Therapeutic targeting of EP300/CBP by bromodomain inhibition in hematologic malignancies.

CCS1477 (inobrodib) is a potent, selective EP300/CBP bromodomain inhibitor which induces cell-cycle arrest and differentiation in hematologic malignancy model systems. In myeloid leukemia cells, it promotes rapid eviction of EP300/CBP from an enhancer subset marked by strong MYB occupancy and high H3K27 acetylation, with downregulation of the subordinate oncogenic network and redistribution to sites close to differentiation genes. In myeloma cells, CCS1477 induces eviction of EP300/CBP from FGFR3, the target of the common (4; 14) translocation, with redistribution away from IRF4-occupied sites to TCF3/E2A-occupied sites. In a subset of patients with relapsed or refractory disease, CCS1477 monotherapy induces differentiation responses in AML and objective responses in heavily pre-treated multiple myeloma. In vivo preclinical combination studies reveal synergistic responses to treatment with standard-of-care agents. Thus, CCS1477 exhibits encouraging preclinical and early-phase clinical activity by disrupting recruitment of EP300/CBP to enhancer networks occupied by critical transcription factors.

A TIAM1-TRIM28 complex mediates epigenetic silencing of protocadherins to promote migration of lung cancer cells.

Lung cancer is the leading cause of cancer deaths. Its high mortality is associated with high metastatic potential. Here, we show that the RAC1-selective guanine nucleotide exchange factor T cell invasion and metastasis-inducing protein 1 (TIAM1) promotes cell migration and invasion in the most common subtype of lung cancer, non-small-cell lung cancer (NSCLC), through an unexpected nuclear function. We show that TIAM1 interacts with TRIM28, a master regulator of gene expression, in the nucleus of NSCLC cells. We reveal that a TIAM1-TRIM28 complex promotes epithelial-to-mesenchymal transition, a phenotypic switch implicated in cell migration and invasion. This occurs through H3K9me3-induced silencing of protocadherins and by decreasing E-cadherin expression, thereby antagonizing cell-cell adhesion. Consistently, TIAM1 or TRIM28 depletion suppresses the migration of NSCLC cells, while migration is restored by the simultaneous depletion of protocadherins. Importantly, high nuclear TIAM1 in clinical specimens is associated with advanced-stage lung adenocarcinoma, decreased patient survival, and inversely correlates with E-cadherin expression.

Differentiation block in acute myeloid leukemia regulated by intronic sequences of FTO.

Iroquois transcription factor gene IRX3 is highly expressed in 20-30% of acute myeloid leukemia (AML) and contributes to the pathognomonic differentiation block. Intron 8 FTO sequences ∼220kB downstream of IRX3 exhibit histone acetylation, DNA methylation, and contacts with the IRX3 promoter, which correlate with IRX3 expression. Deletion of these intronic elements confirms a role in positively regulating IRX3. RNAseq revealed long non-coding (lnc) transcripts arising from this locus. FTO-lncAML knockdown (KD) induced differentiation of AML cells, loss of clonogenic activity, and reduced FTO intron 8:IRX3 promoter contacts. While both FTO-lncAML KD and IRX3 KD induced differentiation, FTO-lncAML but not IRX3 KD led to HOXA downregulation suggesting transcript activity in trans. FTO-lncAMLhigh AML samples expressed higher levels of HOXA and lower levels of differentiation genes. Thus, a regulatory module in FTO intron 8 consisting of clustered enhancer elements and a long non-coding RNA is active in human AML, impeding myeloid differentiation.

Identification of curaxin as a potential new therapeutic for JAK2 V617F mutant patients.

