Single-cell analysis of 5-aminolevulinic acid intraoperative labeling specificity for glioblastoma

OBJECTIVE

Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor, and resection is a key part of the standard of care. In fluorescence-guided surgery (FGS), fluorophores differentiate tumor tissue from surrounding normal brain. The heme synthesis pathway converts 5-aminolevulinic acid (5-ALA), a fluorogenic substrate used for FGS, to fluorescent protoporphyrin IX (PpIX). The resulting fluorescence is believed to be specific to neoplastic glioma cells, but this specificity has not been examined at a single-cell level. The objective of this study was to determine the specificity with which 5-ALA labels the diversity of cell types in GBM.

METHODS

The authors performed single-cell optical phenotyping and expression sequencing-version 2 (SCOPE-seq2), a paired single-cell imaging and RNA sequencing method, of individual cells on human GBM surgical specimens with macroscopically visible PpIX fluorescence from patients who received 5-ALA prior to surgery. SCOPE-seq2 allowed the authors to simultaneously image PpIX fluorescence and unambiguously identify neoplastic cells from single-cell RNA sequencing. Experiments were also conducted in cell culture and co-culture models of glioma and in acute slice cultures from a mouse glioma model to investigate cell- and tissue-specific uptake and secretion of 5-ALA and PpIX.

RESULTS

SCOPE-seq2 analysis of human GBM surgical specimens revealed that 5-ALA treatment resulted in labeling that was not specific to neoplastic glioma cells. The cell culture further demonstrated that nonneoplastic cells could be labeled by 5-ALA directly or by PpIX secreted from surrounding neoplastic cells. Acute slice cultures from mouse glioma models showed that 5-ALA preferentially labeled GBM tumor tissue over nonneoplastic brain tissue with significant labeling in the tumor margins, and that this contrast was not due to blood-brain barrier disruption.

CONCLUSIONS

Together, these findings support the use of 5-ALA as an indicator of GBM tissue but question the main advantage of 5-ALA for specific intracellular labeling of neoplastic glioma cells in FGS. Further studies are needed to systematically compare the performance of 5-ALA to that of potential alternatives for FGS.

Bench-to-bedside imaging in brain metastases: a road to precision oncology

Radiology has seen tremendous evolution in the last few decades. At the same time, oncology has made great strides in diagnosing and treating cancer. Distant metastases of neoplasms are being encountered more often in light of longer patient survival due to better therapeutic strategies and diagnostic methods. Brain metastasis (BM) is a dismal manifestation of systemic cancer. In the present scenario, magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) are playing a big role in providing molecular information about cancer. Lately, molecular imaging has emerged as a stirring arena of dynamic imaging techniques that have enabled clinicians and scientists to noninvasively visualize and understand biological processes at the cellular and molecular levels. This knowledge has impacted etiopathogenesis, detection, personalized treatment, drug development, and our understanding of carcinogenesis. This article offers insight into the molecular biology underlying brain metastasis, its pathogenesis, imaging protocols, and algorithms. It also discusses disease-specific molecular imaging features, focusing on common tumors that spread to the brain, such as lung, breast, colorectal cancer, melanoma, and renal cell carcinoma. Additionally, it covers various targeted treatment options, criteria for assessing treatment response, and the role of artificial intelligence in diagnosing, managing, and predicting prognosis for patients with brain metastases.

Post-treatment imaging of gliomas: challenging the existing dogmas

Gliomas are the commonest malignant central nervous system tumours in adults and imaging is the cornerstone of diagnosis, treatment, and post-treatment follow-up of these patients. With the ever-evolving treatment strategies post-treatment imaging and interpretation in glioma remains challenging, more so with the advent of anti-angiogenic drugs and immunotherapy, which can significantly alter the appearance in this setting, thus making interpretation of routine imaging findings such as contrast enhancement, oedema, and mass effect difficult to interpret. This review details the various methods of management of glioma including the upcoming novel therapies and their impact on imaging findings, with a comprehensive description of the imaging findings in conventional and advanced imaging techniques. A systematic appraisal for the existing and emerging techniques of imaging in these settings and their clinical application including various response assessment guidelines and artificial intelligence based response assessment will also be discussed.

EZH2 Inhibition Sensitizes IDH1R132H-Mutant Gliomas to Histone Deacetylase Inhibitor

Isocitrate Dehydrogenase-1 (IDH1) is commonly mutated in lower-grade diffuse gliomas. The IDH1R132H mutation is an important diagnostic tool for tumor diagnosis and prognosis; however, its role in glioma development, and its impact on response to therapy, is not fully understood. We developed a murine model of proneural IDH1R132H-mutated glioma that shows elevated production of 2-hydroxyglutarate (2-HG) and increased trimethylation of lysine residue K27 on histone H3 (H3K27me3) compared to IDH1 wild-type tumors. We found that using Tazemetostat to inhibit the methyltransferase for H3K27, Enhancer of Zeste 2 (EZH2), reduced H3K27me3 levels and increased acetylation on H3K27. We also found that, although the histone deacetylase inhibitor (HDACi) Panobinostat was less cytotoxic in IDH1R132H-mutated cells (either isolated from murine glioma or oligodendrocyte progenitor cells infected in vitro with a retrovirus expressing IDH1R132H) compared to IDH1-wild-type cells, combination treatment with Tazemetostat is synergistic in both mutant and wild-type models. These findings indicate a novel therapeutic strategy for IDH1-mutated gliomas that targets the specific epigenetic alteration in these tumors.

Glioma-Induced Alterations in Excitatory Neurons are Reversed by mTOR Inhibition

Gliomas are highly aggressive brain tumors characterized by poor prognosis and composed of diffusely infiltrating tumor cells that intermingle with non-neoplastic cells in the tumor microenvironment, including neurons. Neurons are increasingly appreciated as important reactive components of the glioma microenvironment, due to their role in causing hallmark glioma symptoms, such as cognitive deficits and seizures, as well as their potential ability to drive glioma progression. Separately, mTOR signaling has been shown to have pleiotropic effects in the brain tumor microenvironment, including regulation of neuronal hyperexcitability. However, the local cellular-level effects of mTOR inhibition on glioma-induced neuronal alterations are not well understood. Here we employed neuron-specific profiling of ribosome-bound mRNA via 'RiboTag,' morphometric analysis of dendritic spines, and in vivo calcium imaging, along with pharmacological mTOR inhibition to investigate the impact of glioma burden and mTOR inhibition on these neuronal alterations. The RiboTag analysis of tumor-associated excitatory neurons showed a downregulation of transcripts encoding excitatory and inhibitory postsynaptic proteins and dendritic spine development, and an upregulation of transcripts encoding cytoskeletal proteins involved in dendritic spine turnover. Light and electron microscopy of tumor-associated excitatory neurons demonstrated marked decreases in dendritic spine density. In vivo two-photon calcium imaging in tumor-associated excitatory neurons revealed progressive alterations in neuronal activity, both at the population and single-neuron level, throughout tumor growth. This in vivo calcium imaging also revealed altered stimulus-evoked somatic calcium events, with changes in event rate, size, and temporal alignment to stimulus, which was most pronounced in neurons with high-tumor burden. A single acute dose of AZD8055, a combined mTORC1/2 inhibitor, reversed the glioma-induced alterations on the excitatory neurons, including the alterations in ribosome-bound transcripts, dendritic spine density, and stimulus evoked responses seen by calcium imaging. These results point to mTOR-driven pathological plasticity in neurons at the infiltrative margin of glioma - manifested by alterations in ribosome-bound mRNA, dendritic spine density, and stimulus-evoked neuronal activity. Collectively, our work identifies the pathological changes that tumor-associated excitatory neurons experience as both hyperlocal and reversible under the influence of mTOR inhibition, providing a foundation for developing therapies targeting neuronal signaling in glioma.

