Stat3-mediated Atg7 expression regulates anti-tumor immunity in mouse melanoma.

Epigenetic modifications to DNA and chromatin control oncogenic and tumor-suppressive mechanisms in melanoma. Ezh2, the catalytic component of the Polycomb Repressive Complex 2 (PRC2), which mediates methylation of lysine 27 on histone 3 (H3K27me3), can regulate both melanoma initiation and progression. We previously found that mutant Ezh2Y641F interacts with the immune regulator Stat3 and together they affect anti-tumor immunity. However, given the numerous downstream targets and pathways affected by Ezh2, many mechanisms that determine its oncogenic activity remain largely unexplored. Using genetically engineered mouse models, we further investigated the role of pathways downstream of Ezh2 in melanoma carcinogenesis and identified significant enrichment in several autophagy signatures, along with increased expression of autophagy regulators, such as Atg7. In this study, we investigated the effect of Atg7 on melanoma growth and tumor immunity within the context of a wild-type or Ezh2Y641F epigenetic state. We found that the Atg7 locus is controlled by multiple Ezh2 and Stat3 binding sites, Atg7 expression is dependent on Stat3 expression, and that deletion of Atg7 slows down melanoma cell growth in vivo, but not in vitro. Atg7 deletion also results in increased CD8 + T cells in Ezh2Y641F melanomas and reduced myelosuppressive cell infiltration in the tumor microenvironment, particularly in Ezh2WT melanomas, suggesting a strong immune system contribution in the role of Atg7 in melanoma progression. These findings highlight the complex interplay between genetic mutations, epigenetic regulators, and autophagy in shaping tumor immunity in melanoma.

Watchman device migration and embolization: A report from the NCDR LAAO Registry.

INTRODUCTION: Incomplete anchoring of the Watchman left atrial appendage closure (LAAO) device can result in substantial device migration or device embolization (DME) requiring percutaneous or surgical retrieval. METHODS: We performed a retrospective analysis of Watchman procedures (January 2016 through March 2021) reported to the National Cardiovascular Data Registry LAAO Registry. We excluded patients with prior LAAO interventions, no device released, and missing device information. In-hospital events were assessed among all patients and postdischarge events were assessed among patients with 45-day follow-up. RESULTS: Of 120 278 Watchman procedures, the in-hospital DME rate was 0.07% (n = 84) and surgery was commonly performed (n = 39). In-hospital mortality rate was 14% among patients with DME and 20.5% among patients who underwent surgery. In-hospital DME was more common: at hospitals with a lower median annual procedure volume (24 vs. 41 procedures, p < .0001), with Watchman 2.5 versus Watchman FLX devices (0.08% vs. 0.04%, p = .0048), with larger LAA ostia (median 23 vs. 21 mm, p = .004), and with a smaller difference between device and LAA ostial size (median difference 4 vs. 5 mm, p = .04). Of 98 147 patients with 45-day follow-up, postdischarge DME occurred in 0.06% (n = 54) patients and cardiac surgery was performed in 7.4% (n = 4) of cases. The 45-day mortality rate was 3.7% (n = 2) among patients with postdischarge DME. Postdischarge DME was more common among men (79.7% of events but 58.9% of all procedures, p = .0019), taller patients (177.9 vs. 172 cm, p = .0005), and those with greater body mass (99.9 vs. 85.5 kg, p = .0055). The rhythm at implant was less frequently AF among patients with DME compared to those without (38.9% vs. 46.9%, p = .0098). CONCLUSION: While Watchman DME is rare, it is associated with high mortality and frequently requires surgical retrieval, and a substantial proportion of events occur after discharge. Due to the severity of DME events, risk mitigation strategies and on-site cardiac surgical back-up are of paramount importance.

