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Abstract: Brain tumors are one of the most aggressive malignancies in humans. They can be classified as primary tumors, which arise in the brain, or secondary tumors, which arise elsewhere in the body and initially metastaze the brain. The morbidity and mortality of brain tumors is one of the highest among cancers (Siegel et al., 2023). Of particular concern is that mortality and incidence of brain tumors are increasing, especially in the population under 44 years of age. Brain tumor mortality in this population is 13.4%. For example, primary brain tumors are the most common cancer in children and the leading cause of death in pediatric cancer patients (Gould, 2018). Considering the low survival rate of adult and pediatric brain tumor patients and the detrimental impact on patient quality of life, economic costs, and mortality rates, there is an urgent need to develop more effective therapeutic approaches. Despite major research efforts, there are currently no effective treatment modalities or prevention strategies that would significantly improve the quality of life and disease outcome of brain tumor patients.
Keywords: brain tumor, data integration, therapeutic resistance, biomarkers, liquid biopsies
Published in DiRROS: 06.08.2024; Views: 29; Downloads: 18
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Abstract: Brain, the major organ of the central nervous system controls and processes most of body activities. Therefore, the most aggressive brain tumor – glioblastoma and metastases from other organs to the brain are lethal leaving the patients with very short time of survival. The brain tissue landscape is very different from any other tissues and the specific microenvironment, comprising stem cells niches and blood-brain barrier, significantly influences the low rate of glioblastoma metastasis out of the brain, but better accommodates brain-invading cancer. In contrast to low frequency (0.5%) of all glioblastoma metastases, 10%–45% of other primary cancers do metastasize to the brain. This review addresses general cellular and molecular pathways that are to some extent similar in both types of metastases, involving circulating tumor cells (CTCs) with cancer stem cells (CSCs) characteristics, and metastatic niches. The invasion is a dynamic process involving reversible epithelial-to-mesenchymal (EMT) cell process, creating a transient gradient state that is inter-connected with epigenetic plasticity of the metastasizing (m)CSCs. These cells can switch between stationary, low proliferating/dormant state to a migratory, mesenchymal-like state. Settling in their respective niches as dormant CSCs in the secondary organ is a common feature in all types of metastases. In glioblastoma metastasis, the malignant mGSC cells express markers of mesenchymal GSC subtype (MES-GSC), such as CD44 and YK-40 and their major obstacle seems to be propagating in the in various organs’ microenvironments, different from the niches that home GSCs in the primary glioblastoma. Focusing on one stromal component in the glioblastoma niches, the mesenchymal stem cells (MSCs), we report herein on their differential effects on glioblastoma cells, highly depending on their genetic subtype. On the other hand, in brain metastases, the major hindrance to metastatic progression of mCSCs seem to be crossing the blood-brain-barrier. Novel therapeutic approaches for brain metastases from various cancer types are advancing slowly, and the general trends involve targeting metastatic sub-clones and selective determinants of their niches. The update on the four most common brain metastases from lung, breast, melanoma and colorectal carcinoma is presented.
Keywords: glioblastoma, cancer stem cells, invasion, metastasis, tumor microenvironment
Published in DiRROS: 06.08.2024; Views: 50; Downloads: 81
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Abstract: Lysosomal cysteine peptidase cathepsin B, involved in multiple processes associated with tumor progression, is validated as a target for anti-cancer therapy. Nitroxoline, a known antimicrobial agent, is a potent and selective inhibitor of cathepsin B, hence reducing tumor progression in vitro and in vivo. In order to further improve its anti-cancer properties we developed a number of derivatives using structure-based chemical synthesis. Of these, the 7-aminomethylated derivative (compound 17) exhibited significantly improved kinetic properties over nitroxoline, inhibiting cathepsin B endopeptidase activity selectively. In the present study, we have evaluated its anti-cancer properties. It was more effective than nitroxoline in reducing tumor cell invasion and migration, as determined in vitro on two-dimensional cell models and tumor spheroids, under either endpoint or real time conditions. Moreover, it exhibited improved action over nitroxoline in impairing tumor growth in vivo in LPB mouse fibrosarcoma tumors in C57Bl/6 mice. Taken together, the addition of a 2-(ethylamino)acetonitrile group to nitroxoline at position 7 significantly improves its pharmacological characteristics and its potential for use as an anti-cancer drug.
Keywords: nitroxoline derivative, cathepsin B, inhibition, tumor invasion, cell migration
Published in DiRROS: 26.07.2024; Views: 111; Downloads: 97
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Abstract: Background: Intraoperative kidney tumor rupture (TR) can occur during robot-assisted partial nephrectomy (RAPN) in daily clinical practice, but there are no solid guidelines on the management and implications of it. The purpose of the study was to investigate the impact of TR on tumor recurrences, what a surgeon should do if this adverse event occurs, and how to avoid it. Patients and methods: We retrospectively analyzed the first 100 patients who underwent RAPN at University Medical Centre Ljubljana, between 2018 and 2021. Patients were stratified into 2 groups (TR and no-TR) and were compared according to patient, tumor, pathologic, perioperative and postoperative characteristics and tumor recurrences, using the Mann-Whitney U test and chi-squared test. Results: Of the 100 patients, 14 had TR (14%); this occurred in tumors with higher RENAL nephrometry scores (P = 0.028) and mostly with papillary renal cell carcinomas (P = 0.043). Median warm ischemia time was longer for the TR group (22 vs. 15 min, P = 0.026). In terms of studied outcomes, there were no cases of local or distant recurrence after a median observation time of 39 months (interquartile range, 31-47 months) in both groups. We observed positive surgical margins on the final oncologic report in one case in the no-TR group. Conclusions: Tumor rupture during RAPN seems to be of no mid-term oncologic importance. According to presented results, we would recommend surgeons to proceed with tumor resection if this event occurs and abstain from conversion to radical nephrectomy or open partial nephrectomy. However, more similar cases should be studied to make more solid conclusions.
Keywords: enucleation, renal cell carcinoma, robot-assisted partial nephrectomy, tumor recurrence, tumor rupture, warm ischemia time
Published in DiRROS: 25.07.2024; Views: 92; Downloads: 65
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Abstract: Background. Circulating tumor cells (CTCs) have become an important biomarker in breast cancer. Different iso-lation tech-niques based on their biological or physical features were established. Currently, the most widely used methods for visualization after their separation are based on immunofluorescent staining, which does not provide the information on the morphology.Materials and methods. The aim of this study was to evaluate how two different separation techniques affect cell morphology and to analyse cell morphology with techniques used in routine cytopathological laboratory. A direct side-by-side comparison of physical (Parsortix%) and biological (MACS%) separation technique was performed.Results. In the preclinical setting, both isolation techniques retained the viability and antigenic characteristics of MCF7 breast cancer cells. Some signs of degeneration such as cell swelling, cytoplasmic blebs, villous projections and vacuolization were observed. In metastatic breast cancer patient cohort, morphological features of isolated CTCs were dependent on the separation technique. After physical separation, CTCs with preserved cell morphology were detected. After biological separation the majority of the isolated CTCs were so degenerated that their identity was difficult to confirm.Conclusions. Taken together, physical separation is a suitable technique for detection of CTCs with preserved cell morphology for the use in a routine cytopathological laboratory.
Keywords: circulating tumor cells, breast cancer, morphology
Published in DiRROS: 22.07.2024; Views: 146; Downloads: 138
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