RESUMO
The bacterial enzyme asparaginase is the main treatment option for acute lymphoblastic leukemia. However, it causes side effects, such as immunological reactions, and presents undesirable glutaminase activity. As an alternative, we have been studying asparaginase II from Saccharomyces cerevisiae, coded by ASP3 gene, which was cloned and expressed in Pichia pastoris. The recombinant asparaginase (ASP) presented antileukemic activity and a glutaminase activity 100 times lower in comparison to its asparaginase activity. In this work, we describe the development of a delivery system for ASP via its covalent attachment to functionalized polyethylene glycol (PEG) polymer chains in the outer surface of liposomes (ASP-enzymosomes). This new delivery system demonstrated antiproliferative activity against K562 (chronic myeloid leukemia) and Jurkat (acute lymphocytic leukemia) cell lines similar to that of ASP. The antiproliferative response of the ASP-enzymosomes against the Jurkat cells suggests equivalence to that of the free Escherichia coli commercial asparaginase (Aginasa®). Moreover, the ASP-enzymosomes were stable at 4 °C with no significant loss of activity within 4 days and retained 82% activity up to 37 days. Therefore, ASP-enzymosomes are a promising antileukemic drug.
Assuntos
Antineoplásicos/química , Asparaginase/química , Leucemia/tratamento farmacológico , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Asparaginase/genética , Asparaginase/metabolismo , Asparaginase/farmacologia , Composição de Medicamentos/métodos , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células Jurkat , Células K562 , Leucemia/patologia , Lipossomos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Células Tumorais CultivadasRESUMO
La enfermedad de Gaucher es una entidad hereditaria del metabolismo de los esfingolípidos con un patrón de herencia autosómico recesivo determinada por una deficiencia de la actividad de la enzima b-glucosidasa ácida. En este trabajo se presentan 2 pacientes en edad pediátrica, uno del sexo femenino y otro del masculino, ambos con anemia y hepatoesplenomegalia confirmadas por ultrasonido. El aspirado de médula ósea mostró infiltración por células de almacenamiento, niveles bajos de la actividad enzimática de b-glucocerebrosidasa y el diagnóstico molecular de las posibles mutaciones conocidas confirmaron la enfermedad en ambos pacientes que se encuentran en tratamiento con terapia enzimática sustitutiva (imiglucerasa), con evolución favorable en los aspectos clínicos y humorales.
Gaucher's disease is a hereditary entity related to sphingolipids metabolism with an autosomal recessive hereditary pattern determined by a failure of the acid b-glucosidase enzyme. In present paper authors present the case of two pediatric patients (1 female and 1 male) both presenting with anemia and hepatosplenomegaly by ultrasound (US). Bone marrow aspirate showed infiltration by storage cells, low levels of enzymatic activity of b-glucocerebroside and a molecular diagnosis of potential known mutations confirmed the disease in both patients, who are under treatment with substitutive enzymatic therapy (imiglucerase) with a favorable course in clinical and humoral features.