2-hydroxy-9-cis-octadecenoic-acid and Neoplasms

Drug delivery in cationic liposomes seems to be a promising therapeutic approach in cancer treatment. The rational design of the positively charged lipid vesicles as anticancer drug carriers should be supported by a detailed analysis of the interactions of the carrier components with anticancer drugs. In the present work, 2-hydroxyoleic acid (2OHOA; Minerval), a membrane lipid therapy drug, was incorporated into positively charged mono- and bilayer membranes containing 1-palmitoyl-2-oleoyl- sn-glycero-3-ethylphosphocholine (EPOPC), the synthetic cationic lipid, and 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC). The intermolecular interactions, fluidity, and miscibility of the studied monolayers were analyzed by utilizing Langmuir balance experiments. The morphology of two-dimensional films was inspected using a Brewster angle microscopy technique. The properties of the liposomes were investigated by dynamic light scattering (DLS) and zeta potential measurements, steady-state fluorescence anisotropy experiments, and the spectrofluorimetric titration of calcein-encapsulated vesicles with a lysis-inducing agent. According to the collected results, 2OHOA intercalation into films of pure phospholipids or a binary EPOPC/DOPC film is thermodynamically favorable. Surprisingly, no significant effect of the presence of unsaturated 2OHOA chains on the EPOPC/DOPC monolayer order was observed. The experiments carried out for 2OHOA-inserted cationic EPOPC/DOPC (1:4) liposomes indicate effective incorporation of the drug into the liposome bilayer and the formation of stable vesicles without affecting their properties markedly. On the basis of the obtained results, EPOPC/DOPC/2OHOA cationic liposomes with 15% 2OHOA content in the phospholipid bilayer seem to be the most suitable for potential biomedical applications.

Topics: Cations; Drug Delivery Systems; Humans; Lipid Bilayers; Lipids; Liposomes; Neoplasms; Oleic Acids; Particle Size; Surface Properties

2-Hydroxy-oleic acid (2OHOA) is a potent anticancer drug that induces cancer cell cycle arrest and apoptosis. Previous studies have suggested that 2OHOA's anticancer effect is mediated by SMS activation in cancer cells, including A549 and U118 cells. To confirm this phenomenon, in this study, we treated both A549 and U118 cells with 2OHOA and measured SMS activity. To our surprise, we found neither 2OHOA-mediated SMS activation nor sphingomyelin accumulation in the cells. However, we noted that 2OHOA significantly reduces phosphatidylcholine in these cells. We also did not observe 2OHOA-mediated SMS activation in mouse tissue homogenates. Importantly, 2OHOA inhibited rather than activated recombinant SMS1 (rSMS1) and rSMS2 in a dose-dependent fashion. Intra-gastric treatment of C57BL/6J mice with 2OHOA for 10 days had no effects on liver and small intestine SMS activities and plasma sphingomyelin levels. The treatment inhibited lysophosphatidylcholine acyltransferase (LPCAT) activity, consistent with the aforementioned reduction in plasma phosphatidylcholine. Because total cellular phosphatidylcholine is used as a predictive biomarker for monitoring tumor responses, the previously reported 2OHOA-mediated cancer suppression could be related to this phosphatidylcholine reduction, which may influence cell membrane structure and properties. We conclude that 2OHOA is not a SMS activator and that its anticancer property may be related to an effect on phosphatidylcholine metabolism.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Enzyme Activation; Enzyme Activators; Humans; Mice; Mice, Inbred C57BL; Neoplasms; Oleic Acids; Phosphatidylcholines; Sphingomyelins; Transferases (Other Substituted Phosphate Groups)

The synthetic fatty acid 2-hydroxyoleic acid (2OHOA) is a potent antitumor drug that we rationally designed to regulate the membrane lipid composition and structure. The lipid modifications caused by 2OHOA treatments induce important signaling changes that end up with cell death (Terés et al., 2012 [1]). One of these regulatory effects is restoration of sphingomyelin levels, which are markedly lower in cancer cells compared to normal cells (Barceló-Coblijn et al., 2011 [2]). In this study, we report another important regulatory effect of 2OHOA on cancer cell membrane composition: a large increase in 2OHOA levels, accounting for ~15% of the fatty acids present in membrane phospholipids, in human glioma (SF767 and U118) and lung cancer (A549) cells. Concomitantly, we observed marked reductions in oleic acid levels and inhibition of stearoyl-CoA desaturase. The impact of these changes on the biophysical properties of the lipid bilayer was evaluated in liposomes reconstituted from cancer cell membrane lipid extracts. Thus, 2OHOA increased the packing of ordered domains and decreased the global order of the membrane. The present results further support and extend the knowledge about the mechanism of action for 2OHOA, based on the regulation of the membrane lipid composition and structure and subsequent modulation of membrane protein-associated signaling.

