How snoRNAs can contribute to cancer at multiple levels.

snoRNAs are a class of non-coding RNAs known to guide site specifically RNA modifications such as 2'-O-methylation and pseudouridylation. Recent results regarding snoRNA alterations in cancer has been made available and suggest their potential evaluation as diagnostic and prognostic biomarkers. A large part of these data, however, was not consistently confirmed and failed to provide mechanistic insights on the contribution of altered snoRNA expression to the neoplastic process. Here, we aim to critically review the available literature on snoRNA in cancer focusing on the studies elucidating the functional consequences of their deregulation. Beyond the canonical guide function in RNA processing and modification we also considered additional roles in which snoRNA, in various forms and through different modalities, are involved and that have been recently reported.

Alterations of ribosomal RNA pseudouridylation in human breast cancer.

RNA modifications are key regulatory factors for several biological and pathological processes. They are abundantly represented on ribosomal RNA (rRNA), where they contribute to regulate ribosomal function in mRNA translation. Altered RNA modification pathways have been linked to tumorigenesis as well as to other human diseases. In this study we quantitatively evaluated the site-specific pseudouridylation pattern in rRNA in breast cancer samples exploiting the RBS-Seq technique involving RNA bisulfite treatment coupled with a new NGS approach. We found a wide variability among patients at different sites. The most dysregulated positions in tumors turned out to be hypermodified with respect to a reference RNA. As for 2'O-methylation level of rRNA modification, we detected variable and stable pseudouridine sites, with the most stable sites being the most evolutionary conserved. We also observed that pseudouridylation levels at specific sites are related to some clinical and bio-pathological tumor features and they are able to distinguish different patient clusters. This study is the first example of the contribution that newly available high-throughput approaches for site specific pseudouridine detection can provide to the understanding of the intrinsic ribosomal changes occurring in human tumors.

Atrial Natriuretic Peptides as a Bridge between Atrial Fibrillation, Heart Failure, and Amyloidosis of the Atria.

ANP is mainly synthesized by the atria, and upon excretion, it serves two primary purposes: vasodilation and increasing the renal excretion of sodium and water. The understanding of ANP's role in cardiac systems has improved considerably in recent decades. This review focuses on several studies demonstrating the importance of analyzing the regulations between the endocrine and mechanical function of the heart and emphasizes the effect of ANP, as the primary hormone of the atria, on atrial fibrillation (AF) and related diseases. The review first discusses the available data on the diagnostic and therapeutic applications of ANP and then explains effect of ANP on heart failure (HF) and atrial fibrillation (AF) and vice versa, where tracking ANP levels could lead to understanding the pathophysiological mechanisms operating in these diseases. Second, it focuses on conventional treatments for AF, such as cardioversion and catheter ablation, and their effects on cardiac endocrine and mechanical function. Finally, it provides a point of view about the delayed recovery of cardiac mechanical and endocrine function after cardioversion, which can contribute to the occurrence of acute heart failure, and the potential impact of restoration of the sinus rhythm by extensive ablation or surgery in losing ANP-producing sites. Overall, ANP plays a key role in heart failure through its effects on vasodilation and natriuresis, leading to a decrease in the activity of the renin-angiotensin-aldosterone system, but it is crucial to understand the intimate role of ANP in HF and AF to improve their diagnosis and personalizing the patients' treatment.

Ribosomal RNA Pseudouridylation: Will Newly Available Methods Finally Define the Contribution of This Modification to Human Ribosome Plasticity?

In human rRNA, at least 104 specific uridine residues are modified to pseudouridine. Many of these pseudouridylation sites are located within functionally important ribosomal domains and can influence ribosomal functional features. Until recently, available methods failed to reliably quantify the level of modification at each specific rRNA site. Therefore, information obtained so far only partially explained the degree of regulation of pseudouridylation in different physiological and pathological conditions. In this focused review, we provide a summary of the methods that are now available for the study of rRNA pseudouridylation, discussing the perspectives that newly developed approaches are offering.

In vitro thrombogenicity of drug-eluting and bare metal stents.

