Citations

Introduction/Background: CHIP is a risk factor for cardiovascular (CV) disease, cancer, and all-cause mortality. Previous work has shown that CHIP, and particularly larger CHIP clones, are associated with adverse CV outcomes, yet the molecular pathways through which CHIP impacts CV risk are poorly defined. Hypothesis/Research Question: We hypothesize that the integration of whole blood transcriptomics and methylomics will provide novel insights into the pathophysiology of CHIP. Methods/Approach: Whole blood DNA methylation profiling, transcriptomics, and whole exome sequencing with CHIP calling for variant allele frequencies (VAF) of ≥2% (CHIP) and ≥10% (large CHIP) were performed for 507 ISCHEMIA and ISCHEMIA-CKD participants with moderate-severe ischemia. We identified transcriptomic and methylomic differences between participants with CHIP and large CHIP vs no CHIP using DESeq2 and limma, adjusted for age, sex, and race/ethnicity. Gene set enrichment analysis (GSEA) and probe set enrichment analysis (PSEA) were performed to identify pathway-level alterations in transcription and methylation, respectively. Results/Data: Clinical characteristics of study participants are described in Fig 1A . Compared to no CHIP (n=391), transcriptomics identified 6 differentially expressed genes (DEGs) in CHIP (n=116) and 27 DEGs in large CHIP (n=35) (p-adj<0.05; abs(logFC)>0.25) (Fig 1B) . Compared to no CHIP, methylation identified no differentially methylated probes in CHIP and 6 in large CHIP (padj<0.20, abs(logFC)>0.03). GSEA identified 137 pathways significantly different in both CHIP and large CHIP vs. no CHIP (padj<0.05), while PSEA identified 724 and 2356 pathways (padj<0.20), respectively. Given its stronger relationship with methylation and transcription, downstream analyses focused on large CHIP. Integrating these data, we found 58 pathways to be both hypomethylated and transcriptionally upregulated in large CHIP, including azurophil granule-related pathways implicated in neutrophil degranulation (Fig 1C) . Further investigation into the gene-probe pairs driving the azurophil granule pathway enrichment in large CHIP revealed hypomethylation and increased transcription of genes implicated in neutrophil extracellular trap formation, including ELANE, PTRN3, AZU1, and CTSG (Fig 1D) . Conclusions: Integration of the methylome and transcriptome suggests large CHIP is linked to neutrophil-mediated immune pathways in patients with stable coronary artery disease.

EndMT has been reported to contribute to the pathogenesis of PAH. In this study, we aimed to determine the role of Ca 2+ signaling in the development of EndMT in human lung vascular endothelial cells. Our data suggest that TGF-β 1 requires store-operated Ca 2+ entry through STIM1/Orai channels to induce SNAI-mediated EndMT. For the first time, we demonstrated that TGF-β 1 -induced EndMT is a Ca 2+ -dependent event, whereas inhibition of STIM1/Orai interaction attenuated EndMT in response to TGF-β 1 .

Objectives/Goals: The operation of a clinical trials unit involves multifaceted tasks and stakeholders. A competent information system is critical to daily operations while ensuring smooth conduct of clinical research. We share 15 years of experience in the design and implementation of such a system at Mayo Clinic to inform other institutions with similar interests. Methods/Study Population: The Informatics team collaborated closely with nurse leaders and elicited input from additional stakeholders including nurse unit coordinators, lab managers, schedulers, investigators, study coordinators, and regulatory specialists throughout the phases of system design, development and continuous enhancements, and expansion. The stakeholders offered insights on the corresponding requirements throughout the study life cycle, from engaging with the study sponsor, operational review for protocol execution, development of study budgets, human subject protection and risk mitigation, data management and integration, to outcome monitoring, and regulatory reporting. The activities were then translated into functional components and implemented as a seamless and effective solution. Results/Anticipated Results: Patient safety, scientific rigor, operation automation, efficiency, and regulatory requirements were all considered in developing an integrated system, or the clinical research trials unit (CRTU) Tools. Our institution has leveraged the system for essential tasks from the study start-up, visit scheduling and execution, specimen collection and tracking, to individual protocol metrics and billing. We adopted a measure-as-we-go methodology so that data such as visit census, resource usage, and protocol deviation are tracked and collected during routine use of the system. Specifically, an issues/concerns/exceptions (ICE) tool is used for quality control and patient safety. Moreover, data quality greatly benefits from a task dictionary, standardizing the study activities that can be ordered and executed. Discussion/Significance of Impact: The implementation of a well-rounded clinical trials unit information system not only improves the operation efficiency and team productivity but also ensures scientific rigor and contributes to patient safety. We believe the experience can be informative to other institutions. More details will be shared in the poster.

