Robert C. Osorio

Glioblastoma is a lethal brain tumor that is resistant to conventional therapies. Here we present a non-lytic replicating retrovirus (RRV) that delivers an IL-15-receptor-linked fusion protein (RLI) superagonist directly into glioblastoma cells, creating localized immunotherapy biofactories. In orthotopic mouse models, RRV-RLI dramatically suppresses tumor growth, prolongs survival, and induces lasting remission with immunologic memory. Mechanistically, we observe increased CD8⁺ T cell and natural killer cell infiltration and activation, alongside elevated antigen presentation pathways. Combining RRV-RLI with temozolomide, which is standard-of-care chemotherapy for glioblastoma, enhances antitumor immunity. T cell receptor sequencing reveals a polyclonal repertoire of T cells, enhanced by combining RRV-RLI with temozolomide. Analysis of the T-cell repertoire suggests it to be directed against tumor rather than viral antigens, supporting the specificity and re-applicability of our approach. These findings illustrate that RRV-RLI reprograms glioblastoma into an immunostimulatory hub, offering a viral immunotherapy against glioblastoma and potentially other therapy-resistant solid tumors.

Background: Meningioma–induced hyperostosis (MIH) is a frequent radiographic finding, yet its underlying mechanisms remain poorly understoodWhile hyperostosis has traditionally been treated as a binary phenomenon, the aim of this study was to determine whether MIH represents a heterogenous process with distinct radiological subtypes associated with genetic associations. Methods: We retrospectively reviewed the records and imaging of patients with meningiomas resected between 2021–2024 at a single institution. Somatic mutations identified through next–generation sequencing were analyzed. CT images were analyzed for bone involvement and hyperostosis subtype. Type I hyperostosis was defined by destruction of cortical architecture while Type II hyperostosis was defined by the preservation of cortical structure. Associations with TRAF7 mutations were assessed using univariate testing, multivariable logistic regression, and supervised machine–learning models. Quantitative bone density analysis was performed using region–of–interest grayscale histogram analysis. Results: Among 384 tumors, 54 (14.1%) exhibited hyperostosis—23 Type I and 31 Type II. TRAF7 mutations were significantly enriched in Type I hyperostosis compared with Type II and non–hyperostotic tumors (78.3% vs 25.8% vs 17.0%, p<0.001). Type I hyperostosis independently predicted TRAF7 mutations (OR:18.73, p=0.001), along with skull base location, smaller tumor size, homogeneous contrast enhancement, and extensive T2 hyperintensity. Gradient boosting achieved the highest predictive accuracy (AUC=0.854). Quantitative bone density analysis demonstrated preserved cortical–cancellous architecture in Type II hyperostosis, whereas Type I showed architectural disruption. Conclusions: MIH is a radiographically heterogenous phenomenon. Hyperostosis with disrupted cortical architecture is strongly associated with TRAF7 mutations and may represent a key feature of this mutation's radiographic phenotype.

BACKGROUND: CSF leaks can cause resistant subdural hematomas (SDHs). Spinal CSF-venous fistulas (CVFs) are a rare cause of this problem. A better understanding of this phenomenon would guide decision-making when planning treatment and follow-up. The authors reviewed a case of a recurrent right-sided SDH secondary to a previously unknown CVF. In addition, a systematic review was conducted in accordance with PRISMA guidelines for previously documented cases. OBSERVATIONS: Seven cases were found in the literature, with ours representing the eighth case of recurrent SDH due to a CVF-induced CSF leak. The mean age was 60 years, and 75% of patients were male. Common initial presentations included headache (100%), tinnitus (75%), and nausea/vomiting (50%). All patients were treated with Onyx embolization, with 62.5% also receiving middle meningeal artery (MMA) embolization. All patients experienced improvement of SDH size after treatment, with 62.5% demonstrating complete resolution. LESSONS: Spinal CVFs are a rare but serious cause of CSF leaks and recurrent SDHs. Cases typically occur in men around 60 years of age, and common symptoms include headache, tinnitus, and nausea/vomiting. Treatment with CVF embolization results in improvement or resolution of SDH burden, while the role of MMA embolization in the treatment of these SDHs remains unclear. https://thejns.org/doi/10.3171/CASE25338