AIMS: We sought to investigate the thrombogenicity of different DES and BMS in an in vitro system of stent perfusion. MATERIAL AND METHODS: The experimental model consisted of a peristaltic pump connected to 4 parallel silicone tubes in which different stents were deployed. Blood was drawn from healthy volunteers and the amount of stent surfaced-induced thrombus deposition was determined using 125I-fibrinogen. RESULTS: Compared to Resolute, Biomatrix and Vision, Xience was associated with the lowest amount of stent surface-induced thrombus formation, with a significant difference compared to Vision (125I-fibrinogen median value deposition [IQ range]: 50 ng [25-98] versus 560 ng [320-1520], respectively, p < 0.05), but not to other DES. In the second set of experiments Fluoropolymer-coated BMS not eluting drug was associated with a significant 3-fold reduction in 125I-fibrinogen deposition (245 ng [80-300]) compared to Vision (625 ng [320-760], p < 0.05), but a 7-fold increase compared to Xience (35 ng [20-60], p < 0.05). Finally Xience was associated with a significantly greater absorption of albumin compared to BMS. CONCLUSIONS: In an in vitro system of stent perfusion, Xience was associated with the lowest amount of stent surface-induced thrombus formation compared with Resolute, Biomatrix and Vision, with a noted synergistic effect between the fluoropolymer and the drug.

A Combined Targeted and Whole Exome Sequencing Approach Identified Novel Candidate Genes Involved in Heritable Pulmonary Arterial Hypertension.

The pathogenesis of idiopathic and heritable forms of pulmonary arterial hypertension is still not completely understood, even though several causative genes have been proposed, so that a third of patients remains genetically unresolved. Here we applied a multistep approach to extend identification of the genetic bases of such a disease by searching for novel candidate genes/pathways. Twenty-eight patients belonging to 18 families were screened for BMPR2 mutations and BMPR2-negative samples were tested for 12 additional candidate genes by means of a specific massive parallel sequencing-based assay. Finally, whole exome sequencing was performed on four patients showing no mutations at known disease genes, as well as on their unaffected parents. In addition to EIF2AK4, which has been already suggested to be associated with pulmonary veno-occlusive disease, we identified the novel candidate genes ATP13A3, CD248, EFCAB4B, involved in lung vascular remodeling that represent reliable drivers contributing to the disease according to their biological functions/inheritance patterns. Therefore, our results suggest that combining gene panel and whole exome sequencing provides new insights useful for the genetic diagnosis of familial and idiopathic pulmonary arterial hypertension, as well as for the identification of biological pathways that will be potentially targeted by new therapeutic strategies.

Effects of statin therapy on platelet reactivity after percutaneous coronary revascularization in patients with acute coronary syndrome.

Statin use is associated with enhanced pharmacodynamic response to clopidogrel in patients with stable coronary artery disease undergoing percutaneous coronary intervention (PCI). However, the impact of statin therapy on clopidogrel response profiles in patients with acute coronary syndrome (ACS) undergoing PCI has not been established and represents the objective of this investigation. On-treatment P2Y12 platelet reactivity was measured using the vasodilator stimulated phosphoprotein (VASP) phosphorylation assay before PCI, at hospital discharge, and at 1 month after PCI in ACS patients enrolled in the multicenter, prospective GEne polymorphisms, Platelet Reactivity, and Syntax Score (GEPRESS) study (n = 962). High platelet reactivity (HPR) was defined as platelet reactivity index ≥50%. Statins were prescribed at hospital discharge in 87% (n = 835) of patients. All patients were followed for 1 year. The 1-month HPR rate was lower in statin than in non-statin treated patients (39.6 vs 52%, respectively, p = 0.009). This finding was confirmed also among statin-treated patients with high Syntax score (≥15). After adjustment for differences in baseline characteristics, statin use at discharge was independently associated with 1-month HPR rate (odds ratio, 0.58, 95% confidence interval, 0.38-0.89; p = 0.015). In ACS patients undergoing PCI treated with clopidogrel the use of statins at discharge was associated with significantly lower 1-month HPR rates compared with patients not treated with statins.

Relationship between diabetes, platelet reactivity, and the SYNTAX score to one-year clinical outcome in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention.

AIMS: In patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) treated with PCI, high (H) platelet reactivity (PR) significantly affects one-year outcome. The aim of this report was to analyse the relationships between HPR, the SYNTAX score (SS) and one-year major adverse cardiac events (MACE: cardiac death, myocardial infarction, stent thrombosis) according to diabetes mellitus (DM) status in patients included in the GEne Polymorphism, Platelet REactivity, and the Syntax Score (GEPRESS) study. METHODS AND RESULTS: PR was measured using the vasodilator-stimulated phosphoprotein (VASP) assay at three time points (before PCI, at hospital discharge and at one month after PCI), with HPR defined as >50% PR index in 1,042 patients treated with aspirin and clopidogrel for one year after PCI. Patients with DM and an SS ≥15 had the highest MACE rate between one month and one year, further increased by the presence of HPR (16.4%). On the other hand, among all patients with an SS <15, MACE rates remained low (<3%), irrespective of DM status and PR. CONCLUSIONS: Among NSTE-ACS patients treated with PCI, the combination of DM, an SS ≥15 and HPR characterised a cohort with the highest MACE rate from one month to one year. In such high-risk patients, careful clinical monitoring and implementation of secondary prevention measures, including the use of potent P2Y12 inhibitors, are strongly advised.

