The epidermal growth factor receptor (EGFR) is one of the key oncomarkers in glioblastoma (GB) biomedical research. High levels of EGFR expression and mutations have been found in many GB patients, making the EGFR an attractive target for therapeutic treatment. The EGFRvIII mutant is the most studied, it is not found in normal cells and is positively associated with tumor cell aggressiveness and poor patient prognosis, not to mention there is a possibility of it being a tumor stem cell marker. Some anti-EGFR DNA aptamers have already been selected, including the aptamer U2. The goal of this study was to construct a more stable derivative of the aptamer U2, while not ruining its functional potential toward cell cultures from GB patients. A multiloop motif in a putative secondary structure of the aptamer U2 was taken as a key feature to design a novel minimal aptamer, Gol1, using molecular dynamics simulations for predicted 3D models. It turned out that the aptamer Gol1 has a similar putative secondary structure, with G-C base pairs providing its stability. The anti-proliferative activities of the aptamer Gol1 were assessed using patient-derived GB continuous cell cultures, G01 and BU881, with different abundances of EGFR and EGFRvIII. The transcriptome data for the cell culture G01, after aptamer Gol1 treatment, revealed significant changes in gene expression; it induced the transcription of genes associated with neurogenesis and cell differentiation, and it decreased the transcription of genes mediating key nuclear processes. There were significant changes in the gene transcription of key pro-oncogenic signaling pathways mediated by the EGFR. Therefore, the aptamer Gol1 could potentially be an efficient molecule for translation into biomedicine, in order to develop targeted therapy for GB patients.

The glial cell line‐derived neurotrophic factor (GDNF) is involved in the survival of dopaminergic neurons. Besides, GDNF can also induce axonal growth and creation of new functional synapses. GDNF potential is promising for translation to treat diseases associated with neuronal death: neurodegenerative disorders, ischemic stroke, and cerebral or spinal cord damages. Unproductive clinical trials of GDNF for Parkinson’s disease treatment have induced to study this failure. A reason could be due to irrelevant producer cells that cannot perform the required post-translational modifications. The biological activity of recombinant mGDNF produced byE.colihave been compared with mGDNF produced by human cells HEK293. mGDNF variants were tested with PC12 cells, rat embryonic spinal ganglion cells, and SH-SY5Y human neuroblastoma cellsin vitroas well as with a mouse model of the Parkinson’s diseasein vivo. Bothin vitroandin vivothe best neuro-inductive ability belongs to mGDNF produced by HEK293 cells. Keywords: GDNF, neural differentiation, bacterial and mammalian expression systems, cell cultures, model of Parkinson’s disease.

Nucleolus-oriented protein nucleolin plays a significant role in the life of a normal mammalian cell. However, nucleolin is also actively expressed in cells of malignant tumors. At the same time, its expression in different types of cancer is significantly increased compared with normal cells. It is interesting that nucleolin localization often varies in tumor cells, namely in the cytoplasm and on the cell membrane. This fact is considered to be a poor prognostic indicator. This work is devoted to the study of the distribution of nucleolin in human glioblastoma cells. Glioblastoma is one of the most aggressive malignant tumors with an absolutely unfavorable prognosis. These tumors have a high proliferative potential, but in addition they are often characterized by invasive properties. Research on lineage cells does not let to fully study these properties of glioblastoma, since lineage cells are very different from the actual tumor. In our study, we used two primary cell cultures of human glioblastoma with varying degrees of invasiveness of the original tumors. The main interest was directed at studying the localization of nucleolin and its correlation with the invariability of the N- and C-termini of the corresponding protein. Particular attention was paid to the significance of the unaltered C-terminus of nucleolin for its distribution in the cells of transplanted human glioblastoma cultures derived from patient tissues. The aim of this work is to find the relationship between the deformation of the N- or C-terminal sequences of nucleolin and its localization.We showed that in glioblastoma cells, with a high degree of invasion, nucleolin is found in the cytoplasm and close to the cell membrane, and the distribution of nucleolin with undeformed C and N-terminal does not match.

Glial cell line-derived neurotrophic factor (GDNF) is essential in maintaining the viability, function and differentiation of neuronal cells. In addition to its function in healthy nervous tissue, GDNF is involved in pathological processes, such as glioma growth. GDNF is represented by 2 main isoforms: pre-α-pro-GDNF (αGDNF) and pre-β-pro-GDNF (βGDNF). αGDNF maintains cell viability, and βGDNF has neurotrophic properties. The relationship between GDNF expression and human glioma malignancy grade, as well as migratory properties of tumor cells remains poorly understood. Objective. To assess the expression of mRNA splice variants of GDNF in glioma cell cultures with various malignancy grades (I—IV) and degrees of migration. Material and methods. In this study, αGDNF and βGDNF expression was analyzed in 15 human glioma cell cultures using Southern blot hybridization of GDNF cDNA and reverse transcription with PCR to amplify splice variants of GDNF mRNA. Results. The highest expression of αGDNF and βGDNF isoforms was observed in cell cultures of human gliomas with extensive migratory activity. Low βGDNF expression without αGDNF expression is typical only for gliomas with low migratory activity. In addition, we found additional patterns of mRNA expression that have not been previously described. Conclusion. The relationship between GDNF and malignancy grade is unclear. Nevertheless, GDNF expression is higher in glioblastomas. Overall GDNF expression is increased in glioma cells with high migration activity. At the same time, αGDNF and βGDNF isoforms demonstrate higher expression in actively migrating cells that can indicate their participation in regulation of tumor migration properties. No αGDNF expression with simultaneous low βGDNF expression may be a prognostic sign of low migration activity of human glioma cells.