Myelofibrosis is a myeloproliferative neoplasm (MPN) which typically results in reduced length and quality of life due to systemic symptoms and blood count changes arising from fibrotic changes in the bone marrow. While the JAK2 inhibitor ruxolitinib provides some clinical benefit, there remains a substantial unmet need for novel targeted therapies to better modify the disease process or eradicate the cells at the heart of myelofibrosis pathology. Repurposing drugs bypasses many of the hurdles present in drug development, such as toxicity and pharmacodynamic profiling. To this end we undertook a re-analysis of our pre-existing proteomic data sets to identify perturbed biochemical pathways and their associated drugs/inhibitors to potentially target the cells driving myelofibrosis. This approach identified CBL0137 as a candidate for targeting Jak2 mutation-driven malignancies. CBL0137 is a drug derived from curaxin targeting the Facilitates Chromatin Transcription (FACT) complex. It is reported to trap the FACT complex on chromatin thereby activating p53 and inhibiting NF-kB activity. We therefore assessed the activity of CBL0137 in primary patient samples and murine models of Jak2-mutated MPN and found it preferentially targets CD34+ stem and progenitor cells from myelofibrosis patients by comparison with healthy control cells. Further we investigate its mechanism of action in primary haemopoietic progenitor cells and demonstrate its ability to reduce splenomegaly and reticulocyte number in a transgenic murine model of myeloproliferative neoplasms.

A three-gene leukaemic stem cell signature score is robustly prognostic in chronic myelomonocytic leukaemia.

Leukaemic stem cell (LSC) gene expression has recently been linked to prognosis in patients with acute myeloid leukaemia (17-gene LSC score, LSC-17) and myelodysplastic syndromes. Although chronic myelomonocytic leukaemia (CMML) is regarded as a stem cell disorder, the clinical and biological impact of LSCs on CMML patients remains elusive. Making use of multiple independent validation cohorts, we here describe a concise three-gene expression signature (LSC-3, derived from the LSC-17 score) as an independent and robust prognostic factor for leukaemia-free and overall survival in CMML. We propose that LSC-3 could be used to supplement existing risk stratification systems, to improve prognostic performance and guide management decisions.

Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery.

BACKGROUND: Venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE), is the leading cause of preventable death in hospitalised people and the third most common cause of mortality in surgical patients. People undergoing bariatric surgery have the additional risk factor of being overweight. Although VTE prophylaxis in surgical patients is well established, the best way to prevent VTE in those undergoing bariatric surgery is less clear. OBJECTIVES: To evaluate the benefits and harms of pharmacological interventions (alone or in combination) on venous thromboembolism and other health outcomes in people undergoing bariatric surgery compared to the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention or started at a different time point, another pharmacological intervention, no intervention or placebo. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 1 November 2021. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs in males and females of any age undergoing bariatric surgery comparing pharmacological interventions for VTE (alone or in combination) with the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention started at a different time point, a different pharmacological intervention, no treatment or placebo. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. VTE and 2. major bleeding. Our secondary outcomes were 1. all-cause mortality, 2. VTE-related mortality, 3. PE, 4. DVT, 5. adverse effects and 6. quality of life. We used GRADE to assess certainty of evidence for each outcome. MAIN RESULTS: We included seven RCTs with 1045 participants. Data for meta-analysis were available from all participants. Four RCTs (597 participants) compared higher-dose heparin to standard-dose heparin: one of these studies (139 participants) used unfractionated heparin (UFH) and the other three (458 participants) used low-molecular-weight heparin (LMWH). One study compared heparin versus pentasaccharide (198 participants), and one study compared starting heparin before versus after bariatric surgery (100 participants). One study (150 participants) compared combined mechanical and pharmacological (enoxaparin) prophylaxis versus mechanical prophylaxis alone. The duration of the interventions ranged from seven to 15 days, and follow-up ranged from 10 to 180 days. Higher-dose heparin versus standard-dose heparin Compared to standard-dose heparin, higher-dose heparin may result in little or no difference in the risk of VTE (RR 0.55, 95% CI 0.05 to 5.99; 4 studies, 597 participants) or major bleeding (RR 1.19, 95% CI 0.48 to 2.96; I2 = 8%; 4 studies, 597 participants; low-certainty) in people undergoing bariatric surgery. The evidence on all-cause mortality, VTE-related mortality, PE, DVT and adverse events (thrombocytopenia) is uncertain (effect not estimable or very low-certainty evidence). Heparin versus pentasaccharide Heparin compared to a pentasaccharide after bariatric surgery may result in little or no difference in the risk of VTE (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants) or DVT (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants). The evidence on major bleeding, PE and mortality is uncertain (effect not estimable or very low-certainty evidence). Heparin started before versus after the surgical procedure Starting prophylaxis with heparin 12 hours before surgery versus after surgery may result in little or no difference in the risk of VTE (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants) or DVT (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants). The evidence on major bleeding, all-cause mortality and VTE-related mortality is uncertain (effect not estimable or very low-certainty evidence). We were unable to assess the effect of this intervention on PE or adverse effects, as the study did not measure these outcomes. Combined mechanical and pharmacological prophylaxis versus mechanical prophylaxis alone Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery compared to mechanical prophylaxis alone (RR 0.05, 95% CI 0.00 to 0.89; number needed to treat for an additional beneficial outcome (NNTB) = 9; 1 study, 150 participants; low-certainty). We were unable to assess the effect of this intervention on major bleeding or morality (effect not estimable), or on PE or adverse events (not measured). No studies measured quality of life. AUTHORS' CONCLUSIONS: Higher-dose heparin may make little or no difference to venous thromboembolism or major bleeding in people undergoing bariatric surgery when compared to standard-dose heparin. Heparin may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to pentasaccharide. There are inadequate data to draw conclusions about the effects of heparin compared to pentasaccharide on major bleeding. Starting prophylaxis with heparin 12 hours before bariatric surgery may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to starting heparin after bariatric surgery. There are inadequate data to draw conclusions about the effects of heparin started before versus after surgery on major bleeding. Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery when compared to mechanical prophylaxis alone. No data are available relating to major bleeding. The certainty of the evidence is limited by small sample sizes, few or no events, and risk of bias concerns. Future trials must be sufficiently large to enable analysis of relevant clinical outcomes, and should standardise the time of treatment and follow-up. They should also address the effect of direct oral anticoagulants and antiplatelets, preferably grouping them according to the type of intervention.

