Citations

Abstract Extrachromosomal DNA (ecDNA) drives the evolution of cancer cells by conferring survival advantages over normal cells. However, the functional importance of ecDNA replication and maintenance is yet to be evaluated, and the molecular components that contributed to these processes remain largely unknown. Here, using CRISPR-C (circularization of genes and chromosomes by CRISPR) technology and synthetic circular DNA mimicking ecDNA identified in tumors, we generated ecDNA-positive (ecDNA+) cell models. Using these models, we identified the proteins involved in ecDNA replication and maintenance and found DNA damage response (DDR)-related pathways were significantly enriched. We further demonstrated that ecDNA replication led to increased DDR and genome instability and DDR was also essential for ecDNA maintenance, consistent with observations that ecDNA+ tumors exhibited higher DDR scores than ecDNA-negative (ecDNA–) tumors in patients. ATM, MDC1, and CHK2, but not ATR, were activated in ecDNA+ cells compared to ecDNA– cells. Moreover, ecDNA+ cells were more sensitive to ATM and CHK2 inhibition. We further found that type II topoisomerase TOP2B and DNA ligase III (LIG3) were critical regulators for ecDNA replication and maintenance and related DDR. In summary, our findings of the reciprocal interactions between ecDNA and DDR provide new insights into detection and therapy for ecDNA+ tumors.

Context.— The Nottingham Grading System (NGS) developed by Elston and Ellis is used to grade invasive breast cancer (IBC). Glandular (acinar)/tubule formation is a component of NGS. Objective.— To investigate the ability of pathologists to identify individual structures that should be classified as glandular (acinar)/tubule formation. Design.— A total of 58 hematoxylin-eosin photographic images of IBC with 1 structure circled were classified as tubules (41 cases) or nontubules (17 cases) by Professor Ellis. Images were sent as a PowerPoint (Microsoft) file to breast pathologists, who were provided with the World Health Organization definition of a tubule and asked to determine if a circled structure represented a tubule. Results.— Among 35 pathologists, the κ statistic for assessing agreement in evaluating the 58 images was 0.324 (95% CI, 0.314–0.335). The median concordance rate between a participating pathologist and Professor Ellis was 94.1% for evaluating 17 nontubule cases and 53.7% for 41 tubule cases. A total of 41% of the tubule cases were classified correctly by less than 50% of pathologists. Structures classified as tubules by Professor Ellis but often not recognized as tubules by pathologists included glands with complex architecture, mucinous carcinoma, and the “inverted tubule” pattern of micropapillary carcinoma. A total of 80% of participants reported that they did not have clarity on what represented a tubule. Conclusions.— We identified structures that should be included as tubules but that were not readily identified by pathologists. Greater concordance for identification of tubules might be obtained by providing more detailed images and descriptions of the types of structures included as tubules.

Abstract Study Objectives Rapid eye movement sleep behavior disorder (RBD) is strongly associated with phenoconversion to an overt synucleinopathy, e.g. Parkinson’s disease (PD), Lewy body dementia, and related disorders. Comorbid traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD)—henceforth “neurotrauma” (NT)—increase the odds of RBD by ~2.5-fold and are associated with an increased rate of service-connected PD in Veterans. Thus, RBD and NT are both independently associated with PD; however, it is unclear how NT influences neurological function in patients with RBD. Methods Participants ≥18 years with overnight polysomnogram-confirmed RBD were enrolled between 8/2018 to 4/2021 through the North American Prodromal Synucleinopathy Consortium. Standardized assessments for RBD, TBI, and PTSD history, as well as cognitive, motor, sensory, and autonomic function, were completed. This cross-sectional analysis compared cases (n = 24; RBD + NT) to controls (n = 96; RBD), matched for age (~60 years), sex (15% female), and years of education (~15 years). Results RBD + NT reported earlier RBD symptom onset (37.5 ± 11.9 vs. 52.2 ± 15.1 years of age) and a more severe RBD phenotype. Similarly, RBD + NT reported more severe anxiety and depression, greater frequency of hypertension, and significantly worse cognitive, motor, and autonomic function compared to RBD. No differences in olfaction or color vision were observed. Conclusions This cross-sectional, matched case:control study shows individuals with RBD + NT have significantly worse neurological measures related to common features of an overt synucleinopathy. Confirmatory longitudinal studies are ongoing; however, these results suggest RBD + NT may be associated with more advanced neurological symptoms related to an evolving neurodegenerative process.

