Citations

ABSTRACT Evidence indicates that the integrity of in utero development influences late life healthy or unhealthy aging; however, specific links between them are unclear. Histone chaperone HIRA is thought to play a role in both life stages, and here, we explore this role using the murine pigmentary system by investigating and comparing the effects of its lineage‐specific knockout, either conditionally during embryogenesis or postnatally. Embryonic knockout of Hira in tyrosinase+ neural crest‐derived lineages, including melanoblasts, led to reduced melanoblast numbers during embryogenesis, with single‐cell RNA sequencing analysis indicating evidence of lineage‐specificity defects. This was supported in an in vitro model using melb‐a melanoblasts in which Hira knockdown affected lineage identity and melanoblast differentiation potential, with ATAC‐seq data indicating a role of HIRA in orchestrating chromatin accessibility. Interestingly, however, newborn Hira knockout mice had wild type numbers of differentiated melanocytes, albeit functionally defective, as demonstrated by very mild hypopigmentation of the first hair coat, increased melanocyte telomere‐associated DNA damage foci, and impaired response to proliferative challenge. Moreover, as they aged, mice with embryonic melanoblast Hira knockout displayed marked defects in melanocyte stem cell maintenance and premature hair graying. Importantly, this phenotype was not observed after postnatal inducible knockout, indicating an essential role for HIRA at embryonic stages that is transmitted to adulthood, rather than a direct postnatal requirement within the pigmentary system. This genetic model shows that HIRA function during early development lays a foundation for maintaining lineage identity and subsequent maintenance of adult tissue‐specific stem cells during aging.

Abstract Gliomas are highly malignant brain tumors with poor prognosis and short survival. Nicotinamide adenine dinucleotide (NAD+) plays a critical role in cancer progression, yet anti-cancer therapies targeting NAD+ synthesis have had limited clinical success due to an incomplete understanding of its mechanisms. Here, we demonstrate the essential role of the NAD+ synthase nicotinamide mononucleotide adenylyltransferase (NMNAT) in glioma progression and its novel contribution to nuclear atypia. Analysis of the patient glioma transcriptomics dataset (GAPIA) indicated a strong correlation between high NMNAT transcription levels and poorer disease-free survival in low grade glioma (LGG) and glioblastoma multiforme (GBM). Utilizing quantitative statistical analysis to assess the size and circularity of about 3 million cells in glioma tissue samples from 19 patients, we identified the significant association between NMNAT1 protein level and increased nuclear atypia in different types of gliomas. Mechanistic studies in human glioma cells and a Drosophila glial neoplasia model revealed that NMNAT enhances glioma growth by promoting NAD+-dependent post-translational modifications poly(ADP-ribosyl)ation (PARylation) and deacetylation of p53, thereby attenuating the pro-apoptotic activity of p53. Additionally, NMNAT1 disrupts nuclear lamina integrity by altering lamin A/C distribution, further contributing to nuclear atypia and glioma progression. These findings uncover a novel tumorigenic mechanism involving NMNAT's regulation of nuclear architecture and NAD+-mediated metabolic signaling pathways, highlighting its roles in glioma growth and nuclear atypia. This study underscores NMNAT as a potential therapeutic target in glioma treatment. Citation Format: Jiaqi Liu, Xianzun Tao, Yi Zhu, Xiang Gao, Tijana Canic, Kai Ruan, Zoraida Diaz-Perez, Sakir Humayun Gultekin, Priyamvada Rai, Qunfeng Dong, Grace Zhai. NMNAT-mediated NAD+ metabolism promotes glioma growth by modulating p53 post-translational modifications and nuclear atypia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB060.