Non-BMPR2 mutation heritable pulmonary arterial hypertension in Southeast Asia.

A 29-year-old Thai man presented with progressive dyspnea and evidence of pulmonary hypertension. Computed tomography was negative for pulmonary embolism. Cardiac catheterization confirmed the diagnosis of pulmonary arterial hypertension (mean pulmonary artery pressure 54 mm Hg, left ventricular end-diastolic pressure 4 mm Hg, and pulmonary vascular resistance 25 Wood units) without an intracardiac shunt. Two family members had been previously diagnosed with pulmonary hypertension. There was no evidence of left heart disease or respiratory disorders. Based on the definite diagnosis of pulmonary hypertension in 3 family members, heritable pulmonary arterial hypertension was confirmed. Genetic testing indicated no BMPR2 mutation.

Impact of gene polymorphisms, platelet reactivity, and the SYNTAX score on 1-year clinical outcomes in patients with non-ST-segment elevation acute coronary syndrome undergoing percutaneous coronary intervention: the GEPRESS study.

OBJECTIVES: The aim of this study was to investigate the association between high on-treatment platelet reactivity (HPR) and the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (SS) for risk prediction of major adverse cardiovascular events (MACE) in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) undergoing percutaneous coronary intervention (PCI). BACKGROUND: Platelet function testing may be used to optimize antiplatelet therapy in high-risk patients, but identification of this category of patients remains challenging. METHODS: The GEPRESS (Gene Polymorphism, Platelet Reactivity, and the Syntax Score) study was a prospective, multicenter, observational study enrolling 1,053 patients with NSTEACS undergoing PCI and treated with clopidogrel. The platelet reactivity index (PRI) was measured at 3 time points: before PCI, at hospital discharge, and 1 month after PCI. Genetic variants of clopidogrel metabolism were determined in 750 patients. Patients were stratified by the presence of HPR (PRI >50%) and by tertile of the SS (upper SS tertile ≥15). The primary objective of this study was the risk of MACE in the period between 1 month and 1 year. RESULTS: Between 1 month and 1 year, 1-month HPR was an independent predictor of MACE in patients with an SS ≥15, but not in those with an SS <15, displaying a 5-fold increase in event rates (10.4% vs. 2.5%; p < 0.0001). CYP2C19*2 was the only single nucleotide polymorphism associated with HPR, but it was not associated with MACE. Although there was a significant variability in the PRI across the 1-month period, predischarge HPR and SS effectively stratified the risk of subsequent MACE up to 1-year follow-up. CONCLUSIONS: In clopidogrel-treated patients with NSTEACS undergoing PCI, HPR was independently associated with an increased risk of MACE only in the presence of a high SS.

Detection of tissue factor antigen and coagulation activity in coronary artery thrombi isolated from patients with ST-segment elevation acute myocardial infarction.

INTRODUCTION: Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention. METHODS: Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients) or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients). Immunoprecipitation followed by immunoblotting was also performed in 12 patients. RESULTS: Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9) were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; p<0.001). Tissue factor was also identified by immunoprecipitation in 10 patients, with significant variability among band intensities. CONCLUSIONS: Active tissue factor is present in coronary artery thrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to activate the coagulation cascade ensuing in coronary thrombosis.

A randomised study comparing the antiplatelet and antiinflammatory effect of clopidogrel 150 mg/day versus 75 mg/day in patients with ST-segment elevation acute myocardial infarction and poor responsiveness to clopidogrel: results from the DOUBLE study.