Introduction: The ICD Sports Registry demonstrated that many athletes with ICDs can participate in competitive sports without death, failure to defibrillate, or physical injury. However, sudden cardiac arrest is more prevalent and has worse outcomes in Black compared to White individuals in the general population and among athletes. Outcomes of sports participation for Black athletes with ICDs have not been described. Aim: To describe the risk of arrhythmia and efficacy of ICDs in Black athletes. Methods: This is a post-hoc subgroup analysis of the ICD Sports Registry, which enrolled athletes with ICDs age 10 to 60, participating in organized, competitive sports, and followed them prospectively for four years. The endpoints and methods are reported previously. Results: Among the 440 athletes, 15 were Black and 410 white. Among the Black athletes, hypertrophic cardiomyopathy was the most common diagnosis (40%) and 87% were implanted for secondary prevention or syncope (vs 69% in White athletes). Most common sports were basketball (8), softball (4), and running (3), with 7 Black athletes competing on varsity/junior varsity/traveling teams. Among the Black athletes, there were no appropriate shocks during sports, among white athletes, 7% received an appropriate shock during sports. Among Black athletes, there was one appropriate shock event for ventricular tachycardia (7%), a VT storm in an athlete with idiopathic VF, non-sports-related. Among white athletes, 10% received appropriate shocks during non-sports activities. Two Black athletes (13%) received an inappropriate shock, one competition-related (sinus tachycardia) and the other for T wave oversensing at rest, vs 12% of white athletes. There were no sports-related deaths, arrests, or arrhythmia-related injuries in either group. Conclusions: Black athletes represented a small subset of the ICD Sports Registry. Reasons for this are unknown, but may include disparities in ICD implantation and/or in research recruitment/ participation. These Black athletes experienced both appropriate and inappropriate shocks as did white athletes. These data do not suggest a signal for harm for competitive sports participation for Black athletes with ICDs but larger studies are needed.

Validated nonbiopsy methods to assure duodenal mucosal healing in celiac disease are lacking, yet ongoing mucosal injury is associated with anemia, osteoporosis, and lymphoma. Most providers utilize clinical data as surrogates of mucosal status to avoid additional esophagogastroduodenoscopy. The reliability of such surrogates to predict mucosal recovery has been incompletely evaluated. The aim of this study was to rigorously assess patterns of histologic mucosal recovery at follow-up in celiac disease and to correlate findings with clinical data. Gastrointestinal pathologists from 13 centers evaluated initial and follow-up duodenal biopsies from 181 celiac disease patients. Marsh scores and intraepithelial lymphocytes (IELs)/100 enterocytes were assessed blindly. Histology at follow-up was correlated with symptoms, immunoglobulin A anti–tissue transglutaminase titers and gluten-free diet adherence. Fifty-six/181 (31%) patients had persistent villous blunting and 46/181 (25%) patients had just persistently elevated IELs at follow-up, with only 79/181 (44%) patients having complete histologic remission. IEL normalization (82/181; 45%) lagged villous recovery (125/181;69%). In a minority of patients, villous blunting was limited to proximal duodenal biopsies. No correlation was found between Marsh scores and symptoms, normalization of immunoglobulin A anti–tissue transglutaminase serology, or diet adherence. Children showed greater recovery of Marsh score (P<0.001) and IELs (P<0.01) than adults. Persistent mucosal injury is common in celiac disease, with discordant villous/IEL normalization. Pathologist awareness of expected findings in celiac disease follow-up biopsies, including their frequent lack of correlation with clinical data, is important for patient management, and has implications for eligibility criteria for therapeutics currently in development.

Cellular senescence and biliary fibrosis are prototypical features of obliterative cholangiopathies, such as primary sclerosing cholangitis (PSC). Telomere dysfunction can lead to senescence either through telomere erosion or damaged telomeres. Our goal was to investigate a mechanistic relationship between telomere damage and biliary fibrosis in PSC. Telomere attrition was observed in the bile ducts of patients with PSC along with a reduction in telomerase reverse transcriptase (TERT) expression, compared with that in normal livers. Similarly, liver tissue from mouse models of biliary fibrosis showed telomere attrition with increased damage at telomeres measured as telomere-associated foci (TAF). Cellular models of senescence induction increased the TAF in cholangiocytes. This coincided with decreased TERT expression and increased senescence, which was rescued by modulating TERT levels. Epigenetic analysis revealed increased acquisition of repressive histone methylation at the TERT promoter, which correlated with decreased TERT transcription. Cholangiocyte-selective deletion of TERT in mice exacerbated fibrosis, whereas androgen therapy toward telomerase rescued liver fibrosis and liver function in a genetic mouse model of PSC. Our results demonstrate a mechanistic role for telomere dysfunction in cellular senescence and fibrosis that characterize PSC. This suggests that PSC may be, in part, a telomere biology disorder, and identifies TERT as a potential therapeutic target.

