Machine Learning-Directed Conversion of Glioblastoma Cells to Dendritic Cell-like Antigen-Presenting Cells as Cancer Immunotherapy.

Immunotherapy has limited efficacy in glioblastoma (GBM) due to the blood-brain barrier and the immunosuppressed or "cold" tumor microenvironment (TME) of GBM, which is dominated by immune-inhibitory cells and depleted of cytotoxic T lymphocytes (CTL) and dendritic cells (DC). Here, we report the development and application of a machine-learning precision method to identify cell fate determinants (CFD) that specifically reprogram GBM into induced antigen-presenting cells with DC-like functions (iDC-APC). In murine GBM models, iDC-APCs acquired DC-like morphology, regulatory gene expression profile, and functions comparable to natural DCs. Among these acquired functions were phagocytosis, direct presentation of endogenous antigens, and cross presentation of exogenous antigens. The latter endowed the iDC-APCs with the ability to prime naïve CD8+ CTLs, a hallmark DC function critical for antitumor immunity. Intratumor iDC-APCs reduced tumor growth and improved survival only in immunocompetent animals, which coincided with extensive infiltration of CD4+ T cells and activated CD8+ CTLs in the TME. The reactivated TME synergized with an intratumor soluble PD-1 decoy immunotherapy and a DC-based GBM vaccine, resulting in robust killing of highly resistant GBM cells by tumor-specific CD8+ CTLs and significantly extended survival. Lastly, we defined a unique CFD combination specifically for the human GBM to iDC-APC conversion of both glioma stem-like cells (GSC) and non-GSC GBM cells, confirming the clinical utility of a computationally directed, tumor-specific conversion immunotherapy for GBM and potentially other solid tumors.

A Spatial Interpolation Approach to Assign Magnetic Resonance Imaging-Derived Material Properties for Finite Element Models of Adeno-Associated Virus Infusion Into a Recurrent Brain Tumor.

Adeno-associated virus (AAV) is a clinically useful gene delivery vehicle for treating neurological diseases. To deliver AAV to focal targets, direct infusion into brain tissue by convection-enhanced delivery (CED) is often needed due to AAV's limited penetration across the blood-brain-barrier and its low diffusivity in tissue. In this study, computational models that predict the spatial distribution of AAV in brain tissue during CED were developed to guide future placement of infusion catheters in recurrent brain tumors following primary tumor resection. The brain was modeled as a porous medium, and material property fields that account for magnetic resonance imaging (MRI)-derived anatomical regions were interpolated and directly assigned to an unstructured finite element mesh. By eliminating the need to mesh complex surfaces between fluid regions and tissue, mesh preparation was expedited, increasing the model's clinical feasibility. The infusion model predicted preferential fluid diversion into open fluid regions such as the ventricles and subarachnoid space (SAS). Additionally, a sensitivity analysis of AAV delivery demonstrated that improved AAV distribution in the tumor was achieved at higher tumor hydraulic conductivity or lower tumor porosity. Depending on the tumor infusion site, the AAV distribution covered 3.67-70.25% of the tumor volume (using a 10% AAV concentration threshold), demonstrating the model's potential to inform the selection of infusion sites for maximal tumor coverage.

Patterns and predictors of anxiety and depression symptom trajectories in patients diagnosed with primary brain tumors.

