Transcriptional regulation of amino acid metabolism by KDM2B, in the context of ncPRC1.1 and in concert with MYC and ATF4.

INTRODUCTION: KDM2B encodes a JmjC domain-containing histone lysine demethylase, which functions as an oncogene in several types of tumors, including TNBC. This study was initiated to address the cancer relevance of the results of our earlier work, which had shown that overexpression of KDM2B renders mouse embryonic fibroblasts (MEFs) resistant to oxidative stress by regulating antioxidant mechanisms. METHODS: We mainly employed a multi-omics strategy consisting of RNA-Seq, quantitative TMT proteomics, Mass-spectrometry-based global metabolomics, ATAC-Seq and ChIP-seq, to explore the role of KDM2B in the resistance to oxidative stress and intermediary metabolism. These data and data from existing patient datasets were analyzed using bioinformatic tools, including exon-intron-split analysis (EISA), FLUFF and clustering analyses. The main genetic strategy we employed was gene silencing with shRNAs. ROS were measured by flow cytometry, following staining with CellROX and various metabolites were measured with biochemical assays, using commercially available kits. Gene expression was monitored with qRT-PCR and immunoblotting, as indicated. RESULTS: The knockdown of KDM2B in basal-like breast cancer cell lines lowers the levels of GSH and sensitizes the cells to ROS inducers, GSH targeting molecules, and DUB inhibitors. To address the mechanism of GSH regulation, we knocked down KDM2B in MDA-MB-231 cells and we examined the effects of the knockdown, using a multi-omics strategy. The results showed that KDM2B, functioning in the context of ncPRC1.1, regulates a network of epigenetic and transcription factors, which control a host of metabolic enzymes, including those involved in the SGOC, glutamate, and GSH metabolism. They also showed that KDM2B enhances the chromatin accessibility and expression of MYC and ATF4, and that it binds in concert with MYC and ATF4, the promoters of a large number of transcriptionally active genes, including many, encoding metabolic enzymes. Additionally, MYC and ATF4 binding sites were enriched in genes whose accessibility depends on KDM2B, and analysis of a cohort of TNBCs expressing high or low levels of KDM2B, but similar levels of MYC and ATF4 identified a subset of MYC targets, whose expression correlates with the expression of KDM2B. Further analyses of basal-like TNBCs in the same cohort, revealed that tumors expressing high levels of all three regulators exhibit a distinct metabolic signature that carries a poor prognosis. CONCLUSIONS: The present study links KDM2B, ATF4, and MYC in a transcriptional network that regulates the expression of multiple metabolic enzymes, including those that control the interconnected SGOC, glutamate, and GSH metabolic pathways. The co-occupancy of the promoters of many transcriptionally active genes, by all three factors, the enrichment of MYC binding sites in genes whose chromatin accessibility depends on KDM2B, and the correlation of the levels of KDM2B with the expression of a subset of MYC target genes in tumors that express similar levels of MYC, suggest that KDM2B regulates both the expression and the transcriptional activity of MYC. Importantly, the concerted expression of all three factors also defines a distinct metabolic subset of TNBCs with poor prognosis. Overall, this study identifies novel mechanisms of SGOC regulation, suggests novel KDM2B-dependent metabolic vulnerabilities in TNBC, and provides new insights into the role of KDM2B in the epigenetic regulation of transcription.

Integrative Multi-Omics Analysis of Oncogenic EZH2 Mutants: From Epigenetic Reprogramming to Molecular Signatures.

