piperidines and edelfosine

The ether phospholipid AMG-PC (1-O-hexadecyl-2-O-methyl-rac-glycero-3-phosphocholine, ET-16-OCH3) affects rat mast cell responses in a dual manner. A powerful synergistic interaction with the ionophore A23187 and the phorbol ester TPA indicated an involvement of mechanisms relating to activation of protein kinase C. In contrast, the related hexadecylphosphocholine (miltefosine) only causes inhibition. Here, the investigation is extended to include the antineoplastic ether phospholipids ET-18-OCH3 (edelfosine) and BM 41.440 (ilmofosine) as well as the heterocyclic hexadecylphosphocholine analogues D-20133 and D-21266. The four test drugs had an influence very similar to that of AMG-PC on mast cell responses to selected secretagogues, i.e., they both enhanced and inhibited antigen-induced histamine release whereas only inhibition was observed with compound 48/80. They significantly amplified the response to A23187 alone as well as in combination with TPA and, under certain conditions, inhibitory effects were observed with ET-18-OCH3, D-20133 and D-21266 but not with BM 41.440. The latter was more effective in enhancing A23187 mediated responses and had a wider concentration range of activity than the other three drugs. D-20133 and D-21266 influenced mast cells in a manner distinct from that of hexadecylphosphocholine and may share cellular targets with the ether phospholipids. The results raise speculation of an involvement of mast cells in the immunomodulatory action of these drugs.

Topics: Animals; Antineoplastic Agents; Calcimycin; Histamine Release; Ionophores; Male; Mast Cells; Phorbol Esters; Phospholipid Ethers; Phosphorylcholine; Piperidines; Rats; Rats, Wistar

Ether lipid analogues of platelet-activating factor (1-octadecyl-2-acetyl-sn-glycero-3-phosphocholine) possess a wide range of biological activities, including inhibition of neoplastic cell growth in vitro and in vivo. This activity is believed to be membrane mediated. Three different ether lipid analogues, 1-octadecyl-2-methyl-rac-glycero-3-phosphocholine, 1-thiohexadecyl-2-ethyl-rac-glycero-3-phosphocholine, and 4-amino-methyl-1-[2,3-(di-n-decyloxy)-n-propyl]-4-phenylpiperidine , were combined with three DNA-interactive drugs, Adriamycin, 4-hydroperoxycyclophosphamide, and cisplatin, in the expectation that combinations of drugs with different mechanisms of action might show enhanced antitumor activity. The in vitro antiproliferative activity of the combinations was measured with a semisoft agarose clonogenic assay of an ovarian adenocarcinoma cell line. Various permutations of drug combinations were studied. Isobologram analyses and different treatment schedules were performed. Enhanced antiproliferative activity was found with combinations of ether lipids with DNA-interactive drugs in comparison with single agents. Statistical evaluation of the data indicated that the increase in activity was due to an additivity phenomenon. Neither synergism nor antagonism was found.

Topics: Adenocarcinoma; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Division; Cell Survival; Cisplatin; Cyclophosphamide; Doxorubicin; Female; In Vitro Techniques; Ovarian Neoplasms; Phospholipid Ethers; Piperidines; Tumor Cells, Cultured

The antiinvasive activity on MO4 mouse cells of the following lipid derivatives was tested in vitro: an alkyl-lysophospholipid derivative (ET-18-OCH3), a thioether-phospholipid derivative (BM 41.440), an alkyl-linked lipoidal amine (CP-46,665) and a naturally occurring ester-linked phospholipid (2-LPC). In this test, BM 41.440 had the same antiinvasive potency as ET-18-OCH3, whereas CP-46,665 and 2-LPC had no effect on invasion. Comparison of the antiinvasive effect of ET-18-OCH3 on three types of cells showed the following ranking: 12R1C-RK rat kidney adenovirus type 12 transfected cells greater than MO4 mouse cells greater than LLC-H61 Lewis lung carcinoma cells. This ranking was not reflected in ET-18-OCH3-induced changes of cell surface exposed glycopeptides derived from the three types of cells metabolically labeled with radioactive fucose. The present and previous experiments suggested that changes in invasion caused by lipid derivatives depended upon relative cell surface fucosyl-glycopeptide alterations in both the invasive cells and the normal tissue.