Abstract Breast cancer (BC) is the most common cancer diagnosed in American women. The majority of breast cancers express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2). However, 15-20% lack expression of all three and are called triple-negative breast cancer (TNBC). TNBC accounts for a disproportionately large amount of morbidity and mortality due to its aggressive nature and the paucity of effective adjuvant maintenance therapy, driving an urgent need for novel therapeutics. Z-endoxifen (ENDX) is a potent tamoxifen metabolite that dually targets ERα and protein kinase C beta I (PKCβI). We recently described next-generation molecules, the first-in-class endoxifen-PROTAC (ENDX-PROTAC) compounds which incorporate ENDX as the warhead and cereblon (CRBN) as the E3 ubiquitin ligase recruitment moiety (Jayaraman 2024, SABCS). We used the PRISM screen of over 900 cancer cell lines to determine that ENDX-PROTACs have broad antitumor activity in both TNBC and ER+ breast cancer in addition to, leukemia, pancreatic, lymphoma, lung, melanoma, and ovarian cancer cells, among others. ENDX-PROTACs primarily target a key translation termination factor, G to S phase transition 1 (GSPT1). Here, we demonstrate for the first time that these compounds also cause marked DNA damage. The lead compounds of this series, EPrC-007 and EPrC-009 demonstrated potent anti-proliferative effects in MDA-MB-231, BT549, and MDA-MB-436 TNBC cell lines. EPrC-007 induced substantial DNA double strand breaks in MDA-MB-231 cells as assessed by γ-H2AX Western blotting. Interrogation of DNA repair pathways revealed activation of ATM/CHK2 and downregulation of ATR/CHK1, suggesting inhibition of DNA repair as a potential mechanism. Additionally, EPrC-007 also induced γ-H2AX foci in MDA-MB-231 and BT549 cells, but not in the MCF10A normal breast tissue cell line, suggesting selective anti-tumor activity. Since we suspect that EPrC-007 blocks DNA repair machinery, we next sought to determine if these molecules would synergize with DNA damaging agents or other DNA repair inhibitors. Promisingly, EPrC-007 demonstrated remarkable synergy with olaparib (poly-(ADP-ribose) polymerase (PARP) inhibitor), hydroxyurea (ribonucleotide reductase inhibitor), and cisplatin (direct DNA damaging agent), but not camptothecin (topoisomerase I inhibitor). Importantly, only olaparib co-treatment demonstrated synergy in the PARP- and PROTAC-resistant HCC1143 TNBC cell line. Furthermore, the combination of EPrC-007 with olaparib induced markedly more γ-H2AX foci than either agent alone, confirming synergy at the DNA damage level. Taken together, our studies demonstrate the remarkable potential of ENDX-PROTACs in the single-agent setting as well as in combination with PARP inhibitors. Citation Format: Aamod S. Dekhne, Swaathi Jayaraman, Lucy Rai Thulung, Becky Bruinsma, Baustin M. Welch, Samuel Wyatt, Esther P. Rodman, Sayantani Bhattacharya, Thomas R. Caulfield, John R. Hawse, Matthew J. Schellenberg, Matthew P. Goetz. Novel endoxifen-based proteolysis targeting chimera (PROTAC) small molecules synergize with olaparib and exhibit potent antitumor activity in triple negative breast cancer through induction of DNA damage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1666.

Abstract Background Real-time endoscopic optical diagnosis involves detailed visualization of the digestive mucosal and microvascular pattern, allowing for prediction of histology. This is advantageous as it can guide endoscopic resection decisions, surgical referrals and provide cost savings to histopathology. There is, however, no standardized or widely implemented curriculum for endoscopists or trainees to learn optical diagnosis skills. Aims To evaluate the impact of a course for the optical diagnosis of esophageal squamous cell carcinoma (ESCC), early gastric cancer (EGC), Barrett’s esophagus (BE), and colorectal polyps Methods 19 gastroenterology trainees were invited to the 2-day course in Kingston, Canada. Number of procedures previously performed was recorded. The impact of the course on lesion diagnosis accuracy was evaluated using a pre-test, immediate post-test, and delayed post-test administered 6 weeks after the course. A repeated measures ANOVA was performed to compare the mean score (%) between the three tests. Results 13 trainees completed all the tests (Table 1). Mean score % values for the overall tests and test scores for esophageal, gastric, and colon lesions were summarized on Table 1. The repeated measures ANOVA determined that the mean score % had a statistically significant difference between the three tests (F (2,24)=5.63, P=0.01). Pairwise comparisons revealed that there was a statistically significant increase in mean scores between pre- and post-tests (13.86 (95% confidence interval (CI) of 4.36 to 23.33), p<0.01) with no significant difference between post and delayed post-tests (8.46 (95% CI of -0.12 to 17.04), p>0.05) (Figure 1). The mean correct % from the delayed post-test was higher than the pre-test but there was no statistical significance (5.39 (95% CI of -3.72 to 14.49), p>0.05). Conclusions This novel optical diagnosis course improved trainee accuracy in diagnosing ESCC, EGC, BE and colorectal polyps. Learning retention was evident, with no significant score difference between immediate and delayed post-tests. This study was limited by the low sample size and low number of test items. Further investigation is required to validate the course for international trainees and explore its clinical transferability. Demography and Mean Score % Figure 1. Mean score %. (*) denotes p<0.05. Funding Agencies None