Somatic heterozygous mutations in the active site of the enhancer of zeste homolog 2 (EZH2) are prevalent in diffuse large B-cell lymphoma (DLBCL) and acute myeloid leukemia (AML). The methyltransferase activity of EZH2 towards lysine 27 on histone H3 (H3K27) and non-histone proteins is dysregulated by the presence of gain-of-function (GOF) and loss-of-function (LOF) mutations altering chromatin compaction, protein complex recruitment, and transcriptional regulation. In this study, a comprehensive multi-omics approach was carried out to characterize the effects of differential H3K27me3 deposition driven by EZH2 mutations. Three stable isogenic mutants (EZH2Y641F, EZH2A677G, and EZH2H689A/F667I) were examined using EpiProfile, H3K27me3 CUT&Tag, ATAC-Seq, transcriptomics, label-free proteomics, and untargeted metabolomics. A discrete set of genes and downstream targets were identified for the EZH2 GOF and LOF mutants that impacted pathways involved in cellular proliferation, differentiation, and migration. Disruption of protein networks and metabolic signatures able to sustain aberrant cell behavior was observed in response to EZH2 mutations. This systems biology-based analysis sheds light on EZH2-mediated cell transformative processes, from the epigenetic to the phenotypic level. These studies provide novel insights into aberrant EZH2 function along with targets that can be explored for improved diagnostics/treatment in hematologic malignancies with mutated EZH2.

Transcriptional regulation of amino acid metabolism by KDM2B, in the context of ncPRC1.1 and in concert with MYC and ATF4.

Introduction: KDM2B encodes a JmjC domain-containing histone lysine demethylase, which functions as an oncogene in several types of tumors, including TNBC. This study was initiated to address the cancer relevance of the results of our earlier work, which had shown that overexpression of KDM2B renders mouse embryonic fibroblasts (MEFs) resistant to oxidative stress by regulating antioxidant mechanisms. Methods: We mainly employed a multi-omics strategy consisting of RNA-Seq, quantitative TMT proteomics, Mass-spectrometry-based global metabolomics, ATAC-Seq and ChIP-seq, to explore the role of KDM2B in the resistance to oxidative stress and intermediary metabolism. These data and data from existing patient datasets were analyzed using bioinformatic tools, including exon-intron-split analysis (EISA), FLUFF and clustering analyses. The main genetic strategy we employed was gene silencing with shRNAs. ROS were measured by flow cytometry, following staining with CellROX and various metabolites were measured with biochemical assays, using commercially available kits. Gene expression was monitored with qRT-PCR and immunoblotting, as indicated. Results: The knockdown of KDM2B in basal-like breast cancer cell lines lowers the levels of GSH and sensitizes the cells to ROS inducers, GSH targeting molecules, and DUB inhibitors. To address the mechanism of GSH regulation, we knocked down KDM2B in MDA-MB-231 cells and we examined the effects of the knockdown, using a multi-omics strategy. The results showed that KDM2B, functioning in the context of ncPRC1.1, regulates a network of epigenetic and transcription factors, which control a host of metabolic enzymes, including those involved in the SGOC, glutamate, and GSH metabolism. They also showed that KDM2B enhances the chromatin accessibility and expression of MYC and ATF4, and that it binds in concert with MYC and ATF4, the promoters of a large number of transcriptionally active genes, including many, encoding metabolic enzymes. Additionally, MYC and ATF4 binding sites were enriched in genes whose accessibility depends on KDM2B, and analysis of a cohort of TNBCs expressing high or low levels of KDM2B, but similar levels of MYC and ATF4 identified a subset of MYC targets, whose expression correlates with the expression of KDM2B. Further analyses of basal-like TNBCs in the same cohort, revealed that tumors expressing high levels of all three regulators exhibit a distinct metabolic signature that carries a poor prognosis. Conclusions: The present study links KDM2B, ATF4, and MYC in a transcriptional network that regulates the expression of multiple metabolic enzymes, including those that control the interconnected SGOC, glutamate, and GSH metabolic pathways. The co-occupancy of the promoters of many transcriptionally active genes, by all three factors, the enrichment of MYC binding sites in genes whose chromatin accessibility depends on KDM2B, and the correlation of the levels of KDM2B with the expression of a subset of MYC target genes in tumors that express similar levels of MYC, suggest that KDM2B regulates both the expression and the transcriptional activity of MYC. Importantly, the concerted expression of all three factors also defines a distinct metabolic subset of TNBCs with poor prognosis. Overall, this study identifies novel mechanisms of SGOC regulation, suggests novel KDM2B-dependent metabolic vulnerabilities in TNBC, and provides new insights into the role of KDM2B in the epigenetic regulation of transcription.