Stereotactic Radiosurgery (SRS) for Large Brain Metastases: Dosimetric and Clinical Predictors of Local Progression and Radionecrosis

PURPOSE/OBJECTIVE(S)

Stereotactic radiosurgery (SRS) provides high rates of local control for small brain metastases with low rates of radionecrosis (RN). Larger targets are associated with increased risk of both local progression (LP) and RN. In this analysis, we hypothesized that dosimetric and clinical parameters predict for risk of LP and RN in SRS targets larger than two centimeters.

MATERIALS/METHODS

We retrospectively reviewed patients with one or more targets with either an intact versus post-operative cavity larger than 2.0 cm treated with LINAC-based SRS between 2017 and 2022 at one institution. We assessed for association between patient, treatment, and disease variables with LP and RN. Variables assessed included tumor resection status, PDL1 positivity, target volume, maximum and minimum target dose, EQD2 and BED (a/b = 2 for necrosis and a/b = 10 for tumor control), as well as receipt of steroids, bevacizumab, or systemic therapy before or after SRS. Radionecrosis was determined by characteristic radiographic changes. Analyses were performed for the entire cohort and within subsets including by resection status and dose fractionation.

RESULTS

A total of 178 lesions in 143 patients were included. Targets with volume diameters measuring at least 2 cm were used. Median follow-up was 2.3 years. Overall survival at 1 and 2 years was 56% and 32%, respectively. Most lesions (n = 119) were resected and treated with SRS post-operatively. The most common dose and fractionation schemes used were 30 Gy in 5 fractions (n = 89) and 27 Gy in 3 fractions (n = 63). For the entire cohort, the cumulative incidence of LP 1 and 2 years was 26% and 34%, respectively. The cumulative incidence of radiographic radionecrosis at 1 and 2 years was 12% and 17%, respectively. There was no difference in LP or RN between 27 Gy in 3 fractions versus 30 Gy in 5 fractions (p>0.5 for both). Median planning target volume (PTV) size was 18.5 cc for the 27 Gy in 3 fraction group compared to 21.9 cc in the 30 Gy in 5 fraction group. Minimum or maximum dose within the target was not associated with increased risk of LP or RN. Among patients receiving 27 Gy in 3 fractions, patients treated with resection followed by SRS had lower risk of LP compared to those treated with SRS alone (HR: 0.15, 95% CI: 0.03-0.64, p = 0.011). Among patients receiving 30 Gy in 5 fractions, patients who received corticosteroids prior to SRS had a lower risk of RN (HR: 0.14, 95% CI: 0.03-0.66, p = 0.013). For the entire cohort as well as within all subgroups, PD-L1≥1% was associated with increased risk of RN (p<0.001 for all).

CONCLUSION

Selecting the optimal SRS dose fractionation and planning parameters to minimize both LP and RN remains a challenge for large targets. In this analysis, 27 Gy in 3 fractions appeared to provide equivalent LP and RN compared to 30 Gy in 5 fractions, and may be more convenient for patients. Patients with PD-L1≥1% with large brain targets treated with SRS may be at increased risk of RN; corticosteroid prophylaxis may be considered in this population.

Memantine for Pediatric Patients Receiving Cranial Irradiation: A Pilot Study

PURPOSE/OBJECTIVE(S)

While memantine has become standard in certain adults receiving brain RT to decrease the cognitive impacts of RT, it is unknown whether pediatric patients can take and tolerate memantine or experience benefit. In this prospective single-arm feasibility study, we hypothesized pediatric patients receiving brain RT would tolerate memantine with good treatment adherence.

MATERIALS/METHODS

Patients aged 4-18 years with a primary CNS malignancy (excluding WHO Grade IV astrocytoma and glioblastoma) receiving intracranial RT were eligible. A 6-month course of memantine was given during and after RT. Dosing began once daily at 5 mg with up-titration in 5 mg increments over 4 weeks to a weight-based maximum (0.4 mg/kg to the closest 5 mg), not to exceed 10 mg BID. To reduce patient and clinical research associate (CRA) burden, medication adherence was tracked via the Medisafe Pill and Reminder application which study staff helped install on the patient or parent's smart phone. A paper pill diary was provided for those unable to use the app. The primary endpoint was to achieve 80% adherence rate to memantine in 80% of patients measured 1-month post-RT.

RESULTS

Eighteen patients (14 male and 4 female, median age 11.5 years (range: 4-18)) were enrolled from 2020-2022. The study closed early after enrolling 18 of 20 planned patients to avoid competing with the phase III randomized Children's Oncology Group (COG) study AACL2031. One patient withdrew for cognition-altering substance-use, leaving 17 patients with data available for analysis. Histologies included germ cell tumor (n = 6), craniopharyngioma (n = 3), choroid plexus papilloma (n = 2), ependymoma (n = 2), glial/astrocytoma (n = 2), medulloblastoma (n = 1), and meningioma (n = 1). Thirteen had surgery, and 9 received chemotherapy. Eight received craniospinal irradiation (CSI). Median RT dose was 54 Gy (range 36-59.4) in 30 fractions (range: 20-33). At data freeze, all 17 had passed the 1-month post-RT time point. One patient discontinued memantine after a single dose due to nausea. Pill-reports were available for 14 of the remaining 16; two patients did not complete digital pill logs. For those with complete logs, all adherence rates were above 80%, with a median of 99.32% pill completion rate (range: 92.67-100). Seven (50%) took 100% of prescribed doses. Irrespective of adherence for the 2 unavailable for evaluation, the primary endpoint was still achieved. Grade 1 toxicities included headache (n = 6, 35%) and constipation (n = 1, 6%); there were no grade 2+ toxicities. At last follow-up, 15/16 have completed the full 6-month memantine course. Secondary endpoints including neurocognitive evaluations have not yet been met and will be the subject of future reports.

CONCLUSION

Memantine is a feasible and well-tolerated addition to multi-modality treatment for pediatric brain tumors. Secondary endpoints of this study and results of the ongoing COG study are awaited to define the value of memantine in this population.

Clinical Outcomes for Chest Wall Ewing Sarcoma: A Multi-Center Single Institution Experience

PURPOSE/OBJECTIVE(S)

We report tumor and treatment characteristics, oncologic outcomes, and treatment-associated toxicities in a cohort of chest wall Ewing sarcoma (cwES) patients treated at a single tertiary care institution.

MATERIALS/METHODS

After IRB approval, patients with cwES treated from 1997-2022 were retrospectively reviewed. Patient, tumor, treatment, outcomes, and toxicity data were abstracted. Local control (LC), progression-free survival (PFS), and overall survival (OS) were defined from end of treatment and assessed using the Kaplan-Meier method. Log-rank test and unadjusted Cox models were performed to determine factors associated with outcomes.

