Background/Objectives: Glioblastoma is an aggressive brain tumour with a poor prognosis and limited therapy. The truncated aptamer GR20, derived from aptamer U31, was developed to retain EGFR binding while reducing size. This study evaluated how aptamer truncation, while maintaining its tertiary structure, affects its antiproliferative activity against human glioma cells. Methods: Five transplantable human glioblastoma cell cultures (BU73, G22, G23, G01, Sus/fP2) were used. Aptamer binding was assessed by flow cytofluorimetry, intracellular accumulation was tracked by confocal microscopy. Changes in stemness and malignancy gene expression were evaluated by real-time PCR. Protein expression levels were assessed by immunocytochemistry. Proliferative activity was measured using the MTS assay. Results: GR20 retained EGFR binding and demonstrated more than two-fold higher binding efficiency to glioblastoma cells than antibodies or the U31 aptamer. Both aptamers accumulated in cells after 2 h of incubation. GR20 significantly reduced the expression of stemness genes (CD133, OCT4) and malignancy genes (EGFR, PDGFRα, TP53) but showed modest antiproliferative effects (9–11% reduction). U31 exhibited stronger antiproliferative activity, reducing Sus/fP2 viability by 31% and 58%. Molecular dynamics showed that U31 maintains a “multi-loop” conformational state absent in GR20. Conclusions: Although the truncated GR20 still binds to the EGFR and is taken up by cells, its antiproliferative activity is reduced compared to U31. The multi-loop conformation present in U31 but missing in GR20 appears to enhance activity, identifying this motif as a promising target for future aptamer optimization.

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 WHO considers the Epidermal Growth Factor Receptor (EGFR) one of the key biomarkers of glioblastoma (GB). EGFR can be identified and targeted using molecular recognition elements (MoREs), like aptamers and aptamer-drug conjugates (ApDCs). Understanding the kinetics of anti-EGFR ApDC interactions with EGFR as well as the kinetics of their internalization into the cells is a crucial step for the further development of anti-EGFR ApDCs. For the first time, a novel approach was implemented to study real-time kinetics by measuring the cellular index (CI) using impedance (xCELLigence). Doxorubicin (DOX) was used as an indicator drug. Because DOX intercalates into the DNA double helix, aptamer-DOX non-covalent complexes were obtained. For the anti-EGFR DNA aptamer GR20, an additional duplex was constructed by synthesizing the extra region (GR20h) and via hybridization with the complementary oligonucleotide (h') to form a duplex (hh'), thus creating the aptamer construct with complementary oligonucleotide (ACCO) GR20hh'. The original HPLC method quantified the assembly efficiency of an ACCO. The ACCO GR20hh' retained affinity for the recombinant extracellular domain of EGFR, as measured using Biolayer Interferometry (BLI). According to cytofluorimetry, the ACCO GR20hh' interacts with cells of continuous culture from GB patient (CCGBP) surgical samples. The DOX-ACCO GR20hh' complexes are more efficiently internalized by EGFR+ cells lines A-431 and CCGBP 107 than DOX alone.

Incorrect position of craniotomy can seriously complicate the course of operation. Frameless navigation stations (FNS) allow accurate craniotomy marking. However, FNS are cumbersome, time consuming, and not accessible to all neurosurgical centers. Our goal is to develop a simple, fast and low–tech method of navigation, and compare its accuracy and working speed with the FNS. The new method includes redrawing the contours of a DICOM image from a computer screen onto a neurosurgical viewfinder (NVF) – a transparent plastic plate; matching the drawn contours with the patient's head, and transferring the lesion contours to the scalp under visual control. NVF was tested on 20 consecutive operations under the control of FNS – first group, and then on another 20 operations without FNS – second group. All 40 patients had convexital or parasagittal lesions extending to the cerebral cortex. The NVF–FNS deviation (mm) and the marking time (minutes) were measured. The craniotomy accuracy was assessed by the centering error (mm) and by the original CRAC (craniotomy accuracy) scale – from 3 to 15 points, the more the better. The NFV–FNS deviation was 2.3 ± 2.2 mm (0 – 7 mm). The mean marking time with the NVF was 4.1 ± 1.1 min, with the FNS – 28.9 ± 5.5 min (p < 0.001). The centering error in the first group was 4.2 ± 5.2 mm (0 – 20 mm); in the second group – 4.1 ± 4.5 mm (0 – 15 mm); the groups did not differ statistically (p = 0.948). The CRAC score also did not differ (p = 0.767) and was not lower than 12 points in both groups. The NVF demonstrated high accuracy, comparable with FNS, and significantly faster marking time. The invention can be widely used in the surgery of convexital and parasagittal lesions.