HMG20B stabilizes association of LSD1 with GFI1 on chromatin to confer transcription repression and leukemia cell differentiation block.

Pharmacologic inhibition of LSD1 induces molecular and morphologic differentiation of blast cells in acute myeloid leukemia (AML) patients harboring MLL gene translocations. In addition to its demethylase activity, LSD1 has a critical scaffolding function at genomic sites occupied by the SNAG domain transcription repressor GFI1. Importantly, inhibitors block both enzymatic and scaffolding activities, in the latter case by disrupting the protein:protein interaction of GFI1 with LSD1. To explore the wider consequences of LSD1 inhibition on the LSD1 protein complex we applied mass spectrometry technologies. We discovered that the interaction of the HMG-box protein HMG20B with LSD1 was also disrupted by LSD1 inhibition. Downstream investigations revealed that HMG20B is co-located on chromatin with GFI1 and LSD1 genome-wide; the strongest HMG20B binding co-locates with the strongest GFI1 and LSD1 binding. Functional assays demonstrated that HMG20B depletion induces leukemia cell differentiation and further revealed that HMG20B is required for the transcription repressor activity of GFI1 through stabilizing LSD1 on chromatin at GFI1 binding sites. Interaction of HMG20B with LSD1 is through its coiled-coil domain. Thus, HMG20B is a critical component of the GFI1:LSD1 transcription repressor complex which contributes to leukemia cell differentiation block.

What do Cochrane systematic reviews say about congenital vascular anomalies and hemangiomas? A narrative review.

BACKGROUND: Congenital vascular anomalies and hemangiomas (CVAH) such as infantile hemangiomas, port-wine stains and brain arteriovenous malformations (AVMs) impair patients' lives and may require treatment if complications occur. However, a great variety of treatments for those conditions exist and the best interventions remain under discussion. OBJECTIVE: To summarize Cochrane systematic review (SR) evidence on treatments for CVAH. DESIGN AND SETTING: Review of SRs conducted in the Division of Vascular and Endovascular Surgery of Universidade Federal de São Paulo, Brazil. METHODS: A broad search was conducted on March 9, 2021, in the Cochrane Database of Systematic Reviews to retrieve any Cochrane SRs that assessed treatments for CVAH. The key characteristics and results of all SRs included were summarized and discussed. RESULTS: A total of three SRs fulfilled the inclusion criteria and were presented as a qualitative synthesis. One SR reported a significant clinical reduction of skin redness by at least 20%, with more pain, among 103 participants with port-wine stains. One SR reported that propranolol improved the likelihood of clearance 13 to 16-fold among 312 children with hemangiomas. One SR reported that the relative risk of death or dependence was 2.53 times greater in the intervention arm than with conservative management, among 218 participants with brain AVMs. CONCLUSION: Cochrane reviews suggest that treatment of port-wine stains with pulsed-dye laser improves redness; propranolol remains the best option for infantile hemangiomas; and conservative management seems to be superior to surgical intervention for treating brain AVMs.

