Abstract Orthoebolaviruses, including Ebola virus (EBOV) and Bundibugyo virus (BDBV), cause sporadic outbreaks and devastating hemorrhagic infections in humans. A significant challenge that impedes the study of filoviruses is that the infectious virus can only be handled in biosafety level 4 (BSL4) facilities due to their extreme virulence. Life cycle modeling systems that use minigenomes and transcription/replication-competent virus-like particles (trVLPs) are powerful tools for studying these virus’ biology and to explore antiviral therapies under BSL2 conditions. To date, these powerful tools have only been utilized in vitro in cell culture systems. In this work, we demonstrate the use of EBOV trVLPs in vivo. We report the fine specificity of first infection events in a model of EBOV injection in the skin. Cre recombinase expressing monocistronic EBOV trVLPs were packaged and used to inject Cre reporter mice intradermally (ID). Initial infection events were monitored in living animals by luciferase imaging and then by flow cytometry to track cell-specific expression of Cre-activated GFP. By this approach, EBOV trVLPs were shown to directly infect T cells, monocytes, dendritic cells (DCs) with notably high first infections of skin-resident Langerhans cells (LCs) in the skin barrier and its draining lymph node. EBOV trVLPs were next tested as an in vivo tool to assess antiviral therapies by testing the ability of an EBOV vaccine to reduce trVLP luciferase levels after infection in the skin. This work demonstrates first in vivo use of EBOV trVLPs and provides proof of concept for their use as an in vivo BSL2 model to more rapidly develop antiviral agents and vaccines.
Abstract 7903: MiR-362-3p enhances platinum response in breast cancer
Abstract The INFORM trial (NCT01670500) was a randomized, two-arm Phase II neoadjuvant study comparing the efficacy of a platinum-based regimen (cisplatin) versus an anthracycline (AC)-based regimen in participants with germline BRCA1/2 mutations and early-stage, HER2-negative breast cancer. MicroRNAs (miRNAs) are emerging as promising non-invasive biomarkers for disease detection and treatment monitoring. The initial aim of this study was to evaluate whether pretreatment plasma miRNA profiles were associated with treatment outcomes in the INFORM trial cohort. Pretreatment plasma samples from 97 INFORM participants (n=53 cisplatin and n=44 AC) were screened for 352 miRNAs commonly implicated in cancer using the qPCR-based ID3EALTM Cancer Panel. Twenty out of 53 participants achieved residual cancer burden (RCB) score of 0 or 1 with cisplatin and 20/44 with AC. Higher plasma miR-362-3p expression was associated with a favorable response to cisplatin (1.7-fold; p<0.01), but not to AC. MiR-362-3p expression in paired pretreatment tumor biopsies (n=79) did not significantly correlate with plasma expression and was not associated with RCB 0/1 (p>0.05). In TCGA, miR-362-3p expression was higher in breast tumors than in adjacent normal tissue, and higher in triple negative breast cancers (TNBCs) compared with hormone receptor-positive tumors (both FDR<0.001), independent of BRCA mutation or Single Base Substitution Signature 3 (SBS3) status. The miR-362-3p findings in INFORM did not replicate in a sister trial, TBCRC 030 (NCT01982448; 11 out of 46 cisplatin-treated patients achieved RCB 0/1, p=0.46). These results suggest that while miR-362-3p is unsuitable as a circulating biomarker for cisplatin response, it may play an important biological role in mediating cisplatin sensitivity in TNBCs, independent of BRCA1/2 mutations. Functional studies demonstrated that miR-362-3p is expressed and secreted by TNBC cell lines, operates as a tumor suppressor, and generally correlates with cisplatin sensitivity. Overexpression of miR-362-3p rendered MDA-MB-231 and CAL-51 cells cisplatin sensitive, while knockdown induced resistance in MDA-MB-436 cells. Ongoing studies are testing whether these effects translate in xenograft models. In silico and functional assays identified BCLAF1, a DNA damage response (DDR) regulator, as a direct target of miR-362-3p. Overexpression of miR-362-3p suppresses BCLAF1 mRNA and protein levels. Our findings demonstrate that miR-362-3p enhances cisplatin responsiveness by targeting BCLAF1. A miR-362-3p-based therapeutic may be useful as a co-agent to enhance tumor responses to platinum-based chemotherapy. Citation Format: Zhaoji Liu, Shizhong Ke, Xiaohui Li, Catherine Wu, Madison M. Uyemura, Brian R. Sardella, Erica S. Massicott, Lin Wang, Emily K. Aronson, Dimitra Karagkouni, Nikolas Kalavros, Ioannis S. Vlachos, Felipe Batalini, Cristina S. Bogsan, Jit Kong Cheong, Lihan Zhou, He Cheng, Phillip Munson, Erica L. Mayer, Judy E. Garber, Stuart J. Schnitt, Nadine M. Tung, Andrea L. Kasinski, Frank J. Slack, Gerburg M. Wulf, Yujing J. Heng. MiR-362-3p enhances platinum response in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7903.
