Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
PLoS Comput Biol ; 20(5): e1012059, 2024 May.
Article in English | MEDLINE | ID: mdl-38753883

ABSTRACT

The eukaryotic mRNA life cycle includes transcription, nuclear mRNA export and degradation. To quantify all these processes simultaneously, we perform thiol-linked alkylation after metabolic labeling of RNA with 4-thiouridine (4sU), followed by sequencing of RNA (SLAM-seq) in the nuclear and cytosolic compartments of human cancer cells. We develop a model that reliably quantifies mRNA-specific synthesis, nuclear export, and nuclear and cytosolic degradation rates on a genome-wide scale. We find that nuclear degradation of polyadenylated mRNA is negligible and nuclear mRNA export is slow, while cytosolic mRNA degradation is comparatively fast. Consequently, an mRNA molecule generally spends most of its life in the nucleus. We also observe large differences in the nuclear export rates of different 3'UTR transcript isoforms. Furthermore, we identify genes whose expression is abruptly induced upon metabolic labeling. These transcripts are exported substantially faster than average mRNAs, suggesting the existence of alternative export pathways. Our results highlight nuclear mRNA export as a limiting factor in mRNA metabolism and gene regulation.


Subject(s)
Active Transport, Cell Nucleus , Cell Nucleus , RNA, Messenger , RNA, Messenger/metabolism , RNA, Messenger/genetics , Humans , Cell Nucleus/metabolism , RNA Stability/genetics , 3' Untranslated Regions/genetics , Cell Line, Tumor , Cytosol/metabolism
2.
Front Cardiovasc Med ; 10: 1265452, 2023.
Article in English | MEDLINE | ID: mdl-38155989

ABSTRACT

Background: Previous trials investigating antithrombotic therapy with a direct oral anticoagulant (DOAC) and a P2Y12 inhibitor after percutaneous coronary intervention (PCI), termed dual therapy, allowed a short period of triple therapy including a DOAC, a P2Y12 inhibitor, and aspirin. Aims: This study aimed to determine whether discontinuation of aspirin on the first post-procedural day is safe or causes ischemic events. Methods: Ischemic and bleeding events during hospitalization were investigated retrospectively in all patients treated with dual therapy (DOAC + P2Y12 inhibitor, designated as group 1) or triple therapy (DOAC + P2Y12 inhibitor+aspirin, designated as group 2) from day 1 after PCI at our center. Results: Of 4,564 consecutive PCI procedures, 1,059 (23.2%) had an indication for OAC. Of these, 322 met the inclusion criteria for group 1 and 62 for group 2. Baseline characteristics, CHA2DS2-VASc and HAS-BLED scores showed no relevant differences between the two groups, and the main indication for DOAC therapy was atrial fibrillation in both groups. Approximately » of patients were treated for acute coronary syndrome. The mean length of post-procedural hospitalization was 2.1 ± 2.5 and 2.2 ± 3.0 days in group 1 and 2, respectively (p = 0.305). One patient per group suffered a TIA (p = 0.297). There were no other ischemic events and no statistically significant differences in bleeding events. A subgroup analysis of cases hospitalized for ≥2 post-procedural days (group 1: 100 cases, mean 4.4 ± 3.4 days vs. group 2: 25 cases, mean 4.0 ± 4.1 days) confirmed these results. Conclusion: The initiation of dual therapy and thus discontinuation of aspirin on the first postprocedural day appears to be safe with respect to short-term ischemic events in a real-world population. Almost » of patients undergoing PCI have an indication for OAC, highlighting the relevance of this issue.

3.
G3 (Bethesda) ; 12(5)2022 05 06.
Article in English | MEDLINE | ID: mdl-35253846

ABSTRACT

Alu elements are one of the most successful groups of RNA retrotransposons and make up 11% of the human genome with over 1 million individual loci. They are linked to genetic defects, increases in sequence diversity, and influence transcriptional activity. Still, their RNA metabolism is poorly understood yet. It is even unclear whether Alu elements are mostly transcribed by RNA Polymerase II or III. We have conducted a transcription shutoff experiment by α-amanitin and metabolic RNA labeling by 4-thiouridine combined with RNA fragmentation (TT-seq) and RNA-seq to shed further light on the origin and life cycle of Alu transcripts. We find that Alu RNAs are more stable than previously thought and seem to originate in part from RNA Polymerase II activity, as previous reports suggest. Their expression however seems to be independent of the transcriptional activity of adjacent genes. Furthermore, we have developed a novel statistical test for detecting the expression of quantitative trait loci in Alu elements that relies on the de Bruijn graph representation of all Alu sequences. It controls for both statistical significance and biological relevance using a tuned k-mer representation, discovering influential sequence features missed by regular motif search. In addition, we discover several point mutations using a generalized linear model, and motifs of interest, which also match transcription factor-binding motifs.