Topics: Antineoplastic Agents; Biophysical Phenomena; Cell Line; Cell Line, Tumor; Cell Membrane; Chromatography, Thin Layer; Fatty Acids; Humans; Lipid Bilayers; Mass Spectrometry; Membrane Lipids; Neoplasms; Oleic Acids; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Stearoyl-CoA Desaturase; Time Factors; Triglycerides

Minerval is an oleic acid synthetic analogue that impairs lung cancer (A549) cell proliferation upon modulation of the plasma membrane lipid structure and subsequent regulation of protein kinase C localization and activity. However, this mechanism does not fully explain the regression of tumours induced by this drug in animal models of cancer. Here we show that Minerval also induced apoptosis in Jurkat T-lymphoblastic leukaemia and other cancer cells. Minerval inhibited proliferation of Jurkat cells, concomitant with a decrease of cyclin D3 and cdk2 (cyclin-dependent kinase2). In addition, the changes that induced on Jurkat cell membrane organization caused clustering (capping) of the death receptor Fas (CD95), caspase-8 activation and initiation of the extrinsic apoptosis pathway, which finally resulted in programmed cell death. The present results suggest that the intrinsic pathway (associated with caspase-9 function) was activated downstream by caspase-8. In a xenograft model of human leukaemia, Minerval also inhibited tumour progression and induced tumour cell death. Studies carried out in a wide variety of cancer cell types demonstrated that apoptosis was the main molecular mechanism triggered by Minerval. This is the first report on the pro-apoptotic activity of Minerval, and in part explains the effectiveness of this non-toxic anticancer drug and its wide spectrum against different types of cancer.

Topics: Animals; Apoptosis; Caspases; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D3; Cyclin-Dependent Kinase 2; Dose-Response Relationship, Drug; Flow Cytometry; HeLa Cells; HL-60 Cells; HT29 Cells; Humans; Immunoblotting; Jurkat Cells; Leukemia, Experimental; Leukemia, T-Cell; Male; Mice; Mice, Nude; Neoplasms; Oleic Acids; Time Factors; Xenograft Model Antitumor Assays

alpha-Hydroxy-9-cis-octadecenoic acid, a synthetic fatty acid that modifies the composition and structure of lipid membranes. 2-Hydroxyoleic acid (HOA) generated interest due to its potent, yet nontoxic, anticancer activity. It induces cell cycle arrest in human lung cancer (A549) cells and apoptosis in human leukemia (Jurkat) cells. These two pathways may explain how HOA induces regression of a variety of cancers. We showed that HOA repressed the expression of dihydrofolate reductase (DHFR), the enzyme responsible for tetrahydrofolate (THF) synthesis. Folinic acid, which readily produces THF without the participation of DHFR, reverses the antitumor effects of HOA in A549 and Jurkat cells, as well as the inhibitory influence on cyclin D and cdk2 in A549 cells, and on DNA and PARP degradation in Jurkat cells. This effect was very specific, because either elaidic acid (an analog of HOA) or other lipids, failed to alter A549 or Jurkat cell growth. THF is a cofactor necessary for DNA synthesis. Thus, impairment of DNA synthesis appears to be a common mechanism involved in the different responses elicited by cancer cells following treatment with HOA, namely cell cycle arrest or apoptosis. Compared with other antifolates, such as methotrexate, HOA did not directly inhibit DHFR but rather, it repressed its expression, a mode of action that offers certain therapeutic advantages. These results not only demonstrate the effect of a fatty acid on the expression of DHFR, but also emphasize the potential of HOA to be used as a wide-spectrum drug against cancer.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Membrane; Fatty Acids; Folic Acid Antagonists; Humans; Jurkat Cells; Leucovorin; Lipids; Methotrexate; Neoplasms; Oleic Acids; Substrate Specificity; Tetrahydrofolate Dehydrogenase