BACKGROUND: Patients with primary brain tumors (pPBTs) often exhibit heightened distress. This study assesses how symptoms of anxiety and depression change over time in pPBTs and identifies factors that may predict patients' symptom trajectories. METHODS: Ninety-nine adult pPBTs completed psychosocial assessments at neuro-oncology appointments over 6-18 months. Quality of life was assessed with the Functional Assessment of Cancer Therapy-Brain; symptoms of anxiety and depression were assessed with the Patient-Reported Outcomes Measurement Information System short forms. The prevalence of patients with clinically elevated symptoms and those who experienced clinically meaningful changes in symptoms throughout follow-up were examined. Linear mixed-effects models evaluated changes in symptoms over time at the group level, and latent class growth analysis (LCGA) evaluated changes in symptoms over time at the individual level. RESULTS: At enrollment, 51.5% and 32.3% of patients exhibited clinically elevated levels of anxiety and depression, respectively. Of patients with follow-up data (n = 74), 54.1% and 50% experienced clinically meaningful increases in anxiety and depression scores, respectively. There were no significant changes in anxiety or depression scores over time, but better physical, functional, and brain-cancer well-being predicted lower levels of anxiety and depression (p < 0.001). Five sub-groups of patients with distinct symptom trajectories emerged via LCGA. CONCLUSIONS: pPBTs commonly experience elevated symptoms of anxiety and depression that may fluctuate in clinically meaningful manners throughout the disease. Routine screening for elevated symptoms is needed to capture clinically meaningful changes and identify factors affecting symptoms to intervene on.

Association of Autologous Tumor Lysate-Loaded Dendritic Cell Vaccination With Extension of Survival Among Patients With Newly Diagnosed and Recurrent Glioblastoma: A Phase 3 Prospective Externally Controlled Cohort Trial.

Importance: Glioblastoma is the most lethal primary brain cancer. Clinical outcomes for glioblastoma remain poor, and new treatments are needed. Objective: To investigate whether adding autologous tumor lysate-loaded dendritic cell vaccine (DCVax-L) to standard of care (SOC) extends survival among patients with glioblastoma. Design, Setting, and Participants: This phase 3, prospective, externally controlled nonrandomized trial compared overall survival (OS) in patients with newly diagnosed glioblastoma (nGBM) and recurrent glioblastoma (rGBM) treated with DCVax-L plus SOC vs contemporaneous matched external control patients treated with SOC. This international, multicenter trial was conducted at 94 sites in 4 countries from August 2007 to November 2015. Data analysis was conducted from October 2020 to September 2021. Interventions: The active treatment was DCVax-L plus SOC temozolomide. The nGBM external control patients received SOC temozolomide and placebo; the rGBM external controls received approved rGBM therapies. Main Outcomes and Measures: The primary and secondary end points compared overall survival (OS) in nGBM and rGBM, respectively, with contemporaneous matched external control populations from the control groups of other formal randomized clinical trials. Results: A total of 331 patients were enrolled in the trial, with 232 randomized to the DCVax-L group and 99 to the placebo group. Median OS (mOS) for the 232 patients with nGBM receiving DCVax-L was 19.3 (95% CI, 17.5-21.3) months from randomization (22.4 months from surgery) vs 16.5 (95% CI, 16.0-17.5) months from randomization in control patients (HR = 0.80; 98% CI, 0.00-0.94; P = .002). Survival at 48 months from randomization was 15.7% vs 9.9%, and at 60 months, it was 13.0% vs 5.7%. For 64 patients with rGBM receiving DCVax-L, mOS was 13.2 (95% CI, 9.7-16.8) months from relapse vs 7.8 (95% CI, 7.2-8.2) months among control patients (HR, 0.58; 98% CI, 0.00-0.76; P < .001). Survival at 24 and 30 months after recurrence was 20.7% vs 9.6% and 11.1% vs 5.1%, respectively. Survival was improved in patients with nGBM with methylated MGMT receiving DCVax-L compared with external control patients (HR, 0.74; 98% CI, 0.55-1.00; P = .03). Conclusions and Relevance: In this study, adding DCVax-L to SOC resulted in clinically meaningful and statistically significant extension of survival for patients with both nGBM and rGBM compared with contemporaneous, matched external controls who received SOC alone. Trial Registration: ClinicalTrials.gov Identifier: NCT00045968.

The trial effect in patients with glioblastoma: effect of clinical trial enrollment on overall survival.