What do Cochrane systematic reviews say about congenital vascular anomalies and hemangiomas? A narrative review

ABSTRACT BACKGROUND: Congenital vascular anomalies and hemangiomas (CVAH) such as infantile hemangiomas, port-wine stains and brain arteriovenous malformations (AVMs) impair patients' lives and may require treatment if complications occur. However, a great variety of treatments for those conditions exist and the best interventions remain under discussion. OBJECTIVE: To summarize Cochrane systematic review (SR) evidence on treatments for CVAH. DESIGN AND SETTING: Review of SRs conducted in the Division of Vascular and Endovascular Surgery of Universidade Federal de São Paulo, Brazil. METHODS: A broad search was conducted on March 9, 2021, in the Cochrane Database of Systematic Reviews to retrieve any Cochrane SRs that assessed treatments for CVAH. The key characteristics and results of all SRs included were summarized and discussed. RESULTS: A total of three SRs fulfilled the inclusion criteria and were presented as a qualitative synthesis. One SR reported a significant clinical reduction of skin redness by at least 20%, with more pain, among 103 participants with port-wine stains. One SR reported that propranolol improved the likelihood of clearance 13 to 16-fold among 312 children with hemangiomas. One SR reported that the relative risk of death or dependence was 2.53 times greater in the intervention arm than with conservative management, among 218 participants with brain AVMs. CONCLUSION: Cochrane reviews suggest that treatment of port-wine stains with pulsed-dye laser improves redness; propranolol remains the best option for infantile hemangiomas; and conservative management seems to be superior to surgical intervention for treating brain AVMs.

Encouraging outcomes of using a small-donor single graft in pediatric kidney transplantation.

BACKGROUND: The use of small pediatric kidneys as single grafts for transplantation is controversial, due to the potential risk for graft thrombosis and insufficient nephron mass. METHODS: Aiming to test the benefits of transplanting these kidneys, 375 children who underwent kidney transplantation in a single center were evaluated: 49 (13.1%) received a single graft from a small pediatric donor (≤ 15 kg, SPD group), 244 (65.1%) from a bigger pediatric donor (> 15 kg, BPD group), and 82 (21.9%) from adult living donors (group ALD). RESULTS: Groups had similar baseline main characteristics. After 5 years of follow-up, children from the SPD group were comparable to children from BPD and ALD in patient survival (94%, 96%, and 98%, respectively, p = 0.423); graft survival (89%, 88%, and 93%, respectively, p = 0.426); the frequency of acute rejection (p = 0.998); the incidence of post-transplant lymphoproliferative disease (p = 0.671); the odds ratio for severely increased proteinuria (p = 0.357); the rates of vascular thrombosis (p = 0.846); and the necessity for post-transplant surgical intervention prior to discharge (p = 0.905). The longitudinal evolution of eGFR was not uniform among groups. The three groups presented a decrease in eGFR, but the slope of the curve was steeper in ALD children. At 5 years, the eGFR of the ALD group was 10 ml/min/1.73m2 inferior to the others. At that time, the eGFR from the SPD group was statistically similar to the BPD group (p = 0.952). CONCLUSION: In a specialized transplant center, the use of a single small pediatric donor kidney for transplantation is as successful as bigger pediatric or adult living donors, after 5 years of follow-up. A higher resolution version of the Graphical abstract is available as Supplementary information.

Microevolutionary dynamics show tropical valleys are deeper for montane birds of the Atlantic Forest.

Tropical mountains hold more biodiversity than their temperate counterparts, and this disparity is often associated with the latitudinal climatic gradient. However, distinguishing the impact of latitude versus the background effects of species history and traits is challenging due to the evolutionary distance between tropical and temperate assemblages. Here, we test whether microevolutionary processes are linked to environmental variation across a sharp latitudinal transition in 21 montane birds of the southern Atlantic Forest in Brazil. We find that effective dispersal within populations in the tropical mountains is lower and genomic differentiation is better predicted by the current environmental complexity of the region than within the subtropical populations. The concordant response of multiple co-occurring populations is consistent with spatial climatic variability as a major process driving population differentiation. Our results provide evidence for how a narrow latitudinal gradient can shape microevolutionary processes and contribute to broader scale biodiversity patterns.

