e13121 Background: Metastatic breast cancer remains a major clinical challenge, characterized by poor prognosis and limited therapeutic options. The incidence of metastatic female breast cancer increased from 5.8 to 7.9 per 100,000 females from 2001 to 2021. The Hippo pathway effector YAP1 plays a critical role in driving tumor growth and metastasis in many cancers including breast but little is known about the gene-specific changes that occur when breast cancers have metastasized. This study aimed to investigate the extent of genomic alterations, including copy number alterations (CNAs) and mutations, in YAP1 and its downstream genes in metastatic breast cancer compared to nonmetastatic breast cancer. Methods: Genomic data for the YAP1 gene and its downstream target genes (CTGF, Cyr61, MCL-1, TOP2A, FOSL2, and ANKRD1) were obtained from cBioPortal. This included mutation data and CNA data, considering both amplifications and deletions as CNA events. The chi-square test was performed using GraphPad Prism 10 to compare the frequencies of mutations and CNAs between metastatic and non-metastatic breast cancer cases. Results: A total of 2390 samples of metastatic breast cancer and 9289 samples of non-metastatic breast cancer were analyzed for mutations. Among them, a significantly higher percentage of mutations in the YAP1 (P ≤ 0.0001), ANKRD1 (P ≤ 0.0001), MCL-1 (P ≤ 0.0001), and TOP2A (P ≤ 0.0001) genes was observed in metastatic breast cancer compared to non-metastatic breast cancer. Evaluating CNAs in 2197 cases in the metastatic breast cancer group compared to 9289 cases in the non-metastatic breast cancer group demonstrated a significantly higher frequency of CNAs in the YAP1 ( P ≤ 0.0001), Cyr61 (P ≤ 0.0001), CTGF ( P ≤ 0.0001), ANKRD1 ( P ≤ 0.0001), TOP2A (P ≤ 0.0001) and FOSL2 (P ≤ 0.0001) genes among metastatic breast cancer. Conclusions: This study revealed significant genomic alterations in the YAP1 gene and its downstream genes in metastatic breast cancer. These findings highlight the importance of the YAP1 pathway in breast cancer metastasis and suggest that targeting this pathway may have therapeutic potential for primary and metastatic breast cancer. Frequency of mutations and copy number alterations (CNAs) in metastatic vs. non-metastatic breast cancer. Gene Metastatic Breast Cancer Mutation Frequency (%) Non-Metastatic Breast Cancer Mutation Frequency (%) P-value Metastatic Breast Cancer CNA Frequency (%) Non-Metastatic Breast Cancer CNA Frequency (%) P-value YAP1 0.75 0.17 <0.0001 5.1 1.18 <0.0001 CTGF 0.13 0.18 0.781 5.42 0.65 <0.0001 Cyr61 0.17 0.16 0.999 3.9 0.65 <0.0001 MCL-1 0.63 0.11 <0.0001 10.74 11.93 0.121 ANKRD1 1.17 0.09 <0.0001 1.96 0.25 <0.0001 TOP2A 0.96 0.18 <0.0001 8.06 3.6 <0.0001 FOSL2 0.17 0.1 0.317 3.64 0.62 <0.0001
Abstract 14553: Clonal Hematopoiesis of Indeterminate Potential is Associated With Atrial Fibrillation in Patients With Early Coronary Artery Disease
Introduction: The mechanistic link between early coronary artery disease (CAD) and atrial fibrillation (AF) continues to be explored. Clonal hematopoiesis of indeterminate potential (CHIP) is increasingly recognized as a risk factor for cardiovascular disease. We hypothesize CHIP further increases the risk for AF in early CAD. Methods: 184 participants underwent invasive coronary angiogram with endothelial function testing. Buffy coat was used for whole exosome sequencing to identify CHIP (variant allele frequency > 2% and minor allele frequency ≤ 0.1%). Early CAD was defined by the presence of coronary endothelial dysfunction (CED) in the absence of obstructive CAD. Invasive coronary angiography with endothelial function testing characterized CED as ≥ 20% increase in coronary artery diameter or ≤ 50% increase in coronary blood flow in response to acetylcholine. AF was identified by ICD-10 code or patient survey and confirmed by an independent investigator by chart review. Cox proportional hazard regression was adjusted for age, sex, and conventional cardiovascular comorbidities (hypertension, diabetes, and total cholesterol). Results: Of the 184 participants, we identified 23 cases with both early CAD and CHIP and 62 normal controls without CHIP or CAD. Case patients were significantly older (mean 60 ±9 vs 52 ±10 years, p = 0.004 years) and predominantly female (74% vs 81%, p = 0.506). AF was more likely among case participants when compared to normal controls (29% vs 10%, p = 0.036). Mean time to AF or last follow-up was 11 ±7 years. Case patients with both early CAD and CHIP were nearly 10 times more likely to develop AF when compared to normal controls in a Cox regression model adjusted for age, sex, and conventional cardiovascular comorbidities (HR 9.52, 95% CI 1.93 - 47.02, p = 0.006). The risk for AF was not significant if we defined cases by only the presence of CHIP (n = 30) or early CAD (n = 122). Conclusions: Patients with both CHIP and early CAD may have greater risk for developing AF beyond the presence of CHIP or CAD alone. Our findings suggest an added mechanistic role of CHIP that further increases the risk for AF in early CAD.