FDA Approval Summary: Rucaparib for the Treatment of Patients with Deleterious BRCA-Mutated Metastatic Castrate-Resistant Prostate Cancer.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to rucaparib in May 2020 for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane. This approval was based on data from the ongoing multicenter, open-label single-arm trial TRITON2. The primary endpoint, confirmed objective response rate, in the 62 patients who met the above criteria, was 44% (95% confidence interval [CI]: 31%-57%). The median duration of response was not estimable (95% CI: 6.4 to not estimable). Fifty-six percent of patients had a response duration of >6 months and 15% >12 months. The safety profile of rucaparib was generally consistent with that of the class of poly-(ADP-ribose) polymerase enzyme inhibitors and other trials of rucaparib in the treatment of ovarian cancer. Deaths due to adverse events (AEs) occurred in 1.7% of patients, and 8% discontinued rucaparib because of an AE. Grade 3-4 AEs occurred in 59% of patients. No patients with prostate cancer developed myelodysplastic syndrome or acute myeloid leukemia. The trial TRITON3 in patients with mCRPC is ongoing and is planned to verify the clinical benefit of rucaparib in mCRPC. This article summarizes the FDA thought process and data supporting this accelerated approval. IMPLICATIONS FOR PRACTICE: The accelerated approval of rucaparib for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer who have been treated with androgen receptor-directed therapy and a taxane represents the first approved therapy for this selected patient population. This approval was based on a single-arm trial demonstrating a confirmed objective response rate greater than that of available therapy with a favorable duration of response and an acceptable toxicity profile. The ongoing trial TRITON3 is verifying the clinical benefit of this drug.

Mortality among United States aerospace materials manufacturing workers.

OBJECTIVES: To evaluate long-term mortality rates among aerospace material manufacturing workers as follow-up to an earlier observed excess of nephritis/nephrosis. METHODS: Subjects were 2020 workers ever employed in the facility during 1963-2014. Vital status through 2014 was determined for all subjects and cause of death for 99.2% of 492 deaths. We computed standard mortality ratios (SMR) and internal relative risks. RESULTS: SMRs for nephritis/nephrosis were unremarkable. We observed statistically significant elevated SMRs for kidney cancer among all workers and for the category "other lymphatic hematopoietic tissue cancer" (4/5 deaths from multiple myeloma) among long-term workers with potential plant exposure. CONCLUSIONS: We found no evidence of elevated mortality rates for nephritis/nephrosis. Study limitations precluded robust evaluation of whether the elevated rates for kidney cancer and other lymphatic hematopoietic tissue cancer were related to occupational factors at the study site. Our findings for these two cancers warrant continued mortality follow-up.

Sc65-Null Mice Provide Evidence for a Novel Endoplasmic Reticulum Complex Regulating Collagen Lysyl Hydroxylation.

Collagen is a major component of the extracellular matrix and its integrity is essential for connective tissue and organ function. The importance of proteins involved in intracellular collagen post-translational modification, folding and transport was recently highlighted from studies on recessive forms of osteogenesis imperfecta (OI). Here we describe the critical role of SC65 (Synaptonemal Complex 65, P3H4), a leprecan-family member, as part of an endoplasmic reticulum (ER) complex with prolyl 3-hydroxylase 3. This complex affects the activity of lysyl-hydroxylase 1 potentially through interactions with the enzyme and/or cyclophilin B. Loss of Sc65 in the mouse results in instability of this complex, altered collagen lysine hydroxylation and cross-linking leading to connective tissue defects that include low bone mass and skin fragility. This is the first indication of a prolyl-hydroxylase complex in the ER controlling lysyl-hydroxylase activity during collagen synthesis.

A new frontonasal dysplasia syndrome associated with deletion of the SIX2 gene.