Background: High-grade gliomas are treatment-resistant and prone to aggressive recurrence. Although radiation therapy is a fundamental treatment, it often fails to eradicate tumors and can enhance the migratory potential of surviving cells, promoting relapse. Anti-proliferative aptamers are novel agents that show promise, but their combination with radiation therapy and their effects on invasive phenotypes require further investigation. Objectives: This study evaluated the effects of ionizing radiation on the viability and migration of human glioma cells, both alone and in combination with the anti-proliferative aptamer bi-(AID-1-T). The study aimed to determine whether the aptamer could enhance the efficacy of radiotherapy and counteract ionizing radiation-induced pro-migratory effects. Methods: The study was conducted on cell cultures of primary and relapsed human glioma. The effects of combined radiation (single dose of 20 Gy) and the bi-(AID-1-T) aptamer (10 μM) were assessed using the MTS assay, Transwell analysis, immunocytochemistry and transcriptome analysis. Results: Ionizing radiation alone reduced proliferation in primary gliomas, but increased proliferation in recurrent cultures. Ionizing radiation also increased migration in both types of gliomas. Combining ionizing radiation with the bi-(AID-1-T) aptamer produced a synergistic effect: it significantly reduced cell proliferation and migration, and suppressed the ionizing radiation-induced migratory enhancement, more effectively than either treatment alone. Transcriptome analysis revealed that combination treatment decreased the expression of pro-proliferative and migratory genes (e.g., PDPN, CDH3), while increasing the expression of anti-migratory (RND3) and pro-apoptotic genes (e.g., XAF1, SEMA3A). Thus, combination treatment significantly reduces tumor cell proliferation and migration; however, further studies on surviving cells are needed.

Glioblastoma remains an incurable malignancy, driving the continuous search for novel therapeutic strategies. A significant challenge in this pursuit is the transition from in vitro models to in vivo efficacy. Building on our previously patented GQIcombi strategy (Patent RU2820200C2), this study investigates its efficacy in vivo using the rat 101/8 glioblastoma model. We evaluated various administration regimens of the GQIcombi cocktail, which was previously effective against patient-derived human glioma cell cultures. Although we attempted to reduce the dosing frequency to optimize the protocol, our results confirm that sequential exposure to the GQIcombi components is necessary to effectively inhibit tumor growth in vivo, mirroring its requirement in cell cultures.

Current therapy protocols fail to cure high-grade gliomas and prevent recurrence. Therefore, novel approaches need to be developed. A re-programing of glioma cell fate is an alternative attractive way to stop tumor growth. The two-step protocol applies the antiproliferative GQ bi-(AID-1-T) and small molecule inducers with BDNF to trigger neural differentiation into terminally differentiated cells, and it is very effective on GB cell cultures. This original approach is a successful example of the “differentiation therapy”. To demonstrate a versatility of this approach, in this publication we have extended a palette of cell cultures to gliomas of II, III and IV Grades, and proved an applicability of that version of differential therapy for a variety of tumor cells. We have justified a sequential mode of adding of GQIcombi components to the glioma cells. We have shown a significant retardation of tumor growth after a direct injection of GQIcombi into the tumor in rat brain, model 101/8. Thus, the proposed strategy of influencing on cancer cell growth is applicable to be further translated for therapy use.

Background/Objectives: Targeted delivery of chemotherapeutic agents is a well-established approach to cancer therapy. Antibody–drug conjugates (ADCs) typically carry toxic payloads attached to a tumor-associated antigen-targeting IgG antibody via an enzyme-cleavable linker that releases the drug inside the cell. Aptamers are a promising alternative to antibodies in terms of antigen targeting; however, their polynucleotide nature and smaller size result in a completely different PK/PD profile compared to an IgG. This may prove advantageous: owing to their lower molecular weight, aptamer-drug conjugates may achieve better penetration of solid tumors compared to ADCs. Methods: On the way to therapeutic aptamer–drug conjugates, we aimed to develop a versatile and modular approach for the assembly of aptamer–enzymatically cleavable payload conjugates of various drug–aptamer ratios. We chose the epidermal growth factor receptor (EGFR), a transmembrane protein often overexpressed in brain tumors, as the target antigen. We used the 46 mer EGFR-targeting DNA sequence GR-20, monomethylauristatin E (MMAE) on the cathepsin-cleavable ValCit-p-aminobenzylcarbamate linker as the payload, and pentaerythritol-based tetraazide as the branching point for the straightforward synthesis of aptamer–drug conjugates by means of a stepwise Cu-catalyzed azide–alkyne cycloaddition (CuAAC) click reaction. Results: Branched aptamer conjugates of 1:3, 2:2, and 3:1 stoichiometry were synthesized and showed higher cytotoxic activity compared to a 1:1 conjugate, particularly on several glioma cell lines. Conclusions: This approach is convenient and potentially applicable to any aptamer sequence, as well as other payloads and cleavable linkers, thus paving the way for future development of aptamer–drug therapeutics by easily providing a range of branched conjugates for in vitro and in vivo testing.

