Abstract BACKGROUND NAD+ is required for cell metabolism and DNA repair. It is generated from nicotinic acid (NA) by NAPRT and from Nicotinamide (NAM) by NAMPT. D2HG in IDH-mutant tumors methylates and inactivates NAPRT, increasing dependence on NAMPT. Toxic side effects of NAMPT inhibition can be prevented by NA supplementation in healthy cells without NAPRT methylation. A1326133 is a recently described CNS-penetrant NAMPT inhibitor hypothesized to selectively eliminate IDH-mutant NAPRT-methylated gliomas, likely in combination with other therapies. Our group is looking for biomarkers of drug efficacy to augment individualized therapies. To that end, we sought to identify GBM cell lines with varying sensitivity to NAMPT inhibition. METHODS Human non-immortalized astrocytes and human GBM cell lines were utilized from the Mayo Clinic Glioma patient-derived xenograft resource, including IDH-R132Hmutant lines (GBM164, 196) and IDH-WT lines (GBM6, 12, 76). Cell viability was analyzed after 4days incubation with the NAMPT inhibitor, A1326133 +/- Temozolomide (TMZ) or NA. IC50 for A1326133 was estimated based on intracellular ATP using Cell-Titer-Glo. RESULTS Marked heterogeneity between lines was observed in response to A1326133 +/- NA or TMZ. Sensitive and resistant lines were identified among both IDH-mutant and IDH-WT cell lines. IC50s: GBM164, 12, 6, 196 and 76 were 5.6, 9.3, 39.2, 910, and 9455nM, respectively. NA partially rescued GBM164 by NA (IC50 increased to 20.8nM) but not GBM6 nor 12. IC50 for Human astrocytes was 221.7nM, but >10,000nM with NA. Addition of TMZ did not improve A1326133 efficacy. CONCLUSION Our data illustrate the potential utility of NAMPT inhibition to kill a subset of IDH-WT and IDH mutant lines, but conflict with previously reported TMZ synergy and correlation with mutant IDH. NA may increase safety but could decrease efficacy in certain lines. Ongoing studies seek metabolic biomarkers of therapeutic efficacy to guide individualized therapy with NAMPT inhibitors.
Bedside Diffuse Optical Tomography of Disrupted Brain Connectivity During Acute Stroke
Abstract Neurological instability during the first days following ischemic stroke reflects the potential to salvage brain tissue at risk for infarct growth, hemorrhagic transformation, or malignant edema. However, current clinical care provides intermittent assessments on the order of at least an hour apart potentially missing the early detection of neurological deterioration. Optical imaging offers a continuous, portable alternative to the current combination of physical exams and radiological imaging. However, optical imaging technology has heretofore lacked the crucial combination of portability, resolution, and coverage required for assessing distributed brain function. Here, we present a portable high-density diffuse optical tomography (HD-DOT) system that overcomes these limitations to assess neurological disruption at the bedside. We imaged patients within 72 hours after ischemic stroke onset and demonstrate that HD-DOT is sensitive to both the presence of stoke (Cohen’s d = 1.5, p = 1.2 × 10− 3) as well as the degree of neurological disruption measured by NIH Stroke Scale (R2 = 0.69, p = 4.7 × 10− 4).
