Chinese Medicine Amygdalin and ß-Glucosidase Combined with Antibody Enzymatic Prodrug System As A Feasible Antitumor Therapy.

Amarogentin is an efficacious Chinese herbal medicine and a component of the bitter apricot kernel. It is commonly used as an expectorant and supplementary anti-cancer drug. ß-Glucosidase is an enzyme that hydrolyzes the glycosidic bond between aryl and saccharide groups to release glucose. Upon their interaction, ß-glucosidase catalyzes amarogentin to produce considerable amounts of hydrocyanic acid, which inhibits cytochrome C oxidase, the terminal enzyme in the mitochondrial respiration chain, and suspends adenosine triphosphate synthesis, resulting in cell death. Hydrocyanic acid is a cell-cycle-stage-nonspecific agent that kills cancer cells. Thus, ß-glucosidase can be coupled with a tumor-specific monoclonal antibody. ß-Glucosidase can combine with cancer-cell-surface antigens and specifically convert amarogentin to an active drug that acts on cancer cells and the surrounding antibodies to achieve a killing effect. ß-Glucosidase is injected intravenously and recognizes cancer-cell-surface antigens with the help of an antibody. The prodrug amarogentin is infused after ß-glucosidase has reached the target position. Coupling of cell membrane peptides with ß-glucosidase allows the enzyme to penetrate capillary endothelial cells and clear extracellular deep solid tumors to kill the cells therein. The Chinese medicine amarogentin and ß-glucosidase will become an important treatment for various tumors when an appropriate monoclonal antibody is developed.

Skeletal involvement in Gaucher disease: An observational multicenter study of prognostic factors in the Argentine Gaucher disease patients.

Patients with Gaucher type 1 (GD1) throughout Argentina were enrolled in the Argentine bone project to evaluate bone disease and its determinants. We focused on presence and predictors of bone lesions (BL) and their relationship to therapeutic goals (TG) with timing and dose of enzyme replacement therapy (ERT). A total of 124 patients on ERT were enrolled in a multi-center study. All six TG were achieved by 82% of patients: 70.1% for bone pain and 91.1% for bone crisis. However, despite the fact that bone TGs were achieved, residual bone disease was present in 108 patients on ERT (87%) at time 0. 16% of patients showed new irreversible BL (bone infarcts and avascular osteonecrosis) despite ERT, suggesting that they appeared during ERT or were not detected at the moment of diagnosis. We observed 5 prognostic factors that predicted a higher probability of being free of bone disease: optimal ERT compliance; early diagnosis; timely initiation of therapy; ERT initiation dose ≥45 UI/kg/EOW; and the absence of history of splenectomy. Skeletal involvement was classified into 4 major phenotypic groups according to BL: group 1 (12.9%) without BL; group 2 (28.2%) with reversible BL; group 3 (41.9%) with reversible BL and irreversible chronic BL; and group 4 (16.9%) with acute irreversible BL. Our study identifies prognostic factors for achieving best therapeutic outcomes, introduces new risk stratification for patients and suggests the need for a redefinition of bone TG. Am. J. Hematol. 91:E448-E453, 2016. © 2016 Wiley Periodicals, Inc.

Informe de evaluación rápida de tecnología sobre seguridad y efectividad de la imiglucerasa para enfermedad de Gaucher tipo I / Rapid evaluation report of technology on the safety and effectiveness of imiglucerase for Gaucher disease type I

La Enfermedad de Gaucher es la enfermedad más común de depósito lisosomal, pertenece al grupo de enfermedades catalogadas como errores innatos del metabolismo y se trasmite por herencia autosómica recesiva. (1) Se caracteriza por la presencia de mutaciones patológicas en los genes que codifican la enzima ß- glucosidasa-ácida lisosomal produciendo su deficiencia parcial o total, lo que origina depósitos anormales de material glicolípido (glucocerebrósidos) en los lisosomas de los macrófagos mononucleares de los órganos ricos en células de la línea monocitosmacrófagos como el hígado, bazo, médula ósea y parénquima de los nódulos linfáticos. Se reporta después de la intervención aumento sostenido de la hemogloblina, disminución de la hepatomegalia, disminución del volumen esplénico en pacientes con esplenomeglia moderada y severa, resolución del dolor óseo, los niños que reciben la TRE pueden llegar a alcanzar la talla normal en alrededor de 3 años de tratamiento, respuesta a hipertensión pulmonar. Los pacientes con TRE tuvieron mejores puntajes para el funcionamiento físico, el rol físico, el dolor corporal, la salud general y vitalidad. Se recomienda cubrir con generación de evidencia.(AU)

Biochemical evidence for superior correction of neuronal storage by chemically modified enzyme in murine mucopolysaccharidosis VII.

Enzyme replacement therapy has been used successfully in many lysosomal storage diseases. However, correction of brain storage has been limited by the inability of infused enzyme to cross the blood-brain barrier (BBB). We recently reported that PerT-GUS, a form of ß-glucuronidase (GUS) chemically modified to eliminate its uptake and clearance by carbohydrate-dependent receptors, crossed the BBB and cleared neuronal storage in an immunotolerant model of murine mucopolysaccharidosis (MPS) type VII. In this respect, the chemically modified enzyme was superior to native ß-glucuronidase. Chemically modified enzyme was also delivered more effectively to heart, kidney, and muscle. However, liver and spleen, which express high levels of carbohydrate receptors, received nearly fourfold lower levels of PerT-GUS compared with native GUS. A recent report on PerT-treated sulfamidase in murine MPS IIIA confirmed enhanced delivery to other tissues but failed to observe clearance of storage in neurons. To confirm and extend our original observations, we compared the efficacy of 12 weekly i.v. infusions of PerT-GUS versus native GUS on (i) delivery of enzyme to brain; (ii) improvement in histopathology; and (iii) correction of secondary elevations of other lysosomal enzymes. Such correction is a recognized biomarker for correction of neuronal storage. PerT-GUS was superior to native GUS in all three categories. These results provide additional evidence that long-circulating enzyme, chemically modified to escape carbohydrate-mediated clearance, may offer advantages in treating MPS VII. The relevance of this approach to treat other lysosomal storage diseases that affect brain awaits confirmation.