High-grade gliomas are considered an incurable disease. Despite all the various therapy options available, patient survival remains low, and the tumor usually returns. Tumor resistance to conventional therapy and stimulation of the migratory activity of surviving cells are the main factors that lead to recurrent tumors. When developing new treatment approaches, the effect is most often evaluated on standard and phenotypically depleted cancer cell lines. Moreover, there is much focus on the anti-proliferative effect of such therapies without considering the possible stimulation of migratory activity. In this paper, we studied how glioma cell migration changes after exposure to bi-(AID-1-T), an anti-proliferative aptamer. We investigated the effect of this aptamer on eight human glioma cell cultures (Grades III and IV) that were derived from patients' tumor tissue; the difference between primary and recurrent tumors was taken into account. Despite its strong anti-proliferative activity, bi-(AID-1-T) was shown to induce migration of recurrent tumor cells. This result shows the importance of studying the effect of therapeutic molecules on the invasive properties of glioma tumor cells in order to reduce the likelihood of inducing tumor recurrence.

Background: High-grade gliomas remain a virtually incurable form of brain cancer. Current therapies are unable to completely eradicate the tumor, and the tumor cells that survive chemotherapy or radiation therapy often become more aggressive and resistant to further treatment, leading to inevitable relapses. While the antiproliferative effects of new therapeutic molecules are typically the primary focus of research, less attention is given to their influence on tumor cell migratory activity, which can play a significant role in recurrence. A potential solution may lie in the synergistic effects of multiple drugs on the tumor. Objectives: In this study, we investigated the effect of combined exposure to bi-(AID-1-T), an anti-proliferative aptamer, and its analog bi-(AID-1-C), on the migratory activity of human GBM cells. Results: We examined the effects of various sequences of adding bi-(AID-1-T) and bi-(AID-1-C) on five human GBM cell cultures. Our findings indicate that certain sequences significantly reduced the ability of tumor cells to migrate and proliferate. Additionally, the expression of Nestin, PARP1, L1CAM, Caveolin-1, and c-Myc was downregulated in human GBM cells that survived exposure, suggesting that the treatment had a persistent antitumor effect on these cells.

BACKGROUND: Currently, in medicine, including neurosurgery, systemic risk management to improve treatment quality is one of the most urgent tasks. The key indicators of treatment quality in neurosurgery are the characteristics of its outcomes, structure, and number of complications. OBJECTIVE: To formulate the most concise and complete definition of complication and develop a classification scheme that allows the maximum consideration of complications in patients with neurosurgical problems. MATERIALS AND METHODS: A neurosurgical complication was defined as any unwanted, unintended deviation from the ideal course of the treatment process for a patient with neurosurgical pathology. The study included patients operated on for neurosurgical pathology at the Center for Neurosurgery (Moscow) from January 2019 to December 2020. To record all complications, an electronic database was created, where information about all neurosurgical complications was entered. RESULTS. Based on the analysis of annual reports of medical and diagnostic departments, the average incidence of complications was 2529 per 1000 operations (2.52.9%). The study of neurosurgical complications made it possible to determine the general parameters that are of key importance for the registration and analysis of neurosurgical complications and formulate an original classification scheme, and its use makes it possible to consider most of the factors associated with complications and, accordingly, their analysis. CONCLUSION: In the literature analysis, a series of discussions within the neurosurgical community, and our experience, we proposed a definition of neurosurgical complication and an approach to registering complications. With the help of the proposed classification scheme, we could obtain objective data and conduct evidence-based analysis, which makes it possible to evaluate complications using a treatment quality control system by obtaining the most complete amount of data on complications in a neurosurgical clinic.