RESULTS

The cohort includes 45 patients. Median age at diagnosis was 19.8 years (range: 3.5 - 57.8 years). Five patients (11.1%) presented with pleural effusion and eight patients with lung metastases (17.8%). Two (4.4%) patients had metastatic disease outside the thorax. Median tumor volume (TV) was 138.6 mL (range: 3.0-6762.0 mL). All patients received VDC/IE chemotherapy. LC modality was surgery (S) in 21 patients (47%), radiation therapy (RT) in 5 (11%), and S+RT in 19 (42%). Median TV was larger in S+RT patients (319.4 mL, range: 5.3-6761.9 mL) compared to RT (152.3 mL, range: 20.4-366.9 mL) or S (70.4 mL, range: 3.1-1037.8 mL) (p = 0.03). R0 and R1 resections were performed in 36 (90%) and 4 (10%) patients, respectively. Proton beam therapy was used in 15 (63%) patients. Median dose was 50.40 Gy (range: 34.2 - 60 Gy) in 28 fractions to the primary tumor or post operative bed. Median dose for hemithorax (1 patient, 2.2%) and whole lung irradiation (7 patients, 15.6%) was 15.0 Gy (range: 15.0-15.0 Gy) in 10 fractions. Median follow-up was 2.38 years (range: 0 - 21.90 years). Five-year LC, PFS, and OS for all patients was 77.9% (95% CI, 65.3 - 92.9%), 54.2% (95% CI, 39.9 - 73.5%), and 63.5% (95% CI, 49.3 - 81.8%), respectively. In patients with localized disease, 5-year LC, PFS, and OS were 82.4% (95% CI, 67.9-99.8%), 66.4% (95% CI, 49.7-88.8%), and 71.3% (95% CI, 54.2-93.9%), respectively. Two-year LC by modality was 100% for RT (95% CI, 100-100%), 84.2% (95% CI, 69.3- 100%) for S and 73.3% (95% CI, 54 - 99.5%) for S+RT (p = 0.51). On univariate analysis, TV ≥ 200 mL was associated with a significantly worse 5-year OS (49.5%, TV ≥ 200 mL vs. 80.8%, TV < 200 mL; HR 4.44, p = 0.032) and PFS (35.2%, TV ≥ 200 mL vs. 76%, TV < 200 mL; HR 3.55, p = 0.025). TV ≥ 200 mL trended towards worse 5-year LC: 69.2% for TV ≥ 200 mL versus 81.5% for TV <200 mL [HR 2.26(95% CI 0.49 - 10.47), p = 0.287]. Overall, low rates of grade ≥2 toxicity were observed: 4 (8.9%) fatigue, 4 (8.9%) radiation dermatitis, 1 (2.2%) chyle leak, 3 (6.6%) scoliosis, 4 (8.9%) infection, 1 (2.2%) pneumonia, and 1 (2.2%) chest wall deformity.

CONCLUSION

RT is a safe, effective local therapy for small to moderate cwES tumors. Patients with TV ≥ 200 mL had significantly worse survival outcomes and an inferior LC rate. This suggests large cwES tumors may benefit from an aggressive multi-modality approach.

Spot Scanning Proton Therapy for Pregnant Patients with Brain and Head and Neck Tumors

PURPOSE/OBJECTIVE(S)

When radiotherapy is medically necessary, x-ray based treatments (XRT) have traditionally been used to treat pregnant patients. Treatment planning and delivery techniques may be modified to minimize dose to the fetus but results in less optimal plans due to avoiding posterior beams or arcs. Monte Carlo calculations and published case studies suggest spot scanning proton therapy (PRT) reduces the equivalent dose to the fetus by a factor of 10 compared to XRT and does not require modified treatment planning techniques. However, due to concern for dose uncertainties and neutron scatter with PRT, few centers have adopted PRT over XRT for pregnant patients. The purpose of this work is to perform a retrospective study on the pregnant patients previously treated at our institution with XRT to measure the equivalent dose that would be delivered to the fetus with spot scanning PRT compared to XRT.

MATERIALS/METHODS

PRT plans were made for seven pregnant patients, 4 brain tumors and 3 head and neck tumors, who had received XRT. Due to the finite range of protons, the fetal exposure is dominated by neutrons and not the primary beam. Thus, no beam arrangement modifications were required to minimize fetal dose for PRT plans. Fetal dose measurements were performed with the patient plans using a Rando phantom and Wendi-2 (Thermo Scientific) meter placed at the phantom's abdomen. The Wendi-2 measures ambient dose equivalent, which accounts for the biological effect of the neutron energies. Measurements were made at various distances from isocenter to the center of the detector. The total dose equivalent from PRT at several out of field distances was compared to that from XRT. Patient specific measurements were used to determine the total fetal dose from each modality, accounting for the changing position of the fetus each week of the mother's treatment. The imaging dose for standard of practice imaging, including verification CT scans and daily alignment imaging, was also evaluated using a similar setup with a Fluke 451 dose meter.

RESULTS

The average measured fetal equivalent dose for the brain plans was 0.4 mSv for PRT and 7 mSv for XRT. For the head and neck plans, it was 6 mSv for PRT and 90 mSv for XRT. The dose from PRT was consistently at least a factor of 10 less than the XRT plans. In addition, the PRT plans were preferred by the physicians when considering tumor coverage and other normal tissue sparing. Daily imaging added between 0.05 and 1.5 mSv to the total dose in the PRT treatments.

CONCLUSION

This retrospective study showed that when treating brain or head and neck tumors in pregnant patients, the equivalent dose a fetus would receive with PRT is approximately a factor of 10 less than XRT without making any compromises in treatment planning. These results support changing the standard of practice to utilizing spot scanning PRT as the preferred method for treating pregnant patients with brain or head and neck tumors when available instead of XRT. We have brought this process to clinic at our center.

Trends of surgical-care delivery during the COVID-19 pandemic: A multi-centre study in India (IndSurg Collaboration)

Context

The COVID-19 pandemic and subsequent lockdowns adversely affected global healthcare services to varying extents. To accommodate its added burden, emergency services were affected along-with elective surgeries.

Aims

To quantify and analyze the trends of essential surgeries and bellwether procedures during the waxing and waning of the pandemic, across various hospitals in India.

Settings and Design

Multi-centric retrospective study.

Methods and Material

A research consortium led by World Health Organization (WHO) Collaboration Center (WHOCC) for Research in Surgical Care Delivery in Low-and Middle-Income countries, India, conducted this study with 5 centers. All surgeries performed during April 2020 (Wave I), November 2020 (Recovery I), and April 2021 (Wave II) were compared with those performed in April 2019 (pre-pandemic period).

Statistical Analysis Used

Microsoft Excel 2019 and SPSS Version 20.

Results

The total number of surgeries reduced by 77% during Wave I, which improved to a 52% reduction in Recovery I compared to the pre-pandemic period. However, surgeries were reduced again during Wave II to 68%, but the reduction was less compared to Wave I. Emergency and essential surgeries were affected along with the elective ones but to a lesser extent.

Conclusions

The present study has quantified the effects of the pandemic on surgical-care delivery across a timeline and documented a reduction in overall surgical volumes during the peaks of the pandemic (Wave I and II) with minimal improvement as the surge of COVID-19 cases declined (Recovery II). The surgical volumes improved during the second wave compared to the first one which may be attributable to better preparedness. Cesarean sections were affected the least.

Imaging Analytics using Artificial Intelligence in Oncology: A Comprehensive Review

The present era has seen a surge in artificial intelligence-related research in oncology, mainly using deep learning, because of powerful computer hardware, improved algorithms and the availability of large amounts of data from open-source domains and the use of transfer learning. Here we discuss the multifaceted role of deep learning in cancer care, ranging from risk stratification, the screening and diagnosis of cancer, to the prediction of genomic mutations, treatment response and survival outcome prediction, through the use of convolutional neural networks. Another role of artificial intelligence is in the generation of automated radiology reports, which is a boon in high-volume centres to minimise report turnaround time. Although a validated and deployable deep-learning model for clinical use is still in its infancy, there is ongoing research to overcome the barriers for its universal implementation and we also delve into this aspect. We also briefly describe the role of radiomics in oncoimaging. Artificial intelligence can provide answers pertaining to cancer management at baseline imaging, saving cost and time. Imaging biobanks, which are repositories of anonymised images, are also briefly described. We also discuss the commercialisation and ethical issues pertaining to artificial intelligence. The latest generation generalist artificial intelligence model is also briefly described at the end of the article. We believe this article will not only enrich knowledge, but also promote research acumen in the minds of readers to take oncoimaging to another level using artificial intelligence and also work towards clinical translation of such research.

