Liposomal formulation of a methotrexate lipophilic prodrug: assessment in tumor cells and mouse T-cell leukemic lymphoma

Anna A Alekseeva,1 Ekaterina V Moiseeva,1 Natalia R Onishchenko,1 Ivan A Boldyrev,1 Alexander S Singin,2,† Andrey P Budko,2 Zoya S Shprakh,2 Julian G Molotkovsky,1 Elena L Vodovozova1 1M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 2N.N. Blokhin Russian Cancer Research Center, the Ministry of Health of the Russian Federation, Moscow, Russian Federation †Alexander S Singin passed away on October 4, 2011 Abstract: In a previous study, a formulation of methotrexate (MTX) incorporated in the lipid bilayer of 100-nm liposomes in the form of diglyceride ester (MTX-DG, lipophilic prodrug) was developed. In this study, first, the interactions of MTX-DG liposomes with various human and mouse tumor cell lines were studied using fluorescence techniques. The liposomes composed of egg phosphatidylcholine (PC)/yeast phosphatidylinositol/MTX-DG, 8:1:1 by mol, were labeled with fluorescent analogs of PC and MTX-DG. Carcinoma cells accumulated 5 times more MTX-DG liposomes than the empty liposomes. Studies on inhibitors of liposome uptake and processing by cells demonstrated that the formulation used multiple mechanisms to deliver the prodrug inside the cell. According to the data from the present study, undamaged liposomes fuse with the cell membrane only 1.5–2 hours after binding to the cell surface, and then, the components of liposomal bilayer enter the cell separately. The study on the time course of plasma concentration in mice showed that the area under the curve of MTX generated upon intravenous injection of MTX-DG liposomes exceeded that of intact MTX 2.5-fold. These data suggested the advantage of using liposomal formulation to treat systemic manifestation of hematological malignancies. Indeed, the administration of MTX-DG liposomes to recipient mice bearing T-cell leukemic lymphoma using a dose-sparing regimen resulted in lower toxicity and retarded lymphoma growth rate as compared with MTX. Keywords: liposomes, methotrexate, lipophilic prodrug, endocytosis, hematological malignancies, leukemia/lymphom

Russian vaccines against especially dangerous bacterial pathogens

In response to the epidemiological situation, live attenuated or killed vaccines against anthrax, brucellosis, cholera, glanders, plague and tularemia were developed and used for immunization of at-risk populations in the Former Soviet Union. Certain of these vaccines have been updated and currently they are used on a selective basis, mainly for high risk occupations, in the Russian Federation. Except for anthrax and cholera these vaccines currently are the only licensed products available for protection against the most dangerous bacterial pathogens. Development of improved formulations and new products is ongoing

Antidepressive and BDNF effects of enriched environment treatment across ages in mice lacking BDNF expression through promoter IV

Reduced promoter IV-driven expression of brain-derived neurotrophic factor (BDNF) is implicated in stress and major depression. We previously reported that defective promoter IV (KIV) caused depression-like behavior in young adult mice, which was reversed more effectively by enriched environment treatment (EET) than antidepressants. The effects of promoter IV-BDNF deficiency and EET over the life stages remain unknown. Since early-life development (ED) involves dynamic epigenetic processes, we hypothesized that EET during ED would provide maximum antidepressive effects that would persist later in life due to enhanced, long-lasting BDNF induction. We tested this hypothesis by determining EET effects across three life stages: ED (0–2 months), young adult (2–4 months), and old adult (12–14 months). KIV mice at all life stages showed depression-like behavior in the open-field and tail-suspension tests compared with wild-type mice. Two months of EET reduced depression-like behavior in ED and young adult, but not old adult mice, with the largest effect in ED KIV mice. This effect lasted for 1 month after discontinuance of EET only in ED mice. BDNF protein induction by EET in the hippocampus and frontal cortex was also the largest in ED mice and persisted only in the hippocampus of ED KIV mice after discontinuance of EET. No gender-specific effects were observed. The results suggest that defective promoter IV causes depression-like behavior, regardless of age and gender, and that EET during ED is particularly beneficial to individuals with promoter IV-BDNF deficiency, while additional treatment may be needed for older adults

Neurotrophins and psychiatric disorders

Increasing number of studies has during the last decade linked neurotrophic factors with the pathophysiology of neuropsychiatric disorders and with the mechanisms of action of drugs used for the treatment of these disorders. In particular, brain-derived neurotrophic factor BDNF and its receptor TrkB have been connected with the pathophysiology in mood disorders and there is strong evidence that BDNF signaling is critically involved in the recovery from depression with both pharmacological and psychological means. Neurotrophins play a central role in neuronal plasticity and network connectivity in developing and adult brain and recent evidence links plasticity and network rewiring with mood disorders and their treatment. Therefore, neurotrophins should not be seen as happiness factors, but as critical tools in the process where brain networks are optimally tuned to environment and it is against this background that the effects of neurotrophins on neuropsychiatric disorders should be looked at.Peer reviewe