The miR-362-3p/
BCLAF1
axis regulates cisplatin sensitivity and metastatic progression in triple-negative breast cancer
Abstract Platinum-based chemotherapy remains a cornerstone of treatment for triple-negative breast cancer (TNBC), yet the molecular determinants governing platinum response remain poorly defined. By leveraging the randomized Phase II INFORM trial, which compared neoadjuvant cisplatin to anthracycline-based therapy in BRCA1/2 -mutant breast cancer—we identified miR-362-3p as a specific regulator of cisplatin sensitivity. Higher plasma miR-362-3p expression was exclusively associated with favorable clinical outcome in the cisplatin arm, with no association observed in the AC arm, decoupling platinum-specific vulnerability from general chemotherapy response. We used gain- and loss-of-function TNBC models to establish that miR-362-3p functions as a potent sensitizer to cisplatin in vitro and in vivo . Integrated TCGA analysis and experimental validation identified BCLAF1, a key regulator of DNA damage response, as a direct repression target of miR-362-3p. We uncovered a novel role for the miR-362-3p/ BCLAF1 axis in overcoming platinum resistance in TNBC.
Ebola virus matrix protein VP40 triggers inflammatory responses linked to the ebolavirus virulence
Uncontrolled systemic inflammatory responses are a critical pathological feature of fatal Ebola virus (EBOV) infection. While some inflammatory responses may originate from mononuclear phagocytes (MNPs), nonimmune cells vastly outnumber MNPs and may be an important source of inflammation. Here, we demonstrated that highly virulent EBOV induced a high and sustained pro-inflammatory response compared to less virulent ebolaviruses in non-MNPs through TLR4-independent NF-κB activation. We identified the EBOV matrix protein VP40 as a potent activator of NF-κB in non-MNPs, whose intrinsic inflammatory activation ability is higher than VP40 proteins from less virulent ebolaviruses. This suggests that VP40 is a virulence determinant inducing distinct degrees of pro-inflammatory responses among ebolaviruses. Mechanistically, VP40 activated the NF-κB signaling pathway, primarily via TNFR1 using a ligand-independent mechanism. These findings reveal mechanisms that may drive systemic inflammation and promote EBOV pathogenesis, suggesting potential therapeutic strategies to mitigate immune dysregulation in severe EBOV infections.
