Cellular Senescence in Diffuse Gliomas: From Physiopathology to Possible Treatments.

Cellular senescence in gliomas is a complex process that is induced by aging and replication, ionizing radiation, oncogenic stress, and the use of temozolomide. However, the escape routes that gliomas must evade senescence and achieve cellular immortality are much more complex, in which the expression of telomerase and the alternative lengthening of telomeres, as well as the mutation of some proto-oncogenes or tumor suppressor genes, are involved. In gliomas, these molecular mechanisms related to cellular senescence can have a tumor-suppressing or promoting effect and are directly involved in tumor recurrence and progression. From these cellular mechanisms related to cellular senescence, it is possible to generate targeted senostatic and senolytic therapies that improve the response to currently available treatments and improve survival rates. This review aims to summarize the mechanisms of induction and evasion of cellular senescence in gliomas, as well as review possible treatments with therapies targeting pathways related to cellular senescence.

The potential of miRNA-based approaches in glioblastoma: An update in current advances and future perspectives.

Glioblastoma (GBM) is the most common malignant central nervous system tumor. The emerging field of epigenetics stands out as particularly promising. Notably, the discovery of micro RNAs (miRNAs) has paved the way for advancements in diagnosing, treating, and prognosticating patients with brain tumors. We aim to provide an overview of the emergence of miRNAs in GBM and their potential role in the multifaceted management of this disease. We discuss the current state of the art regarding miRNAs and GBM. We performed a narrative review using the MEDLINE/PUBMED database to retrieve peer-reviewed articles related to the use of miRNA approaches for the treatment of GBMs. MiRNAs are intrinsic non-coding RNA molecules that regulate gene expression mainly through post-transcriptional mechanisms. The deregulation of some of these molecules is related to the pathogenesis of GBM. The inclusion of molecular characterization for the diagnosis of brain tumors and the advent of less-invasive diagnostic methods such as liquid biopsies, highlights the potential of these molecules as biomarkers for guiding the management of brain tumors such as GBM. Importantly, there is a need for more studies to better examine the application of these novel molecules. The constantly changing characterization and approach to the diagnosis and management of brain tumors broaden the possibilities for the molecular inclusion of novel epigenetic molecules, such as miRNAs, for a better understanding of this disease.

Differential tractography and whole brain connectometry in primary motor area gliomas resection: A feasibility study.

OBJECTIVE: Establish the evolution of the connectome before and after resection of motor area glioma using a comparison of connectome maps and high-definition differential tractography (DifT). METHODS: DifT was done using normalized quantitative anisotropy (NQA) with DSI Studio. The quantitative analysis involved obtaining mean NQA and fractional anisotropy (FA) values for the disrupted pathways tracing the corticospinal tract (CST), and white fiber network changes over time. RESULTS: We described the baseline tractography, DifT, and white matter network changes from two patients who underwent resection of an oligodendroglioma (Case 1) and an IDH mutant astrocytoma, grade 4 (Case 2). CASE 1: There was a slight decrease in the diffusion signal of the compromised CST in the immediate postop. The NQA and FA values increased at the 1-year follow-up (0.18 vs. 0.32 and 0.35 vs. 0.44, respectively). CASE 2: There was an important decrease in the immediate postop, followed by an increase in the follow-up. In the 1-year follow-up, the patient presented with radiation necrosis and tumor recurrence, increasing NQA from 0.18 in the preop to 0.29. Fiber network analysis: whole-brain connectome comparison demonstrated no significant changes in the immediate postop. However, in the 1-year follow up there was a notorious reorganization of the fibers in both cases, showing the decreased density of connections. CONCLUSIONS: Connectome studies and DifT constitute new potential tools to predict early reorganization changes in a patient's networks, showing the brain plasticity capacity, and helping to establish timelines for the progression of the tumor and treatment-induced changes.

Augmented reality for intracranial meningioma resection: a mini-review.