The frontonasal dysplasias are a group of craniofacial phenotypes characterized by hypertelorism, nasal clefting, frontal bossing, and abnormal hairline. These conditions are caused by recessive mutations in members of the aristaless gene family, resulting in abnormal cranial neural crest migration and differentiation. We report a family with a dominantly inherited craniofacial phenotype comprised of frontal bossing with high hairline, ptosis, hypertelorism, broad nasal tip, large anterior fontanelle, cranial base anomalies, and sagittal synostosis. Chromosomal microarray identified a heterozygous 108.3 kilobase deletion of chromosome 2p21 segregating with phenotype and limited to the sine oculis homeobox gene SIX2 and surrounding noncoding DNA. Similar to the human SIX2 deletion phenotype, one mouse model of frontonasal dysplasia, brachyrrhine, exhibits dominant inheritance and impaired cranial base chondrogenesis associated with reduced Six2 expression. We report the first human autosomal dominant frontonasal dysplasia syndrome associated with SIX2 deletion and with phenotypic similarities to murine models of Six2 Loss-of-function.

A 2015 global update on folic acid-preventable spina bifida and anencephaly.

BACKGROUND: Spina bifida and anencephaly are two major neural tube defects. They contribute substantially to perinatal, neonatal, infant, and under-five mortality and life-long disability. To monitor the progress toward the total prevention of folic acid-preventable spina bifida and anencephaly (FAP SBA), we examined their global status in 2015. METHODS: Based on existing data, we modeled the proportion of FAP SBA that are prevented in the year 2015 through mandatory folic acid fortification globally. We included only those countries with mandatory fortification that added at least 1.0 ppm folic acid as a fortificant to wheat and maize flour, and had complete information on coverage. Our model assumed mandatory folic acid fortification at 200 µg/day is fully protective against FAP SBA, and reduces the rate of spina bifida and anencephaly to a minimum of 0.5 per 1000 births. RESULTS: Our estimates show that, in 2015, 13.2% (35,500 of approximately 268,700 global cases) of FAP SBA were prevented in 58 countries through mandatory folic acid fortification of wheat and maize flour. Most countries in Europe, Africa, and Asia were not implementing mandatory fortification with folic acid. CONCLUSION: Knowledge that folic acid prevents spina bifida and anencephaly has existed for 25 years, yet only a small fraction of FAP SBA is being prevented worldwide. Several countries still have 5- to 20-fold epidemics of FAP SBA. Implementation of mandatory fortification with folic acid offers governments a proven and rapid way to prevent FAP SBA-associated disability and mortality, and to help achieve health-related Sustainable Development Goals. Birth Defects Research (Part A) 106:520-529, 2016. © 2016 Wiley Periodicals, Inc.

Stat3-mediated Atg7 expression enhances anti-tumor immunity in melanoma.

Epigenetic modifications to DNA and chromatin control oncogenic and tumor suppressive mechanisms in melanoma. EZH2, the catalytic component of the Polycomb repressive complex 2 (PRC2), which mediates methylation of lysine 27 on histone 3 (H3K27me3), can regulate both melanoma initiation and progression. We previously found that mutant Ezh2 Y641F interacts with the immune regulator Stat3 and together they affect anti-tumor immunity. However, given the numerous downstream targets and pathways affected by EZH2, many mechanisms that determine its oncogenic activity remain largely unexplored. Using genetically engineered mouse models we further investigated the role of pathways downstream of EZH2 in melanoma carcinogenesis and identified significant enrichment in several autophagy signatures, along with increased expression of autophagy regulators, such as Atg7. In this study, we investigated the effect of Atg7 on melanoma growth and tumor immunity within the context of an Ezh2 Y641F epigenetic state. We found that expression of Atg7 is largely dependent on Stat3 expression and that deletion of Atg7 slows down melanoma cell growth in vivo, but not in vitro. Atg7 deletion also results in increased CD8+ T cells and reduced myelosuppressive cell infiltration in the tumor microenvironment, suggesting a strong immune system contribution in the role of Atg7 in melanoma progression. These findings highlight the complex interplay between genetic mutations, epigenetic regulators, and autophagy in shaping tumor immunity in melanoma.

Frailty and associated outcomes in patients undergoing percutaneous left atrial appendage occlusion: findings from the NCDR LAAO registry.

