-
Cell Reports Feb 2018The diversity and complexity of the cancer transcriptome may contain transcripts unique to the tumor environment. Here, we report a LIN28B variant, LIN28B-TST, which is...
The diversity and complexity of the cancer transcriptome may contain transcripts unique to the tumor environment. Here, we report a LIN28B variant, LIN28B-TST, which is specifically expressed in hepatocellular carcinoma (HCC) and many other cancer types. Expression of LIN28B-TST is associated with significantly poor prognosis in HCC patients. LIN28B-TST initiates from a de novo alternative transcription initiation site that harbors a strong promoter regulated by NFYA but not c-Myc. Demethylation of the LIN28B-TST promoter might be a prerequisite for its transcription and transcriptional regulation. LIN28B-TST encodes a protein isoform with additional N-terminal amino acids and is critical for cancer cell proliferation and tumorigenesis. Our findings reveal a mechanism of LIN28B activation in cancer and the potential utility of LIN28B-TST for clinical purposes.
Topics: Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Demethylation; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Promoter Regions, Genetic; Protein Isoforms; Proto-Oncogene Proteins c-myc; RNA, Messenger; RNA-Binding Proteins; Sequence Analysis, RNA; Transcription, Genetic
PubMed: 29466730
DOI: 10.1016/j.celrep.2018.02.002 -
International Journal of Nanomedicine 2022Compared with traditional drugs, nanomaterial drugs have the benefits of improving the solubility, bioavailability, and absorption rate of insoluble drugs. Nanoporous...
BACKGROUND
Compared with traditional drugs, nanomaterial drugs have the benefits of improving the solubility, bioavailability, and absorption rate of insoluble drugs. Nanoporous complexes can increase the efficiency with which drugs can penetrate the blood-brain barrier and reach target organs. Ginsenoside Rg1 is an effective drug that promotes angiogenesis. Ginsenoside Rg1 composite nanoparticles were employed to induce the expression of several key epigenetic enzymes and then activate the VEGF and Notch pathways after the onset of ischemic brain lesions.
METHODS
We constructed nanoparticles to fully encapsulate the therapeutic drug (ginsenoside Rg1), which can be transferred into brain tissue via the receptor-mediated transfer of drug-encapsulated nanoparticles. Evaluation of the therapeutic effect of ginsenoside Rg1 complex nanovesicles (CNV) was performed by in vitro and in vivo experiments. Real-time polymerase chain reaction (RT- PCR), Western blot, immunohistochemistry staining (IHC), and Co-immunoprecipitation (co-IP) were employed to screen for epigenetic enzymes with an up-regulated expression post ginsenoside Rg1-CNV intervention. RNA sequencing, shRNA knockdown, and chromatin Immunoprecipitation (ChIP) sequencing were performed to detect the target genes of ginsenoside Rg1-CNV that regulate angiogenesis. Then, bioinformatic analysis was performed to investigate the mechanism of action of epigenetic modifying enzymes in regulating target genes.
RESULTS
The average of the synthesized ginsenoside Rg1-CNV was 203.78±6.83 nm, the polydispersion index was 0.135±0.007, and the Zeta potential was 23.13±1.65 mV. Through in vivo and in vitro experiments, we found that it promotes the proliferation, migration, and tubular formation of brain microvascular endothelial cells (BMECs). Meanwhile, the intervention of ginsenoside Rg1-CNV promoted the demethylation of H3K27me3 within the promoter region of VEGF-A and Jagged1 genes and reduced the H3K27me3 modification within this region.
CONCLUSION
The ginsenoside Rg1 nanoparticles may be an available blood-brain barrier penetrating agent for ischemic stroke.
Topics: Humans; Ischemic Stroke; Vascular Endothelial Growth Factor A; Histones; Endothelial Cells; Jagged-1 Protein; Nanoparticles; Promoter Regions, Genetic; Demethylation
PubMed: 36426373
DOI: 10.2147/IJN.S380515 -
Cell Reports Mar 2020Histone methyl groups can be removed by demethylases. Although LSD1 and JmjC domain-containing proteins have been identified as histone demethylases, enzymes for many...
