Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry

The concept of essential genes, whose loss of functionality results in cell death, is one of the fundamental concepts of genetics and is important for basic and applied research. This field is particularly promising in oncology, because using the search for genetic vulnerabilities of cancer cells it is possible to identify new potential targets for antitumor therapy. The modern biotechnology capacities are used in large-scale projects for sequencing of somatic mutations in tumors, as well as for direct action on the genetic apparatus of cancer cells. They provided accumulation of a considerable body of knowledge about genetic variants and their phenotypic manifestations in tumors. In the near future this knowledge will find application in clinical practice. This review describes the main experimental and computational approaches to the search for essential genes with special emphasis on application of these methods in molecular oncology.

Changes in the activity of monoaminergic systems of the left and right hemispheres of the brain were investigated in male albino mice after acute hypoxia with hypercapnia. The concentrations of dopamine (DA), serotonin (5-HT) and their metabolites dihydroxyphenylacetic (DOPAC), homovanillic (HVA), and 5-hydroxyindoleacetic (5-HIAA) acids were measured by HPLC in the brain cortex, hippocampus, and striatum of the right and the left hemispheres. In the control mice (which were not exposed to hypoxia with hypercapnia), a higher concentration of DA in the left cortex was detected. No asymmetry in the content of other substances was identified in the investigated structures. Acute hypoxia with hypercapnia led to the right-sided increase of DA and 5-HT levels and to the left-sided reduction DOPAC in the cerebral cortex. Under the condition of hypoxia with hypercapnia, the left-sided increase of the DA content was detected in the hippocampus. In the striatum the contents of monoamines and their metabolites were insignificantly changed. It has been concluded that acute hypoxia with hypercapnia causes asymmetric changes in monoaminergic systems of the archicortex and the neocortex.

An approach for quick and efficient production of polyclonal antibodies to the target antigen, alpha-synuclein, has been proposed. Two methods have been employed to purify specific rabbit polyclonal antibodies against recombinant human alpha-synuclein, produced by subcutaneous immunization with complete Freund’s adjuvant. It was shown that purification on CNBr-activated Sepharose with immobilized alpha-synuclein resulted in antibody preparation with rabbit serum histidine-rich glycoprotein as a contaminant. Two-stage antibody purification procedure first on Sepharose with immobilized protein G, and then on alpha-synuclein immobilized column helps to avoid contamination and to obtain homogenous antibody preparation. Antibodies recognize different conformations of alpha-synuclein and can be used in a variety of immunochemical approaches, including immunocytochemistry.

Alzheimer’s disease (AD) is characterized by the loss of neurons, the accumulation of intracellular neurofibrillary tangles and extracellular amyloid plaques in the brain. However, contradicting data exist on differences in neurogenesis at the onset of the disease or before the formation of amyloid plaques. Taking into consideration growing awareness of the importance of the pre-symptomatic phase in neurodegenerative diseases in the context of early diagnosis and pathogenesis, we have analyzed critical periods of adult hippocampal neurogenesis at the early stage under the action of soluble forms of amyloid-beta (Aβ_1-42). Using the mouse AD model induced by injection of soluble Aβ oligomers we investigated proliferation, migration, and neuronal cells survival. The injection of Aβ_1-42 oligomers caused a decrease in cell proliferation in the mouse hippocampus. Despite preservation of the neuroblast pool in animals treated with Aβ injection, the process of radial migration impaired, and apoptosis increased. Thus, our results demonstrate that Aβ administration impaired critical stages of neurogenesis including progenitor cells, neuroblast migration, integration of immature neurons, and survival of neurons under application of soluble beta-amyloid oligomers. The data obtained indicate the decline in proliferation rate in the subgranular zone, which is accompanied by ectopic differentiation and disturbed migration, producing, apparently, abnormal neurons that have lower survival rates. That could lead to a decrease in the number of mature neurons and in the number of cells in the granular layer of the dentate gyrus.

Isatin (indol-2,3-dione) is an endogenous indole found in the brain, peripheral tissues and biological body fluids of humans and animals. Its wide spectrum of biological activity is realized via interaction with numerous isatin-binding proteins; these include proteins playing an important role in the development of neurodegenerative pathology. In the context of the neuroprotective effect, the effect of isatin is comparable to the effects of deprenyl, a pharmacological agent used for treatment of Parkinson’s disease. In this study, the effects of the course of deprenyl (1 mg/kg) and isatin (20 mg/kg) administration for 21 days on the profile of the isatin-binding proteins of the liver of mice have been investigated. Proteomic profiling of liver isatin-binding proteins of control mice by means of 5-aminocaproylisatin as an affinity ligand resulted in identification of 105 proteins. Treatment of animals with a low dose of isatin slightly decreased (up to 91), while injections of deprenyl slightly increased (up to 120) the total number of isatin-binding proteins. 75 proteins were common for all three groups; they represented from 62.5% (in deprenyl treated mice) and 71% (in control mice), to 82% (isatin treated mice) of the total number of identified liver isatin-binding proteins. The proteomic analysis of the isatin-binding proteins of mice treated with isatin (20 mg/kg) or deprenyl (1 mg/kg) for 21 days revealed a representative group of proteins (n = 30) that were sensitive to the administration of these compounds. Taking into consideration the previously obtained results, it is reasonable to suggest that the change in the profile of isatin-binding proteins may be attributed to accumulation of isatin and deprenyl in the liver and interaction with target proteins prevents their subsequent binding to the affinity sorbent. In this context, the identified isatin-binding liver proteins of control animals that do not bind to the affinity sorbent (immobilized isatin analogue) after treatment of animals with either deprenyl or isatin appear to be specific targets directly interacting with isatin in vivo.