BACKGROUND: Frailty is associated with significant morbidity and mortality and may have clinical implications in an advanced age population with atrial fibrillation undergoing left atrial appendage occlusion (LAAO). We sought to develop a novel frailty scale to predict worse outcomes in patients undergoing LAAO. METHODS: Patients in the NCDR LAAO Registry between 2016 and 2021 receiving percutaneous LAAO devices were categorized as non-frail (0 points), pre-frail (1-3 points), or frail (4-5 points) based on a 5-point scale representing multiple domains of frailty: hemoglobin <13.0 g/dL in male, <12.0 g/dL in female; creatinine ≥1.2 mg/dL; albumin <3.5 g/dL; body mass index <20 kg/m2; and increased risk of falls. RESULTS: Of 57,728 patients, 44,360 (76.8%) were pre-frail and 7693 (13.3%) were frail. Compared to non-frail, pre-frail and frail patients were older, had a higher burden of co-morbidities, and more disability based on the Modified Rankin Scale. Compared to non-frail patients after adjustment, frail patients were at higher risk of in-hospital major complication (OR 1.29, 95% 1.02-1.62, p = 0.01), any complication (OR 1.29, 95% CI 1.09-1.52, p = 0.0005), and death (OR 5.79, 95% CI 1.75-19.17, p = 0.001), while no difference was observed in pre-frail patients. At 45-day follow-up, there was no difference in the risk of complications in frail patients as compared to non-frail, although mortality was significantly higher (OR 3.01, 95% CI 1.97-4.85, p < 0.0001). CONCLUSION: A simple and practical frailty scale accurately predicts adverse events in patients undergoing LAAO. The 13% of patients considered frail were at significantly higher risk of in-hospital adverse events and 45-day mortality.

Folate and vitamin B12 status and predicted neural tube defects risk among nonpregnant women of reproductive age from the Malawi National Micronutrient Survey, 2015-2016.

BACKGROUND: Maternal folate and vitamin B12 deficiency can lead to serious adverse pregnancy outcomes. There are no nationally representative estimates on folate and vitamin B12 status among women of reproductive age (WRA) in Malawi. OBJECTIVE: We assessed folate and vitamin B12 status among nonpregnant WRA in Malawi and predicted the risk of folate-sensitive neural tube defects (NTDs) were they to become pregnant. METHODS: Using data from the cross-sectional, nationally representative 2015-2016 Malawi Micronutrient Survey, we calculated the proportion of folate and vitamin B12 deficiency and insufficiency by demographic characteristics among 778 nonpregnant WRA (15-49 years). We predicted NTD prevalence using red blood cell (RBC) folate distributions and a published Bayesian model of the association between RBC folate and NTD risk. Analyses accounted for complex survey design. RESULTS: Among WRA, 8.5% (95% CI: 6.2, 11.6) and 13.3% (10.0, 17.4) had serum (<7 nmol/L) and RBC folate (<305 nmol/L) deficiency, respectively. The proportion of vitamin B12 deficiency (<148 pmol/L) and insufficiency (≤221 pmol/L) was 11.8% (8.6, 16.0) and 40.6% (34.1, 47.4), respectively. RBC folate insufficiency (<748 nmol/L, defined as the concentration associated with the threshold for elevated NTD risk: >8 cases per 10,000 births) was widespread: 81.4% (75.0, 86.4). The predicted NTD risk nationally was 24.7 cases per 10,000 live births. RBC folate insufficiency and higher predicted NTD risk were more common among WRA living in urban areas or with higher education. CONCLUSIONS: These findings highlight the importance of nutritional and NTD surveillance in Malawi and the opportunity for improving folate and vitamin B12 nutrition among Malawian WRA.

Procedure Volume and Outcomes With WATCHMAN Left Atrial Appendage Occlusion.