Histone methyl groups can be removed by demethylases. Although LSD1 and JmjC domain-containing proteins have been identified as histone demethylases, enzymes for many histone methylation states or sites are still unknown. Here, we perform a screening of a cDNA library containing 2,500 nuclear proteins and identify hHR23A as a histone H4K20 demethylase. Overexpression of hHR23A reduces the levels of H4K20me1/2/3 in cells. In vitro, hHR23A specifically demethylates H4K20me1/2/3 and generates formaldehyde. The enzymatic activity requires Fe(II) and α-ketoglutarate as cofactors and the UBA domains of hHR23A. hHR23B, a protein homologous to hHR23A, also demethylates H4K20me1/2/3 in vitro and in vivo. We further demonstrate that hHR23A/B activate the transcription of coding genes by demethylating H4K20me1 and the transcription of repetitive elements by demethylating H4K20me3. Nuclear magnetic resonance (NMR) analyses demonstrate that an HxxxE motif in the UBA1 domain is crucial for iron binding and demethylase activity. Thus, we identify two hHR23 proteins as histone demethylases.
Topics: Cell Cycle; DNA Repair Enzymes; DNA-Binding Proteins; Demethylation; Formaldehyde; Genetic Loci; Genome, Human; HEK293 Cells; HeLa Cells; Histones; Humans; Iron; Lysine; Peptides; Protein Domains; RNA, Messenger; Repetitive Sequences, Nucleic Acid; Substrate Specificity; Transcription, Genetic
PubMed: 32209475
DOI: 10.1016/j.celrep.2020.03.001 -
Genome Biology Mar 2022DNA demethylation occurs in many species and is involved in diverse biological processes. However, the occurrence and role of DNA demethylation in maize remain unknown.
BACKGROUND
DNA demethylation occurs in many species and is involved in diverse biological processes. However, the occurrence and role of DNA demethylation in maize remain unknown.
RESULTS
We analyze loss-of-function mutants of two major genes encoding DNA demethylases. No significant change in DNA methylation has been detected in these mutants. However, we detect increased DNA methylation levels in the mutants around genes and some transposons. The increase in DNA methylation is accompanied by alteration in gene expression, with a tendency to show downregulation, especially for the genes that are preferentially expressed in endosperm. Imprinted expression of both maternally and paternally expressed genes changes in F hybrid with the mutant as female and the wild-type as male parental line, but not in the reciprocal hybrid. This alteration in gene expression is accompanied by allele-specific DNA methylation differences, suggesting that removal of DNA methylation of the maternal allele is required for the proper expression of these imprinted genes. Finally, we demonstrate that hypermethylation in the double mutant is associated with reduced binding of transcription factor to its target, and altered gene expression.
CONCLUSIONS
Our results suggest that active removal of DNA methylation is important for transcription factor binding and proper gene expression in maize endosperm.
Topics: Alleles; DNA Demethylation; DNA Methylation; Endosperm; Gene Expression; Gene Expression Regulation, Plant; Genomic Imprinting; Transcription Factors; Zea mays
PubMed: 35264226
DOI: 10.1186/s13059-022-02641-x -
Nature Communications May 2018Development in mammals is accompanied by specific de novo and demethylation events that are thought to stabilize differentiated cell phenotypes. We demonstrate that a...
Development in mammals is accompanied by specific de novo and demethylation events that are thought to stabilize differentiated cell phenotypes. We demonstrate that a large percentage of the tissue-specific methylation pattern is generated postnatally. Demethylation in the liver is observed in thousands of enhancer-like sequences associated with genes that undergo activation during the first few weeks of life. Using. conditional gene ablation strategy we show that the removal of these methyl groups is stable and necessary for assuring proper hepatocyte gene expression and function through its effect on chromatin accessibility. These postnatal changes in methylation come about through exposure to hormone signaling. These results define the molecular rules of 5-methyl-cytosine regulation as an epigenetic mechanism underlying cellular responses to. changing environment.
Topics: 5-Methylcytosine; Animals; Animals, Newborn; Cells, Cultured; DNA Demethylation; DNA-Binding Proteins; Dioxygenases; Epigenesis, Genetic; Female; Gene Expression Regulation, Developmental; Hepatocytes; High-Throughput Nucleotide Sequencing; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Primary Cell Culture; Proto-Oncogene Proteins; Sequence Analysis, RNA; Signal Transduction
PubMed: 29795194
DOI: 10.1038/s41467-018-04456-6 -
Theranostics 2024The therapeutic benefits of targeting follicle-stimulating hormone (FSH) receptor in treatment of ovarian cancer are significant, whereas the role of FSH in ovarian...
