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F1000Research 2023The risk of recurrence after nephrectomy for primary clear cell renal cell carcinoma (ccRCC) is estimated in daily practice solely based on clinical criteria. The aim of...
BACKGROUND
The risk of recurrence after nephrectomy for primary clear cell renal cell carcinoma (ccRCC) is estimated in daily practice solely based on clinical criteria. The aim of this study was to assess the prognostic relevance of common somatic mutations with respect to tumor aggressiveness and outcomes of ccRCC patients after definitive treatment.
METHODS
Primary tumors from 37 patients with ccRCC who underwent radical nephrectomy were analyzed for presence of somatic mutations using a 15-gene targeted next-generation sequencing (NGS) panel. Associations to histopathologic characteristics and outcomes were investigated in the study cohort (n=37) and validated in The Cancer Genome Atlas (TCGA) ccRCC cohort (n=451).
RESULTS
was the most frequently mutated gene (51%), followed by (27%), (13%), (13%), (5%), (5%), (5%), and (3%). One-third of patients did not have any somatic mutations within the 15-gene panel. The vast majority of tumors harboring no mutations at all or VHL-only mutations (51%) were more frequently of smaller size (pT1-2) and earlier stage (I/II), whereas presence of any other gene mutations in various combinations with or without was enriched in larger (pT3) and higher stage tumors (III) (p=0.02). No recurrences were noted in patients with unmutated tumors or -only mutations as opposed to three relapses in patients with non- somatic mutations (p=0.06). Presence of somatic mutations in , or genes in 451 TCGA ccRCC patients was associated with a significantly shorter disease-free survival (DFS) compared to those with unaltered tumors (q=0.01).
CONCLUSIONS
Preliminary findings from this ongoing study support the prognostic value of non- mutations including , and in primary ccRCC tumors as surrogates of earlier recurrence and potential selection for adjuvant immune checkpoint inhibition.
Topics: Humans; Carcinoma, Renal Cell; Male; Female; Kidney Neoplasms; Middle Aged; Mutation; Aged; Immune Checkpoint Inhibitors; Ubiquitin Thiolesterase; Neoplasm Recurrence, Local; Tumor Suppressor Proteins; Ataxia Telangiectasia Mutated Proteins; Von Hippel-Lindau Tumor Suppressor Protein; Prognosis; Histone-Lysine N-Methyltransferase; Adult; Transcription Factors; Aged, 80 and over; Nuclear Proteins; High-Throughput Nucleotide Sequencing; DNA-Binding Proteins; Histone Demethylases
PubMed: 38933491
DOI: 10.12688/f1000research.136087.2 -
Microorganisms Jun 2024Mercury (Hg) methylation in mangrove sediments can result in the accumulation of neurotoxic methylmercury (MeHg). Identification of Hg methyltransferase gene provides...
Mercury (Hg) methylation in mangrove sediments can result in the accumulation of neurotoxic methylmercury (MeHg). Identification of Hg methyltransferase gene provides the means to directly characterize the microbial Hg-methylating consortia in environments. Hitherto, the microbial Hg-methylating community in mangrove sediments was scarcely investigated. An effort to assess the diversity and abundance of genes and transcripts and link them to Hg and MeHg contents was made in the mangrove intertidal sediments along the urbanized Shenzhen Bay, China. The genes and transcripts associated with Thermodesulfobacteria [mainly Geobacteraceae, Syntrophorhabdaceae, Desulfobacterales, and Desulfarculales (these four lineages were previously classified into the Deltaproteobacteria taxon)], as well as Euryarchaeota (mainly Methanomicrobia and Theionarchaea) dominated the -harboring communities, while Chloroflexota, Nitrospirota, Planctomycetota, and Lentisphaerota-like sequences accounted for a small proportion. The genes appeared in greater abundance and diversity than their transcript counterparts in each sampling site. Correlation analysis demonstrated that the MeHg content rather than Hg content significantly correlated with the structure of the existent/active -harboring community and the abundance of genes/transcripts. These findings provide better insights into the microbial Hg methylation drivers in mangrove sediments, which could be helpful for understanding the MeHg biotransformation therein.