Detection of single peptide with only one amino acid modification via electronic fingerprinting using reengineered durable channel of Phi29 DNA packaging motor.

Protein post-translational modification (PTM) is crucial to modulate protein interactions and activity in various biological processes. Emerging evidence has revealed PTM patterns participate in the pathology onset and progression of various diseases. Current PTM identification relies mainly on mass spectrometry-based approaches that limit the assessment to the entire protein population in question. Here we report a label-free method for the detection of the single peptide with only one amino acid modification via electronic fingerprinting using reengineered durable channel of phi29 DNA packaging motor, which bears the deletion of 25-amino acids (AA) at the C-terminus or 17-AA at the internal loop of the channel. The mutant channels were used to detect propionylation modification via single-molecule fingerprinting in either the traditional patch-clamp or the portable MinION™ platform of Oxford Nanopore Technologies. Up to 2000 channels are available in the MinION™ Flow Cells. The current signatures and dwell time of individual channels were identified. Peptides with only one propionylation were differentiated. Excitingly, identification of single or multiple modifications on the MinION™ system was achieved. The successful application of PTM differentiation on the MinION™ system represents a significant advance towards developing a label-free and high-throughput detection platform utilizing nanopores for clinical diagnosis based on PTM.

Surgical site infection in adults undergoing major non-cardiac surgery and its association with anemia, El severe bleeding and intraoperative transfusion: A preliminary report from a prospective registry / Infección de sitio operatorio en adultos llevados a cirugía mayor no cardiaca y su relación con anemia, sangrado mayor y transfusión intraoperatoria: Informe preliminar de un registro prospectivo

Abstract Introduction: Surgical site infection (SSI) is among the most common healthcare-related infections. Given their greater morbidity and surgical complexity, patients undergoing major surgery are exposed to a high risk of SSI. Objective: To determine the incidence of SSI in adult patients undergoing major elective non-cardiac surgery, and to identify risk factors associated with its occurrence within the first 30 days after surgery. Methods: An analytical study was designed on the basis of a prospective institutional registry. Clinical and laboratory variables associated with perioperative management were recorded. An active search was conducted in order to find SSI episodes, renal failure and multiple organ dysfunction during the first 30 days after surgery. Adjusted logistic regression was done to identify potential associations between risk factors and the development of SSI. Results: Overall, 1501 patients were included. The incidence of SSI during the first 30 days after surgery was 6.72% (95% CI 5.57-8.11). ASA III, abdominal surgery and longer procedures were more frequent in the SSI group. Association with the occurrence of SSI was documented for preoperative hemoglobin levels (adjusted OR 0.79 [95% CI 0.72-0.88], p = 0.04), intraoperative transfusion (adjusted OR 2,47 [95% CI 1.16-5.27], p = 0.02) and major blood loss (adjusted OR 3.80 [95% CI 1.63-8.88], p = 0.04). Conclusion: Preoperative hemoglobin level, intraoperative transfusion and major bleeding are independent risk factors associated with the occurrence of SSI in adult patients undergoing major elective non-cardiac surgery.

