Woodworth, Graeme F

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 BACKGROUND Liquid biopsy in glioblastoma (GBM) is hindered by a lack of requisite circulating-free DNA (cfDNA) blood levels in due to the blood-brain barrier (BBB). Real-time image-guided low-intensity focused ultrasound (LIFU) with intravenously administered microbubble oscillators non-invasively causes BBB disruption (BBBD). This clinical trial aimed to evaluate the utility of LIFU for increasing cfDNA in blood for liquid biopsy in GBM. METHODS LIBERATE is an ongoing, prospective, multi-center, self-controlled, ongoing, pivotal trial evaluating the safety and technical efficacy of LIFU for BBBD to increase cfDNA in blood for GBM. Patients aged 18-80 years with suspected GBM planned for tumor biopsy or resection at ten centers in the US are being included. Patients are administered intravenous oscillating microbubbles for enhancing sonication, after which MR-guided BBBD using 220 kHz LIFU device is performed, with real-time acoustic feedback for effective sonication. Pre- and post-procedure, phlebotomies, and MRI brain are performed. The primary study endpoint is defined, per subject, as the ratio between cfDNA levels in blood 1-hour post-LIFU procedure compared to cfDNA level in blood pre-procedure. The primary study hypothesis is that BBBD with LIFU leads to ≥2-fold increase in cfDNA in blood. The secondary hypothesis is that there exists ≥75% concordance between biomarker patterns in the cfDNA sample from 1-hour post-LIFU sample and tumor tissue obtained later. Exploratory endpoints include (1) sensitivity of detection of known somatic mutations in cfDNA from blood samples collected before and after LIFU, (2) estimation of cfDNA levels in samples collected at 30 minutes, 1 hour, 2 hours, and 3 hours post-LIFU to determine the time of greatest yield, (3) correlation of MRI parameters related to BBBD grading and biomarkers in cfDNA from post-LIFU samples. Patient enrollment commenced in 2022, and 13 patients have been recruited by 06/09/2023. Clinical trial information: NCT05383872.

TPS2084 Background: Liquid biopsy in glioblastoma (GBM) is hindered by a lack of requisite circulating-free DNA (cfDNA) levels in blood due to the blood-brain barrier (BBB). This results in challenges to the identification of blood-based biomarkers and the development of novel biomarker-driven systemic therapies. Real-time image-guided low intensity focused ultrasound (LIFU) combined with IV microbubble oscillators (DEFINITY), non-invasively causes BBB disruption (BBBD). This clinical trial aims to evaluate the utility of LIFU for increasing cfDNA in blood for liquid biopsy in GBM. Methods: LIBERATE is a prospective, multi-center, self-controlled, ongoing, pivotal trial evaluating safety and technical efficacy of LIFU for BBBD to increase cfDNA in blood for GBM. Patients aged >18-80 years with suspected GBM planned for tumor biopsy or resection at eleven centers in North America are being included. Patients with multifocal tumors or tumors arising from deep midline, thalamus, cerebellum, or brainstem are excluded. Patients are administered IV oscillating microbubbles for enhancing sonication, after which MR-guided BBBD using a 220 kHz LIFU device is performed with real-time acoustic feedback for effective cavitation. Before and after procedure, phlebotomies and MRI brain are performed to evaluate outcomes. The primary study endpoint is defined, per subject, as the ratio between their cfDNA level in blood 1-hour post-LIFU compared to cfDNA level in blood pre-procedure. The primary study hypothesis is that BBBD with LIFU leads to ≥2-fold increase in cfDNA in blood. The secondary hypothesis is that there exists ≥75% agreement between biomarker pattern in cfDNA sample from 1-hour post-LIFU sample and biomarker pattern in tumor tissue obtained later. The trial has been powered to evaluate both primary and secondary hypotheses. Based on an assumed true agreement rate of 91% and a one-sided alpha of 0.025, an exact test for binomial proportions provides a sample of N=50 with 84% power for the secondary hypothesis. Exploratory endpoints include (1) sensitivity of detection of known somatic mutations in cfDNA from blood samples collected before and after LIFU, (2) estimation of cfDNA levels post-LIFU in samples collected at 30 minutes, 1 hour, 2 hour, and 3 hour to determine time of greatest yield, (3) correlation of MRI parameters related to grading of BBBD and biomarkers positive in cfDNA from post-LIFU blood samples. Patient enrollment commenced in 2022 and 7 patients have been recruited by 02/13/2023. Clinical trial information: NCT05383872 .