While the accumulation of tumor-associated macrophages (TAMs) in glioblastoma (GBM) has been well documented, targeting TAMs has thus far yielded limited clinical success in slowing GBM progression due, in part, to an incomplete understanding of TAM function. Using an engineered 3D hydrogel–based model of the brain tumor microenvironment (TME), we show that M2-polarized macrophages stimulate transcriptional and phenotypic changes in GBM stem cells (GSCs) closely associated with the highly aggressive and invasive mesenchymal subtype. By combining proteomics with GBM patient single-cell transcriptomics, we identify multiple TAM-secreted proteins with putative proinvasive functions and validate TGF-β induced (TGFBI, also known as BIGH3) as a targetable TAM-secreted tumorigenic factor. Our work highlights the utility of coupling multiomics analyses with engineered TME models to investigate TAM–cancer cell crosstalk and offers insights into TAM function to guide TAM-targeting therapies.

Background: Cutaneous melanoma (CM) can be molecularly classified into four groups: BRAF mutant, NRAS mutant, NF1 mutant and triple wild-type (TWT) tumors lacking any of these three alterations. In the era of immune checkpoint inhibition (ICI) and targeted molecular therapy, the clinical significance of these groups remains unclear. Here, we integrate targeted DNA sequencing with comprehensive clinical follow-up in CM patients. Methods: This was a retrospective cohort study that assessed clinical and molecular features from patients with localized or metastatic CM who underwent targeted next-generation sequencing as part of routine clinical care. A total of 254 patients with CM who had a CLIA-certified targeted sequencing assay performed on their tumor tissue were included. Results: Of the 254 patients with cutaneous melanoma, 77 were BRAF mutant (30.3%), 77 were NRAS mutant (30.3%), 47 were NF1 mutant (18.5%), 33 were TWT (13.0%) and the remaining 20 (7.9%) carried mutations in multiple driver genes (BRAF/NRAS/NF1 co-mutated). The majority of this co-mutation group carried mutations in NF1 (n = 19 or 90%) with co-occurring mutations in BRAF or NRAS, often with a weaker oncogenic variant. Consistently, NF1 mutant tumors harbored numerous significantly co-altered genes compared to BRAF or NRAS mutant tumors. The majority of TWT tumors (n = 29, 87.9%) harbor a pathogenic mutation within a known Ras/MAPK signaling pathway component. Of the 154 cases with available TMB data, the median TMB was 20 (range 0.7–266 mutations/Mb). A total of 14 cases (9.1%) were classified as having a low TMB (≤5 mutations/Mb), 64 of 154 (41.6%) had an intermediate TMB (>5 and ≤20 mutations/Mb), 40 of 154 (26.0%) had a high TMB (>20 and ≤50 mutations/Mb) and 36 of 154 (23.4%) were classified as having a very high TMB (>50 mutations/Mb). NRAS mutant melanoma demonstrated significantly decreased overall survival on multivariable analysis (HR for death 2.95, 95% CI 1.13–7.69, p = 0.027, log-rank test) compared with other TCGA molecular subgroups. Of the 116 patients in our cohort with available treatment data, 36 received a combination of dual ICI with anti-CTLA4 and anti-PD1 inhibition as first-line therapy. Elevated TMB was associated with significantly longer progression-free survival following dual-agent ICI (HR 0.26, 95% CI 0.07–0.90, p = 0.033, log-rank test). Conclusions: NRAS mutation in CMs correlated with significantly worse overall survival. Elevated TMB was associated with increased progression-free survival for patients treated with a combination of dual ICI, supporting the potential utility of TMB as a predictive biomarker for ICI response in melanoma.