OBJECTIVE The definitive influence of prestroke disability on outcomes in patients with a low Alberta Stroke Program Early CT Score (ASPECTS) treated with endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) due to large-vessel occlusion (LVO) remains unknown. This study aimed to investigate the impact of prestroke disability on outcomes in this specific population. METHODS Data from 32 international centers for AIS-LVO patients with a low ASPECTS who underwent EVT between January 2013 and December 2022 were analyzed retrospectively. Low ASPECTS and prestroke disability were defined as ASPECTS values of 2–5 and prestroke modified Rankin Scale (mRS) score ≥ 2. The primary outcome was a return to the prestroke mRS score at 90 days. Secondary outcomes were independent ambulation (mRS scores of 0–3) or a return to the prestroke mRS score at 90 days, good functional outcome (mRS scores of 0–2) or a return to the prestroke mRS score at 90 days, successful recanalization, and 90-day mortality. Safety outcomes were any intracranial hemorrhage or symptomatic intracranial hemorrhage. A symptomatic intracranial hemorrhage was defined as an intracranial hemorrhage with an associated worsening of ≥ 4 points in the National Institutes of Health Stroke Scale score. Outcomes were compared between patients with and without prestroke disability. RESULTS Of 293 patients, 50 (17.1%) had a prestroke disability. Of 50 patients, 20 (40.0%), 24 (48.0%), and 6 (12.0%) had prestroke mRS scores of 2, 3, and 4, respectively. The primary outcome showed no significant difference between the two groups. Compared with patients without prestroke disability, those with prestroke disability had a significantly smaller proportion of independent ambulation or return to prestroke mRS score (adjusted OR 0.13, 95% CI 0.03–0.53) and good functional outcome or return to prestroke mRS score (adjusted OR 0.21, 95% CI 0.05–0.91). Other secondary and safety outcomes showed no significant difference between the two groups. CONCLUSIONS The present study indicated that prestroke disability was not associated with a return to the prestroke mRS score at 90 days or intracranial hemorrhage. Physicians should not routinely exclude AIS-LVO patients with a low ASPECTS who have prestroke disability from EVT based on prestroke disability alone.

Background The contact aspiration (CA) technique is often used to perform endovascular thrombectomy (EVT) for acute ischemic stroke (AIS); however, rescue strategies are necessary if CA fails to achieve recanalization. This study investigates the outcomes of incorporating stent retriever (SR) thrombectomy in the rescue strategy following failed CA. Methods EVT patients with failed CA attempts were identified from a large multicenter registry and stratified by rescue technique: CA alone or incorporating SR in the rescue strategy. Outcomes included successful recanalization, 90-day functional outcomes (defined by the modified Rankin Scale (mRS) score), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. Results Among 1885 patients with failed CA attempts, conversion to SR was associated with higher recanalization rates (85.2% vs 80.6%; p=0.03), higher rates of second-pass recanalization (31.2% vs 23.4%; p<0.001), and better 90-day outcomes (mRS 0–2: 35.2% vs 29.9%; p=0.04) when compared with repeated CA attempts. Trevo SRs showed higher odds of successful recanalization (adjusted odds ratio (aOR)=1.9; p=0.02), second-pass recanalization (aOR=1.7; p=0.01), and reduced odds of sICH (aOR=0.3; p=0.02). EmboTrap SRs were associated with higher odds of 90-day mortality (aOR=2.6; p=0.004) and sICH (aOR=2.9; p=0.04) and lower odds of recanalization (aOR=0.5; p=0.03). Conclusions Incorporating SR in the rescue strategy after a failed CA improves recanalization rates and functional outcomes. Trevo SRs demonstrated superior efficacy and safety when incorporated into the rescue strategy.