Clonal Hematopoiesis of Indeterminate Potential Is Associated With Coronary Microvascular Dysfunction In Early Nonobstructive Coronary Artery Disease
Background: Clonal hematopoiesis (CH) of indeterminate potential (CHIP) is a risk factor for cardiovascular disease. The relationship between CHIP and coronary microvascular dysfunction (CMD) is unknown. The current study examines the association between CHIP and CH with CMD and the potential relationships in risk for adverse cardiovascular outcomes. Methods: In this retrospective observational study, targeted next-generation sequencing was performed for 177 participants with no coronary artery disease who presented with chest pain and underwent routine coronary functional angiogram. Patients with somatic mutations in leukemia-associated driver genes in hematopoietic stem and progenitor cells were examined; CHIP was considered at a variant allele fraction ≥2%; CH was considered at a variant allele fraction ≥1%. CMD was defined as coronary flow reserve to intracoronary adenosine of ≤2. Major adverse cardiovascular events considered were myocardial infarction, coronary revascularization, or stroke. Results: A total of 177 participants were examined. Mean follow-up was 12±7 years. A total of 17 patients had CHIP and 28 had CH. Cases with CMD (n=19) were compared with controls with no CMD (n=158). Cases were 56±9 years, were 68% women, and had more CHIP (27%; P =0.028) and CH (42%; P =0.001) than controls. CMD was associated with independent risk for major adverse cardiovascular events (hazard ratio, 3.89 [95% CI, 1.21–12.56]; P =0.023), and 32% of this risk was mediated by CH. The risk mediated by CH was ≈0.5× as large as the direct effect of CMD on major adverse cardiovascular events. Conclusions: In humans, we observe patients with CMD are more likely to have CHIP, and nearly one-third of major adverse cardiovascular events in CMD are mediated by CH.
Carotid Plaques From Symptomatic Patients Are Characterized by Local Increase in Xanthine Oxidase Expression
Background and Purpose: XO (xanthine oxidase) is a key enzyme of uric acid metabolism and is thought to contribute to oxidative pathways that promote atherosclerotic plaque progression, yet its role in plaque destabilization is not well elucidated. We hypothesized that XO is expressed in carotid plaque from symptomatic patients in association with cardiovascular risk factors. Methods: Patients were stratified by symptoms, defined as presentation with an ipsilateral cerebral ischemic event. Carotid atherosclerotic plaques were obtained from 44 patients with symptomatic plaque and 44 patients without ischemic cerebral events. Protein expression of XO was evaluated by immunohistochemical staining and the percentage of cells expressing XO and CD68 (macrophage marker) compared between the groups. Biochemical and demographic cardiometabolic risk factors of study participants also were measured. Results: Carotid atherosclerotic plaques from symptomatic patients were associated with significantly higher XO expression versus asymptomatic plaque (median [interquartile range]: 1.24 [2.09] versus 0.16 [0.34]; P <0.001) and with significantly higher circulating uric acid levels (mean±SD: 7.36±2.10 versus 5.37±1.79 mg/dL; P <0.001, respectively). In addition, XO expression in atherosclerotic carotid plaque was inversely associated with serum high-density lipoproteins cholesterol levels ( P =0.010, r =−0.30) and directly with circulating uric acid levels ( P <0.001, r =0.45). The average percentage of macrophages that expressed XO was significantly higher in symptomatic versus asymptomatic plaques (median [interquartile range]: 93.37% [25] versus 46.15% [21], respectively; P <0.001). Conclusions: XO overexpression in macrophages is associated with increased serum uric acid and low high-density lipoproteins cholesterol levels and may potentially have a mechanistic role in carotid plaque destabilization. The current study supports a potential role for uric acid synthesis pathway as a target for management of carotid atherosclerosis in humans.