Diagnostic and prognostic value of ECG-predicted hypertension-mediated left ventricular hypertrophy using machine learning
Objective: Four hypertension-mediated left ventricular hypertrophy (LVH) phenotypes have been reported using cardiac magnetic resonance (CMR): normal LV, LV remodelling, eccentric and concentric LVH, with varying prognostic implications. The electrocardiogram (ECG) is routinely used to detect LVH; however, its capacity to differentiate between LVH phenotypes is unknown. This study aimed to classify hypertension-mediated LVH from the ECG using machine learning and test for associations of ECG-predicted phenotypes with incident cardiovascular outcomes. Methods: ECG biomarkers were extracted from the 12-lead ECG of 20 439 hypertensive patients in UK Biobank (UKB). Classification models integrating ECG and clinical variables were built using logistic regression, support vector machine (SVM), and random forest. The models were trained in 80% of the participants, and the remaining 20% formed the test set. External validation was sought in 877 hypertensive participants from the Study of Health in Pomerania (SHIP). In the UKB test set, we tested for associations between ECG-predicted LVH phenotypes and incident major adverse cardiovascular events (MACE) and heart failure. Results: Among UKB participants 19 408 had normal LV, 758 LV remodelling, 181 eccentric and 92 concentric LVH. Classification performance of the three models was comparable in UKB. SVM (accuracy 0.79, sensitivity 0.59, specificity 0.87, AUC 0.69) was taken forward for external validation with similar results in SHIP. There was superior prediction of eccentric LVH in both cohorts. In the UKB test set, ECG-predicted eccentric LVH was associated with heart failure (hazard ratio 3.42, 95% CI 1.06–9.86). Conclusion: ECG-based ML classifiers represent a potentially accessible screening strategy for the early detection of hypertension-mediated LVH phenotypes.
Development of a Pentacistronic Ebola Virus Minigenome System
Ebola virus (EBOV) causes severe disease outbreaks in humans with high case fatality rates. EBOV requires adaptation to cause lethal disease in mice by acquiring single mutations in both the nucleoprotein (NP) and VP24 genes. As an attempt to model mouse-adapted EBOV (MA-EBOV), we engineered novel pentacistronic minigenomes (5xMG) containing a reporter gene, VP40, and glycoprotein genes as well as the NP and VP24 genes from either EBOV or MA-EBOV. The 5xMGs were constructed and optimized, and the produced transcription- and replication-competent virus-like particles (trVLPs) were demonstrated to infect several cell lines. Introduction of the mouse-adaptation mutations did not significantly impact the replication and transcription of the 5xMG or the relative infectivity of the trVLPs in vitro. This work demonstrates the development of the 5xMG system as a new versatile tool to study EBOV biology.
pTDP-43 levels correlate with cell type–specific molecular alterations in the prefrontal cortex of
C9orf72
ALS/FTD patients
Repeat expansions in the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis and familial frontotemporal dementia (ALS/FTD). To identify molecular defects that take place in the dorsolateral frontal cortex of patients with C9orf72 ALS/FTD, we compared healthy controls with C9orf72 ALS/FTD donor samples staged based on the levels of cortical phosphorylated TAR DNA binding protein (pTDP-43), a neuropathological hallmark of disease progression. We identified distinct molecular changes in different cell types that take place during FTD development. Loss of neurosurveillance microglia and activation of the complement cascade take place early, when pTDP-43 aggregates are absent or very low, and become more pronounced in late stages, suggesting an initial involvement of microglia in disease progression. Reduction of layer 2-3 cortical projection neurons with high expression of CUX2/LAMP5 also occurs early, and the reduction becomes more pronounced as pTDP-43 accumulates. Several unique features were observed only in samples with high levels of pTDP-43, including global alteration of chromatin accessibility in oligodendrocytes, microglia, and astrocytes; higher ratios of premature oligodendrocytes; increased levels of the noncoding RNA NEAT1 in astrocytes and neurons, and higher amount of phosphorylated ribosomal protein S6. Our findings reveal progressive functional changes in major cell types found in the prefrontal cortex of C9orf72 ALS/FTD patients that shed light on the mechanisms underlying the pathology of this disease.