BACKGROUND: Decompression of the injured spinal cord confers neuroprotection. Compared with timing of surgery, verification of surgical decompression is understudied. OBJECTIVE: To compare the judgment of cervical spinal cord decompression using real-time intraoperative ultrasound (IOUS) following laminectomy with postoperative MRI and CT myelography. METHODS: Fifty-one patients were retrospectively reviewed. Completeness of decompression was evaluated by real-time IOUS and compared with postoperative MRI (47 cases) and CT myelography (4 cases). RESULTS: Five cases (9.8%) underwent additional laminectomy after initial IOUS evaluation to yield a final judgment of adequate decompression using IOUS in all 51 cases (100%). Postoperative MRI/CT myelography showed adequate decompression in 43 cases (84.31%). Six cases had insufficient bony decompression, of which 3 (50%) had cerebrospinal fluid effacement at >1 level. Two cases had severe circumferential intradural swelling despite adequate bony decompression. Between groups with and without adequate decompression on postoperative MRI/CT myelography, there were significant differences for American Spinal Injury Association motor score, American Spinal Injury Association Impairment Scale grade, AO Spine injury morphology, and intramedullary lesion length (IMLL). Multivariate analysis using stepwise variable selection and logistic regression showed that preoperative IMLL was the most significant predictor of inadequate decompression on postoperative imaging ( P = .024). CONCLUSION: Patients with severe clinical injury and large IMLL were more likely to have inadequate decompression on postoperative MRI/CT myelography. IOUS can serve as a supplement to postoperative MRI/CT myelography for the assessment of spinal cord decompression. However, further investigation, additional surgeon experience, and anticipation of prolonged swelling after surgery are required.

Abstract BACKGROUND Glioblastoma (GBM) has dismal outcome of 14-16 months. One of the challenges of drug development in GBM is lack of requisite circulating-free (cfDNA) in blood samples to develop biomarker driven targeted therapy trials. The Exablate focused ultrasound with circulating microbubble resonators uses the concept of real-time imaging to treat small target spots focusing energy in a non-invasive manner, thereby disrupting the Blood-Brain Barrier (BBBD) with potential to increase cfDNA in blood. METHODS LIBERATE is a prospective, multi-center, self-controlled pivotal ongoing clinical trial in subjects with suspected GBM evaluating the safety and effectiveness of Exablate Model 4000 to disrupt BBB to achieve a greater proportion of cfDNA in samples taken post-BBB disruption as compared to the sample taken before BBBD. Fifty eligible subjects with suspected GBM who are scheduled to undergo brain tumor resection or biopsy at 10 centers in the U.S. will participate in this study. The primary endpoint is defined for each subject as ratio between his/her cfDNA amount found in the blood sample 1-hour post-BBBD procedure compared to the cfDNA amount found in the blood sample collected pre-BBBD procedure. This study proposes to demonstrate that on average there is at least 2-fold increase in cfDNA (measured by central laboratory) at 1 hour post BBBD. Confirmatory secondary analysis will evaluate correlation between patterns obtained in panel of biomarkers evaluated in the resected tumor tissue and/or biopsy sample and blood sample collected 1-hour post-BBBD. Exploratory endpoints will include: (1) sensitivity of detection of known somatic mutations in the circulating blood samples (circulating tumor DNA) before and after BBBD, (2) time of greatest yield of cfDNA in the samples collected post BBBD blood samples (at 30 min, 1-hour, 2-hour and 3-hour) to determine time of greatest yield, (3) correlation of biomarkers between the imaging and the post-BBBD biomarker samples. (NCT05383872)

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.