Citations

Abstract The DNA damage response (DDR) and the blood tumor barrier (BTB) restrict chemotherapeutic success for primary brain tumors like glioblastoma (GBM). Coherently, GBM almost invariably relapse with fatal outcome. We here show that interaction of GBM and myeloid cells simultaneously induces chemoresistance on the genetic and the vascular level by activating GP130 receptor signaling, which can be addressed therapeutically. We performed transcriptomic and immunohistochemical screens with human brain material, pharmacological experiments with a humanized organotypic GBM model, proteomics and cell-based assays and observed that nanomolar concentrations of the signaling peptide Humanin promoted TMZ resistance through DDR activation. GBM mouse models recapitulating intratumoral Humanin-release showed accelerated BTB formation. Genetic analysis of pericyte to endothelial cell signaling in transgenic mice revealed increased GP130 activation in Humanin releasing tumors as compared to controls. GP130 blockade attenuated both DDR activity and BTB formation resulting in improved preclinical chemotherapeutic efficacy. Altogether, we describe an overarching mechanism for TMZ resistance and outline a translatable strategy with predictive markers to improve chemotherapy for GBM.

Abstract The prognosis for pediatric high-grade gliomas associated with mutations in the H3-A3 histone gene is very poor. To investigate whether peptide-pulsed dendritic cells (DC) together with checkpoint blockade might be a potential treatment modality for diffuse hemispheric glioma, H3 G34-mutant (DHG), we have developed a novel mouse model, and utilized a novel bioinformatics pipeline to identify tumor-associated peptide antigens (TAs). We used the RCAS/tv-A system to target the expression of H3/G34R and PDGFb, and to knock out p53 in neural progenitors in transgenic C57BL/6 neonatal mice. Three independent cell lines were obtained that expressed transcripts associated with oligodendrocyte and interneuron lineages, and formed lethal tumors after intracranial implantation. To identify TAs, we implemented a new computational workflow to identify nonapeptides generated from alternative splicing of mRNAs that were highly enriched in the tumor transcriptomes of two DHG patients, and predicted to bind the HLA-A*2:01 class I allele carried by these patients. Three of the candidate peptides were conserved in the mouse and also predicted to bind the H2-Kb MHC I allele carried by C57/BL6 mice. Using our syngeneic mouse model, we showed that DCs pulsed with these peptides together with anti-PD1 mAb provided a significant survival benefit compared with checkpoint inhibitor and DCs pulsed with peptides that were not predicted to bind the H2-Kb allele. Splenocytes isolated from successfully treated mice were analyzed through bulk TCR sequencing, and in comparison with control mice and publicly-accessible TCR libraries, 6 highly-represented TCR clonotypes were identified only in treated mice. In summary, we demonstrate that effective TAs can be extracted from RNAseq data, and can be targeted with DC vaccination to generate a systemic anti-tumor cytotoxic T cell response to eliminate DHG in a novel immunocompetent mouse model.

Abstract Despite exhibiting longer overall survival that IDH-wt counterparts, IDH-mutant gliomas remain uniformly deadly and impact patients in the prime of adult life. The immune microenvironment of IDH-mutant gliomas remains incompletely characterized, particularly with regard to distinctions between IDH-mutant astrocytoma and IDH-mutant, 1p/19q codeleted oligodendroglioma. To address this knowledge gap, we subjected dissociated tumor suspensions derived from 7 astrocytoma and 7 oligodendroglioma clinical samples to flow cytometry-based sorting for the pan-immune marker, CD45, and the microglial marker, P2RY12. This process yielded both microglial and non-microglial immune cell populations, which were then analyzed by scRNA sequencing. This workflow revealed a single large cluster of microglia, characterized by expression of Galectin-1 and lysosomal Lipase A, which was present at a significantly higher level in oligodendroglioma. While the biological significance of this cluster is unclear, gene set enrichment analysis exploring phenotypic differences between microglia in astrocytoma and oligodendroglioma revealed significant increases in expression of gene sets related to antigen presentation in astrocytoma. Parallel analysis of the non-microglial immune fraction showed an increase in the expression of pro-inflammatory gene sets, such as genes related to cytokine secretion, within the CD8 T-cell compartment of astrocytomas. We also observed upregulation of the expression of inflammatory gene sets within the dendritic cells of astrocytomas. Taken together, these changes suggest that the immune compartment of astrocytoma is more active and inflamed, and targeting the immune system in these tumors may represent a potential therapeutic avenue.