PURPOSE: To determine whether participation in a clinical trial was associated with improved survival in patients with glioblastoma (GBM). METHODS: Following IRB approval, patients were identified using CPT and ICD codes. Data was collected using retrospective review of electronic medical records. When necessary, death data was obtained from online obituaries. Inverse propensity score matching was utilized to transform the two cohorts to comparable sets. Survival was compared using Kaplan-Meyer curves and Wilcoxon Rank Sum Test. RESULTS: In this cohort of 365 patients, 89 were enrolled in a clinical trial and 276 were not. Patients enrolled in clinical trials had a significantly higher mean baseline KPS score, higher proportion of surgical resections, and were more likely to receive temozolomide treatment than patients not enrolled in a clinical trial. After inverse propensity score matching, patients enrolled in a clinical trial lived significantly longer than those not enrolled (28.8 vs 22.2 months, p = 0.005). A potential confounder of this study is that patients not in a clinical trial had significantly fewer visits with neuro-oncologists than patients enrolled in a clinical trial (7 ± 8 vs 12 ± 9, p < 0. 0001). CONCLUSIONS: Clinical trials enroll patients with the most favorable prognostic features. Even when correcting for this bias, clinical trial enrollment is an independent predictor of increased survival regardless of treatment arm.

Corrigendum to: A phase II study of laser interstitial thermal therapy combined with doxorubicin in patients with recurrent glioblastoma.

[This corrects the article DOI: 10.1093/noajnl/vdab164.].

Tumor Treating Fields dually activate STING and AIM2 inflammasomes to induce adjuvant immunity in glioblastoma.

Tumor Treating Fields (TTFields), an approved therapy for glioblastoma (GBM) and malignant mesothelioma, employ noninvasive application of low-intensity, intermediate-frequency, alternating electric fields to disrupt the mitotic spindle, leading to chromosome missegregation and apoptosis. Emerging evidence suggests that TTFields may also induce inflammation. However, the mechanism underlying this property and whether it can be harnessed therapeutically are unclear. Here, we report that TTFields induced focal disruption of the nuclear envelope, leading to cytosolic release of large micronuclei clusters that intensely recruited and activated 2 major DNA sensors - cyclic GMP-AMP synthase (cGAS) and absent in melanoma 2 (AIM2) - and their cognate cGAS/stimulator of interferon genes (STING) and AIM2/caspase 1 inflammasomes to produce proinflammatory cytokines, type 1 interferons (T1IFNs), and T1IFN-responsive genes. In syngeneic murine GBM models, TTFields-treated GBM cells induced antitumor memory immunity and a cure rate of 42% to 66% in a STING- and AIM2-dependent manner. Using single-cell and bulk RNA sequencing of peripheral blood mononuclear cells, we detected robust post-TTFields activation of adaptive immunity in patients with GBM via a T1IFN-based trajectory and identified a gene panel signature of TTFields effects on T cell activation and clonal expansion. Collectively, these studies defined a therapeutic strategy using TTFields as cancer immunotherapy in GBM and potentially other solid tumors.

Tumor Treating Fields for Glioblastoma Therapy During the COVID-19 Pandemic.

BACKGROUND: The COVID-19 pandemic has placed excessive strain on health care systems and is especially evident in treatment decision-making for cancer patients. Glioblastoma (GBM) patients are among the most vulnerable due to increased incidence in the elderly and the short survival time. A virtual meeting was convened on May 9, 2020 with a panel of neuro-oncology experts with experience using Tumor Treating Fields (TTFields). The objective was to assess the risk-to-benefit ratio and provide guidance for using TTFields in GBM during the COVID-19 pandemic. PANEL DISCUSSION: Topics discussed included support and delivery of TTFields during the COVID-19 pandemic, concomitant use of TTFields with chemotherapy, and any potential impact of TTFields on the immune system in an intrinsically immunosuppressed GBM population. Special consideration was given to TTFields' use in elderly patients and in combination with radiotherapy regimens. Finally, the panel discussed the need to better capture data on COVID-19positive brain tumor patients to analyze longitudinal outcomes and changes in treatment decision-making during the pandemic. EXPERT OPINION: TTFields is a portable home-use device which can be managed via telemedicine and safely used in GBM patients during the COVID-19 pandemic. TTFields has no known immunosuppressive effects which is important during a crisis where other treatment methods might be limited, especially for elderly patients with multiple co-morbidities. It is too early to estimate the full impact of COVID-19 on the global healthcare system and on patient outcomes and the panel strongly recommended collaboration with existing cancer COVID-19 registries to follow CNS tumor patients.