Subject(s)
RNA Polymerase II , RNA , Alu Elements/genetics , Humans , RNA/genetics , RNA Polymerase II/metabolism , Retroelements/genetics , Transcription, Genetic
4.
World J Radiol ; 14(12): 375-383, 2022 Dec 28.
Article in English | MEDLINE | ID: mdl-36605886

ABSTRACT

BACKGROUND: Bleeding in the gastrointestinal tract is common and transarterial embolization enables the clinician to control gastrointestinal bleeding. Contrast extravasation is a prerequisite for successful embolization. Provocative angiography is helpful in the detection of elusive bleeding. AIM: We performed a retrospective analysis of angiographic treatment in patients with lower gastrointestinal hemorrhage and initially negative angiographies, as well as the role of norepinephrine (NE) in unmasking bleeding. METHODS: We analyzed 41 patients with lower gastrointestinal bleeding after angiography who had undergone treatment over a period of 10 years. All patients had a positive shock index and needed intensive care. RESULTS: In three of four patients, angiography disclosed the site of bleeding when NE was used during the procedure for hemodynamic stabilization. CONCLUSION: We suggest that angiography performed after the administration of NE in unstable patients with gastrointestinal bleeding and an initially negative angiography has the potential to unmask bleeding sites for successful embolization. However, this statement must be confirmed in prospective studies.

5.
World J Gastrointest Endosc ; 13(7): 221-232, 2021 Jul 16.
Article in English | MEDLINE | ID: mdl-34326943

ABSTRACT

BACKGROUND: The large majority of gastrointestinal bleedings subside on their own or after endoscopic treatment. However, a small number of these may pose a challenge in terms of therapy because the patients develop hemodynamic instability, and endoscopy does not achieve adequate hemostasis. Interventional radiology supplemented with catheter angiography (CA) and transarterial embolization have gained importance in recent times. AIM: To evaluate clinical predictors for angiography in patients with lower gastrointestinal bleeding (LGIB). METHODS: We compared two groups of patients in a retrospective analysis. One group had been treated for more than 10 years with CA for LGIB (n = 41). The control group had undergone non-endoscopic or endoscopic treatment for two years and been registered in a bleeding registry (n = 92). The differences between the two groups were analyzed using decision trees with the goal of defining clear rules for optimal treatment. RESULTS: Patients in the CA group had a higher shock index, a higher Glasgow-Blatchford bleeding score (GBS), lower serum hemoglobin levels, and more rarely achieved hemostasis in primary endoscopy. These patients needed more transfusions, had longer hospital stays, and had to undergo subsequent surgery more frequently (P < 0.001). CONCLUSION: Endoscopic hemostasis proved to be the crucial difference between the two patient groups. Primary endoscopic hemostasis, along with GBS and the number of transfusions, would permit a stratification of risks. After prospective confirmation of the present findings, the use of decision trees would permit the identification of patients at risk for subsequent diagnosis and treatment based on interventional radiology.