The therapeutic benefits of targeting follicle-stimulating hormone (FSH) receptor in treatment of ovarian cancer are significant, whereas the role of FSH in ovarian cancer progresses and the underlying mechanism remains to be developed. Tissue microarray of human ovarian cancer, tumor xenograft mouse model, and cell culture were used to investigate the role of FSH in ovarian carcinogenesis. siRNA, lentivirus and inhibitors were used to trigger the inactivation of genes, and plasmids were used to increase transcription of genes. Specifically, pathological characteristic was assessed by histology and immunohistochemistry (IHC), while signaling pathway was studied using western blot, quantitative RT-PCR, and immunofluorescence. Histology and IHC of human normal ovarian and tumor tissue confirmed the association between FSH and Snail in ovarian cancer metastasis. Moreover, in epithelial ovarian cancer cells and xenograft mice, FSH was showed to promote epithelial mesenchymal transition (EMT) progress and metastasis of ovarian cancer via prolonging the half-life of mRNA in a N6-methyladenine methylation (m6A) dependent manner, which was mechanistically through the CREB/ALKBH5 signaling pathway. These findings indicated that FSH induces EMT progression and ovarian cancer metastasis via CREB/ALKBH5/Snail pathway. Thus, this study provided new insight into the therapeutic strategy of ovarian cancer patients with high level of FSH.
Topics: Humans; Animals; Female; Mice; Cell Line, Tumor; Ovarian Neoplasms; Follicle Stimulating Hormone; Epithelial-Mesenchymal Transition; Demethylation; AlkB Homolog 5, RNA Demethylase; Adenine
PubMed: 38505602
DOI: 10.7150/thno.94161 -
Archives of Toxicology Sep 2023The risk of methylmercury (MeHg) toxicity following ingestion of contaminated foodstuffs (e.g., fish) is directly related to the kinetics of MeHg elimination among...
The risk of methylmercury (MeHg) toxicity following ingestion of contaminated foodstuffs (e.g., fish) is directly related to the kinetics of MeHg elimination among individuals. Yet, the factors driving the wide range of inter-individual variability in MeHg elimination within a population are poorly understood. Here, we investigated the relationship between MeHg elimination, gut microbiome demethylation activity, and gut microbiome composition using a coordinated human clinical trial and gnotobiotic mouse modeling approach together with metagenomic sequence analysis. We first observed MeHg elimination half-lives (t) ranging from 28 to 90 days across 27 volunteers. Subsequently, we found that ingestion of a prebiotic induced changes in the gut microbiome and mixed effects (increased, decrease, and no effect) on elimination in these same individuals. Nonetheless, elimination rates were found to correlate with MeHg demethylation activity in cultured stool samples. In mice, attempts to remove the microbiome via generation of germ-free (GF) animals or through antibiotic (Abx) treatment both diminished MeHg demethylation to a similar extent. While both conditions substantially slowed elimination, Abx treatment resulted in significantly slower elimination than the GF condition, indicating an additional role for host-derived factors in supporting elimination. Human fecal microbiomes transplanted to GF mice restored elimination rates to that seen in control mice. Metagenomic sequence analysis of human fecal DNA did not identify genes encoding proteins typically involved in demethylation (e.g., merB, organomercury lyase). However, the abundance of several anaerobic taxa, notably Alistipes onderdonkii, were positively correlated with MeHg elimination. Surprisingly, mono-colonization of GF free mice with A. onderdonkii did not restore MeHg elimination to control levels. Collectively, our findings indicate the human gut microbiome uses a non-conventional pathway of demethylation to increase MeHg elimination that relies on yet to be resolved functions encoded by the gut microbes and the hostClinical Trial NCT04060212, prospectively registered 10/1/2019.
Topics: Humans; Animals; Mice; Methylmercury Compounds; Gastrointestinal Microbiome; Microbiota; Kinetics; Demethylation
PubMed: 37392210
DOI: 10.1007/s00204-023-03548-7 -
Clinical Epigenetics Nov 2023Cholangiocarcinoma (CCA) refers to a collection of malignant tumors that develop from the biliary epithelium. Extensive clinical evidence and epidemiological...
BACKGROUND
Cholangiocarcinoma (CCA) refers to a collection of malignant tumors that develop from the biliary epithelium. Extensive clinical evidence and epidemiological observations indicate a concerning increase in both the incidence and mortality rates of CCA. Surgical resection is currently the sole available cure for CCA. However, it is unfortunate that only a fraction of patients has access to surgery at the time of diagnosis. Moreover, there is a high incidence of cancer recurrence after resection, and systemic treatments have limited efficacy. Therefore, the identification of novel biomarkers for CCA-targeted molecular therapy remains a crucial task in oncology research.