BACKGROUND: Procedure volumes are associated with outcomes for many cardiovascular procedures, leading to guidelines on minimum volume thresholds for certain procedures; however, the volume-outcome relationship with left atrial appendage occlusion is poorly understood. As such, we sought to determine the relationship between hospital and physician volume and WATCHMAN left atrial appendage occlusion procedural success overall and with the new generation WATCHMAN FLX device. METHODS: We performed an analysis of WATCHMAN procedures (January 2019 to October 2021) from the National Cardiovascular Data Registry LAAO Registry. Three-level hierarchical generalized linear models were used to assess the adjusted relationship between procedure volume and procedural success (device released with peridevice leak <5 mm, no in-hospital major adverse events). RESULTS: Among 87 480 patients (76.2±8.0 years; 58.8% men; mean CHA2DS2-VASc score, 4.8±1.5) from 693 hospitals, the procedural success rate was 94.2%. With hospital volume Q4 (greatest volume) as the reference, the likelihood of procedural success was significantly less among Q1 (odds ratio [OR], 0.66 [CI, 0.57-0.77]) and Q2 (OR, 0.78 [CI, 0.69-0.90]) but not Q3 (OR, 0.95 [CI, 0.84-1.07]). With physician volume Q4 (greatest volume) as the reference, the likelihood of procedural success was significantly less among Q1 (OR, 0.72 [CI, 0.63-0.82]), Q2 (OR, 0.79 [CI, 0.71-0.89]), and Q3 (OR, 0.88 [CI, 0.79-0.97]). Among WATCHMAN FLX procedures, there was attenuation of the volume-outcome relationships, with statistically significant but modest absolute differences of only ≈1% across volume quartiles. CONCLUSIONS: In this contemporary national analysis, greater hospital and physician WATCHMAN volumes were associated with increased procedure success. The WATCHMAN FLX transition was associated with increased procedural success and less heterogeneity in outcomes across volume quartiles. These findings indicate the importance of understanding the volume-outcome relationship for individual left atrial appendage occlusion devices.

Association of Physician Certification and Outcomes Among Patients Undergoing Left Atrial Appendage Occlusion.

BACKGROUND: Percutaneous left atrial appendage occlusion (LAAO) is indicated in patients with atrial fibrillation for whom long-term oral anticoagulation is contraindicated. Whether outcomes are different based on operator certification [interventional cardiology (IC) versus electrophysiology (EP)] is unclear. OBJECTIVES: To compare LAAO outcomes by physician certification (EP versus IC) in the NCDR LAAO Registry. METHODS: We identified patients from 2020-2022 undergoing implantation of a Watchman FLX or Amulet LAAO device and stratified patients by primary operator certification. Outcomes of interest included: (1) any major adverse event (MAE), 2) mortality, 3) ischemic stroke, and 4) major bleeding during the initial hospitalization and at 45 days. We performed multivariable Cox proportional hazards regression analysis to determine the risk of adverse events by physician certification. RESULTS: A total of 1,638 physicians (57% electrophysiologists) performing 91,711 procedures during the study period were included. EPs were more likely to use intracardiac echocardiography (25.2% vs 9.7%, p<0.001) and had lower radiation total (235 mGy vs 305 mGy, p<0.001). EPs were more likely than ICs to discharge patients on DOAC+aspirin, whereas ICs were more likely to discharge patients on single or dual antiplatelet therapy (all p<0.001). In-hospital death (0.1% vs. 0.1%, p=0.46) and MAE (1.5% vs 1.6%, p=0.42) were similar by physician certification. At 45 days, there was no difference in death [HRdeath 1.03, 95% CI (0.89-1.2)] or MAE [HRMAE 0.97, 95% CI (0.91-1.03)] after multivariable regression. CONCLUSIONS: Contemporary LAAO is safe with low rates of procedural complications and no significant differences in procedural outcomes by operator subspecialty after multivariable adjustment. Continued utilization of technology by EPs and ICs is necessary to allow for broad access to this treatment for eligible patients.

Predicting Major Adverse Events in Patients Undergoing Transcatheter Left Atrial Appendage Occlusion.