Comparative connectivity correlates of dystonic and essential tremor deep brain stimulation
AbstractThe pathophysiology of dystonic tremor and essential tremor remains partially understood. In patients with medication-refractory dystonic tremor or essential tremor, deep brain stimulation (DBS) targeting the thalamus or posterior subthalamic area has evolved into a promising treatment option. However, the optimal DBS targets for these disorders remains unknown. This retrospective study explored the optimal targets for DBS in essential tremor and dystonic tremor using a combination of volumes of tissue activated estimation and functional and structural connectivity analyses. We included 20 patients with dystonic tremor who underwent unilateral thalamic DBS, along with a matched cohort of 20 patients with essential tremor DBS. Tremor severity was assessed preoperatively and approximately 6 months after DBS implantation using the Fahn-Tolosa-Marin Tremor Rating Scale. The tremor-suppressing effects of DBS were estimated using the percentage improvement in the unilateral tremor-rating scale score contralateral to the side of implantation. The optimal stimulation region, based on the cluster centre of gravity for peak contralateral motor score improvement, for essential tremor was located in the ventral intermediate nucleus region and for dystonic tremor in the ventralis oralis posterior nucleus region along the ventral intermediate nucleus/ventralis oralis posterior nucleus border (4 mm anterior and 3 mm superior to that for essential tremor). Both disorders showed similar functional connectivity patterns: a positive correlation between tremor improvement and involvement of the primary sensorimotor, secondary motor and associative prefrontal regions. Tremor improvement, however, was tightly correlated with the primary sensorimotor regions in essential tremor, whereas in dystonic tremor, the correlation was tighter with the premotor and prefrontal regions. The dentato-rubro-thalamic tract, comprising the decussating and non-decussating fibres, significantly correlated with tremor improvement in both dystonic and essential tremor. In contrast, the pallidothalamic tracts, which primarily project to the ventralis oralis posterior nucleus region, significantly correlated with tremor improvement only in dystonic tremor. Our findings support the hypothesis that the pathophysiology underpinning dystonic tremor involves both the cerebello-thalamo-cortical network and the basal ganglia-thalamo-cortical network. Further our data suggest that the pathophysiology of essential tremor is primarily attributable to the abnormalities within the cerebello-thalamo-cortical network. We conclude that the ventral intermediate nucleus/ventralis oralis posterior nucleus border and ventral intermediate nucleus region may be a reasonable DBS target for patients with medication-refractory dystonic tremor and essential tremor, respectively. Uncovering the pathophysiology of these disorders may in the future aid in further improving DBS outcomes.
Ovarian Cancer, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology
Epithelial ovarian cancer is the leading cause of death from gynecologic cancer in the United States and is the country’s fifth most common cause of cancer mortality in women. A major challenge in treating ovarian cancer is that most patients have advanced disease at initial diagnosis. These NCCN Guidelines discuss cancers originating in the ovary, fallopian tube, or peritoneum, as these are all managed in a similar manner. Most of the recommendations are based on data from patients with the most common subtypes─high-grade serous and grade 2/3 endometrioid. The NCCN Guidelines also include recommendations specifically for patients with less common ovarian cancers, which in the guidelines include the following: carcinosarcoma, clear cell carcinoma, mucinous carcinoma, low-grade serous, grade 1 endometrioid, borderline epithelial, malignant sex cord-stromal, and malignant germ cell tumors. This manuscript focuses on certain aspects of primary treatment, including primary surgery, adjuvant therapy, and maintenance therapy options (including PARP inhibitors) after completion of first-line chemotherapy.
Developing Novel Targeted Therapies Using the High-Risk Vq Myeloma Model
Multiple myeloma (MM) is characterized by clonal expansion of malignant plasma cells (PCs) and aberrant production of monoclonal immunoglobulin detected as an M spike using serum protein electrophoresis. In the United States, MM represents ~15% of hematologic malignancies and is one of the few cancers increasing in incidence (e.g., 14,400 in 1996 to 32,270 in 2020, from SEER). Despite recent treatment advances, patients diagnosed with high risk/refractory MM (hrrMM) have an overall survival of only three years. Recently, our lab developed the first genetically engineered NrasQ61R; Myc-driven myeloma model (VQ mice). The VQ model recapitulates most biological and clinical features of hrrMM. VQ cells are serially transplantable into syngeneic recipients and can be propagated in vitro. As such, the VQ model could serve as a robust pre-clinical platform for drug screening and in vivo testing of new therapies to treat hrrMM. Whole exome sequencing (WES) of CD138+ cells from five primary VQ mice identified eight recurrently mutated genes. Of these eight genes, two have been previously identified as recurrently mutated in MM patients while the remainder appear to be unique to VQ myeloma. Meanwhile, RNA sequencing of CD138+ cells taken from both primary VQ mice and secondary VQ recipients show differential gene expression for five of these eight genes. Gene ontology analysis of recurrently mutated genes indicates that these genes play a role in