BACKGROUND AND OBJECTIVES: To date, there are no tools to intraoperatively predict postoperative visual function after endoscopic endonasal surgery (EES) for suprasellar lesions. The objective of this study was to retrospectively evaluate the utility of indocyanine green (ICG) angiography as an intraoperative tool to measure optic chiasm perfusion and determine its relationship with postoperative visual function. METHODS: Videos of patients undergoing EES for resection of suprasellar lesions were reviewed, where 5 mg of ICG was diluted in 10 mL of saline and administered. Time between luminescence of the anterior cerebral artery and the superior hypophyseal artery branches supplying the optic chiasm was noted, and the percentage of optic chiasm vessels that luminesced was recorded. Postoperative examinations and imaging studies were used to assess visual function. Patients with and without new deficits were compared with examination of trends in ICG findings. RESULTS: A total of 7 trials were reviewed on 6 patients, with no complications occurring from ICG administration. Mean time to chiasm peak luminescence was 3.8 seconds, and 81.8% of chiasm vessels luminesced. Patients with stable or improved vision after resection demonstrated over 90% chiasm luminescence in every case, and mean chiasm time in these postresection ICG administrations was 4.0 seconds. One patient experienced new postoperative visual deficits; on review of their ICG administration, 11.5% of chiasm vessels luminesced, and the chiasm itself failed to display robust luminescence after 30 seconds of direct observation. CONCLUSION: This pilot study showed the capability of intraoperative ICG angiography to demonstrate perfusion of the optic chiasm during EES for resection of suprasellar lesions. While larger studies are required, preliminary results suggest chiasm times under 5 seconds and over 90% chiasm vessel illumination may reflect adequate chiasm perfusion, while those with delayed or absent chiasm luminescence may have compromised chiasm perfusion.

Glioblastoma (GBM) is the most common primary brain tumor with a poor prognosis with the current standard of care treatment. To address the need for novel therapeutic options in GBM, immunotherapies which target cancer cells through stimulating an anti-tumoral immune response have been investigated in GBM. However, immunotherapies in GBM have not met with anywhere near the level of success they have encountered in other cancers. The immunosuppressive tumor microenvironment in GBM is thought to contribute significantly to resistance to immunotherapy. Metabolic alterations employed by cancer cells to promote their own growth and proliferation have been shown to impact the distribution and function of immune cells in the tumor microenvironment. More recently, the diminished function of anti-tumoral effector immune cells and promotion of immunosuppressive populations resulting from metabolic alterations have been investigated as contributory to therapeutic resistance. The GBM tumor cell metabolism of four nutrients (glucose, glutamine, tryptophan, and lipids) has recently been described as contributory to an immunosuppressive tumor microenvironment and immunotherapy resistance. Understanding metabolic mechanisms of resistance to immunotherapy in GBM can provide insight into future directions targeting the anti-tumor immune response in combination with tumor metabolism.

The pituitary gland is one of the most cellularly diverse regions of the brain. Recent advancements in transcriptomic biology, such as single-cell RNA sequencing, bring an unprecedented glimpse into the molecular composition of the pituitary, both in its normal physiological state and in disease. Deciphering the normal pituitary transcriptomic signatures provides a better insight into the ontological origin and development of five types of endocrine cells, a process involving complex cascades of transcription factors that are still being established. In parallel with these observations about normal pituitary development, recent transcriptomic findings on pituitary neuroendocrine tumors (PitNETs) demonstrate both preservations and changes in transcription factor expression patterns compared to those seen during gland development. Furthermore, recent studies also identify differentially expressed genes that drive various tumor behaviors, including hormone hypersecretion and tumor aggression. Understanding the comprehensive multiomic profiles of PitNETs is essential in developing molecular profile-based therapies for PitNETs not curable with current treatment modalities and could eventually help align PitNETs with the breakthroughs being made in applying precision medicine to other tumors.