A phase II study of laser interstitial thermal therapy combined with doxorubicin in patients with recurrent glioblastoma.

BACKGROUND: The blood-brain barrier (BBB) is a major limiting factor for drug delivery in brain tumors. Laser interstitial thermal therapy (LITT) disrupts the peritumoral BBB. In this study, we examine survival in patients with recurrent glioblastoma (GBM) treated with LITT followed by low-dose doxorubicin, a potent anti-neoplastic drug with poor BBB permeability. METHODS: Forty-one patients with recurrent GBM were enrolled; thirty patients were evaluable. Participants underwent LITT followed by 6 weekly doxorubicin treatments starting within one week (Early Arm) or at 6-8 weeks (Late Arm) after LITT. The overall survival (OS), local progression-free survival (PFS), and any PFS were compared to historical controls treated with bevacizumab salvage therapy (n = 50) or LITT with standard BBB-permeable salvage therapy (n = 28). Cox proportional-hazards models examined the contribution of age, gender, MGMT promoter status, and IDH-mutation status on any PFS and OS. Adverse events were also cataloged. RESULTS: The Late Arm and all patients (Early Arm + Late Arm) demonstrated significant improvement in OS compared to historical controls treated with bevacizumab (p < 0.001) and LITT with standard salvage therapy (p < 0.05). No significant difference in any PFS was observed between either arm and historical controls. Low-dose doxorubicin was well tolerated with comparable adverse event rates between the arms. CONCLUSIONS: Low-dose doxorubicin given after LITT is well tolerated and correlated with higher OS compared to historical controls treated with bevacizumab or LITT with standard salvage chemotherapy. A larger study is needed to further characterize survival and progression patterns.

In situ vaccination with laser interstitial thermal therapy augments immunotherapy in malignant gliomas.

INTRODUCTION: Laser interstitial thermal therapy (LITT) remains a promising advance in the treatment of primary central nervous system malignancies. As indications for its use continue to expand, there has been growing interest in its ability to induce prolonged blood brain barrier (BBB) permeability through hyperthermia, potentially increasing the effectiveness of current therapeutics including BBB-impermeant agents and immunotherapy platforms. METHODS: In this review, we highlight the mechanism of hyperthermic BBB disruption and LITT-induced immunogenic cell death in preclinical models and humans. Additionally, we summarize ongoing clinical trials evaluating a combination approach of LITT and immunotherapy, which will likely serve as the basis for future neuro-oncologic treatment paradigms. RESULTS: There is evidence to suggest a highly immunogenic response to laser interstitial thermal therapy through activation of both the innate and adaptive immune response. These mechanisms have been shown to potentiate standard methods of oncologic care. There are only a limited number of clinical trials are ongoing to evaluate the utility of LITT in combination with immunotherapy. CONCLUSION: LITT continues to be studied as a possible technique to bridge the gap between exciting preclinical results and the limited successes seen in the field of neuro-oncology. Preliminary data suggests a substantial benefit for use of LITT as a combination therapy in several clinical trials. Further investigation is required to determine whether or not this treatment paradigm can translate into long-term durable results for primary intracranial malignancies.

Tumor Treating Fields in the Management of Patients with Malignant Gliomas.

OPINION STATEMENT: Malignant gliomas remain a challenging cancer to treat due to limitations in both therapeutic and efficacious options. Tumor treating fields (TTFields) have emerged as a novel, locoregional, antineoplastic treatment modality with favorable efficacy and safety being demonstrated in the most aggressive type of malignant gliomas, glioblastoma (GBM). In 2 large randomized, controlled phase 3 trials, the addition of TTFields was associated with increased overall survival when combined with adjuvant temozolomide (TMZ) chemotherapy in patients with newly diagnosed GBM (ndGBM) and comparable overall survival compared with standard chemotherapy in patients with recurrent GBM (rGBM). TTFields target cancer cells by several mechanisms of action (MoA) including suppression of proliferation, migration and invasion, disruption of DNA repair and angiogenesis, antimitotic effects, and induction of apoptosis and immunogenic cell death. Having several MoAs makes TTFields an attractive modality to combine with standard, salvage, and novel treatment regimens (e.g., radiotherapy, chemotherapy, and immunotherapy). Treatment within the field of malignant gliomas is evolving to emphasize combinatorial approaches that work synergistically to improve patient outcomes. Here, we review the current use of TTFields in GBM, discuss MOA and treatment delivery, and consider the potential for its wider adoption in other gliomas.