BACKGROUND: The National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry (LAAO) includes the vast majority of transcatheter LAAO procedures performed in the United States. The objective of this study was to develop a model predicting adverse events among patients undergoing LAAO with Watchman FLX. METHODS: Data from 41 001 LAAO procedures with Watchman FLX from July 2020 to September 2021 were used to develop and validate a model predicting in-hospital major adverse events. Randomly selected development (70%, n=28 530) and validation (30%, n=12 471) cohorts were analyzed with 1000 bootstrapped samples, using forward stepwise logistic regression to create the final model. A simplified bedside risk score was also developed using this model. RESULTS: Increased age, female sex, low preprocedure hemoglobin, no prior attempt at atrial fibrillation termination, and increased fall risk most strongly predicted in-hospital major adverse events and were included in the final model along with other clinically relevant variables. The median in-hospital risk-standardized adverse event rate was 1.50% (range, 1.03%-2.84%; interquartile range, 1.42%-1.64%). The model demonstrated moderate discrimination (development C-index, 0.67 [95% CI, 0.65-0.70] and validation C-index, 0.66 [95% CI, 0.62-0.70]) with good calibration. The simplified risk score was well calibrated with risk of in-hospital major adverse events ranging from 0.26% to 3.90% for a score of 0 to 8, respectively. CONCLUSIONS: A transcatheter LAAO risk model using National Cardiovascular Data Registry and LAAO Registry data can predict in-hospital major adverse events, demonstrated consistency across hospitals and can be used for quality improvement efforts. A simple bedside risk score was similarly predictive and may inform shared decision-making.

Differential drug-drug interactions of the synthetic Cannabinoids JWH-018 and JWH-073: implications for drug abuse liability and pain therapy.

Marijuana substitutes often contain blends of multiple psychoactive synthetic cannabinoids (SCBs), including the prevalent SCBs (1-pentyl-1H-indole-3-yl)-1-naphthalenyl-methanone (JWH-018) and (1-butyl-1H-indole-3-yl)-1-naphthalenyl-methanone (JWH-073). Because SCBs are frequently used in combinations, we hypothesized that coadministering multiple SCBs induces synergistic drug-drug interactions. Drug-drug interactions between JWH-018 and JWH-073 were investigated in vivo for Δ(9)-tetrahydrocannabinol (Δ(9)-THC)-like discriminative stimulus effects, analgesia, task disruption, and hypothermia. Combinations (JWH-018:JWH-073) of these drugs were administered to mice in assays of Δ(9)-THC discrimination, tail-immersion, and food-maintained responding, and rectal temperatures were measured. Synergism occurred in the Δ(9)-THC discrimination assay for two constant dose ratio combinations (1:3 and 1:1). A 1:1 and 2:3 dose ratio induced additivity and synergy, respectively, in the tail-immersion assay. Both 1:1 and 2:3 dose ratios were additive for hypothermia, whereas a 1:3 dose ratio induced subadditive suppression of food-maintained responding. In vitro drug-drug interactions were assessed using competition receptor-binding assays employing mouse brain homogenates and cannabinoid 1 receptor (CB1R)-mediated inhibition of adenylyl cyclase activity in Neuro2A wild-type cells. Interestingly, synergy occurred in the competition receptor-binding assay for two dose ratios (1:5 and 1:10), but not in the adenylyl cyclase activity assay (1:5). Altogether, these data indicate that drug-drug interactions between JWH-018 and JWH-073 are effect- and ratio-dependent and may increase the relative potency of marijuana substitutes for subjective Δ(9)-THC-like effects. Combinations may improve the therapeutic profile of cannabinoids, considering that analgesia but not hypothermia or task disruption was potentiated. Importantly, synergy in the competition receptor-binding assay suggests multiple CB1R-SCB binding sites.

Regions of homozygosity identified by SNP microarray analysis aid in the diagnosis of autosomal recessive disease and incidentally detect parental blood relationships.

