Masaryk Memorial Cancer Institute

Abstract Background Wire-free localization systems are essential for removing nonpalpable breast cancer lesions, a crucial aspect of surgical outcomes. These systems vary in mechanisms (radioactive, magnetic, radar), making direct comparisons across patients during surgery challenging. This study evaluated the performance of four localization systems through ex vivo experiments. Methods The systems evaluated were magnetically guided Pintuition and Magseed, radar-guided SCOUT, and radioactive seed localization (RSL). The assessment included signal propagation in water, the accuracy of displayed distances, and the accuracy of detection by surgeons in a tissue model. Results The experiment in water demonstrated disparate maximal detection ranges (50 mm for Pintuition, 30 mm for SCOUT, 25–30 mm for Magseed, and ≥ 50 mm for RSL) and different signal directionality. The signal presence behind the marker position axis was properly absent for Pintuition and SCOUT. For SCOUT, inconsistent behavior depending on the marker orientation and a bias in displayed distances were observed. The accuracy of the detection by the surgeons was the highest using Pintuition (indistinct from SCOUT, p = 0.1585 and significantly distinct from RSL, p = 0.0263), whereas Magseed was significantly inferior to that of all other systems ( p < 0.0001). Conclusion All evaluated systems were capable of detecting the marker. Nevertheless, notable inter-system differences in performance observed under controlled ex vivo conditions should be considered, particularly given their significant practical implications for breast cancer surgeons. Relative performance trends favored the Pintuition and SCOUT, followed by RSL and Magseed. Awareness of system-specific physical behavior may support informed system selection in clinical practice.

Human galectin-1 (hGal-1) is an abundant β-galactoside-binding animal lectin that plays an essential role in promoting the immunosuppressive tumor microenvironment. Although hGal-1 has been identified as a promising target for pharmacological inhibition, developing potent and selective hGal-1 inhibitors has been complicated by the high degree of sequence similarity of the glycan-binding site across the galectin family. Herein, we present potent nanomolar hGal-1 inhibitors with unprecedented selectivity of 2 to 3 orders of magnitude over human galectin-3 (hGal-3). Their primary structural feature is the modification of a thiodigalactoside scaffold at the 3- and 3'-positions with a half-sandwich ruthenium(II) arene complex containing a bidentate 4-(2-pyridyl)-1H-1,2,3-triazol-1-yl ligand. The most potent inhibitor in the series efficiently blocked the binding of hGal-1 to the surface of MDA-MB-231 tumor cells, reduced their viability, and completely suppressed hGal-1-induced phosphatidylserine exposure in Jurkat cells, a process previously described as preaparesis rather than classical apoptosis.

We have recently identified transcription factor c-Myb as a negative prognostic factor in osteosarcoma (OSA) patients associated with metastatic disease. Transcriptomic analysis identified creatine kinase B (CKB) as one of the most deregulated genes in OSA cell lines with depleted MYB. CKB is a component of the creatine/phosphocreatine system that plays a key role in maintaining cellular energy homeostasis and energy transport to sites with high demand. This study was therefore conducted to investigate the functional significance of CKB in OSA. Deregulation of CKB by c-Myb in OSA cells was analyzed using gain-of-function/loss-of-function approach. Transactivation of the CKB promoter by c-Myb was assessed using a reporter assay. CRISPR/Cas9, RNAi and cyclocreatine were used to inhibit the expression/activity of CKB in OSA cells. Cell growth, colony-forming capacity, cell migration, chemosensitivity in vitro and metastatic capacity in vivo was examined. CKB protein effectors were identified using liquid chromatography-mass spectrometry (LC-MS) in data-independent acquisition-parallel accumulation serial fragmentation mode. CKB was validated as c-Myb target in OSA cell lines. Depletion of CKB using CRISPR/Cas9 resulted in slower migration of OSA cells in vitro and reduced metastatic capacity in immunodeficient mice. siRNA and cyclocreatine inhibited OSA cell migration as well but in this case, cell proliferation was also reduced. A total of 8474 protein groups were quantified, with 147 downregulated and 143 upregulated protein groups associated with the CKB knockout phenotype. The deregulated proteins were enriched for those associated with cell migration and motility. N-cadherin, an established regulator of cell migration, was identified as a target of CKB signaling and its role in OSA cell migration and metastasis was confirmed. c-Myb - CKB - N-cadherin axis was identified as pathway regulating OSA cell migration and metastasis.