Multi-OMIC analysis of Huntington disease reveals a neuroprotective astrocyte state

Huntington disease (HD) is an incurable neurodegenerative disease characterized by neuronal loss and astrogliosis. One hallmark of HD is the selective neuronal vulnerability of striatal medium spiny neurons. To date, the underlying mechanisms of this selective vulnerability have not been fully defined. Here, we employed a multi-omic approach including single nucleus RNAseq (snRNAseq), bulk RNAseq, lipidomics, HTT gene CAG repeat length measurements, and multiplexed immunofluorescence on post-mortem brain tissue from multiple brain regions of HD and control donors. We defined a signature of genes that is driven by CAG repeat length and found it enriched in astrocytic and microglial genes. Moreover, weighted gene correlation network analysis showed loss of connectivity of astrocytic and microglial modules in HD and identified modules that correlated with CAG-repeat length which further implicated inflammatory pathways and metabolism. We performed lipidomic analysis of HD and control brains and identified several lipid species that correlate with HD grade, including ceramides and very long chain fatty acids. Integration of lipidomics and bulk transcriptomics identified a consensus gene signature that correlates with HD grade and HD lipidomic abnormalities and implicated the unfolded protein response pathway. Because astrocytes are critical for brain lipid metabolism and play important roles in regulating inflammation, we analyzed our snRNAseq dataset with an emphasis on astrocyte pathology. We found two main astrocyte types that spanned multiple brain regions; these types correspond to protoplasmic astrocytes, and fibrous-like - CD44-positive, astrocytes. HD pathology was differentially associated with these cell types in a region-specific manner. One protoplasmic astrocyte cluster showed high expression of metallothionein genes, the depletion of this cluster positively correlated with the depletion of vulnerable medium spiny neurons in the caudate nucleus. We confirmed that metallothioneins were increased in cingulate HD astrocytes but were unchanged or even decreased in caudate astrocytes. We combined existing genome-wide association studies (GWAS) with a GWA study conducted on HD patients from the original Venezuelan cohort and identified a single-nucleotide polymorphism in the metallothionein gene locus associated with delayed age of onset. Functional studies found that metallothionein overexpressing astrocytes are better able to buffer glutamate and were neuroprotective of patient-derived directly reprogrammed HD MSNs as well as against rotenone-induced neuronal death in vitro. Finally, we found that metallothionein-overexpressing astrocytes increased the phagocytic activity of microglia in vitro and increased the expression of genes involved in fatty acid binding. Together, we identified an astrocytic phenotype that is regionally-enriched in less vulnerable brain regions that can be leveraged to protect neurons in HD.

Imaging of Neck Nodes in Head and Neck Cancers - a Comprehensive Update

Cervical lymph node metastases from head and neck squamous cell cancers significantly reduce disease-free survival and worsen overall prognosis and, hence, deserve more aggressive management and follow-up. As per the eighth edition of the American Joint Committee on Cancer staging manual, extranodal extension, especially in human papillomavirus-negative cancers, has been incorporated in staging as it is important in deciding management and significantly impacts the outcome of head and neck squamous cell cancer. Lymph node imaging with various radiological modalities, including ultrasound, computed tomography and magnetic resonance imaging, has been widely used, not only to demonstrate nodal involvement but also for guided histopathological evaluation and therapeutic intervention. Computed tomography and magnetic resonance imaging, together with positron emission tomography, are used widely for the follow-up of treated patients. Finally, there is an emerging role for artificial intelligence in neck node imaging that has shown promising results, increasing the accuracy of detection of nodal involvement, especially normal-appearing nodes. The aim of this review is to provide a comprehensive overview of the diagnosis and management of involved neck nodes with a focus on sentinel node anatomy, pathogenesis, imaging correlates (including radiogenomics and artificial intelligence) and the role of image-guided interventions.

Anatomical categorization of isolated non-focal dystonia: novel and existing patterns using a data-driven approach

According to expert consensus, dystonia can be classified as focal, segmental, multifocal, and generalized, based on the affected body distribution. To provide an empirical and data-driven approach to categorizing these distributions, we used a data-driven clustering approach to compare frequency and co-occurrence rates of non-focal dystonia in pre-defined body regions using the Dystonia Coalition (DC) dataset. We analyzed 1,618 participants with isolated non-focal dystonia from the DC database. The analytic approach included construction of frequency tables, variable-wise analysis using hierarchical clustering and independent component analysis (ICA), and case-wise consensus hierarchical clustering to describe associations and clusters for dystonia affecting any combination of eighteen pre-defined body regions. Variable-wise hierarchical clustering demonstrated closest relationships between bilateral upper legs (distance = 0.40), upper and lower face (distance = 0.45), bilateral hands (distance = 0.53), and bilateral feet (distance = 0.53). ICA demonstrated clear grouping for the a) bilateral hands, b) neck, and c) upper and lower face. Case-wise consensus hierarchical clustering at k = 9 identified 3 major clusters. Major clusters consisted primarily of a) cervical dystonia with nearby regions, b) bilateral hand dystonia, and c) cranial dystonia. Our data-driven approach in a large dataset of isolated non-focal dystonia reinforces common segmental patterns in cranial and cervical regions. We observed unexpectedly strong associations between bilateral upper or lower limbs, which suggests that symmetric multifocal patterns may represent a previously underrecognized dystonia subtype.

Re-convolving the compositional landscape of primary and recurrent glioblastoma reveals prognostic and targetable tissue states

Glioblastoma (GBM) diffusely infiltrates the brain and intermingles with non-neoplastic brain cells, including astrocytes, neurons and microglia/myeloid cells. This complex mixture of cell types forms the biological context for therapeutic response and tumor recurrence. We used single-nucleus RNA sequencing and spatial transcriptomics to determine the cellular composition and transcriptional states in primary and recurrent glioma and identified three compositional 'tissue-states' defined by cohabitation patterns between specific subpopulations of neoplastic and non-neoplastic brain cells. These tissue-states correlated with radiographic, histopathologic, and prognostic features and were enriched in distinct metabolic pathways. Fatty acid biosynthesis was enriched in the tissue-state defined by the cohabitation of astrocyte-like/mesenchymal glioma cells, reactive astrocytes, and macrophages, and was associated with recurrent GBM and shorter survival. Treating acute slices of GBM with a fatty acid synthesis inhibitor depleted the transcriptional signature of this pernicious tissue-state. These findings point to therapies that target interdependencies in the GBM microenvironment.

Dietary restriction of cysteine and methionine sensitizes gliomas to ferroptosis and induces alterations in energetic metabolism

Ferroptosis is mediated by lipid peroxidation of phospholipids containing polyunsaturated fatty acyl moieties. Glutathione, the key cellular antioxidant capable of inhibiting lipid peroxidation via the activity of the enzyme glutathione peroxidase 4 (GPX-4), is generated directly from the sulfur-containing amino acid cysteine, and indirectly from methionine via the transsulfuration pathway. Herein we show that cysteine and methionine deprivation (CMD) can synergize with the GPX4 inhibitor RSL3 to increase ferroptotic cell death and lipid peroxidation in both murine and human glioma cell lines and in ex vivo organotypic slice cultures. We also show that a cysteine-depleted, methionine-restricted diet can improve therapeutic response to RSL3 and prolong survival in a syngeneic orthotopic murine glioma model. Finally, this CMD diet leads to profound in vivo metabolomic, proteomic and lipidomic alterations, highlighting the potential for improving the efficacy of ferroptotic therapies in glioma treatment with a non-invasive dietary modification.