Resumen Introducción: La infección del sitio operatorio (ISO) ocupa los primeros lugares entre las infecciones asociadas a la atención en salud. Con una mayor morbilidad y complejidad quirúrgica, los pacientes de cirugía mayor están expuestos a un alto riesgo de ISO. Objetivo: Determinar la incidencia de ISO en pacientes adultos sometidos a cirugía mayor electiva no cardiaca e identificar factores de riesgo relacionados con su aparición durante los primeros 30 días postoperatorios. Métodos: Se diseñó un estudio analítico a partir de un registro institucional prospectivo. Se registraron variables clínicas y de laboratorio relacionadas con el manejo perioperatorio. Se realizó una búsqueda activa de episodios de ISO, sepsis, falla renal y disfunción multiorgánica durante los primeros 30 días postoperatorios. Las potenciales asociaciones entre factores de riesgo y el desarrollo de ISO fueron identificadas mediante regresión logística ajustada. Resultados: Se incluyeron 1.501 pacientes. La incidencia de ISO durante los 30 días postoperatorios fue de 6,72 % [IC 95 % 5,57-8,11). El estado ASA III, la cirugía abdominal y los procedimientos de duración prolongada fueron más frecuentes en el grupo ISO. Se documentó asociación con la ocurrencia de ISO para los niveles de hemoglobina preoperatoria (OR ajustado 0,79 [IC 95 % 0,72-0,88], p = 0,04), transfusión intraoperatoria (OR ajustado 2,47 [IC 95 % 1,16-5,27], p = 0,02) y sangrado mayor intraoperatorio (OR ajustado 3,80 [IC 95 % 1,63-8,88], p = 0,04). Conclusiones: El nivel de hemoglobina preoperatoria, la transfusión intraoperatoria y el sangrado mayor son factores de riesgo asociados de forma independiente a la ocurrencia de ISO en pacientes adultos llevados a cirugía mayor electiva no cardiaca.

Multiplatform plasma metabolic and lipid fingerprinting of breast cancer: A pilot control-case study in Colombian Hispanic women.

Breast cancer (BC) is a highly heterogeneous disease associated with metabolic reprogramming. The shifts in the metabolome caused by BC still lack data from Latin populations of Hispanic origin. In this pilot study, metabolomic and lipidomic approaches were performed to establish a plasma metabolic fingerprint of Colombian Hispanic women with BC. Data from 1H-NMR, GC-MS and LC-MS were combined and compared. Statistics showed discrimination between breast cancer and healthy subjects on all analytical platforms. The differentiating metabolites were involved in glycerolipid, glycerophospholipid, amino acid and fatty acid metabolism. This study demonstrates the usefulness of multiplatform approaches in metabolic/lipid fingerprinting studies to broaden the outlook of possible shifts in metabolism. Our findings propose relevant plasma metabolites that could contribute to a better understanding of underlying metabolic shifts driven by BC in women of Colombian Hispanic origin. Particularly, the understanding of the up-regulation of long chain fatty acyl carnitines and the down-regulation of cyclic phosphatidic acid (cPA). In addition, the mapped metabolic signatures in breast cancer were similar but not identical to those reported for non-Hispanic women, despite racial differences.

Urinary metabolite and lipid alterations in Colombian Hispanic women with breast cancer: A pilot study.

Metabolic biomarkers for breast cancer (BC) prognosis and diagnosis are required, given the increment of BC incidence rates in developing countries and its prevalence in women worldwide. Human urine represents a useful resource of metabolites for biomarker discovery, because it could reflect metabolic alterations caused by a particular pathological state. Furthermore, urine analysis is readily available, it is non-invasive and allows in-time monitoring. Therefore, in present study, a metabolic- and lipid fingerprinting of urine was performed using an analytical multiplatform approach. The study was conducted in order to identify alterated metabolites which can be helpful in the understanding of metabolic alterations driven by BC as well as their potential usage as biomarkers. Urine samples collected from healthy controls and BC subjects were analyzed using LC-MS and GC-MS. Subsequently, significantly altered metabolites were determined by employing univariate and multivariate statistical analyses. An overall decrease of intermediates of the tricarboxylic acid cycle and metabolites belonging to amino acids and nucleotides were observed, along with an increment of lipid-related compounds. Receiver operating characteristic analysis evaluated the combination of dimethylheptanoylcarnitine and succinic acid as potential urinary markers, achieving a sensitivity of 93% and a specificity of 86%. The present analytical multiplatform approach enabled a wide coverage of urine metabolites that revealed significant alterations in BC samples, demonstrating its usefulness for biomarker discovery in selected populations.