PURPOSE: The purpose of this study was to document the ability of single-nucleotide polymorphism microarray to identify copy-neutral regions of homozygosity, demonstrate clinical utility of regions of homozygosity, and discuss ethical/legal implications when regions of homozygosity are associated with a parental blood relationship. METHODS: Study data were compiled from consecutive samples sent to our clinical laboratory over a 3-year period. A cytogenetics database identified patients with at least two regions of homozygosity >10 Mb on two separate chromosomes. A chart review was conducted on patients who met the criteria. RESULTS: Of 3,217 single-nucleotide polymorphism microarrays, 59 (1.8%) patients met inclusion criteria. The percentage of homozygosity ranged from 0.9 to 30.1%, indicating parental relationships from distant to first-degree relatives. First-degree kinship was suspected in the parents of at least 11 patients with regions of homozygosity covering >21.3% of their autosome. In four patients from two families, homozygosity mapping discovered a candidate gene that was sequenced to identify a clinically significant mutation. CONCLUSION: This study demonstrates clinical utility in the identification of regions of homozygosity, as these regions may aid in diagnosis of the patient. This study establishes the need for careful reporting, thorough pretest counseling, and careful electronic documentation, as microarray has the capability of detecting previously unknown/unreported relationships.

Non-canonical functions of EZH2 in cancer.

Mutations in chromatin modifying genes frequently occur in many kinds of cancer. Most mechanistic studies focus on their canonical functions, while therapeutic approaches target their enzymatic activity. Recent studies, however, demonstrate that non-canonical functions of chromatin modifiers may be equally important and therapeutically actionable in different types of cancer. One epigenetic regulator that demonstrates such a dual role in cancer is the histone methyltransferase EZH2. EZH2 is a core component of the polycomb repressive complex 2 (PRC2), which plays a crucial role in cell identity, differentiation, proliferation, stemness and plasticity. While much of the regulatory functions and oncogenic activity of EZH2 have been attributed to its canonical, enzymatic activity of methylating lysine 27 on histone 3 (H3K27me3), a repressive chromatin mark, recent studies suggest that non-canonical functions that are independent of H3K27me3 also contribute towards the oncogenic activity of EZH2. Contrary to PRC2's canonical repressive activity, mediated by H3K27me3, outside of the complex EZH2 can directly interact with transcription factors and oncogenes to activate gene expression. A more focused investigation into these non-canonical interactions of EZH2 and other epigenetic/chromatin regulators may uncover new and more effective therapeutic strategies. Here, we summarize major findings on the non-canonical functions of EZH2 and how they are related to different aspects of carcinogenesis.

Tetrasomy 15q25.2→qter identified with SNP microarray in a patient with multiple anomalies including complex cardiovascular malformation.

We report on a male neonate with prenatally diagnosed mosaicism for a supernumerary marker chromosome and multiple congenital anomalies. Prenatal ultrasound imaging revealed a heart defect, pleural effusion, clubbed feet, and absent right kidney. Clinical cytogenetic analysis of amniocytes identified a marker chromosome present in 10 out of 15 cells analyzed. Clinical evaluation of the neonate revealed distinct facial features, complex heart defects, solitary left kidney, and arachnodactyly. Chromosome analysis of lymphocytes demonstrated an abnormal male karyotype with a marker chromosome present in all 24 cells examined. To identify the marker chromosome, SNP microarray analysis was performed which detected the presence of a two copy gain of 17.7 Mb of DNA from the distal long arm of chromosome 15 (15q25.2-qter). FISH analysis using a probe specific to the 15q26.3 region showed one signal on each normal 15q and two signals, one on each arm of the marker chromosome resulting in four copies. Distal tetrasomy 15q is rare. Only 11 cases have been described in the literature, all due to a supernumerary analphoid marker chromosome consisting of an inverted duplication of the distal long arm of chromosome 15. We report on a unique patient with tetrasomy 15q with complex cardiovascular malformation (CVM) involving progressive diffuse pulmonary vein stenosis (PVS). We propose overexpression of three genes, ADAMTSL3, MESP1, and MESP2 as a potential mechanism for cardiac and vessel malformations associated with tetrasomy 15q. Finally, we believe cardiac defects with this genetic syndrome are a poor prognostic finding associated with high mortality.