PubMed: 38930626
DOI: 10.3390/microorganisms12061245 -
Antioxidants (Basel, Switzerland) May 2024The level of tumor necrosis factor-α (TNF-α) is upregulated during the development of pulmonary vascular remodeling and pulmonary hypertension. A hallmark of...
The level of tumor necrosis factor-α (TNF-α) is upregulated during the development of pulmonary vascular remodeling and pulmonary hypertension. A hallmark of pulmonary arterial (PA) remodeling is the excessive proliferation of PA smooth muscle cells (PASMCs). The purpose of this study is to investigate whether TNF-α induces PASMC proliferation and explore the potential mechanisms. PASMCs were isolated from 8-week-old male Sprague-Dawley rats and treated with 0, 20, or 200 ng/mL TNF-α for 24 or 48 h. After treatment, cell number, superoxide production, histone acetylation, DNA methylation, and histone methylation were assessed. TNF-α treatment increased NADPH oxidase activity, superoxide production, and cell numbers compared to untreated controls. TNF-α-induced PASMC proliferation was rescued by a superoxide dismutase mimetic tempol. TNF-α treatment did not affect histone acetylation at either dose but did significantly decrease DNA methylation. DNA methyltransferase 1 activity was unchanged by TNF-α treatment. Further investigation using QRT-RT-PCR revealed that GADD45-α, a potential mediator of DNA demethylation, was increased after TNF-α treatment. RNAi inhibition of GADD45-α alone increased DNA methylation. TNF-α impaired the epigenetic mechanism leading to DNA hypomethylation, which can be abolished by a superoxide scavenger tempol. TNF-α treatment also decreased H3-K4 methylation. TNF-α-induced PASMC proliferation may involve the H3-K4 demethylase enzyme, lysine-specific demethylase 1 (LSD1). TNF-α-induced PASMC proliferation may be partly associated with excessive superoxide formation and histone and DNA methylation.
PubMed: 38929115
DOI: 10.3390/antiox13060677 -
Cancers Jun 2024G9a, also named EHMT2, is a histone 3 lysine 9 (H3K9) methyltransferase responsible for catalyzing H3K9 mono- and dimethylation (H3K9me1 and H3K9me2). G9a contributes to... (Review)
Review
G9a, also named EHMT2, is a histone 3 lysine 9 (H3K9) methyltransferase responsible for catalyzing H3K9 mono- and dimethylation (H3K9me1 and H3K9me2). G9a contributes to various aspects of embryonic development and tissue differentiation through epigenetic regulation. Furthermore, the aberrant expression of G9a is frequently observed in various tumors, particularly in prostate cancer, where it contributes to cancer pathogenesis and progression. This review highlights the critical role of G9a in multiple cancer-related processes, such as epigenetic dysregulation, tumor suppressor gene silencing, cancer lineage plasticity, hypoxia adaption, and cancer progression. Despite the increased research on G9a in prostate cancer, there are still significant gaps, particularly in understanding its interactions within the tumor microenvironment and its broader epigenetic effects. Furthermore, this review discusses the recent advancements in G9a inhibitors, including the development of dual-target inhibitors that target G9a along with other epigenetic factors such as EZH2 and HDAC. It aims to bring together the existing knowledge, identify gaps in the current research, and suggest future directions for research and treatment strategies.
PubMed: 38927881
DOI: 10.3390/cancers16122175 -
Genes May 2024Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma. The oncogene product Tax of HTLV-I is thought to play crucial roles...
Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma. The oncogene product Tax of HTLV-I is thought to play crucial roles in leukemogenesis by promoting proliferation of the virus-infected cells through activation of growth-promoting genes. These genes code for growth factors and their receptors, cytokines, cell adhesion molecules, growth signal transducers, transcription factors and cell cycle regulators. We show here that Tax activates the gene coding for coactivator-associated arginine methyltransferase 1 (CARM1), which epigenetically enhances gene expression through methylation of histones. Tax activated the gene and increased protein expression, not only in human T-cell lines but also in normal peripheral blood lymphocytes (PHA-PBLs). Tax increased R17-methylated histone H3 on the target gene , concomitant with increased expression of CARM1. Short hairpin RNA (shRNA)-mediated knockdown of CARM1 decreased Tax-mediated induction of and gene expression, reduced E2F activation and inhibited cell cycle progression. Tax acted via response elements in intron 1 of the gene, through the NF-κB pathway. These results suggest that Tax-mediated activation of the gene contributes to leukemogenic target-gene expression and cell cycle progression, identifying the first epigenetic target gene for Tax-mediated trans-activation in cell growth promotion.
Topics: Humans; Protein-Arginine N-Methyltransferases; Gene Products, tax; Human T-lymphotropic virus 1; Cyclin D2; Transcriptional Activation; Interleukin-2 Receptor alpha Subunit; NF-kappa B; Histones; Epigenesis, Genetic; Jurkat Cells
PubMed: 38927636
DOI: 10.3390/genes15060698 -
Biology May 2024Methyltransferases are a wide-ranging, yet well-conserved, class of molecules that have been found to modify a wide variety of substrates. Interest in RNA methylation... (Review)
Review
Methyltransferases are a wide-ranging, yet well-conserved, class of molecules that have been found to modify a wide variety of substrates. Interest in RNA methylation has surged in recent years with the identification of the major eukaryotic mRNA m6A methyltransferase METTL3. METTL16 has also been identified as an RNA m6A methyltransferase; however, much less is known about its targets and actions. Interestingly, in addition to their catalytic activities, both METTL3 and METTL16 also have "methylation-independent" functions, including translational regulation, which have been discovered. However, evidence suggests that METTL16's role as an RNA-binding protein may be more significant than is currently recognized. In this review, we will introduce RNA methylation, specifically m6A, and the enzymes responsible for its deposition. We will discuss the varying roles that these enzymes perform and delve deeper into their RNA targets and possible roles as methylation-independent RNA binding proteins. Finally, we will touch upon the many open questions still remaining.
PubMed: 38927271
DOI: 10.3390/biology13060391 -
Nature Communications Jun 2024METTL3 is the catalytic subunit of the methyltransferase complex, which mediates mA modification to regulate gene expression. In addition, METTL3 regulates transcription...
METTL3 is the catalytic subunit of the methyltransferase complex, which mediates mA modification to regulate gene expression. In addition, METTL3 regulates transcription in an enzymatic activity-independent manner by driving changes in high-order chromatin structure. However, how these functions of the methyltransferase complex are coordinated remains unknown. Here we show that the methyltransferase complex coordinates its enzymatic activity-dependent and independent functions to regulate cellular senescence, a state of stable cell growth arrest. Specifically, METTL3-mediated chromatin loops induce Hexokinase 2 expression through the three-dimensional chromatin organization during senescence. Elevated Hexokinase 2 expression subsequently promotes liquid-liquid phase separation, manifesting as stress granule phase separation, by driving metabolic reprogramming. This correlates with an impairment of translation of cell-cycle related mRNAs harboring polymethylated mA sites. In summary, our results report a coordination of mA-dependent and -independent function of the methyltransferase complex in regulating senescence through phase separation driven by metabolic reprogramming.
Topics: Methyltransferases; Chromatin; Cellular Senescence; Humans; Stress Granules; Hexokinase; RNA, Messenger; Adenosine; HEK293 Cells; Metabolic Reprogramming; Phase Separation
PubMed: 38926365
DOI: 10.1038/s41467-024-49745-5 -
Science Advances Jun 2024Histone H3 lysine-9 methylation (H3K9me) is a hallmark of the condensed and transcriptionally silent heterochromatin. It remains unclear how H3K9me controls...
