Winkles, Jeffrey A.

Abstract Glioblastoma (GBM) is a lethal, treatment-resistant brain cancer characterized by diffuse brain invasion, complex neuron-glioma signaling, and cellular, molecular, and spatial heterogeneity. Surgery is the current mainstay of treatment, aimed at maximizing tumor cytoreduction, decompressing the brain to improve neurological function, and providing material for analyses to inform prognostication and adjuvant treatment selection. To accurately model GBM surgical resection and tissue sampling in preclinical animal models, we developed the Maximal Safe Intracranial Surgery (MSIS) system. MSIS integrated a miniaturized neurosurgical resection device and enabled a safe, tunable, and reproducible approach for intracranial tumor resection, multi-regional biopsy, and longitudinal tissue sampling in murine models, with stereotactic, sterile, and high-viability tissue collection. MSIS was applied across five distinct orthotopic brain tumor models to reproducibly generate histologically and radiologically representative models of post-surgical GBM. Similar to humans, increasing the extent of resection correlated with improved animal survival, and recurrent growth patterns varied significantly by model type. Transcriptional profiles of matched primary vs. post-surgical recurrent tumors revealed enrichment of margin-associated transcriptional states consistent with neuron-glioma signaling. Overall, the MSIS system offers opportunities to model the standard-of-care, dissect the spatial and temporal dynamics of GBM, and pair therapeutic discovery with contextual tumor pathobiology.

Abstract Introduction Immunotherapy approaches against glioblastoma (GBM) such as immune checkpoint inhibitors (ICI), dendritic cell vaccination, and CAR-T have failed to durably cure most patients. Studies analyzing tumors from ICI responders show that abundance of CD4 and CD8 T cells prior to initiation of therapy predicts responsiveness. Thus, targeting the microenvironment to promote CD4 activity may synergize with ICI. The glioblastoma microenvironment contains high proportions of monocyte-derived macrophages which have potent immunosuppressive capabilities. Characterizing and targeting these immunosuppressive programs is a promising strategy for designing effective combination immunotherapies for glioblastoma patients. Methods We analyzed human glioblastoma snRNAseq datasets to find signaling receptors associated with myeloid immunosuppression and employed murine models of glioblastoma for functional validation. Results By analyzing patient-derived -omics datasets, we identified an understudied TNF-superfamily receptor, Fn14, as being upregulated in glioblastoma-associated myeloid cells with immunosuppressive gene signatures. Using in vitro approaches, we found that Fn14 activation in the tumor microenvironment can drive cytokines implicated in GBM immunosuppression such as IL6, IL1B, and IL8. Thus, Fn14 may serve as a surface marker for microenvironment-remodeling myeloid cells recruited to the tumor from peripheral circulation. Furthermore, in murine models of glioblastoma, we discovered Fn14 KO among glioblastoma-associated myeloid cells increases conventional dendritic cell type 1 (cDC1) and Th1 CD4+ T cell abundance in the tumor microenvironment and significantly prolongs survival. Conclusion These results suggest that blocking Fn14 in glioblastoma-associated myeloid cells can enhance Th1 immunity. Thus, Fn14 may represent a promising dual therapy target. Funding Source NIH Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

Abstract Background Fibroblast growth factor-inducible 14 (Fn14) belongs to the TNFR superfamily. Fn14 overexpression can drive receptor-autonomous signaling, increase both cell invasion and tumor-associated macrophages/microglia (TAMMs) recruitment, and correlates with reduced survival in glioblastoma (GBM) patients and rat gliomas. While prior studies report Fn14 expression in non-tumor cells within the GBM tumor microenvironment (TME), their relative contributions to glioma pathobiology remain unclear. Methods Using tumor-host pairings of Fn14-positive and -knockout (-KO) cells and mice, we examined the role of Fn14 in glioma biology. Mouse glioma and human GBM datasets were analyzed at the cellular, protein, and transcriptomic levels to assess Fn14-associated changes in the glioma TME and survival outcomes. Results Fn14 was found to be highly expressed in tumor cells and TAMMs in human GBM and 2 well-characterized murine glioma models. Fn14 KO in both tumor and host cells increased overall survival. Notably, this survival benefit was greater in the glioma model characterized by a more immunologically activated TME. Immunophenotyping revealed that Fn14 loss reshapes the tumor-immune landscape, reducing the presence of immunosuppressive macrophages and exhausted T-cells, suggesting that Fn14 modulates both innate and adaptive immune responses. These findings were supported by analyses of human GBM datasets, where high Fn14 expression correlated with immunosuppressive shifts and poor patient responses to immune checkpoint inhibitor therapy. Conclusions This study provides the first description of the contributions of both tumor- and host-derived Fn14 expression to tumor immunity and survival and identifies Fn14 as an important mediator of innate and adaptive immune responses in gliomas.