Imaging of brain metastasis in non-small-cell lung cancer: indications, protocols, diagnosis, post-therapy imaging, and implications regarding management

Increased survival (due to the use of targeted therapies based on genomic profiling) has resulted in the increased incidence of brain metastasis during the course of disease, and thus, made it essential to have proper imaging guidelines in place for brain metastasis from non-small-cell lung cancer (NSCLC). Brain parenchymal metastases can have varied imaging appearances, and it is pertinent to be aware of the various molecular risk factors for brain metastasis from NSCLC along with their suggestive imaging appearances, so as to identify them early. Leptomeningeal metastasis requires additional imaging of the spine and an early cerebrospinal fluid (CSF) analysis. Differentiation of post-therapy change from recurrence on imaging has a bearing on the management, hence the need for its awareness. This article will provide in-depth literature review of the epidemiology, aetiopathogenesis, screening, detection, diagnosis, post-therapy imaging, and implications regarding the management of brain metastasis from NSCLC. In addition, we will also briefly highlight the role of artificial intelligence (AI) in brain metastasis screening.

A cell state specific metabolic vulnerability to GPX4-dependent ferroptosis in glioblastoma

Glioma cells hijack developmental transcriptional programs to control cell state. During neural development, lineage trajectories rely on specialized metabolic pathways. However, the link between tumor cell state and metabolic programs is poorly understood in glioma. Here we uncover a glioma cell state-specific metabolic liability that can be leveraged therapeutically. To model cell state diversity, we generated genetically engineered murine gliomas, induced by deletion of p53 alone (p53) or with constitutively active Notch signaling (N1IC), a pathway critical in controlling cellular fate. N1IC tumors harbored quiescent astrocyte-like transformed cell states while p53 tumors were predominantly comprised of proliferating progenitor-like cell states. N1IC cells exhibit distinct metabolic alterations, with mitochondrial uncoupling and increased ROS production rendering them more sensitive to inhibition of the lipid hydroperoxidase GPX4 and induction of ferroptosis. Importantly, treating patient-derived organotypic slices with a GPX4 inhibitor induced selective depletion of quiescent astrocyte-like glioma cell populations with similar metabolic profiles.

Chronic convection-enhanced delivery of topotecan for patients with recurrent glioblastoma: a first-in-patient, single-centre, single-arm, phase 1b trial

BACKGROUND

Topotecan is cytotoxic to glioma cells but is clinically ineffective because of drug delivery limitations. Systemic delivery is limited by toxicity and insufficient brain penetrance, and, to date, convection-enhanced delivery (CED) has been restricted to a single treatment of restricted duration. To address this problem, we engineered a subcutaneously implanted catheter-pump system capable of repeated, chronic (prolonged, pulsatile) CED of topotecan into the brain and tested its safety and biological effects in patients with recurrent glioblastoma.

METHODS

We did a single-centre, open-label, single-arm, phase 1b clinical trial at Columbia University Irving Medical Center (New York, NY, USA). Eligible patients were at least 18 years of age with solitary, histologically confirmed recurrent glioblastoma showing radiographic progression after surgery, radiotherapy, and chemotherapy, and a Karnofsky Performance Status of at least 70. Five patients had catheters stereotactically implanted into the glioma-infiltrated peritumoural brain and connected to subcutaneously implanted pumps that infused 146 μM topotecan 200 μL/h for 48 h, followed by a 5-7-day washout period before the next infusion, with four total infusions. After the fourth infusion, the pump was removed and the tumour was resected. The primary endpoint of the study was safety of the treatment regimen as defined by presence of serious adverse events. Analyses were done in all treated patients. The trial is closed, and is registered with ClinicalTrials.gov, NCT03154996.

FINDINGS

Between Jan 22, 2018, and July 8, 2019, chronic CED of topotecan was successfully completed safely in all five patients, and was well tolerated without substantial complications. The only grade 3 adverse event related to treatment was intraoperative supplemental motor area syndrome (one [20%] of five patients in the treatment group), and there were no grade 4 adverse events. Other serious adverse events were related to surgical resection and not the study treatment. Median follow-up was 12 months (IQR 10-17) from pump explant. Post-treatment tissue analysis showed that topotecan significantly reduced proliferating tumour cells in all five patients.

INTERPRETATION

In this small patient cohort, we showed that chronic CED of topotecan is a potentially safe and active therapy for recurrent glioblastoma. Our analysis provided a unique tissue-based assessment of treatment response without the need for large patient numbers. This novel delivery of topotecan overcomes limitations in delivery and treatment response assessment for patients with glioblastoma and could be applicable for other anti-glioma drugs or other CNS diseases. Further studies are warranted to determine the effect of this drug delivery approach on clinical outcomes.

FUNDING

US National Institutes of Health, The William Rhodes and Louise Tilzer Rhodes Center for Glioblastoma, the Michael Weiner Glioblastoma Research Into Treatment Fund, the Gary and Yael Fegel Foundation, and The Khatib Foundation.

Lactate is an epigenetic metabolite that drives survival in model systems of glioblastoma

Lactate accumulates to a significant amount in glioblastomas (GBMs), the most common primary malignant brain tumor with an unfavorable prognosis. However, it remains unclear whether lactate is metabolized by GBMs. Here, we demonstrated that lactate rescued patient-derived xenograft (PDX) GBM cells from nutrient-deprivation-mediated cell death. Transcriptome analysis, ATAC-seq, and ChIP-seq showed that lactate entertained a signature of oxidative energy metabolism. LC/MS analysis demonstrated that U-13C-lactate elicited substantial labeling of TCA-cycle metabolites, acetyl-CoA, and histone protein acetyl-residues in GBM cells. Lactate enhanced chromatin accessibility and histone acetylation in a manner dependent on oxidative energy metabolism and the ATP-citrate lyase (ACLY). Utilizing orthotopic PDX models of GBM, a combined tracer experiment unraveled that lactate carbons were substantially labeling the TCA-cycle metabolites. Finally, pharmacological blockage of oxidative energy metabolism extended overall survival in two orthotopic PDX models in mice. These results establish lactate metabolism as a novel druggable pathway for GBM.

O108 Central adiposity influences serum calcium concentrations and increases risk of kidney stone disease

Introduction

Serum calcium (SCa) and adiposity are associated with kidney stone disease (KSD). We used conventional and genetic epidemiological approaches to further understanding of these relationships.

Methods

Waist-hip ratio (WHR), a marker of central adiposity, SCa and KSD data were analysed by adjusted linear regression using UK Biobank participants. Univariable, multivariable and mediation Mendelian randomisation (MR) were undertaken using 316 and 246 genetic instruments for WHR and SCa, respectively.

Results

Observational analyses of 3,466 KSD cases and 489,944 controls showed that participants of normal BMI (20–25kg/m2) but in the fifth quintile for WHR have greater risk of incident KSD compared to the first quintile (HR=1.39 (95%CI=1.18–1.63)). After adjustment for sex, age, serum vitamin D, and phosphate, higher WHR was positively associated with SCa (ß=0.04, 95%=CI 0.04–0.05, P&lt;0.001). Univariable MR demonstrated that relative risk of KSD increases with increasing WHR and SCa; 1 standard deviation (SD) increases relative risk by 46% (95%CI=1.27–1.67, P=5.9e-8) and 63% (95%CI=1.37–1.93, P=2.0E-8), respectively. A 1 SD increase in WHR increases SCa by 0.11mmol/L (95%CI=0.07–0.14, P=1.8e-8). Multivariable MR revealed that SCa and WHR independently increase KSD relative risk (OR=1.71, 95%CI=1.49–1.96, P&lt;0.001 and OR=1.41, 95%CI=1.17–1.69, P&lt;0.001 respectively). Mediation MR established that 14% of the effect of WHR on KSD risk is mediated via alterations in SCa.

Conclusion

Central adiposity is causally linked to KSD, partly by raising SCa. Mechanisms by which central adiposity increases KSD risk, independent of and via SCa, remain to be revealed and may identify novel therapeutic methods for KSD.