The clinical phenotype of children with Fanconi anemia caused by biallelic FANCD1/BRCA2 mutations.

Fanconi anemia (FA) is characterized by progressive marrow failure, congenital anomalies, and predisposition to malignancy. Biallelic FANCD1/BRCA2 mutations are the genetic basis of disease in a small proportion of children with FA with earlier onset and increased incidence of leukemia and solid tumors. Patients with FA have increased sensitivity to chemotherapy and radiation, and upon development of a solid tumor, require modification of these therapies. We report clinical and molecular features of three patients with FA associated with FANCD1/BRCA2 mutations, including two novel mutations, and discuss treatment of malignancy and associated side effects in this particularly vulnerable group.

Ezh2Y641F mutations co-operate with Stat3 to regulate MHC class I antigen processing and alter the tumor immune response in melanoma.

Enhancer of Zeste Homolog 2 (EZH2) is the catalytic component of the Polycomb Repressive Complex 2, a chromatin modifying complex, which mediates methylation of lysine 27 on histone 3 (H3K27me3), a repressive chromatin mark. Genetic alterations in EZH2 in melanoma include amplifications and activating point mutations at tyrosine 641 (Y641) whose underlying oncogenic mechanisms remain largely unknown. Here, we found that expression of Ezh2Y641F causes upregulation of a subset of interferon-regulated genes in melanoma cells. Upregulation of these genes was not a direct effect of changes in H3K27me3, but via a non-canonical interaction between Ezh2 and Signal Transducer and Activator of Transcription 3 (Stat3). Ezh2 and Stat3 together function as transcriptional activators to mediate gene activation of numerous genes, including MHC Class 1b antigen processing genes. Furthermore, expression of Stat3 is required to maintain an anti-tumor immune response in Ezh2Y641F melanomas and to prevent melanoma progression and recurrence.

Periprocedural Pericardial Effusion Complicating Transcatheter Left Atrial Appendage Occlusion: A Report From the NCDR LAAO Registry.

BACKGROUND: Pericardial effusion (PE) is a potential complication of transcatheter left atrial appendage occlusion. The objective of this study was to investigate the incidence, associated characteristics, and outcomes of PE following left atrial appendage occlusion. METHODS: Patients in the NCDR LAAO Registry who underwent a Watchman procedure between January 1, 2016 and December 31, 2019 were included. The primary outcome was in-hospital PE requiring intervention (percutaneous drainage or surgery). Odds ratios (ORs) were calculated for adverse event rates associated with PE. RESULTS: The study population consisted of 65 355 patients. The mean patient age was 76.2±8.1 years, and the mean CHA2DS2-VASc score was 4.6±1.5. PE occurred in 881 patients (1.35%). Clinical variables independently associated with PE included older age, female sex, left ventricular function, paroxysmal atrial fibrillation, prior bleeding, lower serum albumin, and preprocedural dual antiplatelet therapy; procedural variables included number of delivery sheaths used, sinus rhythm during the procedure, and moderate sedation rather than general anesthesia. PE was associated with increased risk of in-hospital stroke (OR, 6.58 [95% CI, 3.32-13.06]; P<0.0001), death (OR, 56.88 [95% CI, 39.79-81.32]; P<0.0001), and the composite of death, stroke, or systemic embolism (OR, 28.64 [95% CI, 21.24-38.61]; P<0.0001). PE during the index hospitalization was associated with increased risk of death (OR, 3.52 [95% CI, 2.23-5.54]; P<0.0001) and the composite of death, stroke, or systemic embolism (OR, 3.42 [95% CI, 2.31-5.07]; P<0.0001) between discharge and 45-day follow-up. CONCLUSIONS: In-hospital PE during transcatheter left atrial appendage occlusion is infrequent but associated with a substantially higher risk of adverse events, including in-hospital and early postdischarge mortality. Strategies to minimize PE are critical to improve the risk-benefit ratio for this therapy.