Outcomes with Venetoclax-Based Treatment in Patients with Covalent Bruton Tyrosine Kinase Inhibitor (cBTKi)-Treated, Chemotherapy-Naïve Chronic Lymphocytic Leukemia (CLL): An International Retrospective Study
Introduction Venetoclax + rituximab resulted in a 2-year progression-free survival estimate of 85% in the mostly 2nd-line, post-chemotherapy setting of the MURANO clinical trial (Seymour NEJM 2018). Short remissions with venetoclax in patients (pts) with prior cBTKi treatment (tx) for CLL are reported. However, these cohorts have included heavily pre-treated pts. Here, we report outcomes with venetoclax-based regimens in a contemporary cohort with cBTKi-exposed CLL and no prior chemotherapy. Methods We conducted a retrospective study of pts who received venetoclax for relapsed CLL after prior cBTKi tx at Mayo Clinic and across 8 centers in France. Pts with any prior chemotherapy tx were excluded. Pts were grouped as cBTKi-resistant (CLL disease progression on cBTKi) and cBTKi-exposed (any prior cBTKi tx but without disease progression). Overall survival (OS) was analyzed as the time from initiation of venetoclax until date of death or last known to be alive. Time to next therapy or death (TTNTD) after venetoclax was defined as the time from venetoclax initiation until the earliest date of next tx or death. Cox proportional hazards regression models were used to estimate associations of factors with OS and TTNTD. Results A total of 85 pts received venetoclax, including: venetoclax monotherapy (n=13, 15%), venetoclax + rituximab (n=45, 53%), and venetoclax + obinutuzumab (n=27, 32%). Patient characteristics at the time of venetoclax start were as follows: median age 69 years (interquartile range [IQR] 62-77), 59 (69%) male, 45% (33/73 evaluated) with TP53 disruption (del(17p) or TP53 mutation), 82% (46/56 evaluated) with unmutated IGHV, and 41% (15/37 evaluated) with complex karyotype (CK; ≥3 clonal structural or numerical abnormalities on karyotype). The median prior lines of therapy was 1 (IQR 1, 2); 32 (38%) pts had received prior anti-CD20 monoclonal antibody and 8 (9%) pts had received 2 prior cBTKi. Prior cBTKi tx was stopped for a reason other than disease progression in 46 (54%) pts (cBTKi-exposed) and due to CLL progression in 39 (46%) pts (cBTKi-resistant). TP53 disruption, unmutated IGHV, and CK were more common in the cBTKi-resistant subgroup. Among pts with cBTKi-resistant CLL, 60% (12/20 evaluated) had a BTK and/or PLCG2 mutation. Median follow-up from start of venetoclax-based therapy was 20 months. The median TTNTD and OS for the entire cohort was 36 (95% CI 29-not evaluable [NE]) and 68 (95% CI 39-NE) months, respectively. Among the 46 pts with cBTKi-exposed CLL, the median duration of prior cBTKi tx was 6.7 months (IQR 1.8, 23.7). The median TTNTD and OS from venetoclax start were both 78 months in pts with cBTKi-exposed CLL. The 24-month TTNTD and OS estimates were 73% and 81%, respectively. Among the 39 pts with cBTKi-resistant CLL, the median duration of prior cBTKi tx was 42.3 months (IQR 23.4, 60.1). The median TTNTD from venetoclax start in pts with cBTKi-resistant CLL was 30 months. The 24-month TTNTD estimate was 65% in the cBTKi-resistant subgroup, 53% with venetoclax monotherapy (n=5), 62% with venetoclax + rituximab (n=30), and 100% venetoclax + obinutuzumab (n=4). The median OS from venetoclax initiation was 39 months overall in pts with cBTKi-resistant CLL. The 24-month OS estimate was 84% in the cBTKi-resistant subgroup overall, 53% with venetoclax monotherapy, 87% with venetoclax + rituximab, and 100% with venetoclax + obinutuzumab. On a univariate analysis in the whole cohort, only TP53 disruption was associated with shorter TTNTD (HR 2.23; 95% CI 1.02-4.87; P=0.04) and only older age was associated with shorter OS (HR 1.05; 95% CI 1.007-1.095, P=0.02). On a univariate analysis in the cBTKi-resistant subgroup, only TP53 disruption was associated with shorter TTNTD (HR 6.68; 95% CI 1.51-29.46; P=0.01) and OS (HR 7.95; 95% CI 1.02-61.97; P=0.04). Duration of prior cBTKi exposure (as a continuous variable) was not associated with survival outcomes in the cBTKi-resistant subgroup. Conclusions Pts with chemotherapy-naïve, cBTKi-treated CLL had worse than expected outcomes with venetoclax-based tx in a mostly 2nd-line tx cohort, particularly pts with cBTKi-resistant CLL. The frequency of high-risk disease features, shorter duration of disease control with their initial cBTKi tx, and small cohort size warrant caution in generalizing these results to all pts with cBTKi-resistant disease. Novel tx trial strategies in 1st- and 2nd-line settings remain a high priority for high-risk pts.