interferon signaling, as well as receptor tyrosine kinase signaling. Here, we report the results of a high-throughput repurposing screen using the NCI's AOD IX library, which consists of 147 FDA-approved anti-cancer drugs. VQ cells were treated with 0.1 and 1µM of each compound in the presence or absence of 10nM of Trametinib (Tra), a potent MEK inhibitor. Screening results returned expected positive hits that were previously FDA approved for MM treatment (green dots, Panel 1B), such as proteasome inhibitors, histone deacetylase inhibitors, and chemotherapy drugs. Importantly, VQ cells were resistant to some compounds currently used to treat MM, including the BCL-2 inhibitor Venetoclax, the alkylating agent Melphalan, and the topoisomerase II inhibitor Etoposide (red dots, Panel 1B). De novo resistance to these therapies further indicates that the VQ cells model a multi-drug resistant MM. Two compounds were chosen for further testing: the protein translation inhibitor Omacetaxine (Oma) based on its single agent efficacy, and the multi-receptor tyrosine kinase inhibitor Ponatinib (Pot) based on its high synergy with Tra. Combination Index testing confirmed initial drug screening results but showed some antagonism between combination Oma and Pot treatment. We proceeded with in vivo testing of two novel combination therapies, in which 3-week treatment cycles were followed by a 1-week rest period between cycles: Three weeks of daily Tra and Pot treatment (TP), or two weeks of Tra and Pot treatment followed by one week of Oma (TPO) treatment. Vehicle (Veh) treated and Tra only treated mice were used as controls. Treatment efficacy was assessed against VQ-D1 MM, which grows primarily in the bone marrow (BM) and metastasizes to the spleen and liver of recipient mice. Four weeks post-treatment, myeloma growth in the BM was significantly reduced in both combo treatment groups, while MM burden in the spleen was also reduced. Overall, both TP and TPO treatment significantly extended survival compared to Veh or Tra treated mice, and significantly reduced liver extramedullary disease. To further test the range of Tra/Pot synergy in vivo, Tra dosage was reduced and treatment was administered daily. Interestingly, both low dose Tra monotherapy and TP combo therapy significantly extended survival compared to Veh control or Pot alone, and TP treated mice had increased survival compared to the Tra only treated mice. Taken together, our results show that low dose daily Trametinib treatment is superior to cycling dosage, and that Ponatinib treatment synergizes with both dosing schedules to extend survival in vivo. Our study demonstrates the utility of the VQ model for identifying new treatments for hrrMM and testing their efficacy in vivo. As part of our ongoing drug repurposing experiments, we have expanded our screening to a panel of 2,580 FDA-approved drugs, including but not limited to anti-cancer and anti-inflammatory drugs. Figure Disclosures Callander: Cellectar: Research Funding; University of Wisconsin: Current Employment.
552: Hybrid ECMO as a Rescue Strategy for Cardiorespiratory Compromise Following Liver Transplantation
Abstract Introduction Musculoskeletal injuries are an endemic amongst U.S. Military Service Members and significantly strain the Department of Defense’s Military Health System. The Military Health System aims to provide Service Members, military retirees, and their families the right care at the right time. The Military Orthopedics Tracking Injuries and Outcomes Network (MOTION) captures the data that can optimize musculoskeletal care within the Military Health System. This report provides MOTION structural framework and highlights how it can be used to optimize musculoskeletal care. Materials and Methods MOTION established an internet-based data capture system, the MOTION Musculoskeletal Data Portal. All adult Military Health System patients who undergo orthopedic surgery are eligible for entry into the database. All data are collected as routine standard of care, with patients and orthopedic surgeons inputting validated global and condition-specific patient reported outcomes and operative case data, respectively. Patients have the option to consent to allow their standard of care data to be utilized within an institutional review board approved observational research study. MOTION data can be merged with other existing data systems (e.g., electronic medical record) to develop a comprehensive dataset of relevant information. In pursuit of enhancing musculoskeletal injury patient outcomes MOTION aims to: (1) identify factors which predict favorable outcomes; (2) develop models which inform the surgeon and military commanders if patients are behind, on, or ahead of schedule for their targeted return-to-duty/activity; and (3) develop predictive models to better inform patients and surgeons of the likelihood of a positive outcome for various treatment options to enhance patient counseling and expectation management. Results This is a protocol article describing the intent and methodology for MOTION; thus, to date, there are no results to report. Conclusions MOTION was established to capture the data that are necessary to improve military medical readiness and optimize medical resource utilization through the systematic evaluation of short- and long-term musculoskeletal injury patient outcomes. The systematic enhancement of musculoskeletal injury care through data analyses aligns with the National Defense Authorization Act (2017) and Defense Health Agency’s Quadruple Aim, which emphasizes optimizing healthcare delivery and Service Member medical readiness. This transformative approach to musculoskeletal care can be applied across disciplines within the Military Health System.