INTRODUCTION: The antiplatelet effect of standard or increased clopidogrel doses in patients with ST- segment elevation acute myocardial infarction (STEMI) has never been studied. In this study we compared the antiplatelet effect of a 75 mg daily maintenance dose of clopidogrel with 150 mg in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). MATERIALS AND METHODS: Fifty-four patients with STEMI undergoing PCI were randomly allocated to receive either 75 mg/day clopidogrel (group 1) or 150 mg/day (group 2) for 1 month. Platelet function, measured by 5 different assays, was determined at 3 time points: 38+/-8 hours after the procedure, 1 week and 1 month after randomization. RESULTS: In group 1, mean +/- SD platelet reactivity index (PRI) measured with the VASP assay was 57.7+/-15.7% and 46.9+/-15.7% at 1 week and 1 month, respectively, compared to 38.8+/-15.7% and 34.9+/-12.6% in group 2 (p=0.0001). Same results were observed for light transmittance aggregometry, whole blood aggregometry and VerifyNow, but not for thromboelastometry. In contrast to what may be expected, the 75 mg daily maintenance dose took longer than 1-week to provide the full clopidogrel antiplatelet effect. Furthermore, patients in group 2 had a nearly 50% reduction in C-reactive protein levels both at 1 week and 1 month. CONCLUSION: In patients with STEMI and poor responsiveness to clopidogrel a 150 mg daily maintenance dose of clopidogrel is associated with a significant reduction of platelet aggregation and a trend towards reduced inflammation.

Expression, regulation, and function of alpha V integrins in hepatocellular carcinoma: an in vivo and in vitro study.

The expression of alpha V integrins by neoplastic cells contributes to the promotion of local invasion and metastasis. The most characteristic extracellular ligands of alpha V integrins are vitronectin and fibronectin. Hepatocytes are the main source of vitronectin, and the capacity to synthesize and secrete vitronectin is usually retained in hepatocellular carcinoma. The aim of this study was to explore the expression, regulation, and functional role of alpha V integrins in hepatocellular carcinoma. We first analyzed the expression of alpha V integrins and their ligands fibronectin and vitronectin in 80 cases of hepatocellular carcinoma. alpha V integrin chain was detected in 44 cases and vitronectin in 50. Twenty-four of the 44 alpha V-positive tumors contained large amounts of vitronectin. These cases presented more frequently with adverse histoprognostic factors, including infiltrative growth pattern (62.5%), lack of capsule (71%), presence of capsular invasion (57%), and satellite nodules (50%). We then used HepG2 and Hep3B cell lines as in vitro models to study alpha V integrin regulation and function. HepG2 and Hep3B cells expressed alpha V integrin chain and used alpha V beta 1 and alpha V beta 5 for adhesion and migration on vitronectin. Tumor necrosis factor (TNF) alpha and transforming growth factor (TGF) beta significantly increased the expression levels of alpha V integrins and stimulated the adhesion and migration of both HepG2 and Hep3B cell lines on vitronectin. The effects of growth factors on cell adhesion and migration were reproduced by incubation with conditioned medium from rat liver myofibroblasts. In conclusion, our results support the existence of an alpha V integrin/vitronectin connection in hepatocellular carcinoma and suggest that this connection may be an adverse prognostic factor.

Relevance of biologic markers in colorectal carcinoma: a comparative study of a broad panel.

BACKGROUND: Although pathologic stage is currently the main prognostic indicator for patients with colorectal carcinoma (CRC), mounting evidence suggests that, in its current form, it is insufficient to predict clinical outcome. To assess biologic markers of primary CRC that may improve clinical staging and provide useful information for the application of novel therapeutic strategies, the authors investigated a panel of markers that included transforming growth factor alpha (TGF alpha), epithelial growth factor receptor (EGF-R; the protein product of the c-erb B2/HER-2 oncogene), matrix metalloproteinase 2 (MMP-2), insulin-like growth factor II (IGF-II), vascular endothelial growth factor (VEGF), and angiogenesis, as evaluated by microvessel density (MVD). METHODS: Two groups of CRC were studied: 1) surgical samples from patients who achieved a disease free survival of at least 6 years (CRC-M0) and 2) surgical specimens of both primary tumors and synchronous or metachronous liver metastases (CRC-M1). RESULTS: Chi-square analysis revealed that expression levels of TGF-alpha, c-erb B2/HER-2, MMP-2, IGF-II, VEGF, and MVD (but not EGF-R) were significantly higher in CRC-M1 samples compared with CRC-M0 samples (P < 0.001, P < 0.05, P < 0.001, P < 0.001, P < 0.01, and P < 0.001, respectively). Logistic regression analysis showed that TGF-alpha, IGF-II, and MMP-2 had significantly greater expression in CRC-M1 samples independent of the other variables (including tumor classification, histologic grade, and patient age). If all three markers had > or = 25% expression, then the probability of developing liver metastasis was 99.5%. CONCLUSIONS: Based on the evidence of this study, TGF-alpha MMP-2, and IGF-II seem suitable candidates for a selective panel of markers designed to provide significant additional information with respect to the current pathologic staging system for patients with colorectal carcinoma.