Background: Acute stroke lesions become more hypodense on non-contrast CT as the ischemic injury matures. Lesions transition to established infarcts at which time recanalization treatment is thought to be futile, if not harmful. As it is not possible to directly quantify the degree of injury progression, eligibility for treatment is determined using temporal criteria. In this study we used an AI approach to segment and quantify the degree of hypoattenuation of acute stroke lesions on baseline CTs, and explored its impact on clinical outcome following mechanical thrombectomy. Methods: Imaging was collected from a multicentric registry (across 4 US and 5 EU sites) of consecutive large vessel occlusion (LVO) stroke patients who underwent mechanical thrombectomy. Baseline NCCT scans were processed using Brainomix 360 to automatically segment the ischemic core. Lesion hypoattenuation was then quantified by in-house software using the mean Net-Water-Uptake (NWU). Multivariate models were used to explore the association between NWU and clinical outcome (3-month modified Rankin scale–mRS), controlling for e-ASPECTS scores, age, and recanalization status. Interaction models were also used to examine the relationship between NWU e-ASPECTS scores. Results: Of the 1363 patients included (age: median 70, IQR: 50-79; 571 females), successful recanalization (mTICI 2b-3) was achieved for 1119 patients. Multivariate analysis found NWU (p=<.001, t=4.62; Fig1) to remain an independent predictor of outcome. There was a significant interaction effect between and ASPECTS score (p=0.029, Fig 2), suggesting that degree of hypoattenuation played a larger role in patients with lower aspects value. In subgroup analysis, NWU was not a significant predictor of outcome in patients that did not achieve successful recanalizion (mTICI 0-2a). Conclusions: These findings suggest that stroke lesion hypodensity measured using NWU might help identify patients at risk of futile recanalization, and that incorporating this information might be more relevant in patients with lower ASPECTS. The ability to determine treatment eligibility using information extracted from routine imaging would allow safe extension of treatment to patients with unclear onset time, and would account for differences in rates of infarct progression.

Background: There is an unmet need to better understand the likelihood of a good functional outcome in older and frailer populations undergoing endovascular therapy (EVT) following large-vessel occlusion (LVO) ischemic stroke. One approach is to improve the understanding of pre-morbid brain health (“brain frailty”) as a predictor of functional outcome. This study explored the relationship between the spatial pattern of brain atrophy and functional outcome to determine whether this is a predictor of outcomes following EVT. Methods: Patients with LVO from four hospitals in Europe and the USA were included. Three cohorts were used as a derivation cohort, and the fourth served for validation. Presenting CT imaging was processed using Brainomix in-house software to automatically localize and quantify atrophy (frailty-index). Masks from the derivation cohort were used to localize regions of atrophy significantly associated with poorer functional outcome (modified Ranking Scale 3-6) using a voxel-based, multivariate method (Sparse Canonical-Correlation-Analysis) (see Figure 1). For both derivation and validation cohorts, the degrees of overlap between each patient’s atrophy mask and the regions associated at a group level with poor outcome were calculated. This was used as an independent predictor of functional outcome in multivariate analysis adjusting for overall brain frailty-index, recanalization status, and ASPECT score Results: The derivation cohort consisted of 658 patients (mean age 69.6±15.0, median ASPECTS 9 [7-10]), while the validation cohort consisted of 447 patients (mean age 64.7 ±15.5, median ASPECTS 8 [5-10] ). Atrophy localized to the lateral ventricles and sylvian fissure was significantly associated with poorer outcomes (Figure 1). In both derivation and validation cohort, the presence of this spatial pattern of brain frailty (quantified using the degree of overlap) was an independent predictor of poor functional outcome (Table 1). Conclusion: A better understanding of pre-stroke brain health, such as the distribution of atrophy, may provide additional information to inform the prediction of outcome following LVO. This could improve patient selection for treatment following ischemic stroke through better prognostication and a more personalized approach to decision making.