Background: Pulsed field ablation (PFA) is a promising modality for treatment of cardiac arrhythmias. PFA increases cell permeability, thereby promoting cell apoptosis. Although greater PFA energy may produce larger lesions, it also carries risks of side effects such as arcing, hemolysis, and microbubbles. Chemical ablation using ethanol (EtOH), such as with injection of the Vein of Marshall, has been used to treat atrial myocardium for refractory atrial arrhythmias. Hypothesis: We hypothesize that PFA in the atria can increase EtOH uptake through PFA-generated pores, thereby augmenting ablation efficacy by utilizing the cell permeability effects of PFA. Aim: The aim of this study is to investigate the effects of local EtOH infusion after PFA on lesion size in porcine atria. Methods: The atria of five porcine subjects were ablated in vivo with low PFA power settings (250V, at 20μs for 50 pulses separated by 200 ms) using a focal bipolar irrigated ablation catheter and BTX 830 electroporation generator (Harvard Apparatus). After PFA, 2 ml of 90 % EtOH vs. saline (control) was infused through the catheter tip to the site of ablation. We compared electrogram voltage amplitude reduction and ablation lesion parameters before and after PFA. Results: A total of 14 control lesions and 14 EtOH lesions were analyzed. There was significant difference in voltage reduction between two groups ( Figure 1A-B ). On gross pathology, there were significant differences in ablation lesion maximum surface diameter, lesion depth, and volume between the 2 lesion sets ( Figure 1C ). Conclusion: Concurrent EtOH infusion after PFA enhanced acute efficacy of electroporation in porcine atria. Adjuvant therapy has the potential to improve efficacy without requiring higher energy parameters, thereby reducing PFA risks. Further studies to assess chronic efficacy are warranted.

Abstract This study reports the first pig-to-human lung xenotransplantation using a six gene-edited pig lung. A left lung from a gene-edited Chinese Bama Xiang pig was transplanted into a 39-year-old brain-dead human recipient. The xenograft maintained viability and functionality for 216 hours without signs of hyperacute rejection. Postoperatively, severe edema resembling primary graft dysfunction (PGD) was observed, potentially due to ischemia-reperfusion injury. Antibody-mediated rejection appeared to contribute to xenograft damage on postoperative days 3 and 6, with partial recovery by day 9 under the current immunosuppressive regimen. This pioneering study suggests that genetically modified pig lungs could potentially be used for future clinical applications in xenotransplantation.

Abstract Background and Aims Individuals with inflammatory bowel disease (IBD) experience a high symptom burden, including abdominal pain, fatigue, anxiety, depression, and sleep disturbances; yet, little is known regarding the relationship between sex and gender on symptoms. We sought to report symptom severity for cisgender men, cisgender women, and transgender and gender-diverse (TGD) individuals. In addition, we used network analysis to identify core symptoms and explore if symptoms and their relationships differ between cisgender men and cisgender women. Methods This was a cross-sectional study. We recruited adults with IBD online through ResearchMatch. Individuals responded to Patient-Reported Outcomes Measurement Information symptom questionnaires, as well as demographic and clinical questionnaires. Network analysis was used to identify the core symptoms driving the symptom structure. Results One-hundred and fifty-seven (63.3%) participants identified as cisgender women, 84 (33.9%) as cisgender men, and 7 (2.8%) as TGD. Cisgender men (M = 61.8) and TGD (M = 61.3) groups reported higher abdominal pain levels compared with cisgender women (M = 57.8; P = .02). Transgender and gender-diverse individuals reported higher depression levels (M = 64.8) compared with cisgender men (M = 56.7) and cisgender women (M = 54.4; P = .01). Using a network analysis approach, anxiety and fatigue emerged as core symptoms for the entire sample (clinically active and inactive disease), and among only those with active clinical disease. Fatigue was a top core symptom for cisgender women; anxiety emerged as a top core symptom for cisgender men. Conclusions This study highlights that fatigue and anxiety are core symptoms among individuals with IBD and demonstrates a potential sex and/or gender difference in core symptoms. Replication of this study is needed with further consideration of inclusion of TGD patients.

ABSTRACT Background The sterol regulatory element‐binding protein (SREBP) pathway is essential for maintaining sterol homeostasis during B cell activation and germinal center B cell proliferation. However, its potential as a therapeutic target to treat B‐cell lymphoma remains unclear. Methods We examined SREBP protein expression in human B‐cell lymphoma samples using immunohistochemistry. Additionally, we conducted in vitro studies using SREBP signaling inhibitors in combination with rapamycin to assess their effects on cell proliferation and lipid metabolism in B‐cell lymphoma cells. Results Our analysis revealed high levels of SREBP2 protein expression in human B‐cell lymphoma samples. Inhibiting SREBP signaling or its downstream target HMG‐CoA reductase (HMGCR) with Fatostatin or Simvastatin effectively suppressed B‐cell lymphoma cell proliferation. However, B‐cell lymphoma cells responded to statin treatment by activating the mTORC1‐pS6 pathway, suggesting a compensatory mechanism to overcome statin‐induced cell cycle arrest. Combining low‐dose statin treatment with the mTOR inhibitor rapamycin produced a synergistic effect, significantly inhibiting B‐cell lymphoma proliferation, cell cycle progression, and lipid raft formation. Conclusions These results highlight the potential of a combined therapeutic approach targeting both SREBP and mTORC1 as a novel strategy for treating B‐cell lymphoma.