Histone H3 lysine-9 methylation (H3K9me) is a hallmark of the condensed and transcriptionally silent heterochromatin. It remains unclear how H3K9me controls transcription silencing and how cells delimit H3K9me domains to avoid silencing essential genes. Here, using genetic systems that induce H3K9me2 in genes and transposons de novo, we show that H3K9me2 accumulation paradoxically also causes the deposition of the euchromatic mark H3K36me3 by a SET domain methyltransferase, ASHH3. ASHH3-induced H3K36me3 confers anti-silencing by preventing the demethylation of H3K4me1 by LDL2, which mediates transcriptional silencing downstream of H3K9me2. These results demonstrate that H3K9me2 not only facilitates but orchestrates silencing by actuating antagonistic silencing and anti-silencing pathways, providing insights into the molecular basis underlying proper partitioning of chromatin domains and the creation of metastable epigenetic variation.
Topics: Heterochromatin; Histones; Gene Silencing; Arabidopsis; Methylation; Arabidopsis Proteins; Gene Expression Regulation, Plant; Histone-Lysine N-Methyltransferase; Lysine; Epigenesis, Genetic
PubMed: 38924413
DOI: 10.1126/sciadv.adn4149 -
Cell Reports Jun 2024The RNA cap methyltransferase CMTR1 methylates the first transcribed nucleotide of RNA polymerase II transcripts, impacting gene expression mechanisms, including during...
The RNA cap methyltransferase CMTR1 methylates the first transcribed nucleotide of RNA polymerase II transcripts, impacting gene expression mechanisms, including during innate immune responses. Using mass spectrometry, we identify a multiply phosphorylated region of CMTR1 (phospho-patch [P-Patch]), which is a substrate for the kinase CK2 (casein kinase II). CMTR1 phosphorylation alters intramolecular interactions, increases recruitment to RNA polymerase II, and promotes RNA cap methylation. P-Patch phosphorylation occurs during the G1 phase of the cell cycle, recruiting CMTR1 to RNA polymerase II during a period of rapid transcription and RNA cap formation. CMTR1 phosphorylation is required for the expression of specific RNAs, including ribosomal protein gene transcripts, and promotes cell proliferation. CMTR1 phosphorylation is also required for interferon-stimulated gene expression. The cap-snatching virus, influenza A, utilizes host CMTR1 phosphorylation to produce the caps required for virus production and infection. We present an RNA cap methylation control mechanism whereby CK2 controls CMTR1, enhancing co-transcriptional capping.
PubMed: 38923463
DOI: 10.1016/j.celrep.2024.114405 -
Cell Reports Jun 2024The intricate interplay between resident cells and the extracellular matrix (ECM) profoundly influences cancer progression. In triple-negative breast cancer (TNBC), ECM...
The intricate interplay between resident cells and the extracellular matrix (ECM) profoundly influences cancer progression. In triple-negative breast cancer (TNBC), ECM architecture evolves due to the enrichment of lysyl oxidase, fibronectin, and collagen, promoting distant metastasis. Here we uncover a pivotal transcription regulatory mechanism involving the epigenetic regulator UBR7 and histone methyltransferase EZH2 in regulating transforming growth factor (TGF)-β/Smad signaling, affecting the expression of ECM genes. UBR7 loss leads to a dramatic reduction in facultative heterochromatin mark H3K27me3, activating ECM genes. UBR7 plays a crucial role in matrix deposition in adherent cancer cells and spheroids, altering collagen content and lysyl oxidase activity, directly affecting matrix stiffness and invasiveness. These findings are further validated in vivo in mice models and TNBC patients, where reduced UBR7 levels are accompanied by increased ECM component expression and activity, leading to fibrosis-mediated matrix stiffness. Thus, UBR7 is a master regulator of matrix stiffening, influencing the metastatic potential of TNBC.
PubMed: 38923455
DOI: 10.1016/j.celrep.2024.114394