Augmented reality (AR) integrates computer-generated content and real-world scenarios. Artificial intelligence's continuous development has allowed AR to be integrated into medicine. Neurosurgery has progressively introduced image-guided technologies. Integration of AR into the operating room has permitted a new perception of neurosurgical diseases, not only for neurosurgical planning, patient positioning, and incision design but also for intraoperative maneuvering and identification of critical neurovascular structures and tumor boundaries. Implementing AR, virtual reality, and mixed reality has introduced neurosurgeons into a new era of artificial interfaces. Meningiomas are the most frequent primary benign tumors commonly related to paramount neurovascular structures and bone landmarks. Integration of preoperative 3D reconstructions used for surgical planning into AR can now be inserted into the microsurgical field, injecting information into head-up displays and microscopes with integrated head-up displays, aiming to guide neurosurgeons intraoperatively to prevent potential injuries. This manuscript aims to provide a mini-review of the usage of AR for intracranial meningioma resection.

The state of art of awake craniotomy in Latin American countries: a scoping review.

BACKGROUND AND OBJECTIVE: Awake craniotomy (AC) is a valuable technique for surgical interventions in eloquent areas, but its adoption in low- and middle-income countries faces challenges like limited infrastructure, trained personnel shortage, and inadequate funding. This scoping review explores AC techniques in Latin American countries, focusing on patient characteristics, tumor location, symptomatology, and outcomes. METHODS: A scoping review followed PRISMA guidelines, searching five databases in English, Spanish, and Portuguese. We included 28 studies with 258 patients (mean age: 43, range: 11-92). Patterns in AC use in Latin America were analyzed. RESULTS: Most studies were from Brazil and Mexico (53.6%) and public institutions (70%). Low-grade gliomas were the most common lesions (55%), most of them located in the left hemisphere (52.3%) and frontal lobe (52.3%). Gross-total resection was achieved in 34.3% of cases. 62.9% used an Asleep-Awake-Asleep protocol, and 14.8% used Awake-Awake-Awake. The main complication was seizures (14.6%). Mean post-surgery discharge time was 68 h. Challenges included limited training, infrastructure, and instrumentation availability. Strategies discussed involve training in specialized centers, seeking sponsorships, applying for awards, and multidisciplinary collaborations with neuropsychology. CONCLUSION: Improved accessibility to resources, infrastructure, and adequate instrumentation is crucial for wider AC availability in Latin America. Despite disparities, AC implementation with proper training and teamwork yields favorable outcomes in resource-limited centers. Efforts should focus on addressing challenges and promoting equitable access to this valuable surgical technique in the region.

Understanding the molecular profiling of diffuse gliomas classification: A brief overview.

Background: Gliomas represent almost 30% of all primary brain tumors and account for 80% of malignant primary ones. In the last two decades, significant progress has been made in understanding gliomas' molecular origin and development. These advancements have demonstrated a remarkable improvement in classification systems based on mutational markers, which contribute paramount information in addition to traditional histology-based classification. Methods: We performed a narrative review of the literature including each molecular marker described for adult diffuse gliomas used in the World Health Organization (WHO) central nervous system 5. Results: The 2021 WHO classification of diffuse gliomas encompasses many molecular aspects considered in the latest proposed hallmarks of cancer. The outcome of patients with diffuse gliomas relies on their molecular behavior and consequently, to determine clinical outcomes for these patients, molecular profiling should be mandatory. At least, the following molecular markers are necessary for the current most accurate classification of these tumors: (1) isocitrate dehydrogenase (IDH) IDH-1 mutation, (2) 1p/19q codeletion, (3) cyclin-dependent kinase inhibitor 2A/B deletion, (4) telomerase reverse transcriptase promoter mutation, (5) α-thalassemia/ mental retardation syndrome X-linked loss, (6) epidermal growth factor receptor amplification, and (7) tumor protein P53 mutation. These molecular markers have allowed the differentiation of multiple variations of the same disease, including the differentiation of distinct molecular Grade 4 gliomas. This could imply different clinical outcomes and possibly impact targeted therapies in the years to come. Conclusion: Physicians face different challenging scenarios according to the clinical features of patients with gliomas. In addition to the current advances in clinical decision-making, including radiological and surgical techniques, understanding the disease's molecular pathogenesis is paramount to improving the benefits of its clinical treatments. This review aims to describe straightforwardly the most remarkable aspects of the molecular pathogenesis of diffuse gliomas.