title: Potential antitumor activity of novel DODAC/PHO-S liposomes.
abstract: In recent studies, we showed that synthetic phosphoethanolamine (PHO-S) has a great potential for inducing cell death in several tumor cell lines without damage to normal cells. However, its cytotoxic effect and selectivity against tumor cells could increase with encapsulation in cationic liposomes, such as dioctadecyldimethylammonium chloride (DODAC), due to electrostatic interactions between these liposomes and tumor cell membranes. Our aim was to use cationic liposomes to deliver PHO-S and to furthermore maximize the therapeutic effect of this compound. DODAC liposomes containing PHO-S (DODAC/PHO-S), at concentrations of 0.3-2.0 mM, prepared by ultrasonication, were analyzed by scanning electron microscopy (SEM) and dynamic light scattering. The cytotoxic effect of DODAC/PHO-S on B16F10 cells, Hepa1c1c7 cells, and human umbilical vein endothelial cells (HUVECs) was assessed by MTT assay. Cell cycle phases of B16F10 cells were analyzed by flow cytometry and the morphological changes by SEM, after treatment. The liposomes were spherical and polydisperse in solution. The liposomes were stable, presenting an average of ∼ 50% of PHO-S encapsulation, with a small reduction after 40 days. DODAC demonstrated efficient PHO-S delivery, with the lowest values of IC50% (concentration that inhibits 50% of the growth of cells) for tumor cells, compared with PHO-S alone, with an IC50% value of 0.8 mM for B16F10 cells and 0.2 mM for Hepa1c1c7 cells, and without significant effects on endothelial cells. The Hepa1c1c7 cells showed greater sensitivity to the DODAC/PHO-S formulation when compared to B16F10 cells and HUVECs. The use of DODAC/PHO-S on B16F10 cells induced G2/M-phase cell cycle arrest, with the proportion significantly greater than that treated with PHO-S alone. The morphological analysis of B16F10 cells by SEM showed changes such as "bleb" formation, cell detachment, cytoplasmic retraction, and apoptotic bodies after DODAC/PHO-S treatment. Cationic liposomal formulation for PHO-S delivery promoted cytotoxicity more selectively and effectively against B16F10 and Hepa1c1c7 cells. Thus, the DODAC/PHO-S liposomal formulation presents great potential for preclinical studies.
authors.affiliation: Biochemistry and Biophysical Laboratory, Butantan Institute, University of Sao Paulo, Sao Paulo, Brazil; Department of Medical Sciences, Medical School, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Arthur Cássio de Lima
authors.initials: AC
authors.lastname: Luna
authors.affiliation: Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Greice Kelle Viegas
authors.initials: GK
authors.lastname: Saraiva
authors.affiliation: Environmental Health Surveillance, Municipality of Uberaba, Minas Gerais, Brazil.
authors.forename: Otaviano Mendonça Ribeiro
authors.initials: OM
authors.lastname: Filho
authors.affiliation: Department of Chemistry and Molecular Physics, University of Sao Paulo, Sao Carlos, Brazil.
authors.forename: Gilberto Orivaldo
authors.initials: GO
authors.lastname: Chierice
authors.affiliation: Department of Chemistry and Molecular Physics, University of Sao Paulo, Sao Carlos, Brazil.
authors.forename: Salvador Claro
authors.initials: SC
authors.lastname: Neto
authors.affiliation: Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Iolanda Midea
authors.initials: IM
authors.lastname: Cuccovia
authors.affiliation: Biochemistry and Biophysical Laboratory, Butantan Institute, University of Sao Paulo, Sao Paulo, Brazil; Department of Medical Sciences, Medical School, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Durvanei Augusto
authors.initials: DA
authors.lastname: Maria
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects; D004983:Ethanolamines / Q000737:chemistry / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D008081:Liposomes / Q000008:administration & dosage* / Q000737:chemistry; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology*; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D004983:Ethanolamines; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C015831:dimethyldioctadecylammonium; C005448:phosphorylethanolamine
keywords: hepatocellular carcinoma; lipossomal formulation; nanocarriers; synthetic phosphoethanolamine