Introduction: CHIP is associated with CAD and mortality. The prognostic relevance of CHIP for high-risk patients with confirmed CAD is unknown. Hypothesis: CHIP variants are associated with cardiovascular (CV) events and mortality in high-risk patients with known CAD in the ISCHEMIA Trials Biorepository. Methods: 895 ISCHEMIA and ISCHEMIA-CKD (hereafter, ISCHEMIA Trials) participants with moderate-severe ischemia and next-generation sequencing performed for CHIP variant allele fractions of ≥2% (CHIP) and ≥10% (large CHIP) were included. Unadjusted and multivariable adjusted (age, sex, diabetes, eGFR not on HD, HD, and LVEF) associations of CHIP and large CHIP with a) ISCHEMIA Trials initial phase primary endpoint (CV death, myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest, RCA) and b) ISCHEMIA Trials combined initial and extended follow-up phase (hereafter, Cumulative) endpoint of all-cause death . Results: Median (IQR) age of sequenced participants was 67 (56 – 79) years, 19% were female, 83% white, and 6% Hispanic. Hypertension (84%), diabetes (45%) and obesity (47%) were common, 26% had an eGFR <60 ml/min/1.73m 2 . The prevalence of CHIP and large CHIP was 23% and 7%, and both increased with age ( Figure 1a ). CHIP mutations in DNMT3A were detected in 106 (12%), TET2 CHIP in 44 (5%), and ASXL1 CHIP in 21 (2%) participants ( Figure 1b ). DNMT3A, TET2, and CREBBP mutations collectively comprised 199 (52%) of overall CHIP mutations, including individuals with multiple mutations in the same gene (N overall = 385); 67 participants (7%) had mutations in >1 gene. Over 3.1 years of RCT follow-up there were 135 (20%), 32 (16%) and 15 (18%) primary endpoints for no CHIP, CHIP and large CHIP, respectively. Over 6.8 years of EXTEND follow-up, there were 126 (18%), 47 (23%) and 24 (29%) deaths in the no CHIP, CHIP and large CHIP groups, respectively. After multivariable adjustment there was no association between CHIP or large CHIP and CV events or mortality ( Figure 1c ). Conclusion: Neither CHIP nor large CHIP was associated with adverse outcomes in 895 high-risk individuals with confirmed CAD, despite a high prevalence of these mutations.

AbstractDNA damage plays a significant role in the tumorigenesis and progression of the disease. Abnormal DNA repair affects the therapy and prognosis of cancer. In this study, it is demonstrated that the deubiquitinase USP25 promotes non‐homologous end joining (NHEJ), which in turn contributes to chemoresistance in cancer. It is shown that USP25 deubiquitinates SHLD2 at the K64 site, which enhances its binding with REV7 and promotes NHEJ. Furthermore, USP25 deficiency impairs NHEJ‐mediated DNA repair and reduces class switch recombination (CSR) in USP25‐deficient mice. USP25 is overexpressed in a subset of colon cancers. Depletion of USP25 sensitizes colon cancer cells to IR, 5‐Fu, and cisplatin. TRIM25 is also identified, an E3 ligase, as the enzyme responsible for degrading USP25. Downregulation of TRIM25 leads to an increase in USP25 levels, which in turn induces chemoresistance in colon cancer cells. Finally, a peptide that disrupts the USP25‐SHLD2 interaction is successfully identified, impairing NHEJ and increasing sensitivity to chemotherapy in PDX model. Overall, these findings reveal USP25 as a critical effector of SHLD2 in regulating the NHEJ repair pathway and suggest its potential as a therapeutic target for cancer therapy.

AbstractUnesbulin is being investigated in combination with dacarbazine (DTIC) as a potential therapeutic agent in patients with advanced leiomyosarcoma (LMS). This paper reports the pharmacokinetics (PK) of unesbulin, DTIC, and its unreactive surrogate metabolite 5‐aminoimidazole‐4‐carboxamide (AIC) in 29 patients with advanced LMS. Drug interactions between DTIC (and AIC) and unesbulin were evaluated. DTIC (1000 mg/m2) was administered to patients with LMS via 1‐h intravenous (i.v.) infusion on day 1 of every 21‐day (q21d) cycle. Unesbulin dispersible tablets were administered orally twice weekly (b.i.w.), starting on day 2 of every cycle, except for cycle 2 (C2), where unesbulin was dosed either on day 1 together with DTIC or on day 2, 1 day after DTIC administration. The PK of DTIC, AIC, and unesbulin in cycle 1 (C1) and C2 were estimated using noncompartmental analysis. DTIC and AIC were measurable immediately after the start of infusion and reached maximum plasma concentration (Cmax) immediately or shortly after end of infusion at 1.0 and 1.4 h (time to Cmax), respectively. Co‐administration of unesbulin orally at 200 mg or above with DTIC inhibited cytochrome P450 (CYP)1A2‐mediated DTIC metabolism, resulting in 66.7% reduction of AIC exposures. Such inhibition could be mitigated when unesbulin was dosed the day following DTIC infusion. Repeated unesbulin dosing demonstrated evidence of clinical CYP1A2 induction and increased AIC Cmax by 69.4% and area under concentration‐time curve to infinity by 57.9%. No meaningful difference in unesbulin PK was observed between C2 and C1. The combination therapy of 1000 mg/m2 i.v. DTIC q21d and 300 mg unesbulin b.i.w. in a staggered regimen is well‐tolerated in patients with LMS.