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1 *04 subtypes best accounted for the association, strongest with HLA-DRB1 *04:04 and HLA-DRB1 *04:07, and intermediary with HLA-DRB1 *04:01 and HLA-DRB1 *04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1 *04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1 *04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues.

AbstractSynucleinopathies‐related disorders such as Lewy body dementia (LBD) and isolated/idiopathic REM sleep behavior disorder (iRBD) have been associated with neuroinflammation. In this study, we examined whether the human leukocyte antigen (HLA) locus plays a role in iRBD and LBD. In iRBD, HLA‐DRB1*11:01 was the only allele passing FDR correction (OR = 1.57, 95% CI = 1.27–1.93, p = 2.70e‐05). We also discovered associations between iRBD and HLA‐DRB1 70D (OR = 1.26, 95%CI = 1.12–1.41, p = 8.76e‐05), 70Q (OR = 0.81, 95%CI = 0.72–0.91, p = 3.65e‐04) and 71R (OR = 1.21, 95%CI = 1.08–1.35, p = 1.35e‐03). Position 71 (pomnibus = 0.00102) and 70 (pomnibus = 0.00125) were associated with iRBD. Our results suggest that the HLA locus may have different roles across synucleinopathies.

2653 Background: Given underlying differences in the tumor microenvironment across metastatic sites, ICIs demonstrate variable efficacy depending on sites of met involvement. Data on the safety and outcomes of pts on ICIs with cardiac mets are limited. Methods: In an international multi-center retrospective study, pts with solid tumors and baseline mets to the heart who had received ≥1 cycle of ICIs were included. Immune-related adverse events (irAEs) were graded per CTCAE v5.0. Objective response rates (ORR) were evaluated by RECIST1.1 when available. Median overall survival (mOS) and median progression-free survival (mPFS) were calculated from time of ICI initiation using the Kaplan-Meier method. Results: 110 pts across 20 institutions were identified with a median follow-up of 36 (95% CI 26-51) months. Melanoma (38%, n=42) and non-small cell lung cancer (NSCLC, 24%, n=26) were the most common cancers. Median age at ICI initiation was 65 (IQR: 59-75) years and 29% (n=26) received combination ICI therapy with anti-PD1 and anti-CTLA4. Overall, 62% (n=68) received ICIs as 1st line. The mets were mostly located in the atria (37%, n=41) and ventricles (35%, n=39). At ICI initiation, 21% (n=23) had a cardiac thrombus. Of 78 pts with available echocardiographic data at time of ICI initiation, the mean ejection fraction was 61+/- 7.1%. Cardiology referrals and cardiac MRIs since time of cancer diagnosis were completed on 53% (n=58) and 47% (n=52) of pts, respectively. Overall, 36.4% (n=40) of pts had cardiac complications from the mets, including arrhythmias (13%, n=14), arterial/venous emboli (3.6%, n=4), and cardiac tamponade (2.7%, n=3). For NSCLC, ORR, mPFS (95% CI), and mOS (95% CI) were 23%, 4.4 months (3.0-7.5), and 9.9 months (5.9-14.7), respectively. For melanoma, ORR, mPFS, and mOS were 35.7%, 9.1 months (5.2-20), and 29 months (14-58), respectively. Cardiac met ORRs for NSCLC and melanoma were 27% and 43%, respectively. 74% (N=71/96) of pts with evaluable response data had concordant response in the burden of overall disease and cardiac disease. IrAEs are shown. Conclusions: Although cardiac mets are frequently associated with cardiac complications, ICIs demonstrate meaningful efficacy with no overtly concerning safety signals. Close to three-quarter of pts have concordant response in the overall disease and cardiac disease burden. Multi-disciplinary approach involving cardiologists and oncologists need to be implemented to appropriately manage pts with cardiac mets. [Table: see text]