6.
Histopathology ; 78(4): 578-585, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32946634

ABSTRACT

AIMS: The advent of specific ALK-targeting drugs has radically changed the outcome of patients with ALK translocated non-small-cell lung cancer (NSCLC). However, emerging resistance to treatment with ALK inhibitors in these patients remains a major concern. In previous studies, we analysed two ALK+ patient cohorts (TP53 wild-type/TP53 mutated) in terms of copy number alterations. All patients belonging to the TP53 wild-type group had mainly genetically stable genomes, with one exception showing chromosomal instability and amplifications of several gene loci, including TERT. Here, we aimed to determine the prevalence of TERT amplifications in these ALK+ lung cancer patients by analysing an independent cohort of 109 ALK translocated cases. We further analysed the copy numbers of numerous cancer-relevant genes and other genetic aberrations. METHODS AND RESULTS: The prevalence of TERT amplifications was determined by means of FISH analyses. Copy numbers of 87 cancer-relevant genes were determined by NanoString nCounter® technology, FoundationOne® and lung-specific NGS panels in some of these TERT-amplified samples, and clinical data on patients with TERT-amplified tumours were collected. Our data revealed that five (4.6%) of all 109 analysed ALK+ patients harboured amplification of TERT and that these patients had genetically unstable genomes. CONCLUSIONS: Our preliminary study shows that ALK+ adenocarcinomas should be evaluated in the context of their genomic background in order to more clearly understand and predict patients' individual course of disease.


Subject(s)
Adenocarcinoma of Lung/genetics , Anaplastic Lymphoma Kinase/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/genetics , Telomerase/genetics , Adenocarcinoma of Lung/pathology , Anaplastic Lymphoma Kinase/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Humans , In Situ Hybridization, Fluorescence , Lung/pathology , Lung Neoplasms/pathology , Telomerase/metabolism , Translocation, Genetic
7.
Front Cardiovasc Med ; 8: 744181, 2021.
Article in English | MEDLINE | ID: mdl-35004875

ABSTRACT

Objective: The aim of this study was to evaluate non-hyperemic resting pressure ratios (NHPRs), especially the novel "resting full-cycle ratio" (RFR; lowest pressure distal to the stenosis/aortic pressure during the entire cardiac cycle), compared to the gold standard fractional flow reserve (FFR) in a "real-world" setting. Methods: The study included patients undergoing coronary pressure wire studies at one German University Hospital. No patients were excluded based on any baseline or procedural characteristics, except for insufficient quality of traces. The diagnostic performance of four NHPRs vs. FFR ≤ 0.80 was tested. Morphological characteristics of stenoses were analyzed by quantitative coronary angiography. Results: 617 patients with 712 coronary lesions were included. RFR showed a significant correlation with FFR (r = 0.766, p < 0.01). Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of RFR were 78% (95% confidence interval = 75; 81), 72% (65; 78), 81% (77; 84), 63% (57; 69), and 86% (83; 89). Relevant predictors for discordance of RFR ≤ 0.89/FFR > 0.8 were LAD lesions, peripheral artery disease, age, female sex and non-focal stenoses. Predictors for discordance of RFR > 0.89/FFR ≤ 0.8 included non-LCX lesions, percent diameter stenosis and previous percutaneous coronary intervention in the target vessel. RFR and all other NHPRs were highly correlated with each other. Conclusion: All NHPRs have a similar correlation with the gold standard FFR and may facilitate the acceptance and implementation of physiological assessments of lesion severity. However, we found ~20% discordant results between NHPRs and FFR in our "all-comers" German cohort.

8.
J Thorac Dis ; 11(Suppl 1): S3-S8, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30775023

ABSTRACT

One distinct molecular subtype of non-small cell lung cancer (NSCLC) is defined by rearrangement of the anaplastic lymphoma kinase (ALK). The increasing knowledge over the last years has enabled the continuous improvement of ALK inhibitors; however, resistance in these patients remains a major concern. In this review, we summarize recent findings in ALK+-adenocarcinoma of the lung, highlighting the role of TP53 mutations in this specific cancer type and suggest new diagnostic strategies for the future, in order to improve patient's outcome.