Radiotherapy‐Induced Astrocyte Senescence Promotes an Immunosuppressive Microenvironment in Glioblastoma to Facilitate Tumor Regrowth
Abstract Accumulating evidence suggests that changes in the tumor microenvironment caused by radiotherapy are closely related to the recurrence of glioma. However, the mechanisms by which such radiation‐induced changes are involved in tumor regrowth have not yet been fully investigated. In the present study, how cranial irradiation‐induced senescence in non‐neoplastic brain cells contributes to glioma progression is explored. It is observed that senescent brain cells facilitated tumor regrowth by enhancing the peripheral recruitment of myeloid inflammatory cells in glioblastoma. Further, it is identified that astrocytes are one of the most susceptible senescent populations and that they promoted chemokine secretion in glioma cells via the senescence‐associated secretory phenotype. By using senolytic agents after radiotherapy to eliminate these senescent cells substantially prolonged survival time in preclinical models. The findings suggest the tumor‐promoting role of senescent astrocytes in the irradiated glioma microenvironment and emphasize the translational relevance of senolytic agents for enhancing the efficacy of radiotherapy in gliomas.
Predicting left ventricular hypertrophy from the 12-lead electrocardiogram in the UK Biobank imaging study using machine learning
Abstract Aims Left ventricular hypertrophy (LVH) is an established, independent predictor of cardiovascular disease. Indices derived from the electrocardiogram (ECG) have been used to infer the presence of LVH with limited sensitivity. This study aimed to classify LVH defined by cardiovascular magnetic resonance (CMR) imaging using the 12-lead ECG for cost-effective patient stratification. Methods and results We extracted ECG biomarkers with a known physiological association with LVH from the 12-lead ECG of 37 534 participants in the UK Biobank imaging study. Classification models integrating ECG biomarkers and clinical variables were built using logistic regression, support vector machine (SVM) and random forest (RF). The dataset was split into 80% training and 20% test sets for performance evaluation. Ten-fold cross validation was applied with further validation testing performed by separating data based on UK Biobank imaging centres. QRS amplitude and blood pressure (P < 0.001) were the features most strongly associated with LVH. Classification with logistic regression had an accuracy of 81% [sensitivity 70%, specificity 81%, Area under the receiver operator curve (AUC) 0.86], SVM 81% accuracy (sensitivity 72%, specificity 81%, AUC 0.85) and RF 72% accuracy (sensitivity 74%, specificity 72%, AUC 0.83). ECG biomarkers enhanced model performance of all classifiers, compared to using clinical variables alone. Validation testing by UK Biobank imaging centres demonstrated robustness of our models. Conclusion A combination of ECG biomarkers and clinical variables were able to predict LVH defined by CMR. Our findings provide support for the ECG as an inexpensive screening tool to risk stratify patients with LVH as a prelude to advanced imaging.