Blast cells surviving acute myeloid leukemia induction therapy are in cycle with a signature of FOXM1 activity.

BACKGROUND: Disease relapse remains common following treatment of acute myeloid leukemia (AML) and is due to chemoresistance of leukemia cells with disease repopulating potential. To date, attempts to define the characteristics of in vivo resistant blasts have focused on comparisons between leukemic cells at presentation and relapse. However, further treatment responses are often seen following relapse, suggesting that most blasts remain chemosensitive. We sought to characterise in vivo chemoresistant blasts by studying the transcriptional and genetic features of blasts from before and shortly after induction chemotherapy using paired samples from six patients with primary refractory AML. METHODS: Leukemic blasts were isolated by fluorescence-activated cell sorting. Fluorescence in situ hybridization (FISH), targeted genetic sequencing and detailed immunophenotypic analysis were used to confirm that sorted cells were leukemic. Sorted blasts were subjected to RNA sequencing. Lentiviral vectors expressing short hairpin RNAs were used to assess the effect of FOXM1 knockdown on colony forming capacity, proliferative capacity and apoptosis in cell lines, primary AML cells and CD34+ cells from healthy donors. RESULTS: Molecular genetic analysis revealed early clonal selection occurring after induction chemotherapy. Immunophenotypic characterisation found leukemia-associated immunophenotypes in all cases that persisted following treatment. Despite the genetic heterogeneity of the leukemias studied, transcriptional analysis found concerted changes in gene expression in resistant blasts. Remarkably, the gene expression signature suggested that post-chemotherapy blasts were more proliferative than those at presentation. Resistant blasts also appeared less differentiated and expressed leukemia stem cell (LSC) maintenance genes. However, the proportion of immunophenotypically defined LSCs appeared to decrease following treatment, with implications for the targeting of these cells on the basis of cell surface antigen expression. The refractory gene signature was highly enriched with targets of the transcription factor FOXM1. shRNA knockdown experiments demonstrated that the viability of primary AML cells, but not normal CD34+ cells, depended on FOXM1 expression. CONCLUSIONS: We found that chemorefractory blasts from leukemias with varied genetic backgrounds expressed a common transcriptional program. In contrast to the notion that LSC quiescence confers resistance to chemotherapy we find that refractory blasts are both actively proliferating and enriched with LSC maintenance genes. Using primary patient material from a relevant clinical context we also provide further support for the role of FOXM1 in chemotherapy resistance, proliferation and stem cell function in AML.

Enhancer recruitment of transcription repressors RUNX1 and TLE3 by mis-expressed FOXC1 blocks differentiation in acute myeloid leukemia.

Despite absent expression in normal hematopoiesis, the Forkhead factor FOXC1, a critical mesenchymal differentiation regulator, is highly expressed in ∼30% of HOXAhigh acute myeloid leukemia (AML) cases to confer blocked monocyte/macrophage differentiation. Through integrated proteomics and bioinformatics, we find that FOXC1 and RUNX1 interact through Forkhead and Runt domains, respectively, and co-occupy primed and active enhancers distributed close to differentiation genes. FOXC1 stabilizes association of RUNX1, HDAC1, and Groucho repressor TLE3 to limit enhancer activity: FOXC1 knockdown induces loss of repressor proteins, gain of CEBPA binding, enhancer acetylation, and upregulation of nearby genes, including KLF2. Furthermore, it triggers genome-wide redistribution of RUNX1, TLE3, and HDAC1 from enhancers to promoters, leading to repression of self-renewal genes, including MYC and MYB. Our studies highlight RUNX1 and CEBPA transcription factor swapping as a feature of leukemia cell differentiation and reveal that FOXC1 prevents this by stabilizing enhancer binding of a RUNX1/HDAC1/TLE3 transcription repressor complex to oncogenic effect.

Rugged relief and climate promote isolation and divergence between two neotropical cold-associated birds.