Rindopepimut with Bevacizumab for Patients with Relapsed EGFRvIII-Expressing Glioblastoma (ReACT): Results of a Double-Blind Randomized Phase II Trial.

PURPOSE: Rindopepimut is a vaccine targeting the tumor-specific EGF driver mutation, EGFRvIII. The ReACT study investigated whether the addition of rindopepimut to standard bevacizumab improved outcome for patients with relapsed, EGFRvIII-positive glioblastoma. PATIENTS AND METHODS: In this double-blind, randomized, phase II study (NCT01498328) conducted at 26 hospitals in the United States, bevacizumab-naïve patients with recurrent EGFRvIII-positive glioblastoma were randomized to receive rindopepimut or a control injection of keyhole limpet hemocyanin, each concurrent with bevacizumab. The primary endpoint was 6-month progression-free survival (PFS6) by central review with a one-sided significance of 0.2. RESULTS: Between May 2012 and 2014, 73 patients were randomized (36 rindopepimut, 37 control). Rindopepimut toxicity included transient, low-grade local reactions. As primary endpoint, PFS6 was 28% (10/36) for rindopepimut compared with 16% (6/37) for control (P = 0.12, one-sided). Secondary and exploratory endpoints also favored the rindopepimut group including a statistically significant survival advantage [HR, 0.53; 95% confidence interval (CI), 0.32-0.88; two-sided log-rank P = 0.01], a higher ORR [30% (9/30) vs. 18% (6/34; P = 0.38)], median duration of response [7.8 months (95% CI, 3.5-22.2) vs. 5.6 (95% CI, 3.7-7.4)], and ability to discontinue steroids for ≥6 months [33% (6/18) vs. 0% (0/19)]. Eighty percent of rindopepimut-treated patients achieved robust anti-EGFRvIII titers (≥1:12,800), which were associated with prolonged survival (HR = 0.17; 95% CI, 0.07-0.45; P < 0.0001). CONCLUSIONS: Our randomized trial supports the potential for targeted immunotherapy among patients with GBM, but the therapeutic benefit requires validation due to the small sample size and potential heterogeneity of bevacizumab response among recurrent patients with GBM.See related commentary by Wick and Wagener, p. 1535.

Combining CDK4/6 inhibitors ribociclib and palbociclib with cytotoxic agents does not enhance cytotoxicity.

Cyclin-dependent kinases 4 and 6 (CDK4/6) play critical roles in the G1 to S checkpoint of the cell cycle and have been shown to be overactive in several human cancers. Small-molecule inhibitors of CDK4/6 have demonstrated significant efficacy against many solid tumors. Since CDK4/6 inhibition is thought to induce cell cycle arrest at the G1/S checkpoint, much interest has been focused on combining CDK4/6 inhibitors with cytotoxic agents active against the S or M phase of the cell cycle to enhance therapeutic efficacy. However, it remains unclear how best to combine these two classes of drugs to avoid their potentially antagonistic effects. Here, we test various combinations of highly selective and potent CDK4/6 inhibitors with commonly used cytotoxic drugs in several cancer cell lines derived from lung, breast and brain cancers, for their cell-killing effects as compared to monotherapy. All combinations, either concurrent or sequential, failed to enhance cell-killing effects. Importantly, in certain schedules, especially pre-treatment with a CDK4/6 inhibitor, combining these drugs resulted in reduced cytotoxicity of cytotoxic agents. These findings urge cautions when combining these two classes of agents in clinical settings.