Diffuse gliomas continue to be an important problem in neuro-oncology. To solve it, studies have considered the issues of molecular pathogenesis from the intratumoral heterogeneity point. Here, we carried out a comparative dynamic analysis of the different cell populations' content in diffuse gliomas of different molecular profiles and grades, considering the cell populations' functional properties and the relationship with patient survival, using flow cytometry, immunofluorescence, multiparametric fluorescent in situ hybridization, polymerase chain reaction, and cultural methods. It was shown that an increase in the IDH-mutant astrocytomas and oligodendrogliomas malignancy is accompanied by an increase in stem cells' proportion and mesenchymal cell populations' appearance arising from oligodendrocyte-progenitor-like cells with cell plasticity and cells' hypoxia response programs' activation. In glioblastomas, malignancy increase is accompanied by an increase in both stem and definitive cells with mesenchymal differentiation, while proneuronal glioma stem cells are the most likely the source of mesenchymal glioma stem cells, which, in hypoxic conditions, further give rise to mesenchymal-like cells. Clinical confirmation was a mesenchymal-like cell and mesenchymal glioma stem cell number, and the hypoxic and plastic molecular programs' activation degree had a significant effect on relapse-free and overall survival. In general, we built a multi-vector model of diffuse gliomas' pathogenetic tracing up to the practical plane.

(1) Purpose: To determine the borders of malignant gliomas with diffusion kurtosis and perfusion MRI biomarkers. (2) Methods: In 50 high-grade glioma patients, diffusion kurtosis and pseudo-continuous arterial spin labeling (pCASL) cerebral blood flow (CBF) values were determined in contrast-enhancing area, in perifocal infiltrative edema zone, in the normal-appearing peritumoral white matter of the affected cerebral hemisphere, and in the unaffected contralateral hemisphere. Neuronavigation-guided biopsy was performed from all affected hemisphere regions. (3) Results: We showed significant differences between the DKI values in normal-appearing peritumoral white matter and unaffected contralateral hemisphere white matter. We also established significant (p < 0.05) correlations of DKI with Ki-67 labeling index and Bcl-2 expression activity in highly perfused enhancing tumor core and in perifocal infiltrative edema zone. CBF correlated with Ki-67 LI in highly perfused enhancing tumor core. One hundred percent of perifocal infiltrative edema tissue samples contained tumor cells. All glioblastoma samples expressed CD133. In the glioblastoma group, several normal-appearing white matter specimens were infiltrated by tumor cells and expressed CD133. (4) Conclusions: DKI parameters reveal changes in brain microstructure invisible on conventional MRI, e.g., possible infiltration of normal-appearing peritumoral white matter by glioma cells. Our results may be useful for plotting individual tumor invasion maps for brain glioma surgery or radiotherapy planning.

Objectives This study sought to assess 18 F-fludarabine ( 18 F-FLUDA) PET/CT’s ability in differentiating primary central nervous system lymphomas (PCNSLs) from glioblastoma multiformes (GBMs). Patients and Methods Patients harboring either PCNSL (n = 8) before any treatment, PCNSL treated using corticosteroids (PCNSLh; n = 10), or GBM (n = 13) were investigated with conventional MRI and PET/CT, using 11 C-MET and 18 F-FLUDA. The main parameters measured with each tracer were SUV T and T/N ratios for the first 30 minutes of 11 C-MET acquisition, as well as at 3 different times after 18 F-FLUDA injection. The early 18 F-FLUDA uptake within the first minute of injection was equally considered, whereas this parameter was combined with the later uptakes to obtain R FLUDA 2 and R FLUDA 3 ratios. Results No significant differences in 11 C-MET uptakes were observed among PCNSL, PCNSLh, and GBM. With 18 F-FLUDA, a clear difference in dynamic GBM uptake was observed, which decreased over time after an early maximum, as compared with that of PCNSL, which steadily increased over time, PCNSLh exhibiting intermediate values. The most discriminative parameters consisting of R FLUDA 2 and R FLUDA 3 integrated the early tracer uptake (first 60 seconds), thereby provided 100% specificity and sensitivity. Conclusions 18 F-FLUDA was shown to likely be a promising radiopharmaceutical for differentiating PCNSL from other malignancies, although a pretreatment with corticosteroids might compromise this differential diagnostic ability. The diagnostic role of 18 F-FLUDA should be further investigating, along with its potential of defining therapeutic strategies in patients with PCNSL, while assessing the treatments’ effectiveness.