems; Sphingosine; Thiocarbamates; Thiones; Time Factors; Transforming Growth Factor beta; Tumor Cells, Cultured; Type C Phospholipases

The pro-inflammatory effects of IL-1beta have been linked to the induction of the enzyme COX-2. We now show that in addition to increasing the expression of COX-2, IL-1beta concomittantly decreased the expression of lipocortin 1 on the surface of A549 cells. Furthermore, cytosolic PLA2 is concomittantly activated by phosphorylation-resulting in a stimulation of arachidonic acid and PGE2 release. All of these effects appear to be mediated via a common pathway of PLC and PKC activation. Activation of cPLA2 is inhibited by dexamethasone in a lipocortin 1-dependent mechanism. We present a novel hypothesis whereby the effects of IL-1beta are not only due to activation of enzymes necessary for generation of eicosanoids but also to an inhibition of mechanisms that regulate the supply of arachidonic acid.

Topics: Adenocarcinoma; Annexin A1; Antibodies, Monoclonal; Arachidonic Acid; Blotting, Western; Bridged-Ring Compounds; Cell Line; Cytosol; Dexamethasone; Enzyme Activation; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Humans; Interleukin-1; Lung Neoplasms; Norbornanes; Phospholipases A; Phospholipases A2; Prostaglandin-Endoperoxide Synthases; Protein Kinase C; Thiocarbamates; Thiones; Tumor Cells, Cultured; Type C Phospholipases

Therapeutic effects were obtained after systemic treatment of athymic mice bearing an epidermoid non-small cell human lung carcinoma (NSCLC) xenograft with tricyclodecan-9-yl xanthogenate (D609) and the potassium salt of a fatty (dodecanoic) acid. Extensive intratumoral necrosis was observed 3 days after the treatment.

Topics: Animals; Antineoplastic Agents; Bridged-Ring Compounds; Carcinoma, Non-Small-Cell Lung; Drug Combinations; Humans; Lauric Acids; Lung Neoplasms; Mice; Mice, Nude; Necrosis; Neoplasm Transplantation; Norbornanes; Thiocarbamates; Thiones

The combinations of tricyclodecan-9-yl-xanthogenate (D 609) with undecanoic acid (C11) and D 609 with myristic acid (C14) were tested in 3 rodent tumor models in vivo. D 609 in combination with C11 or C14 did not show antitumoral efficacy in 3-Lewis lung carcinoma (3-LL) growing in syngeneic C57BL6-mice (primary tumor and metastasis) or in WEHI-3B myelomonocytic leukemia growing in Balb/c mice, when given in a dose range lower than the lethal dose for 10% of the treated animals (LD10). In L 1210 mouse lymphoid leukemia growing in CD2F1 mice the combination of D 609/C11 given intraperitoneally in a concentration of 100 mg/kg for more than 1 day effected a significant difference in the survival curves between the control and therapeutic groups in 1 out of 2 experiments. In conclusion, the treatment schedules of D 609/C11 or D 609/C14 used in this study has not revealed significant therapeutic effects in mouse tumors or leukemias in vivo.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Bridged-Ring Compounds; Fatty Acids; Female; Leukemia L1210; Leukemia, Experimental; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Myristic Acids; Neoplasms, Experimental; Norbornanes; Thiocarbamates; Thiones