RESULTS
Our study demonstrated that low expression of RSPO3 was associated with poorer survival rates in patients with CCA. We found that the RSPO3 promoter DNA was hypermethylated in CCA, which was correlated with the low expression of RSPO3. The expression of RSPO3 was influenced by the balance between the DNA methyltransferase DNMT3a and the DNA demethylase TET1 in CCA. In vitro and in vivo experiments showed that targeting RSPO3 promoter DNA methylation using dCas9DNMT3a promoted tumorigenicity of CCA, while targeted RSPO3 promoter DNA demethylation using dCas9TET1CD inhibited CCA tumorigenicity. Additionally, in our primary CCA model, knockdown of Rspo3 promoted CCA progression, whereas overexpression of Rspo3 inhibited CCA progression.
CONCLUSIONS
Our findings suggest that increased methylation and decreased expression of RSPO3 may indicate a poor prognosis in CCA. Restoring RSPO3 expression by targeting promoter DNA demethylation could offer insights for precise treatment of CCA.
Topics: Humans; Up-Regulation; DNA Demethylation; Bile Duct Neoplasms; DNA Methylation; Neoplasm Recurrence, Local; Cholangiocarcinoma; Bile Ducts, Intrahepatic; DNA; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Mixed Function Oxygenases; Proto-Oncogene Proteins
PubMed: 37932819
DOI: 10.1186/s13148-023-01592-9 -
Asian Pacific Journal of Cancer... Jun 2022The aim of this study was to investigate the expression and the promoter methylation level of PLAGL1 gene and the mechanism of epigallocatechin gallate (EGCG) that...
OBJECTIVE
The aim of this study was to investigate the expression and the promoter methylation level of PLAGL1 gene and the mechanism of epigallocatechin gallate (EGCG) that induces PLAGL1 gene demethylation and promotes the apoptosis of pheochromocytoma (PCC) in PC12 cell line.
METHODS
The PC12 cells were treated with 25, 50, 75, 100, and 150 μg/mL EGCG for 48 hours. MSP was used to examine PLAGL1 gene methylation and an MTT assay was performed to detect the cell proliferation. The cell apoptosis was detected using flow cytometry. The mRNA and protein expressions of DNMT1, PLAGL1, Wnt, and β-catenin were detected using RT-quantitative PCR and Western blot.
RESULTS
EGCG dose-dependently reduced the cell viability and reversed PLAGL1 gene hypermethylation in PC12 cells (P<0.05). The cell apoptosis was significantly increased in PC12 cells treated with EGCG. The EGCG treatment restored the expressions of PLAGL1 and downregulated the expression of DNMT1, Wnt, and β-catenin in PC12 cells (P<0.05).
CONCLUSION
The EGCG induces the demethylation process of PLAGL1 gene through down-regulating DNMT1 and restores the PLAGL1 mRNA and protein expression. The Wnt/β-catenin signaling pathway is involved in the regulation of PCC cell apoptosis promoted by EGCG inducing PLAGL1 gene demethylation.
Topics: Adrenal Gland Neoplasms; Animals; Apoptosis; Catechin; Cell Cycle Proteins; Demethylation; Genes, Tumor Suppressor; Humans; PC12 Cells; Pheochromocytoma; RNA, Messenger; Rats; Transcription Factors; Tumor Suppressor Proteins; Wnt Signaling Pathway; beta Catenin
PubMed: 35763656
DOI: 10.31557/APJCP.2022.23.6.2119 -
Chemistry (Weinheim An Der Bergstrasse,... Mar 2020N-Demethylation of oxycodone is one of the key steps in the synthesis of important opioid antagonists like naloxone or analgesics like nalbuphine. The reaction is...
N-Demethylation of oxycodone is one of the key steps in the synthesis of important opioid antagonists like naloxone or analgesics like nalbuphine. The reaction is typically carried out using stoichiometric amounts of toxic and corrosive reagents. Herein, we present a green and scalable organophotocatalytic procedure that accomplishes the N-demethylation step using molecular oxygen as the terminal oxidant and an organic dye (rose bengal) as an effective photocatalyst. Optimization of the reaction conditions under continuous flow conditions using visible-light irradiation led to an efficient, reliable, and scalable process, producing noroxycodone hydrochloride in high isolated yield and purity after a simple workup.
Topics: Analgesics; Demethylation; Humans; Morphinans; Oxycodone
PubMed: 31898822
DOI: 10.1002/chem.201905505