Abstract 17182: Coronary Endothelial Dysfunction in Humans is Associated With Elevated Expression of Clonal Hematopoiesis of Indeterminate Potential
Introduction: Recent evidence has demonstrated that Clonal Hematopoiesis of Indeterminate Potential (CHIP) increases the risk of cardiovascular events. However, the exact role played by CHIP in early stages of coronary atherosclerosis, characterized by coronary endothelial dysfunction remains to be elucidated. Hypothesis: The current study was designed to test the hypothesis that the presence of CHIP in peripheral blood cells is associated with coronary endothelial dysfunction and increased levels of inflammatory markers. Methods: Next generation sequencing was used to detect mutations among patients who had coronary endothelial dysfunction and control group (normal coronary endothelial function). Endothelial dysfunction was defined by ≥ 20% decrease in coronary artery diameter or ≤50% increase in blood flow in response to acetylcholine injection compared to baseline. Plasma cytokine levels of Interleukin (IL)-6 and IL-8 were also assessed. Results: Clonal hematopoiesis relevant gene mutations were found in 1 out of 64 patients with normal endothelial function (1.5%) and 11 out of 119 cases in the endothelial dysfunction group (9.2%) (P = 0.04) with ASXL1 (Additional sex combs-like 1) being the most frequent gene (4.2%) mutated. Cytokine analysis demonstrated that mutations in ASXL1, DNMT3A (DNA methyltransferase 3A) and TET2 (Ten-eleven-translocation-2) in the endothelial dysfunction group were associated with increased levels of IL-6 and IL-8 (P = 0.001, P = 0.003; respectively). Conclusions: The current study supports a potential role for CHIP in mechanisms of coronary artery disease starting at early stage of atherosclerosis. Furthermore, enhanced expression levels of IL-6 and IL-8 seem to be related to mutations in DNMT3A, ASXL1 and TET2 genes, more than other gene mutations relevant CHIP.
Elevated expression of clonal hematopoiesis of indeterminate potential in patients with coronary endothelial dysfunction is associated with future cardiovascular events
Abstract Aims We aimed to test the hypothesis that the presence of clonal hematopoiesis of indeterminate potential (CHIP) in peripheral blood cells is associated with coronary endothelial dysfunction, enhanced inflammatory markers, and major adverse cardiovascular events (MACE).Methods and results We compared targeted next generation sequencing (35 CHIP related genes) between patients with coronary endothelial dysfunction (n = 123) and controls (n=65). Coronary endothelial dysfunction was defined by ≥ 20% decrease in coronary artery diameter (CAD) or ≤ 50% increase in coronary blood flow (CBF) in response to acetylcholine injection compared to baseline. Plasma cytokine levels of Interleukin (IL)-6 and IL-8 were also assessed. Patients were subsequently followed for 12.2 ± 4.3 years. Clonal hematopoiesis relevant gene mutations were found in 1 individual in normal endothelial function group (1.5%) and 11 cases in endothelial dysfunction group (9.3%) (p = 0.04). Additionally, CHIP mutations were associated with an increased risk of MACE (OR = 4.08, P = 0.04). Mutations in ASXL1, DNMT3A and TET2 in the endothelial dysfunction group were also associated with increased levels of IL-6 and IL-8 (P = 0.001, P = 0.003; respectively).Conclusion The current study demonstrates a high frequency of CHIP in patients with coronary endothelial dysfunction as well as an association between mutations in three most common epigenetic regulator genes and increased levels of IL-6 and IL-8. Therefore it infers a probable relationship between CHIP, endothelial dysfunction and cardiovascular adverse events.