Abstract Glioblastoma remains difficult to treat with immunotherapy due to the immunosuppressive tumor microenvironment and the ability of glioma cells to invade diffusely into normal brain parenchyma. While it is known that glioblastoma-associated myeloid cells (GAMs) comprise a large proportion of the tumor microenvironment and can suppress adaptive and innate immune responses through various mechanisms, detailed mapping of myeloid lineages in glioblastoma is still missing. Further characterization of pro-tumoral myeloid-lineages in glioblastoma is important for identifying myeloid-based drug targets that may synergize with T cell-based therapies and produce a more meaningful anti-tumor immune response. Towards this end, we examined numerous scRNAseq datasets derived from glioblastoma patients and identified expression of TNFRSF12A, the gene encoding the TNF- family receptor, Fn14, in a subset of GAMs enriched for expression of cytokines such as CCL3, CCL5, IL-6, and IL-8. This result is intriguing since TWEAK (TNFSF12), the ligand for Fn14, is abundantly expressed within numerous patient-derived glioblastoma cell lines, namely GBM6, GBM8, GBM22, and GBM39. To validate Fn14 protein expression in GAMs, we isolated murine bone-marrow derived macrophages and treated them with glioma-conditioned media, which induced Fn14 gene expression. We then conducted in vitro experiments utilizing the human microglia line HMC3, the murine microglia line SIM-A9, and primary murine bone-marrow-derived macrophages to assess the effects of Fn14 activation in myeloid cells. We found that treatment of Fn14+ myeloid cells with TWEAK ligand upregulates CCL3, CCL5, IL-6, and IL-8 expression. We tested the conditioned media generated from TWEAK-treated Fn14+ myeloid cell lines and found that it promotes glioblastoma invasion in a CCL5-dependent manner. This aligns with previous reports demonstrating the CCL5-CCR5 signaling in glioma cells promotes invasion through calcium-dependent matrix metalloproteinase 2. To assess the spatial distribution of this myeloid subpopulation, we performed RNAscope hybridization against AIF1, TMEM119, CCR5, CCL5, and Fn14 transcripts on sections of murine gliomas generated using the RCAS/tv-a model of human glioblastoma. We found an abundance of Fn14+ plus AIF1+ as well as Fn14+plus TMEM119+ myeloid cells throughout the tumor core and rim of murine tumors and identified CCL5 expression in pseudo-palisades bordering necrotic regions. Our results to date suggest that Fn14 expression in GAMs can promote the invasion of tumor cells into normal brain parenchyma by release of CCL5. Currently, we are utilizing orthotopic patient-derived xenograft models co-implanted with Fn14+/- myeloid cells to test the hypothesis that TWEAK-Fn14 signaling in GAMs provides strong pro-tumoral signals in the glioblastoma microenvironment. Citation Format: Angad Beniwal, Matthew Dufault, Pranjali Kanvinde, David Nascari, Ryan Eghlimi, Adarsha Malla, Dolores Hambardzumyan, Henrique Borges da Silva, Graeme Woodworth, Jeffrey Winkles, Nhan Tran. TWEAK-Fn14 signaling in glioblastoma-associated myeloid cells promotes tumor invasion via CCL5-CCR5 axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6867.