9.
Mod Pathol ; 32(5): 627-638, 2019 05.
Article in English | MEDLINE | ID: mdl-30459450

ABSTRACT

Although non-small-cell lung cancer is a leading cause of cancer-related deaths, the molecular characterization and classification of its genetic alterations has drastically changed treatment options and overall survival within the last few decades. In particular, tyrosine kinase inhibitors targeting specific molecular alterations, among other MET, have greatly improved the prognosis of non-small-cell lung cancer patients. Here, we compare the genomic background of a subset of non-small-cell lung cancer cases harboring either a MET high-level amplification (n = 24) or a MET exon 14 skipping mutation (n = 26), using next-generatison sequencing, fluorescence in situ hybridization, immunohistochemistry, and Nanostring nCounter® technology. We demonstrate that the MET-amplified cohort shows a higher genetic instability, compared with the mutant cohort (p < 0.001). Furthermore, MET mutations occur at high allele frequency and in the presence of co-occurring TP53 mutations (n = 7), as well as MDM2 (n = 7), CDK4 (n = 6), and HMGA2 (n = 5) co-amplifications. No other potential driver mutation has been detected. Conversely, in the MET-amplified group, we identify co-occurring pathogenic NRAS and KRAS mutations (n = 5) and a significantly higher number of TP53 mutations, compared with the MET-mutant cohort (p = 0.048). Of note, MET amplifications occur more frequently as subclonal events. Interestingly, despite the significantly (p = 0.00103) older age at diagnosis of stage IIIb/IV of MET-mutant patients (median 77 years), compared with MET high-level amplified patients (median 69 years), MET-mutant patients with advanced-stage tumors showed a significantly better prognosis at 12 months (p = 0.04). In conclusion, the two groups of MET genetic alterations differ, both clinically and genetically: our data strongly suggest that MET exon 14 skipping mutations represent an early driver mutation. In opposition, MET amplifications occur usually in the background of other strong genetic events and therefore MET amplifications should be interpreted in the context of each tumor's genetic background, rather than as an isolated driver event, especially when considering MET-specific treatment options.


Subject(s)
Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Gene Amplification , Lung Neoplasms/genetics , Mutation , Proto-Oncogene Proteins c-met/genetics , Aged , Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Cyclin-Dependent Kinase 4/genetics , Female , GTP Phosphohydrolases/genetics , Genetic Predisposition to Disease , Genomic Instability , HMGA2 Protein/genetics , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Male , Membrane Proteins/genetics , Middle Aged , Molecular Targeted Therapy , Mutation Rate , Phenotype , Prognosis , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-mdm2/genetics , Proto-Oncogene Proteins c-met/antagonists & inhibitors , Proto-Oncogene Proteins p21(ras)/genetics , Retrospective Studies , Tumor Suppressor Protein p53/genetics
10.
J Pathol ; 246(1): 67-76, 2018 09.
Article in English | MEDLINE | ID: mdl-29885057

ABSTRACT

The anaplastic lymphoma kinase (ALK) rearrangement defines a distinct molecular subtype of non-small cell lung cancer (NSCLC). Despite the excellent initial efficacy of ALK inhibitors in patients with ALK+ lung cancer, resistance occurs almost inevitably. To date, there is no reliable biomarker allowing the identification of patients at higher risk of relapse. Here, we analysed a subset of 53 ALK+ tumours with and without TP53 mutation and ALK+ NSCLC cell lines by NanoString nCounter technology. We found that the co-occurrence of early TP53 mutations in ALK+ NSCLC can lead to chromosomal instability: 24% of TP53-mutated patients showed amplifications of known cancer genes such as MYC (14%), CCND1 (10%), TERT (5%), BIRC2 (5%), ORAOV1 (5%), and YAP1 (5%). MYC-overexpressing ALK+ TP53-mutated cells had a proliferative advantage compared to wild-type cells. ChIP-Seq data revealed MYC-binding sites within the promoter region of EML4, and MYC overexpression in ALK+ TP53-mutated cells resulted in an upregulation of EML4-ALK, indicating a potential MYC-dependent resistance mechanism in patients with increased MYC copy number. Our study reveals that ALK+ NSCLC represents a more heterogeneous subgroup of tumours than initially thought, and that TP53 mutations in that particular cancer type define a subset of tumours that harbour chromosomal instability, leading to the co-occurrence of pathogenic aberrations. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Subject(s)
Anaplastic Lymphoma Kinase/genetics , Biomarkers, Tumor/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Gene Amplification , Genomic Instability , Lung Neoplasms/genetics , Mutation , Proto-Oncogene Proteins c-myc/genetics , Translocation, Genetic , Tumor Suppressor Protein p53/genetics , Adult , Aged , Aged, 80 and over , Anaplastic Lymphoma Kinase/metabolism , Carcinoma, Non-Small-Cell Lung/enzymology , Carcinoma, Non-Small-Cell Lung/pathology , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cell Proliferation , Female , Genetic Predisposition to Disease , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/pathology , Male , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Middle Aged , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Phenotype , Proto-Oncogene Proteins c-myc/metabolism , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Signal Transduction , Tumor Suppressor Protein p53/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...