Vol 467, No 1 (2016)

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignant neoplasm of the lymphocyte precursors that suffered malignant transformation arresting the lymphoid cell differentiation. Clinical studies revealed monoor, more rarely, oligoclonal nature of the disease. A precise identification of malignant clone markers is both the crucial stage of early diagnostics and the essential prognostic factor for therapeutic treatment. Here we present an improved system for unbiased detection of lymphoblastic clones in bone marrow aspirates of T-ALL patients. The system based on multiplex PCR of rearranged T-cell receptor locus (TRB) and straightforward sequencing of the resulted PCR fragments. Testing of the system on genomic DNA from Jurkat cell line and four clinical bone marrow aspirates revealed a set of unique TRB rearrangements that precisely characterize each of tested samples. Therefore, the outcome of the system produces highly informative molecular genetic markers for further monitoring of minimal residual disease in T-ALL patients.

The article presents the results of investigation of antitumor properties of platinum–arabinogalactan complex. We showed the ability of the complex to inhibit the growth of Ehrlich ascites tumor cells. It is found that the distribution of the platinum–arabinogalactan complex is not specific only for tumor cells in mice. The complex was found in all tissues and organs examined (ascites cells, embryonic cells, kidney, and liver). The mechanism of action of the arabinogalactan–platinum complex may be similar to cisplatin as the complex is able to accumulate in tumor cells.

It was first shown that DNA damage induction in mitomycin C-treated HeLa cells leads to a change in the selection of 5p and 3p microRNA duplex strands in the formation of the RNA-induced silencing complex (RISC).

The differences in the average fluorescence lifetime (τ_av) of tryptophanyls in photosynthetic reaction center (RC) of the purple bacteria Rb. sphaeroides frozen to 80 K in the dark or on the actinic light was found. This difference disappeared during subsequent heating at the temperatures above 250 K. The computer-based calculation of vibration spectra of the tryptophan molecule was performed. As a result, the normal vibrational modes associated with deformational vibrations of the aromatic ring of the tryptophan molecule were found. These deformational vibrations may be active during the nonradiative transition of the molecule from the excited to the ground state. We assume that the differences in τ_av may be associated with the change in the activity of these vibration modes due to local variations in the microenvironment of tryptophanyls during the light activation.

Using EPR spectroscopy it was established that the determination of the concentration of paramagnetic centers in lyophilized tissues allows indirect evaluation of the quality of decellularization of intrathoracic organs (diaphragm, heart, and lungs), since the content of paramagnetic particles in them can serve as a criterion of cell viability and points to the necessity to repeat decellularization. Experiments in rats showed that the EPR spectra of the native thoracic organs contained paramagnetic centers with g-factor values ranging from 2.007 to 2.011 at a concentration of 10^–8 to 6.62 × 10^–7 mol/g of lyophilized tissue, whereas in all decellularized tissues of the same organs paramagnetic particles were not detected.

The effect of the transcription factor Oct-1 (POU2F1) on the expression of the tumor cell marker metastasin (Mts1/S100A4) was studied. Comparative analysis of various tumor lines showed no clear correlation between the expression level of Mts1/S100A4 and the content of Oct-1. However, at stable transfection of tumor cells with Oct-1A, Oct-1L, and Oct-1X isoforms we detected an elevated level of Oct-1, which stimulated Mts1/S100A4 secretion. These findings extend our understanding of the molecular mechanisms of the tumorigenic effect of Oct-1.

For the first time, the induced oxidative modification of cellular fibrin-stabilizing factor (cFXIII) has been studied. According to the electrophoresis analysis, the conversion of oxidized cFXIII into FXIIIa resulted in producing the enzyme that significantly lost the initial enzymatic activity. At the same time, FXIIIa subjected to induced oxidation was completely devoid of enzymatic activity. The results of FTIR spectroscopy showed that the oxidation of cFXIII or FXIIIa was accompanied by profound changes both in chemical and spatial structures of the protein. The results of this study are in good agreement with our earlier assumption regarding the antioxidant role of the regulatory subunits B of plasma fibrin-stabilizing factor.

Using femtosecond laser radiation, nucleolus-like bodies (NLBs) of mouse oocytes were locally dissected without damage to zona pellucida, cytoplasmic membrane, nuclear membrane, and nucleoplasm surrounding NLB. It was found that, after dissection of 2.7 × 10^–11 cm³ of NLB material, which is approximately 5.2% of 10 μm NLB volume, the probability of germinal vesicle oocyte development to metaphase II stage of meiosis decreased 3–7 times compared to the non-treated oocytes. This result indicates that NLB material organization is significant for mouse oocyte maturation.

In search for new targets for obesity treatment, we have studied the effect of several transcription factors on the conversion of murine preadipocytes from the 3T3-L1 cell line into adipocytes. We have found that knockdown of Prep1 gene expression affects adipogenic differentiation and results in significant increase in the insulin-sensitive glucose carrier Glut4 gene expression.

Spontaneous and K⁺-stimulated release of noradrenaline from the hypothalamus, adrenal gland, and organ of Zuckerkandl under their flowing incubation was investigated in the perinatal period of ontogenesis of rats. The results suggest that, during the investigated period of ontogenesis, adrenal glands are the main source of noradrenaline in the blood, whereas the contributions of the organ of Zuckerkandl and the brain are not as significant and change during this period.

Mts1 (S100A4) protein is a marker of metastatic tumor cells, which is associated with a poor diagnostic prognosis for cancer progression. Therefore, it is important to study the S100A4 gene expression. According to our preliminary data, PHF10, a PBAF remodeling complex component, can play an important role in the transcription regulation of the S100A4 gene. We studied the expression of S100A4 and the total PHF10 protein in some cell lines. We have found that, in the cell lines studied, the PHF10 expression is correlated with the S100A4 expression.