AbstractHigh‐grade gliomas (HGGs) are aggressive, treatment‐resistant, and often fatal human brain cancers. The TNF‐like weak inducer of apoptosis (TWEAK)/fibroblast growth factor‐inducible 14 (Fn14) signaling axis is involved in tissue repair after injury and constitutive signaling has been implicated in the pathogenesis of numerous solid cancers. The Fn14 gene is expressed at low levels in the normal, uninjured brain but is highly expressed in primary isocitrate dehydrogenase wild‐type and recurrent HGGs. Fn14 signaling is implicated in numerous aspects of glioma biology including brain invasion and chemotherapy resistance, but whether Fn14 overexpression can directly promote tumor malignancy has not been reported. Here, we used the replication‐competent avian sarcoma‐leukosis virus/tumor virus A system to examine the impact of Fn14 expression on glioma development and pathobiology. We found that the sole addition of Fn14 to an established oncogenic cocktail previously shown to generate proneural‐like gliomas led to the development of highly invasive and lethal brain cancer with striking biological features including extensive pseudopalisading necrosis, constitutive canonical and noncanonical NF‐κB pathway signaling, and high plasminogen activator inhibitor‐1 (PAI‐1) expression. Analyses of HGG patient datasets revealed that high human PAI‐1 gene (SERPINE1) expression correlates with shorter patient survival, and that the SERPINE1 and Fn14 (TNFRSF12A) genes are frequently co‐expressed in bulk tumor tissues, in tumor subregions, and in malignant cells residing in the tumor microenvironment. These findings provide new insights into the potential importance of Fn14 in human HGG pathobiology and designate both the NF‐κB signaling node and PAI‐1 as potential targets for therapeutic intervention.Main PointsThis work demonstrates that elevated levels of the TWEAK receptor Fn14 in tumor‐initiating, neural progenitor cells leads to the transformation of proneural‐like gliomas into more aggressive and lethal tumors that exhibit constitutive NF‐κB pathway activation and plasminogen activator inhibitor‐1 overexpression.

DART nanoparticles overcome critical drug delivery barriers for primary tumors and brain metastases.

Abstract Fibroblast growth factor-inducible 14 (Fn14) is the cell surface receptor for the tumor necrosis factor (TNF) family member TNF-like weak inducer of apoptosis (TWEAK). The Fn14 gene is not normally expressed in healthy tissues, but expression is significantly increased in many primary solid tumor types, including glioblastoma (GBM). High Fn14 expression in tumors is often associated with the stimulation of cancer cell invasion leading to diffuse, aggressive tumors and metastasis. To investigate the effects of increased Fn14 expression in brain tumors, two different tumor types were developed using the RCAS/tv-a transgenic rat model: a low-Fn14, “proneural-like” (PDGFA/shP53 derived) tumor and a high-Fn14 (PDGFA/shP53/Fn14-derived) tumor. Interestingly, rats with high-Fn14 brain tumors had a significantly shorter median survival compared to those with low-Fn14 with 42 days and 70 days median survival, respectively. Using MR proton spectroscopy, both tumor types exhibited the markers of a malignant glioma such as increases in choline to creatinine ratio (Cho/Cr) and decreases in neuronal activity (NAA); however, high-Fn14 tumors also displayed an increase in lactate during tumor progression which is often a sign of high grade, necrotic tumors and poor prognosis. Morphologically, the two tumor subtypes appear quite different. H&E staining of the high-Fn14 tumors showed a highly malignant tumor with several areas of pseudopalisading necrosis within the tumor core. This is different than the somewhat more homogeneous morphology of the low-Fn14 proneural-like tumor. The pattern of tumor cell invasion also differs between the two brain cancer subtypes. High-Fn14 tumors show a more human GBM-like pattern by invading along the white matter tracts whereas low-Fn14 tumors appear to invade more locally with minimal white matter invasion. High-Fn14 tumors were positive for Fn14 throughout the tumor including the invasive rim of the tumor, which is also seen in human GBM, whereas the low-Fn14 tumor revealed very little staining even at the invasive rim. These findings indicate that increased Fn14 expression creates a more malignant brain tumors that develops and behaves more aggressively then low-Fn14 tumors. Citation Format: Nina Connolly, Heather Ames, Nhan L. Tran, Anthony Kim, Jeff Winkles, Graeme Woodworth. Fn14 overexpression in RCAS/tv-a rat gliomas promotes tumor progression, increases invasion and decreases survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3701.