[Enzyme replacement therapy for Gaucher disease introduced in late adulthood]. / Idoskorban kezdett enzimszubsztitúciós terápia Gaucher-kórban.

Gaucher disease is the most prevalent lysosomal storage disorder caused by recessive mutation of the beta-glucocerebrosidase gene, which leads to massive lysosomal accumulation of glucocerebrosids especially in macrophages of bone marrow, liver and spleen. The most common presenting signs and symptoms are hepatosplenomegaly, bone pain, pathologic fractures, fatigue, bleeding tendency and recurrent infections. Regular enzyme replacement therapy which is available since 1992 in Hungary successfully reverses the symptoms of the disorder, including hematological abnormalities, bone infiltration and hepatosplenomegaly. Authors present here two cases diagnosed in late adulthood to emphasize the importance of early diagnosis and treatment.

Chemically modified beta-glucuronidase crosses blood-brain barrier and clears neuronal storage in murine mucopolysaccharidosis VII.

Enzyme replacement therapy has been used successfully in many lysosomal storage diseases. However, correction of brain storage has been limited by the inability of infused enzyme to cross the blood-brain barrier. The newborn mouse is an exception because recombinant enzyme is delivered to neonatal brain after mannose 6-phosphate receptor-mediated transcytosis. Access to this route is very limited after 2 weeks of age. Recently, several studies showed that multiple infusions of high doses of enzyme partially cleared storage in adult brain. These results raised the question of whether correction of brain storage by repeated high doses of enzyme depends on mannose 6-phosphate receptor-mediated uptake or whether enzyme gains access to brain storage by another route when brain capillaries are exposed to prolonged, high levels of circulating enzyme. To address this question, we used an enzyme whose carbohydrate-dependent receptor-mediated uptake was inactivated by chemical modification. Treatment of human beta-glucuronidase (GUS) with sodium metaperiodate followed by sodium borohydride reduction (PerT-GUS) eliminated uptake by mannose 6-phosphate and mannose receptors in cultured cells and dramatically slowed its plasma clearance from a t(1/2) of <10 min to 18 h. Surprisingly, PerT-GUS infused weekly for 12 weeks was more effective in clearing central nervous system storage than native GUS at the same dose. In fact, PerT-GUS resulted in almost complete reversal of storage in neocortical and hippocampal neurons. This enhanced correction of neuronal storage by long-circulating enzyme, which targets no known receptor, suggests a delivery system across the blood-brain barrier that might be exploited therapeutically.

Targeting macrophages with baculovirus-produced lysosomal enzymes: implications for enzyme replacement therapy of the glycoprotein storage disorder galactosialidosis.

Lysosomal storage diseases (LSDs) are monogenic disorders of metabolism caused by deficiency of hydrolytic enzymes. In several LSDs, cells of the reticuloendothelial (RE) system are the primary targets of the disease. Exogenous administration of recombinant enzymes overproduced in mammalian cells has proved effective for treating the systemic phenotype in nonneuropathic patients with LSDs. However, for the treatment of diseases with primary involvement of the RE system, the production of the therapeutic enzyme in insect cells could be an alternative and advantageous method because glycoproteins expressed in insect cells carry carbohydrates of the pauci-mannose or core-type. These recombinant enzymes are in principle already poised to be internalized by cells that express mannose receptors, including macrophages. Here, we demonstrate that three baculovirus-expressed enzymes, protective protein/cathepsin A (PPCA), neuraminidase (Neu1), and beta-glucosidase, were readily taken up and restored lysosomal function in enzyme-deficient mouse macrophages. The capacity of recombinant PPCA and Neu1 to clear the lysosomal storage in target cells was assessed in PPCA-/- mice, a model of galactosialidosis. Intravenously injected PPCA-/- mice efficiently internalized the corrective enzymes in resident macrophages of many organs. In addition, treated mice showed overall clearance of lysosomal storage in the most affected systemic organs, kidney, liver, and spleen. Our results suggest that ERT with baculovirus-expressed enzymes might be an effective treatment for nonneuropathic patients with galactosialidosis and possibly for others with LSDs that primarily involve the RE system.

Current issues in enzyme therapy for Gaucher disease.

Enzyme therapy has altered forever the management of patients with Gaucher disease. Studies in over 1200 treated Gaucher disease patients have demonstrated regression of hepatic, splenic, bony and haematological abnormalities, with a return towards health in many affected patients. The therapy is well tolerated, with approximately 7% of patients having adverse effects. However, the lack of standardised clinical staging and tracking procedures, and a poor understanding of the basic biochemistry and cell biology of the administered enzyme, continue to inhibit optimisation of treatment. Ultimately, preventive intervention with enzyme therapy will require absolute safety and much less expensive preparations, and accurate predictive genotype testing to fully optimise this mode of therapy. The success and pitfalls encountered in enzyme therapy for Gaucher disease provide a map for the development of such therapies for other inborn errors of metabolism.