The role of historical factors in establishing patterns of diversity in tropical mountains is of interest to understand the buildup of megadiverse biotas. In these regions, the historical processes of range fragmentation and contraction followed by dispersal are thought to be mediated by the interplay between rugged relief (complex topography) and climate fluctuations and likely explain most of the dynamics of diversification in plants and animals. Although empirical studies addressing the interaction between climate and topography have provided invaluable insights into population divergence and speciation patterns in tropical montane organisms, a more detailed and robust test of such processes in an explicit spatio-temporal framework is still lacking. Consequently, our ability to gain insights into historical range shifts over time and the genomic footprint left by them is limited. Here, we used niche modeling and subgenomic population-level datasets to explore the evolution of two species of warbling finches (genus Microspingus) disjunctly distributed across the Montane Atlantic Forest, a Neotropical region with complex geological and environmental histories. Population structure inferences suggest a scenario of three genetically differentiated populations, which are congruent with both geography and phenotypic variation. Demographic simulations support asynchronous isolation of these populations as recently as ∼40,000 years ago, relatively stable population sizes over recent time, and past gene flow subsequent to divergence. Throughout the last 800,000 years, niche models predicted extensive expansion into lowland areas with increasing overlap of species distributions during glacial periods, with prominent retractions and isolation into higher altitudes during interglacials, which are in line with signs of introgression of currently isolated populations. These results support a dual role of cyclical climatic changes: population divergence and persistence in mountain tops during warm periods followed by periods of expansion and admixture in lower elevations during cold periods. Our results underscore the role of the interplay between landscape and climate as an important mechanism in the evolution of the Neotropical montane biota.

Towards Providing Effective Data-Driven Responses to Predict the Covid-19 in São Paulo and Brazil.

São Paulo is the most populous state in Brazil, home to around 22% of the country's population. The total number of Covid-19-infected people in São Paulo has reached more than 1 million, while its total death toll stands at 25% of all the country's fatalities. Joining the Brazilian academia efforts in the fight against Covid-19, in this paper we describe a unified framework for monitoring and forecasting the Covid-19 progress in the state of São Paulo. More specifically, a freely available, online platform to collect and exploit Covid-19 time-series data is presented, supporting decision-makers while still allowing the general public to interact with data from different regions of the state. Moreover, a novel forecasting data-driven method has also been proposed, by combining the so-called Susceptible-Infectious-Recovered-Deceased model with machine learning strategies to better fit the mathematical model's coefficients for predicting Infections, Recoveries, Deaths, and Viral Reproduction Numbers. We show that the obtained predictor is capable of dealing with badly conditioned data samples while still delivering accurate 10-day predictions. Our integrated computational system can be used for guiding government actions mainly in two basic aspects: real-time data assessment and dynamic predictions of Covid-19 curves for different regions of the state. We extend our analysis and investigation to inspect the virus spreading in Brazil in its regions. Finally, experiments involving the Covid-19 advance in other countries are also given.

Targeted nanopore sequencing for the identification of ABCB1 promoter translocations in cancer.

BACKGROUND: Resistance to chemotherapy is the most common cause of treatment failure in acute myeloid leukemia (AML) and the drug efflux pump ABCB1 is a critical mediator. Recent studies have identified promoter translocations as common drivers of high ABCB1 expression in recurrent, chemotherapy-treated high-grade serous ovarian cancer (HGSC) and breast cancer. These fusions place ABCB1 under the control of a strong promoter while leaving its open reading frame intact. The mechanisms controlling high ABCB1 expression in AML are largely unknown. We therefore established an experimental system and analysis pipeline to determine whether promoter translocations account for high ABCB1 expression in cases of relapsed human AML. METHODS: The human AML cell line THP-1 was used to create a model of chemotherapy resistance in which ABCB1 expression was driven by a promoter fusion. The THP-1 model was used to establish a targeted nanopore long-read sequencing approach that was then applied to cases of ABCB1high HGSC and AML. H3K27Ac ChIP sequencing was used to assess the activity of native promoters in cases of ABCB1high AML. RESULTS: Prolonged in vitro daunorubicin exposure induced activating ABCB1 promoter translocations in human THP-1 AML cells, similar to those recently described in recurrent high-grade serous ovarian and breast cancers. Targeted nanopore sequencing proved an efficient method for identifying ABCB1 structural variants in THP-1 AML cells and HGSC; the promoter translocations identified in HGSC were both previously described and novel. In contrast, activating ABCB1 promoter translocations were not identified in ABCB1high AML; instead H3K27Ac ChIP sequencing demonstrated active native promoters in all cases studied. CONCLUSIONS: Despite frequent high level expression of ABCB1 in relapsed primary AML we found no evidence of ABCB1 translocations and instead confirmed high-level activity of native ABCB1 promoters, consistent with endogenous regulation.

