RESUMO
Anaplastic large cell lymphoma (ALCL) is a peripheral T-cell lymphoma presenting mostly in children and young adults. The natural progression of this disease is largely unknown as is the identity of its true cell of origin. Here we present a model of peripheral ALCL pathogenesis where the malignancy is initiated in early thymocytes, before T-cell receptor (TCR) ß-rearrangement, which is bypassed in CD4/NPM-ALK transgenic mice following Notch1 expression. However, we find that a TCR is required for thymic egress and development of peripheral murine tumours, yet this TCR must be downregulated for T-cell lymphomagenesis. In keeping with this, clonal TCR rearrangements in human ALCL are predominantly in-frame, but often aberrant, with clonal TCRα but no comparable clonal TCRß rearrangement, yielding events that would not normally be permissive for survival during thymic development. Children affected by ALCL may thus harbour thymic lymphoma-initiating cells capable of seeding relapse after chemotherapy.
Assuntos
Genes Codificadores da Cadeia alfa de Receptores de Linfócitos T , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T , Linfoma Anaplásico de Células Grandes/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Timócitos/metabolismo , Timo/citologia , Adulto , Animais , Antígenos CD4/metabolismo , Linhagem Celular Tumoral , Criança , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Rearranjo Gênico do Linfócito T , Genes RAG-1/genética , Humanos , Imuno-Histoquímica , Células Jurkat , Masculino , Camundongos , Camundongos Transgênicos , Proteínas Tirosina Quinases/metabolismo , Receptor Notch1/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Cationic nucleoside lipids based on a 3-nitropyrrole universal base were prepared from D-ribose using a straightforward chemical synthesis. Several studies including DLS, TEM, and ethidium bromide (EthBr) assay demonstrated that these amphiphilic molecules form supramolecular organizations of nanometer size in aqueous solutions and are able to bind nucleic acids. siRNA knockdown experiments were performed with these nucleolipids, and we observed protein knockdown activity similar to the siPORT NeoFX positive control. No significant cytotoxicity was found.
Assuntos
Lipídeos/química , Pirróis/química , Pirróis/metabolismo , RNA Interferente Pequeno/metabolismo , Ribonucleosídeos/química , Ribonucleosídeos/metabolismo , Transfecção/métodos , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Pirróis/toxicidade , Ribonucleosídeos/toxicidadeRESUMO
A novel uridine-based nucleo-lipid, DOTAU (N-[5'-(2',3'-dioleoyl)uridine]-N',N',N'-trimethylammonium tosylate) was prepared by using a convenient four-step synthetic pathway. From the preliminary physicochemical studies (quasielastic light scattering and light microscopy), this amphiphilic structure forms supramolecular organizations in aqueous solution. In addition, in the presence of nucleic acids, transmission electronic microscopy experiments (TEM) and small angle X-ray scattering (SAXS) reveal the formation of multilamellar structures similar to lipoplexes (cationic liposome-DNA complexes) with cationic lipids. The formation of a complex was confirmed by fluorescence spectroscopic assays involving ethidium bromide. Transfection assays of mammalian cell lines (HeLa and MCF-7) indicate that DOTAU can transfect efficiently an expression vector (pEGFP) encoding GFP. Proliferation assays realized on these cell lines show that DOTAU does not inhibit cell proliferation and is less toxic than the commercial Lipofectamine 2000.