Abstract Glioblastoma multiforme (GBM) remains the most common and deadly primary brain tumor with minimal advances in therapeutic development for pharmacological treatment. Tumor resection followed by temozolomide (TMZ) and radiotherapy adds months to survival; however, tumor recurrence usually occurs. The fibroblast growth factor-inducible 14 (Fn14) receptor has been shown to be up-regulated in the GBM cells left behind after surgery and contributes to an invasive and pro-survival phenotype, providing a desirable molecule to target after removal of the primary tumor. Previously, L524-0366 was reported by our lab to be the first antagonist of Fn14 signaling; however, minimal efficacy/potency has limited this drug from progressing from a useful research tool to preclinical studies. Structure activity relationship (SAR) studies using the parent L524-0366 compound gave rise to K78, which was found to bind to Fn14 with enhanced affinity, while showing no binding to the structurally-related TNFα receptor. Furthermore, K78 was able to abate the downstream signaling effects initiated by the Fn14 ligand, tumor necrosis factor-like weak inducer of apoptosis (TWEAK), as well as sensitize GBM cells to the cytotoxic effects of TMZ. TWEAK-induced cellular migration was also mitigated with co-treatment of K78 in GBM cells, compared to a vehicle control. It is anticipated that further development of Fn14 antagonists will be of great importance for the advancement of GBM patient treatment and warrant further investigation as primary and combination therapy, especially for the prevention of recurrent disease. Citation Format: Bryan Harder, Chris Sereduk, Harshil Dhruv, Nghia Millard, Anthony Kim, Jeffrey Winkles, Graeme Woodworth, Holly Yin, Nhan L. Tran. Development of an antagonist to the TWEAK-Fn14 ligand-receptor interaction with enhanced efficacy/potency in glioblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4910.

Abstract Glioblastoma Multiforme (GBM) is the most common malignant brain tumor in adults. Most GBM patients succumb to the disease less than one-year post diagnosis due to the highly invasive nature of the tumor, which prevents complete surgical resection and gives rise to tumor recurrence. The invasive phenotype also confers radio and chemoresistant properties to the tumor cells; therefore, there is a need to develop new therapeutics that target drivers of GBM invasion. Amplification of EGFR is observed in over 50% of GBM tumors, of which half concurrently overexpress the variant EGFRvIII, and expression of both receptors confers a worse prognosis. EGFR and EGFRvIII cooperate to promote tumor progression and invasion, in part, through activation of the Stat-signaling pathway. Here we report that EGFRvIII activates Stat5 and GBM invasion, in part, by inducing the expression of a previously established mediator of glioma cell invasion and survival, fibroblast growth factor-inducible 14 (Fn14). EGFRvIII-mediated induction of Fn14 expression is dependent upon Stat5 and requires activation of Src, whereas EGFR regulation of Fn14 is dependent upon MEK/ERK-Stat3 activation. Notably, treatment of EGFRvIII expressing GBM cells with the FDA approved Stat5 inhibitor pimozide blocked Stat5 phosphorylation, Fn14 expression, and cell migration. Since EGFR inhibitors display limited therapeutic efficacy in GBM patients, we hypothesize that the EGFRvIII-Stat5-Fn14 signaling pathway represents a node of vulnerability in the invasive GB cell population and that targeting critical effectors in this pathway will limit GBM tumor dispersion, mitigate therapeutic resistance, and increase survival. Citation Format: Alison Roos, Harshil D. Dhruv, Sen Peng, Landon J. Inge, Serdar Tuncali, Michael Pineda, Nghia Millard, Jeffrey A. Winkles, Joseph C. Loftus, Nhan L. Tran. EGFRvIII-Stat5 signaling enhances glioblastoma cell invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3462.