Quantitative characterization of 3D bioprinted structural elements under cell generated forces.

With improving biofabrication technology, 3D bioprinted constructs increasingly resemble real tissues. However, the fundamental principles describing how cell-generated forces within these constructs drive deformations, mechanical instabilities, and structural failures have not been established, even for basic biofabricated building blocks. Here we investigate mechanical behaviours of 3D printed microbeams made from living cells and extracellular matrix, bioprinting these simple structural elements into a 3D culture medium made from packed microgels, creating a mechanically controlled environment that allows the beams to evolve under cell-generated forces. By varying the properties of the beams and the surrounding microgel medium, we explore the mechanical behaviours exhibited by these structures. We observe buckling, axial contraction, failure, and total static stability, and we develop mechanical models of cell-ECM microbeam mechanics. We envision these models and their generalizations to other fundamental 3D shapes to facilitate the predictable design of biofabricated structures using simple building blocks in the future.

Correction to: First results on survival from a large Phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma.

Following publication of the original article [1], the authors reported an error in the spelling of one of the author names. In this Correction the incorrect and correct author names are indicated and the author name has been updated in the original publication. The authors also reported an error in the Methods section of the original article. In this Correction the incorrect and correct versions of the affected sentence are indicated. The original article has not been updated with regards to the error in the Methods section.

First results on survival from a large Phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma.

BACKGROUND: Standard therapy for glioblastoma includes surgery, radiotherapy, and temozolomide. This Phase 3 trial evaluates the addition of an autologous tumor lysate-pulsed dendritic cell vaccine (DCVax®-L) to standard therapy for newly diagnosed glioblastoma. METHODS: After surgery and chemoradiotherapy, patients were randomized (2:1) to receive temozolomide plus DCVax-L (n = 232) or temozolomide and placebo (n = 99). Following recurrence, all patients were allowed to receive DCVax-L, without unblinding. The primary endpoint was progression free survival (PFS); the secondary endpoint was overall survival (OS). RESULTS: For the intent-to-treat (ITT) population (n = 331), median OS (mOS) was 23.1 months from surgery. Because of the cross-over trial design, nearly 90% of the ITT population received DCVax-L. For patients with methylated MGMT (n = 131), mOS was 34.7 months from surgery, with a 3-year survival of 46.4%. As of this analysis, 223 patients are ≥ 30 months past their surgery date; 67 of these (30.0%) have lived ≥ 30 months and have a Kaplan-Meier (KM)-derived mOS of 46.5 months. 182 patients are ≥ 36 months past surgery; 44 of these (24.2%) have lived ≥ 36 months and have a KM-derived mOS of 88.2 months. A population of extended survivors (n = 100) with mOS of 40.5 months, not explained by known prognostic factors, will be analyzed further. Only 2.1% of ITT patients (n = 7) had a grade 3 or 4 adverse event that was deemed at least possibly related to the vaccine. Overall adverse events with DCVax were comparable to standard therapy alone. CONCLUSIONS: Addition of DCVax-L to standard therapy is feasible and safe in glioblastoma patients, and may extend survival. Trial registration Funded by Northwest Biotherapeutics; Clinicaltrials.gov number: NCT00045968; https://clinicaltrials.gov/ct2/show/NCT00045968?term=NCT00045968&rank=1 ; initially registered 19 September 2002.

Final results of a phase I dose-escalation, dose-expansion study of adding disulfiram with or without copper to adjuvant temozolomide for newly diagnosed glioblastoma.