EVI1 phosphorylation at S436 regulates interactions with CtBP1 and DNMT3A and promotes self-renewal.

The transcriptional regulator EVI1 has an essential role in early development and haematopoiesis. However, acute myeloid leukaemia (AML) driven by aberrantly high EVI1 expression has very poor prognosis. To investigate the effects of post-translational modifications on EVI1 function, we carried out a mass spectrometry (MS) analysis of EVI1 in AML and detected dynamic phosphorylation at serine 436 (S436). Wild-type EVI1 (EVI1-WT) with S436 available for phosphorylation, but not non-phosphorylatable EVI1-S436A, conferred haematopoietic progenitor cell self-renewal and was associated with significantly higher organised transcriptional patterns. In silico modelling of EVI1-S436 phosphorylation showed reduced affinity to CtBP1, and CtBP1 showed reduced interaction with EVI1-WT compared with EVI1-S436A. The motif harbouring S436 is a target of CDK2 and CDK3 kinases, which interacted with EVI1-WT. The methyltransferase DNMT3A bound preferentially to EVI1-WT compared with EVI1-S436A, and a hypomethylated cell population associated by EVI1-WT expression in murine haematopoietic progenitors is not maintained with EVI1-S436A. These data point to EVI1-S436 phosphorylation directing functional protein interactions for haematopoietic self-renewal. Targeting EVI1-S436 phosphorylation may be of therapeutic benefit when treating EVI1-driven leukaemia.

Peripherally inserted central catheter versus central venous catheter for intravenous access: A protocol for systematic review and meta-analysis.

BACKGROUND: Since the first description of the central venous catheter (CVC) in 1952, it has been used for the rapid administration of drugs, chemotherapy, as a route for nutritional support, blood components, monitoring patients, or combinations of these. When CVC is used in the traditional routes (eg, subclavian, jugular, and femoral veins), the complication rates range up to 15% and are mainly due to mechanical dysfunction, infection, and thrombosis. The peripherally inserted central catheter (PICC) is an alternative option for CVC access. However, the clinical evidence for PICC compared to CVC is still under discussion. In this setting, this systematic review (SR) aims to assess the effects of PICC compared to CVC for intravenous access. METHODS: We will perform a comprehensive search for randomised controlled trials (RCTs), which compare PICC and traditional CVC for intravenous access. The search strategy will consider free text terms and controlled vocabulary (eg, MeSH and Entree) related to "peripherally inserted central venous catheter," "central venous access," "central venous catheter," "catheterisation, peripheral," "vascular access devices," "infusions, intravenous," "administration, intravenous," and "injections, intravenous." Searches will be carried out in these databases: MEDLINE (via PubMed), EMBASE (via Elsevier), Cochrane CENTRAL (via Wiley), IBECS, and LILACS (both via Virtual Health Library). We will consider catheter-related deep venous thrombosis and overall successful insertion rates as primary outcomes and haematoma, venous thromboembolism, reintervention derived from catheter dysfunction, catheter-related infections, and quality of life as secondary outcomes. Where results are not appropriate for a meta-analysis using RevMan 5 software (eg, if the data have considerable heterogeneity and are drawn from different comparisons), a descriptive analysis will be performed. RESULTS: Our SR will be conducted according to the Cochrane Handbook of Systematic Reviews of Interventions and the findings will be reported in compliance with PRISMA. CONCLUSION: Our study will provide evidence for the effects of PICC versus CVC for venous access. ETHICS AND DISSEMINATION: This SR has obtained formal ethical approval and was prospectively registered in Open Science Framework. The findings of this SR will be disseminated through peer-reviewed publications or conference presentations. REGISTRATION:: osf.io/xvhzf. ETHICAL APPROVAL: 69003717.2.0000.5505.