TAMI-13. IMPORTANCE OF CD38 INHIBITION IN PRE-RECURRENT GLIOBLASTOMA
Abstract Glioblastoma multiforme (GBM) is the most aggressive CNS neoplasm with a mere 15 month progression-free survival following current standards-of-care. Furthermore, conventional therapies have been effective, in part, by inducing a senescent-like phenotype in at least a proportion of glioma, as well as within the tumor-adjacent, healthy brain cells. Through an N-glyco-capture large-scale screening method, we were able to identify 25 genes exclusively overexpressed on glioma cell surfaces. Of those 25 targets, CD38 was an attractive target due to pre-existing FDA approved therapeutics. Recent studies have shown, however, that senescent cells, such as those induced via chemo- and radiotherapies, secrete a pro-inflammatory array of cytokines, known collectively as senescence associated secretory phenotype (SASP), that are capable of increasing CD38 expression in monocytes. CD38 functions as an ectoenzyme to convert extracellular NAD+ to nicotinamide (required for glioma cell salvage pathway NAD+ synthesis) and ADPR/cADPR (a cellular proliferation signal). To examine the effects of radiation on human glioma tissue, we performed reverse cyclase assays (RCA) on paired primary and recurrent human glioma tissue samples and found an increase in CD38 activity in post-irradiated tissues (recurrent glioma) compared to pre-irradiated (primary glioma). Through proliferation assays, we also found an increase in glioma cell growth following treatment with cADPR compared to untreated. Our results demonstrate that CD38 activity is tumorgenic, and furthermore that conventional chemo- and radiotherapies increase this CD38 activity. This indicates that treating CD38 with previously FDA approved therapeutics may provide hope for increasing progression free survival in our GBM patient population, and moreover emphasize the importance of leveraging novel large scale screening methods for identifying additional opportunities for treatment.
SURG-31. SURGICAL OUTCOME ANALYSES ON 244 CENTRAL NERVOUS SYSTEM HEMANGIOBLASTOMA
Abstract BACKGROUND Surgical resection of the central nervous system hemangioblastoma is often challenging, with vascular-rich nature and surrounding critical structures. von Hippel-Lindau (VHL) disease cases make the management more difficult with repeated surgeries required for multiple lesions. Here we investigated the surgical outcome of CNS HGBs on a large cohort to clarify the clinical and radiological parameters pertaining to the surgical success. METHODS Retrospective analysis of consecutive, neurosurgically managed CNS HGB at Mayo Clinic, 1988-2018. RESULTS Total 244 surgeries were performed for 172 patients. Gross total resection (GTR) was achieved in 90.0%, which was lower in cases brainstem lesions (78.3%) and was associated with the tumor, especially solid-portion volume (p=0.017). Intraoperative blood loss correlated with the size of solid portions, and the transfusion was performed in 7.5%. Postoperative complication was observed in 52.2%, including new/worsening neurological deficit in 45.4%, wound complication in 9.1% and systemic complication in 4.0%. Postoperative rehabilitation was introduced in 61.7% of the patients, which was statistically associated with age, non-GTR and tumor location (brainstem and spine) on multivariate analysis (p=0.0031, 0.027 and 0.0066, respectively). Treatment-free survival was longer in VHL (vs sporadic) cases and GTR (vs non-GTR) cases, and multivariate analysis showed GTR was the only factor associated with treatment-free survival (p=0.0015). CONCLUSIONS Surgery for CNS HGBs was shown to be challenging, with abundant intraoperative bleeding and high risk of postoperative complications necessitating rehabilitation. GTR of the lesion is of utmost importance, which increases the chance of long treatment-free survival as well as favorable direct postoperative clinical course.