Topics: Animals; Antineoplastic Agents; Cell Line; Lysophospholipids; Membrane Glycoproteins; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Neoplasm Invasiveness; Organophosphates; Organophosphorus Compounds; Phospholipid Ethers; Piperidines; Rats; Tumor Cells, Cultured

Two ether lipids, CP-46,665-1 (4-aminomethyl-1-[2,3-(di-n-decyloxy)-n- propyl]-4-phenylpiperidine) and ET-18-OCH3 (racemic 1-O-octadecyl-2-O-methylglycero-3-phosphocholine) have been shown to possess antileukemic activity in vitro. To explore the possible use of these compounds for purging remission bone marrow cells of leukemic cells, we examined the cytotoxic effect of these compounds on normal hematopoietic progenitor cells and leukemic cell line cells (HL-60, K-562, KG-1a, KG-1, and Daudi) by using the clonogenic assay. When cells were treated with CP-46,665-1 or ET-18-OCH3 (50 micrograms/ml for 1 h), these compounds did not inhibit the growth of normal progenitors, whereas the growth of the clonogenic leukemic cells was inhibited with differences in their sensitivities to the cytotoxic effect of CP-46,665-1 and ET-18-OCH3. Incubation of leukemic cells (HL-60 and Daudi cells) with both CP-46,665-1 (50 micrograms/ml) and ET-18-OCH3 (50 micrograms/ml) for 1 h resulted in a greater reduction of clonogenic leukemic cells than treated with each compound alone. Approximately a 3 log killing of clonogenic HL-60 cells and a 5 log killing of Daudi cells was achieved; however, the combined treatment of normal bone marrow cells with CP-46,665-1 and ET-18-OCH3 did not alter the growth of normal progenitors. This combined treatment also selectively eliminated the leukemic cells (HL-60 and Daudi cells) from a mixture (1000:1) of normal bone marrow cells and leukemic cells. It is conceivable that the pronounced difference in sensitivity to this combined treatment can be exploited for the elimination of residual leukemic cells in autologous remission marrow grafts.

Topics: Blood; Cell Line; Cell Survival; Clone Cells; Drug Synergism; Humans; In Vitro Techniques; Leukemia, Myeloid, Acute; Lysophosphatidylcholines; Phospholipid Ethers; Piperidines; Stem Cells; Temperature

The antineoplastic activity of two ether lipid derivatives, the alkyl-lysophospholipid derivative (ALP) ET-18-OCH3 and the ether-linked lipoidal amine CP-46,665 was tested in a human tumor clonogenic assay (HTCA) in vitro. CP-46,665 suppressed the colony formation of various human tumors with a slight dose response relation after 1 hr incubation and with a clear optimum (85% response rate) after continuous exposure in the higher dose range tested (10 micrograms/ml). ET-18-OCH3 did not have substantial activity after 1 hr of incubation. However, when continuous exposure to the compound was used, ET-18-OCH3 seemed to have a modest dose response effect and yielded a response in about 60% of the tumor cell samples tested in the higher dose range (10 micrograms/ml). Thus, both compounds have in vitro antitumor activity in the HTCA within a dose range of 1-10 micrograms/ml, especially during continuous exposure. The tumor specific type activity was found in breast cancer, ovarian cancer, lung cancer and mesothelioma. Both compounds caused decreases in colony formation down to the 0%, 2% and 4% levels. In a comparison of specimens in which both compounds were used, only one of five times showed a discordance in sensitivity or resistance; therefore the compounds appear similar in their in vitro activity. In a second set of experiments we tested the structure-activity relationship among a variety of ALP in the [3H]thymidine incorporation assay after incubation with HL-60 leukemic blasts and other neoplastic cells from human origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antineoplastic Agents; Cell Survival; Female; Humans; Lysophosphatidylcholines; Neoplasms; Phospholipid Ethers; Piperidines; Structure-Activity Relationship