Take-home message

Central adiposity and serum calcium are independent, causal risk factors for kidney stone disease. One mechanism by which central obesity increases risk of kidney stone disease is by influencing serum calcium concentrations.

Dissecting the treatment-naive ecosystem of human melanoma brain metastasis

Melanoma brain metastasis (MBM) frequently occurs in patients with advanced melanoma; yet, our understanding of the underlying salient biology is rudimentary. Here, we performed single-cell/nucleus RNA-seq in 22 treatment-naive MBMs and 10 extracranial melanoma metastases (ECMs) and matched spatial single-cell transcriptomics and T cell receptor (TCR)-seq. Cancer cells from MBM were more chromosomally unstable, adopted a neuronal-like cell state, and enriched for spatially variably expressed metabolic pathways. Key observations were validated in independent patient cohorts, patient-derived MBM/ECM xenograft models, RNA/ATAC-seq, proteomics, and multiplexed imaging. Integrated spatial analyses revealed distinct geography of putative cancer immune evasion and evidence for more abundant intra-tumoral B to plasma cell differentiation in lymphoid aggregates in MBM. MBM harbored larger fractions of monocyte-derived macrophages and dysfunctional TOX+CD8+ T cells with distinct expression of immune checkpoints. This work provides comprehensive insights into MBM biology and serves as a foundational resource for further discovery and therapeutic exploration.

Human Induced Pluripotent Stem Cell Models of Frontotemporal Dementia With Tau Pathology

Neurodegenerative dementias are the most common group of neurodegenerative diseases affecting more than 40 million people worldwide. One of these diseases is frontotemporal dementia (FTD), an early onset dementia and one of the leading causes of dementia in people under the age of 60. FTD is a heterogeneous group of neurodegenerative disorders with pathological accumulation of particular proteins in neurons and glial cells including the microtubule-associated protein tau, which is deposited in its hyperphosphorylated form in about half of all patients with FTD. As for other patients with dementia, there is currently no cure for patients with FTD and thus several lines of research focus on the characterization of underlying pathogenic mechanisms with the goal to identify therapeutic targets. In this review, we provide an overview of reported disease phenotypes in induced pluripotent stem cell (iPSC)-derived neurons and glial cells from patients with tau-associated FTD with the aim to highlight recent progress in this fast-moving field of iPSC disease modeling. We put a particular focus on genetic forms of the disease that are linked to mutations in the gene encoding tau and summarize mutation-associated changes in FTD patient cells related to tau splicing and tau phosphorylation, microtubule function and cell metabolism as well as calcium homeostasis and cellular stress. In addition, we discuss challenges and limitations but also opportunities using differentiated patient-derived iPSCs for disease modeling and biomedical research on neurodegenerative diseases including FTD.

Comparison of Clinical Characteristics and Outcome of Critically Ill Patients Admitted to Tertiary Care Intensive Care Units in India during the Peak Months of First and Second Waves of COVID-19 Pandemic: A Retrospective Analysis

BACKGROUND

Coronavirus disease-2019 (COVID-19) continues to pose serious challenges to healthcare systems globally with the disease progressing over time in crest-trough pattern of waves. We compared the patient characteristics and outcomes of critically ill patients admitted during the first and second waves of COVID-19 pandemic.

MATERIALS AND METHODS

We did a retrospective analysis of medical records of critically ill patients admitted to intensive care unit (ICU) at the peak period of both waves. The data on demographics, symptoms, treatment received, and outcomes of patients were recorded.

RESULTS

Compared to first wave, significantly more females, younger age group, and those without underlying comorbidities required ICU admission during the second wave. The treatments received during both periods were similar except for preferential use of methylprednisolone over dexamethasone and proclivity of bilevel positive airway pressure (BiPAP) ventilation over high-flow nasal cannula (HFNC). There was no significant difference in the duration of ICU stay and mortality of patients. During the first wave, the factors associated with nonsurvival of patients were advanced age, comorbidities, severe disease, and a lesser number of days on HFNC. All these factors along with higher Sequential Organ Failure Assessment (SOFA) score were observed to be linked with patient nonsurvival during the second wave.

CONCLUSION

In India, the second wave of COVID-19 significantly influenced ICU demographics with a predominance of females and young adults requiring critical care. During both time periods, patients received similar treatment except for the propensity to use methylprednisolone and BiPAP as opposed to dexamethasone and HFNC in second wave. No significant difference in ICU mortality was noted.

HOW TO CITE THIS ARTICLE

Kerai S, Singh R, Dutta S, Mahajan A, Agarwal M. Comparison of Clinical Characteristics and Outcome of Critically Ill Patients Admitted to Tertiary Care Intensive Care Units in India during the Peak Months of First and Second Waves of COVID-19 Pandemic: A Retrospective Analysis. Indian J Crit Care Med 2021;25(12):1349-1356.

Prevalence of growth hormone deficiency in patients with unexplained chronic fatigue after undergoing bone marrow transplantation in adulthood

PURPOSE

Many patients who undergo bone marrow transplantation (BMT) in adulthood experience unexplained chronic fatigue which can have a major impact on their health-related quality of life (QoL). Pre-BMT treatment regimens increase the risk of developing acquired growth hormone deficiency (GHD), which results in a clinical syndrome with decreased energy and has additionally been linked to metabolic syndrome.

METHODS

Using the gold-standard insulin hypoglycemic test (IHT), we evaluated the prevalence of GHD in 18 post-BMT adult patients with unexplained chronic fatigue, as well as the correlation between peak serum GH response and QoL scores, the metabolic syndrome, and insulin resistance. Peak serum GH cut-point less than 3.0 ug/L was used for the diagnosis of severe GHD. The Fatigue Severity Scale and Quality of Life in Adult GHD Assessment questionnaires were used to quantify fatigue symptoms.

RESULTS

The prevalence of severe GHD within this sample of 18 patients was 50%. A trend between lower peak serum GH response and higher fatigue and QoL-AGHDA scores was observed.

CONCLUSIONS

GHD may represent a remediable contributor to post-BMT chronic fatigue in adults, further studies are needed to evaluate the potential role of screening and GH replacement therapy in this vulnerable patient population.

IMPLICATIONS FOR CANCER SURVIVORS

GHD may be a treatable explanation for disabling post-BMT fatigue pending results of intervention studies.

TAMI-70. METABOLIC VULNERABILITY TO GPX4 INHIBITION AND FERROPTOSIS OF QUIESCENT ASTROCYTE-LIKE GLIOMA CELL POPULATIONS

Diversity is a key feature in the glioma ecosystem. Adaptation to a changing tumor microenvironment is achieved through cellular and metabolic plasticity. Here we show that slow-cycling, astrocyte-like glioma cell subpopulations activate distinct metabolic programs, rendering them susceptible to novel treatments. We performed multi-omics analysis on transgenic murine glioma models to characterize cellular heterogeneity. Bulk RNAseq on targeted time-dependent biopsies combined with scRNAseq uncovered distinct tumor cell populations, including a quiescent, astrocyte-like population relatively insensitive to conventional chemotherapy targeting proliferating cells. Using scRNAseq, we identified a persistently conserved astrocytic population in human IDH1-mt/wt high-grade gliomas. This astrocytic tumor population was more abundant in mouse models with constitutive Notch activation, however it was associated with alterations in several other transcriptional programs, suggesting that targeted therapies would likely be ineffective at eradicating it. Gene ontology analysis revealed enrichment in mitochondrial genes specifically regulating oxidative phosphorylation and tricarboxylic acid cycle. Energetic, lipidomic and metabolomic analyses revealed significant mitochondrial β-fatty acid oxidation and lipid catabolism, with less effective oxygen consumption rate and higher basal oxidative stress. Furthermore, this astrocytic tumor population had depleted levels of basal GSH and was more sensitive to reactive oxygen species. Leveraging this metabolic vulnerability, we performed drug screens and found that therapeutic inhibition of complex I or GPX4 was highly effective and synergistic. GPX4 inhibition induced ferroptosis, a newly-discovered form of programmed non-necroptotic cell death mediated by iron-driven lipid peroxidation. Using scRNAseq and RNAscope on ex vivo slice cultures from murine and human gliomas, we found that GPX4 inhibition and ferroptosis induction in the glioma microenvironment selectively eradicated the quiescent astrocytic subpopulation whereas proliferating glioma were less sensitive. Our data therefore supports a novel treatment paradigm, employing metabolic strategies, such as ferroptosis, in conjunction with chemotherapy and RT to target distinct tumor cell populations with different therapeutic vulnerabilities.