Disulfiram has shown promising activity including proteasome inhibitory properties and synergy with temozolomide in preclinical glioblastoma (GBM) models. In a phase I study for newly diagnosed GBM after chemoradiotherapy, we have previously reported our initial dose-escalation results combining disulfiram with adjuvant temozolomide and established the maximum tolerated dose (MTD) as 500 mg per day. Here we report the final results of the phase I study including an additional dose-expansion cohort of disulfiram with concurrent copper. The phase I study consisted of an initial dose-escalation phase of disulfiram 500-1000 mg daily during adjuvant temozolomide, followed by a dose-expansion phase of disulfiram 500 mg daily with copper 2 mg three times daily. Proteasome inhibition was assessed using fluorometric 20S proteasome assay on peripheral blood cell. A total of 18 patients were enrolled: 7 patients received 500 mg disulfiram, 5 patients received 1000 mg disulfiram, and 6 patients received 500 mg disulfiram with copper. Two dose-limiting toxicities occurred with 1000 mg disulfiram. At disulfiram 500 mg with or without copper, only 1 patient (7%) required dose-reduction during the first month of therapy. Addition of copper to disulfiram did not increase toxicity nor proteasome inhibition. The median progression-free survival was 4.5 months (95% CI 0.8-8.2). The median overall survival (OS) was 14.0 months (95% CI 8.3-19.6), and the 2-year OS was 24%. The MTD of disulfiram at 500 mg daily in combination with adjuvant temozolomide was well tolerated by GBM patients, but 1000 mg daily was not. Toxicity and pharmacodynamic effect of disulfiram were similar with or without concurrent copper. The clinical efficacy appeared to be comparable to historical data. Additional clinical trials to combine disulfiram and copper with chemoradiotherapy or to resensitize recurrent GBM to temozolomide are ongoing.

Biological and therapeutic implications of multisector sequencing in newly diagnosed glioblastoma.

Background: Diagnostic workflows for glioblastoma (GBM) patients increasingly include DNA sequencing-based analysis of a single tumor site following biopsy or resection. We hypothesized that sequencing of multiple sectors within a given tumor would provide a more comprehensive representation of the molecular landscape and potentially inform therapeutic strategies. Methods: Ten newly diagnosed, isocitrate dehydrogenase 1 (IDH1) wildtype GBM tumor samples were obtained from 2 (n = 9) or 4 (n = 1) spatially distinct tumor regions. Tumor and matched blood DNA samples underwent whole-exome sequencing. Results: Across all 10 tumors, 51% of mutations were clonal and 3% were subclonal and shared in different sectors, whereas 46% of mutations were subclonal and private. Two of the 10 tumors exhibited a regional hypermutator state despite being treatment naïve, and remarkably, the high mutational load was predominantly limited to one sector in each tumor. Among the canonical cancer-associated genes, only telomerase reverse transcriptase (TERT) promoter mutations were observed in the founding clone in all tumors. Reconstruction of the clonal architecture in different sectors revealed regionally divergent evolution, and integration of data from 2 sectors increased the resolution of inferred clonal architecture in a given tumor. Predicted therapeutic mutations differed in presence and frequency between tumor regions. Similarly, different sectors exhibited significant divergence in the predicted neoantigen landscape. Conclusions: The substantial spatial heterogeneity observed in different GBM tumor sectors, especially in spatially restricted hypermutator cases, raises important caveats to our current dependence on single-sector molecular information to guide either targeted or immune-based treatments.

Machine Learning of Human Pluripotent Stem Cell-Derived Engineered Cardiac Tissue Contractility for Automated Drug Classification.

Accurately predicting cardioactive effects of new molecular entities for therapeutics remains a daunting challenge. Immense research effort has been focused toward creating new screening platforms that utilize human pluripotent stem cell (hPSC)-derived cardiomyocytes and three-dimensional engineered cardiac tissue constructs to better recapitulate human heart function and drug responses. As these new platforms become increasingly sophisticated and high throughput, the drug screens result in larger multidimensional datasets. Improved automated analysis methods must therefore be developed in parallel to fully comprehend the cellular response across a multidimensional parameter space. Here, we describe the use of machine learning to comprehensively analyze 17 functional parameters derived from force readouts of hPSC-derived ventricular cardiac tissue strips (hvCTS) electrically paced at a range of frequencies and exposed to a library of compounds. A generated metric is effective for then determining the cardioactivity of a given drug. Furthermore, we demonstrate a classification model that can automatically predict the mechanistic action of an unknown cardioactive drug.