Protein dimerization is a crucial biological process in which proteins interact into homo- or heterodimers to form a functional assembly. Understanding and modulating the molecular mechanisms of protein dimerization and their function represent the cutting edge of research and provide multiple entries for biomedical applications. Label-free methods sensitive to homodimer formation are still required. Electrochemical methods are sensitive to small structural changes due to the presence of a surface and polarization to high negative/positive potentials, where partial denaturation/unfolding can appear. Since the dimeric structure is usually more flexible, the electric field effects induce more salient structural changes close to the electrode surface, accompanied by higher chronopotentiometric/voltammetric responses. Serum albumin and anterior gradient receptor-2 were studied as model homodimeric proteins.

The care of patients with brain tumors is a complex task that requires quality standards and quality assurance indicators. In the present study, several quality indicators were evaluated in routine clinical care. The EORTC Brain Tumor Group (BTG) developed quality indicators from published guidelines and tested them in 19 BTG sites across Europe. Each site extracted data from the files of 20 randomly selected glioblastoma patients diagnosed in 2018. Associations between quality indicators, site characteristics and median overall survival (mOS) were examined. A total of 364 patient files were evaluated at 19 sites. Excellent compliance was observed in the documentation of neuropathology report with isocitrate dehydrogenase (IDH) status (92.0%), O6 -methylguanine DNA methyltransferase promoter methylation (MGMT) status (78.0%), multidisciplinary case discussion (95.3 %), extent of resection (87.1%), and radiotherapy details (96.9%) as well as consent to chemotherapy (75.5%). Performance was not as good for early postoperative MRI (67.2%), psycho-oncological care (40.5%), avoiding antineoplastic therapy in the last weeks of life (63.1%) and early referral to palliative services (23.5%). Timely start of radiotherapy (P = .0153), the presence of a radiotherapy report in the medical record (P = .0077), and patient education on oral chemotherapy (P = .0002) were positively associated with mOS, while early referral to palliative care was associated with shorter mOS (P < .0001). The quality indicators tested in this research project performed with some variability between sites. Significant associations between individual quality indicators and mOS were observed. The proposed quality indicators should be validated prospectively.

Abstract BACKGROUND Astrocytoma, IDH-mutant, is the most common primary brain tumor in young adults, with peak incidence between 30 and 40 years of age. It is defined by mutations in the IDH1 or IDH2 genes and the absence of 1p/19q codeletion, and it frequently harbors alterations in ATRX and TP53. Rarely, astrocytoma, IDH-mutant, amay exhibit primitive neuronal differentiation, morphologically resembling “small round blue cell” tumors or large anaplastic embryonal-like cells. METHODS We analyzed 18 cases of astrocytoma, IDH-mutant, with primitive neuronal differentiation. In 11 cases where both the primitive neuronal and glial components were available, macrodissection was performed by a pathologist. Each component was subjected to separate genetic (next-generation sequencing) and epigenetic (DNA methylation profiling) analyses. Morphological and immunophenotypic features were also evaluated. RESULTS The primitive neuronal component was characterized by absent or markedly reduced GFAP expression, positivity for neuronal markers, a high Ki-67 proliferation index, and frequent TTF1 expression. This component also exhibited distinct epigenetic signatures and copy number alterations compared to the glial component. All tumors were high-grade, with extensive copy number variations, frequent MYCN amplification, and RB1 loss. DISCUSSION Astrocytoma, IDH-mutant, with a primitive neuronal component expands the morphological spectrum of IDH-mutant astrocytomas and presents a significant diagnostic challenge. Recognition of this rare subtype is critical due to its aggressive biological behavior. This work was supported by Masaryk University in Brno, Czech Republic, under Grant MUNI/A/1621/2024, the Ministry of Health, Czech Republic, grant project no. NU23-03-00100 and by the project National Institute for Cancer Research (Programme EXCELES, ID Project No. LX22NPO5102) - Funded by the European Union - Next Generation EU.