TAMI-57. INDUCTION OF FERROPTOSIS PROMOTES IMMUNOGENIC CELL DEATH AND ACTIVATION OF THE IMMUNE MICROENVIRONMENT IN GLIOMA

Gliomas are immune cold tumors. Effective therapeutic strategies capable of inducing an immune response are lacking.Here we present evidence that ferroptosis, a form of iron-mediated lipid peroxidation-based cell death, may promote anti-tumor immunity via stimulation of phagocytosis and pro-inflammatory activities in microglia. While ferroptosis has shown promise in induction of glioma cell death, the immunogenic and microenvironmental effects of glioma ferroptosis are poorly understood. First, we tested the in vitro effects of the glutathione peroxidase 4 (GPX4) inhibitor RSL3, a ferroptosis inducer, on murine glioma cell lines. Using flow cytometry, we discovered that RSL3 treatment led to membrane translocation of the pro-phagocytic antigen calreticulin, known hallmark of immunogenic cell death, by an average log2-fold-change of 2.53 (p= 0.03) compared to DMSO-treated controls. This effect correlated with lipid peroxidation, as assessed by BODIPY-C11 staining. To further test the effects of ferroptosis on glioma cell-microglia crosstalk, we prepared acute brain tumor slices from both mouse and human glioma samples, and treated them with RSL3. Quantification of immunofluorescent staining from three independent human slice cultures after RSL3 treatment demonstrated a significant increase in calreticulin abundance as compared to control (p &lt; 0.001). Importantly, this effect was significantly diminished with addition of ferrostatin, an inhibitor of ferroptosis, demonstrating that ferroptosis induction was directly responsible for calreticulin translocation. Single-cell RNAseq on mouse and human acute glioma slice cultures treated with RSL3 demonstrated significant overexpression of calreticulin in the tumor population, and positive enrichment of interferon signaling, antigen presentation, and phagocytosis ontologies in both tumor and myeloid compartments. These findings suggest that ferroptosis-induced translocation of calreticulin on the surface of glioma cells promotes activation of the local immune microenvironment by increasing tumor antigen presentation and pro-inflammatory cytokine release by tumor-associated microglia. Thus, ferroptosis-inducing drugs may promote anti-tumor immunity through the activation of immunogenic cell death signals.

Listening to community concerns in the COVID-19 infodemic: A WHO digital approach

Background

The Infodemic (too much information including false or misleading information in digital and physical environments) during the COVID-19 pandemic has led to confusion, risk-taking and behaviors that can amplify outbreaks, and reduce effectiveness of pandemic response efforts. To address this challenge, the WHO Information Network for Epidemics (EPI-WIN), in collaboration with research partners, developed a public health Infodemic intelligence analysis methodology for weekly analysis of digital media data to identify, categorize, and understand key concerns expressed in online conversations.

Methods

Thirty-five keyword-based searches (per language) using Meltwater Explore and Google Trends were created and grouped according to a set of pandemic public health taxonomy categories developed specifically for this analysis. The taxonomy has five thematic categories of conversation about COVID-19 and public health response: (1) the cause of the illness, (2) the illness, (3) the treatment, (4) the interventions and (5) Information.

Results

The two most recurring topics to attract increasing interest were Vaccines and Asymptomatic transmission followed by Immunity, Cause of the virus, Vulnerable communities and Reduction of movement, and Risk factors based on demographics and risk of misinformation.

Conclusions

The application of this taxonomy to online social listening week-on-week resulted in a better in-time understanding of the evolution and dynamics of high velocity conversations about COVID-19 globally during the pandemic and proposes a quantifiable approach to support planning of risk communication response.

Key messages

Describe widespread innovation in social listening methods for greater accountability to affected populations. Formulate insights into how digital media can be better utilized for more rapidly responding to the evolving needs of communities.

WHO public health research agenda for managing infodemics

Background

Following the World Health Organization's initial infodemic consultation in April 2020, a major infodemic conference was organised virtually in June-July 2020. Hundreds of experts participated to define science of infodemiology and build a public health research agenda that serves as a playbook for conducting relevant researches. Research Agenda provides guidance to invest in research and innovation so that we have better interventions and tools to understand, measure and respond to infodemics, and steer people towards timely, accessible, understandable information for good health choices.

Methods

The research agenda was developed during a virtual meeting, followed by research question prioritization exercise. It consisted of eight days spread out over four weeks. These were made up of: public preconference meeting; scientific conference, consisting of opening/closing plenary meetings either side of four separate “topic sprint” days; final public meeting to present the meeting outcomes.

After the meeting, a process took place to gather and rank research questions based on the research agenda created during the meeting.

Results

The following five streams and 65 research questions were developed. Measuring and monitoring the impact of infodemics during health emergencies Detecting and understanding the spread and impact of infodemics Responding and deploying interventions that protect against the infodemic and mitigate its harmful effects Evaluating infodemic interventions and strengthening resilience of individuals and communities to infodemics Promoting the development, adaptation and application of tools for managing infodemics.

Conclusions

Five streams with 65 research questions were developed and prioritized to structuralise infodemic management based on evidence. The conference yielded on the development of an infodemiology glossary, which can be used by the community of research.

Key messages

Discuss investments in research and innovation to enable a whole-of-society response to infodemics. Explain the practice of infodemic management as a discipline.

Advances in real-time social listening for an adaptive public health response: WHO’s EARS platform

Background

COVID-19 pandemic was accompanied by an Infodemic (overabundance of information, including misinformation and disinformation, both online and offline); in response to this Infodemic, WHO launched the EARS platform (Early AI-assisted Response with Social Listening), showing real-time information about how people are talking about COVID-19 online. This information is intended to serve health information professionals to understand narratives and needs of the general public, in order to inform policy or communications decisions.

Methods

Data is collected daily from online conversations in publicly available sources, including Twitter, online forums, and blogs in English, French, Spanish and Portuguese, for 20 pilot countries. Once the data is collected, it is processed and classified into 39 categories, according to a set of pandemic public health taxonomy. The classification is made based on semi-supervised machine learning.

Results

Top 5 categories across regions are Covid-19 vaccine, Transmission settings, Personal measures, Testing and Industry (industry refers to the impact of the pandemic on the economy). We find that conversations around Covid-19 vaccines usually rank in the second or third position in all regions and represent 9%-12% of the conversation.

Conclusions

The configuration and application of the EARS platform has enabled progress towards more scalable and sustainable social listening to inform Infodemic management and response, compared to previous methods which were more manual, required data scientists in the team, or had fewer analytics capabilities. Future work will focus on gradually adding more data sources which can expand coverage and representativity.

Key messages

Discuss social listening methods for greater accountability to affected populations. Formulate insights into how digital media and information technology can be better utilized for more rapidly responding to the evolving needs of communities.

50 Global Actions to Manage the COVID-19 Infodemic: A WHO Framework

Issue

The World Health Organization describes an infodemic as an “overabundance of information - good or bad - that makes it difficult for people to make decisions for their health.”

