-
Epigenetics 2022Increasing use of non-combusted forms of nicotine such as e-cigarettes poses important public health questions regarding their specific risks relative to combusted...
Increasing use of non-combusted forms of nicotine such as e-cigarettes poses important public health questions regarding their specific risks relative to combusted tobacco products such as cigarettes. To fully delineate these risks, improved biomarkers that can distinguish between these forms of nicotine use are needed. Prior work has suggested that methylation status at cg05575921 may serve as a specific biomarker of combusted tobacco smoke exposure. We hypothesized combining this epigenetic biomarker with conventional metabolite assays could classify the type of nicotine product consumption. Therefore, we determined DNA methylation and serum cotinine values in samples from 112 smokers, 35 e-cigarette users, 19 smokeless tobacco users, and 269 controls, and performed mass spectroscopy analyses of urine samples from all nicotine users and 22 verified controls to determine urinary levels of putatively nicotine product-specific substances; propylene glycol, 2-cyanoethylmercapturic acid (CEMA), and anabasine. 1) Cigarette smoking was associated with a dose dependent demethylation of cg05575921 and increased urinary CEMA and anabasine levels, 2) e-cigarette use did not demethylate cg05575921, 3) smokeless tobacco use also did not demethylate cg05575921 but was positively associated with anabasine levels 4) CEMA and cg05575921 levels were highly correlated and 5) propylene glycol levels did not reliably distinguish use groups. Cg05575921 assessments distinguish exposure to tobacco smoke from smokeless sources of nicotine including e-cigarettes and smokeless tobacco, neither of which are associated with cg05575921 demethylation. A combination of methylomic and metabolite profiling may allow for accurate classification use status of a variety of nicotine containing products.
Topics: DNA Methylation; Electronic Nicotine Delivery Systems; Nicotine; Nicotiana; Tobacco Products; Vaping
PubMed: 33588690
DOI: 10.1080/15592294.2021.1890875 -
Frontiers in Immunology 2022Human resident memory regulatory T cells (Tregs) exist in the normal, noninflamed skin. Except one, all previous studies analyzed skin Tregs using full-thickness human...
Human resident memory regulatory T cells (Tregs) exist in the normal, noninflamed skin. Except one, all previous studies analyzed skin Tregs using full-thickness human skin. Considering that thick dermis contains more Tregs than thin epidermis, the current understanding of skin Tregs might be biased toward dermal Tregs. Therefore, we sought to determine the phenotype and function of human epidermal and epithelial Tregs. Human epidermis and epithelium were allowed to float on a medium without adding any exogenous cytokines and stimulations for two days and then emigrants from the explants were analyzed. Foxp3 was selectively expressed in CD4CD103 T cells in the various human epithelia, as it is highly demethylated. CD4CD103Foxp3 cells suppressed proliferation of other resident memory T cells. The generation and maintenance of epithelial Tregs were independent of hair density and Langerhans cells. Collectively, immune-suppressive CD4CD103Foxp3 Tregs are present in the normal, noninflamed human epidermis and mucosal epithelia.
Topics: Cytokines; Forkhead Transcription Factors; Humans; T-Lymphocytes, Regulatory
PubMed: 36059538
DOI: 10.3389/fimmu.2022.962167 -
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 -
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 -
Neuro-oncology Jan 2021
Topics: Brain Neoplasms; Decitabine; Glioma; Humans; Telomerase
PubMed: 33264399
DOI: 10.1093/neuonc/noaa272 -
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 -
Nucleic Acids Research Apr 2022AlkB homologue 5 (ALKBH5) is a ferrous iron and 2-oxoglutarate dependent oxygenase that demethylates RNA N6-methyladenosine (m6A), a post-transcriptional RNA...
AlkB homologue 5 (ALKBH5) is a ferrous iron and 2-oxoglutarate dependent oxygenase that demethylates RNA N6-methyladenosine (m6A), a post-transcriptional RNA modification with an emerging set of regulatory roles. Along with the fat mass and obesity-associated protein (FTO), ALKBH5 is one of only two identified human m6A RNA oxidizing enzymes and is a potential target for cancer treatment. Unlike FTO, ALKBH5 efficiently catalyzes fragmentation of its proposed nascent hemiaminal intermediate to give formaldehyde and a demethylated nucleoside. A detailed analysis of the molecular mechanisms used by ALKBH5 for substrate recognition and m6A demethylation is lacking. We report three crystal structures of ALKBH5 in complex with an m6A-ssRNA 8-mer substrate and supporting biochemical analyses. Strikingly, the single-stranded RNA substrate binds to the active site of ALKBH5 in a 5'-3' orientation that is opposite to single-stranded or double-stranded DNA substrates observed for other AlkB subfamily members, including single-stranded DNA bound to FTO. The combined structural and biochemical results provide insight into the preference of ALKBH5 for substrates containing a (A/G)m6AC consensus sequence motif. The results support a mechanism involving formation of an m6A hemiaminal intermediate, followed by efficient ALKBH5 catalyzed demethylation, enabled by a proton shuttle network involving Lys132 and Tyr139.
Topics: Adenosine; AlkB Homolog 5, RNA Demethylase; Alpha-Ketoglutarate-Dependent Dioxygenase FTO; Demethylation; Humans; RNA
PubMed: 35333330
DOI: 10.1093/nar/gkac195 -
Biomedicine & Pharmacotherapy =... Sep 2020In recent years, there have been remarkable scientific advancements in the understanding of lysine demethylases (KDMs) because of their demethylation of diverse... (Review)
Review
In recent years, there have been remarkable scientific advancements in the understanding of lysine demethylases (KDMs) because of their demethylation of diverse substrates, including nucleic acids and proteins. Novel structural architectures, physiological roles in the gene expression regulation, and ability to modify protein functions made KDMs the topic of interest in biomedical research. These structural diversities allow them to exert their function either alone or in complex with numerous other bio-macromolecules. Impressive number of studies have demonstrated that KDMs are localized dynamically across the cellular and tissue microenvironment. Their dysregulation is often associated with human diseases, such as cancer, immune disorders, neurological disorders, and developmental abnormalities. Advancements in the knowledge of the underlying biochemistry and disease associations have led to the development of a series of modulators and technical compounds. Given the distinct biophysical and biochemical properties of KDMs, in this review we have focused on advances related to the structure, function, disease association, and therapeutic targeting of KDMs highlighting improvements in both the specificity and efficacy of KDM modulation.
Topics: Animals; Cellular Microenvironment; DNA Demethylation; Enzyme Inhibitors; Histone Demethylases; Histones; Humans; Molecular Targeted Therapy; Protein Domains; Protein Processing, Post-Translational; Structure-Activity Relationship; Substrate Specificity
PubMed: 32574968
DOI: 10.1016/j.biopha.2020.110392