Description of the problem

On April 7-8, 2020, the WHO Information Network for Epidemics (EPI-WIN) held a global online to crowdsource ideas from an interdisciplinary group of experts to form a novel COVID-19 infodemic response framework. The online consultation comprised of four plenary sessions and a brainstorming session conducted entirely online. Nearly 1500 individuals from over 100 countries and territories spanning social scientists, epidemiologists, staff from ministries of health and institutes of public health, registered for the consultation.

Results

A set of 50 proposed actions for a framework for managing infodemics in health emergencies was developed that will provide guidance for governments and public health institutions to take in five key areas of action that emerged from the consultation:

strengthening evidence and information

simplifying and explaining what is known fact-checking and addressing misinformation

amplifying messages and reaching the communities and individuals who need the information

quantifying and analysing the infodemic, including information flows, monitoring the acceptance of public health interventions, and assessing factors affecting behaviour at individual and population levels

strengthening systems for infodemic management in health emergencies

Lessons

Everyone has a role to play

Read the Call for Action

Sign the Call for Action

https://www.who.int/news/item/11-12-2020-call-for-action-managing-the-infode

Key messages

The confusion due to Infodemic can lead people to ignore public health measures and take risks that can cause serious harm.

Recognizing this WHO convened an interdisciplinary group of experts 7-8 April 2020 virtually to form a novel COVID-19 infodemic response framework.

TOP2B Enzymatic Activity on Promoters and Introns Modulates Multiple Oncogenes in Human Gliomas

PURPOSE

The epigenetic mechanisms involved in transcriptional regulation leading to malignant phenotype in gliomas remains poorly understood. Topoisomerase IIB (TOP2B), an enzyme that decoils and releases torsional forces in DNA, is overexpressed in a subset of gliomas. Therefore, we investigated its role in epigenetic regulation in these tumors.

EXPERIMENTAL DESIGN

To investigate the role of TOP2B in epigenetic regulation in gliomas, we performed paired chromatin immunoprecipitation sequencing for TOP2B and RNA-sequencing analysis of glioma cell lines with and without TOP2B inhibition and in human glioma specimens. These experiments were complemented with assay for transposase-accessible chromatin using sequencing, gene silencing, and mouse xenograft experiments to investigate the function of TOP2B and its role in glioma phenotypes.

RESULTS

We discovered that TOP2B modulates transcription of multiple oncogenes in human gliomas. TOP2B regulated transcription only at sites where it was enzymatically active, but not at all native binding sites. In particular, TOP2B activity localized in enhancers, promoters, and introns of PDGFRA and MYC, facilitating their expression. TOP2B levels and genomic localization was associated with PDGFRA and MYC expression across glioma specimens, which was not seen in nontumoral human brain tissue. In vivo, TOP2B knockdown of human glioma intracranial implants prolonged survival and downregulated PDGFRA.

CONCLUSIONS

Our results indicate that TOP2B activity exerts a pleiotropic role in transcriptional regulation of oncogenes in a subset of gliomas promoting a proliferative phenotype.

Cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare inheritable fatal arrhythmogenic disorder, is difficult to diagnose and is a challenge to manage. A 21-years-old man presented with recurrent exertional syncope and complex multifocal ventricular ectopy. CPVT was diagnosed based on the clinical criteria, despite the absence of some classical findings. The patient underwent cardiac sympathetic denervation (CSD) after lifestyle modification and pharmacological management were ineffective. CSD proved to be effective. The patient did not have any exertional symptoms or recurrence of syncope at follow-up period of 1 year. The present case report adds to the growing evidence in favour of CSD for CPVT.

ETMM-05. LACTIC ACID FACILITATES GLIOBLASTOMA GROWTH THROUGH MODULATION OF THE EPIGENOME

Glioblastoma (GBM) is the most common primary malignant brain tumor with an unfavorable prognosis. While GBMs utilize glucose, there are other carbon sources at their disposal. Lactate accumulates to a significant amount in the infiltrative margin of GBMs. In the current study, we demonstrated that lactate rescued patient-derived xenograft (PDX) GBM cells from nutrient deprivation mediated cell death and inhibition of growth. Transcriptome analysis, ATAC-seq and CHIP-seq. showed that lactic acid exposure entertained a signature of cell cycle progression and oxidative phosphorylation (OXPHOS) /tricarboxylic acid (TCA)-cycle. LC/MS analysis demonstrated that U-13C-Lactate elicited substantial labeling of TCA-cycle metabolites, acetyl-CoA and histone protein acetyl-residues in PDX derived GBM cells. Given that acetyl-CoA is pivotal for histone acetylation we observed a dose-dependent elevation of histone marks (e.g. H3K27ac), which was rescued by genetic and pharmacological inhibition of lactic acid-uptake, ATP-citrate lyase, p300 histone-acetyl-transferase and OXPHOS, resulting in reversal of lactate mediated protection from cell death. CHIP-seq. analysis demonstrated that lactic acid facilitated enhanced binding of H3K27ac to gene promoters and cis-regulatory elements. Consistently, ATAC-seq. analysis highlighted enhanced accessibility of the chromatin by lactic acid. In a combined tracer experiment (U-13C-glucose and 3-C13-lactate), we made the fundamental observation that lactic acid carbons were predominantly labeling the TCA cycle metabolites over glucose, implying a critical role of lactic acid in GBMs. Finally, pharmacological blockage of the TCA-cycle, using a clinically validated drug, extended overall survival in an orthotopic PDX model in mice without induction of toxicity, implying a critical role of lactic acid in GBMs and establishing lactic acid metabolism as a novel drug target for GBM.

ETMM-04. AURKA INHIBITION REPROGRAMS METABOLISM AND IS SYNTHETICALLY LETHAL WITH FATTY ACID OXIDATION INHIBITION IN GLIOBLASTOMA MODEL SYSTEMS

Aurora kinase A (AURKA) has emerged as a viable drug target for glioblastoma (GBM), the most common malignant primary brain tumor in adults with a life expectancy of 12–15 months. However, resistance to therapy remains a critical issue, which partially may be driven by reprogramming of metabolism. By integration of transcriptome, chromatin immunoprecipitation with sequencing (CHIP-seq.), assay for transposase-accessible chromatin with sequencing (ATAC-seq.), proteomic and metabolite screening followed by carbon tracing (U-¹³C-Glucose, U-¹³C-Glutamine and U-¹³C-Palmitic acid) and extracellular flux analysis we provided evidence that genetic (shRNA and CRISPR/Cas9) and pharmacological (Alisertib) AURKA inhibition elicited substantial metabolic reprogramming supported in part by inhibition of MYC targets and concomitant activation of PPARA signaling. While glycolysis was suppressed by AURKA inhibition, we noted a compensatory increase in oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO). Whereas interference with AURKA elicited a suppression of c-Myc, we detected an upregulation of PGC1A, a master regulator of oxidative metabolism. Silencing of PGC1A reversed AURKAi mediated metabolic reprogramming and sensitized GBM cells to AURKAi driven reduction of cellular viability. Chromatin immunoprecipitation experiments showed binding of c-Myc to the promoter region of PGC1A, which is abrogated by AURKA inhibition and in turn unleashed PGC1A expression. Consistently, ATAC-seq. confirmed higher accessibility of a MYC binding region within the PGC1A promoter, suggesting that MYC acts as a repressor of PGC1A. Combining alisertib with inhibitors of FAO or the electron transport chain exerted substantial synergistic growth inhibition in PDX lines in vitro and extension of overall survival in orthotopic GBM PDX models without induction of toxicity in normal tissue. In summary, these findings support that simultaneous targeting of oxidative energy metabolism and AURKAi might be a potential novel therapy against GBM.