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Cancer Research Communications Aug 2023Epigenetic reprogramming, mediated by genomic alterations and dysregulation of histone reader and writer proteins, plays a critical role in driving prostate cancer...
UNLABELLED
Epigenetic reprogramming, mediated by genomic alterations and dysregulation of histone reader and writer proteins, plays a critical role in driving prostate cancer progression and treatment resistance. However, the specific function and regulation of EHMT1 (also known as GLP) and EHMT2 (also known as G9A), well-known histone 3 lysine 9 methyltransferases, in prostate cancer progression remain poorly understood. Through comprehensive investigations, we discovered that both EHMT1 and EHMT2 proteins have the ability to activate oncogenic transcription programs in prostate cancer cells. Silencing EHMT1/2 or targeting their enzymatic activity with small-molecule inhibitors can markedly decrease prostate cancer cell proliferation and metastasis and . In-depth analysis of posttranslational modifications of EHMT1 protein revealed the presence of methylation at lysine 450 and 451 residues in multiple prostate cancer models. Notably, we found that lysine 450 can be demethylated by LSD1. Strikingly, concurrent demethylation of both lysine residues resulted in a rapid and profound expansion of EHMT1's chromatin binding capacity, enabling EHMT1 to reprogram the transcription networks in prostate cancer cells and activate oncogenic signaling pathways. Overall, our studies provide valuable molecular insights into the activity and function of EHMT proteins during prostate cancer progression. Moreover, we propose that the dual-lysine demethylation of EHMT1 acts as a critical molecular switch, triggering the induction of oncogenic transcriptional reprogramming in prostate cancer cells. These findings highlight the potential of targeting EHMT1/2 and their demethylation processes as promising therapeutic strategies for combating prostate cancer progression and overcoming treatment resistance.
SIGNIFICANCE
In this study, we demonstrate that EHMT1 and EHMT2 proteins drive prostate cancer development by transcriptionally activating multiple oncogenic pathways. Mechanistically, the chromatin binding of EHMT1 is significantly expanded through demethylation of both lysine 450 and 451 residues, which can serve as a critical molecular switch to induce oncogenic transcriptional reprogramming in prostate cancer cells.
Topics: Male; Humans; Lysine; Histones; Neoplastic Processes; Prostatic Neoplasms; Prostatic Hyperplasia; Histone-Lysine N-Methyltransferase; Chromatin; Demethylation; Histocompatibility Antigens
PubMed: 37663929
DOI: 10.1158/2767-9764.CRC-23-0208 -
Signal Transduction and Targeted Therapy Sep 2023The mineral dust-induced gene (MDIG) comprises a conserved JmjC domain and has the ability to demethylate histone H3 lysine 9 trimethylation (H3K9me3). Previous studies...
The mineral dust-induced gene (MDIG) comprises a conserved JmjC domain and has the ability to demethylate histone H3 lysine 9 trimethylation (H3K9me3). Previous studies have indicated the significance of MDIG in promoting cell proliferation by modulating cell-cycle transition. However, its involvement in liver regeneration has not been extensively investigated. In this study, we generated mice with liver-specific knockout of MDIG and applied partial hepatectomy or carbon tetrachloride mouse models to investigate the biological contribution of MDIG in liver regeneration. The MDIG levels showed initial upregulation followed by downregulation as the recovery progressed. Genetic MDIG deficiency resulted in dramatically impaired liver regeneration and delayed cell cycle progression. However, the MDIG-deleted liver was eventually restored over a long latency. RNA-seq analysis revealed Myc as a crucial effector downstream of MDIG. However, ATAC-seq identified the reduced chromatin accessibility of OTX2 locus in MDIG-ablated regenerating liver, with unaltered chromatin accessibility of Myc locus. Mechanistically, MDIG altered chromatin accessibility to allow transcription by demethylating H3K9me3 at the OTX2 promoter region. As a consequence, the transcription factor OTX2 binding at the Myc promoter region was decreased in MDIG-deficient hepatocytes, which in turn repressed Myc expression. Reciprocally, Myc enhanced MDIG expression by regulating MDIG promoter activity, forming a positive feedback loop to sustain hepatocyte proliferation. Altogether, our results prove the essential role of MDIG in facilitating liver regeneration via regulating histone methylation to alter chromatin accessibility and provide valuable insights into the epi-transcriptomic regulation during liver regeneration.
Topics: Animals; Mice; Liver Regeneration; Cell Proliferation; Chromatin; Liver; Demethylation
PubMed: 37709738
DOI: 10.1038/s41392-023-01575-5 -
The New England Journal of Medicine May 2022Although hypomethylating agents are currently used to treat patients with cancer, whether they can also reactivate and up-regulate oncogenes is not well elucidated.
BACKGROUND
Although hypomethylating agents are currently used to treat patients with cancer, whether they can also reactivate and up-regulate oncogenes is not well elucidated.
METHODS
We examined the effect of hypomethylating agents on , a known oncogene that plays an important role in myelodysplastic syndrome and other cancers. Paired bone marrow samples that were obtained from two cohorts of patients with myelodysplastic syndrome before and after treatment with a hypomethylating agent were used to explore the relationships among changes in expression, treatment response, and clinical outcome. Leukemic cell lines with low or undetectable expression were used to study the relationship between methylation and expression. A locus-specific demethylation technology, CRISPR-DNMT1-interacting RNA (CRISPR-DiR), was used to identify the CpG island that is critical for expression.
RESULTS
up-regulation after treatment with hypomethylating agents was observed in 10 of 25 patients (40%) in cohort 1 and in 13 of 43 patients (30%) in cohort 2 and was associated with a worse outcome. Using CRISPR-DiR, we discovered that demethylation of a CpG island within the 5' untranslated region was critical for expression. In cell lines and patients, we confirmed that treatment with a hypomethylating agent led to demethylation of the same CpG region and up-regulation of expression.
CONCLUSIONS
By combining analysis of patient samples with CRISPR-DiR technology, we found that demethylation and up-regulation of an oncogene after treatment with a hypomethylating agent can indeed occur and should be further studied. (Funded by Associazione Italiana per la Ricerca sul Cancro and others.).
Topics: Antineoplastic Agents; Clustered Regularly Interspaced Short Palindromic Repeats; Demethylation; Humans; Myelodysplastic Syndromes; Neoplasms; Oncogenes; Transcription Factors; Up-Regulation
PubMed: 35613022
DOI: 10.1056/NEJMoa2119771 -
Seminars in Cancer Biology Feb 2022Several studies have shown that cancer cells can be "phenotypically reversed", thus achieving a "tumor reversion", by losing malignant hallmarks as migrating and... (Review)
Review
Several studies have shown that cancer cells can be "phenotypically reversed", thus achieving a "tumor reversion", by losing malignant hallmarks as migrating and invasive capabilities. These findings suggest that genome activity can switch to assume a different functional configuration, i.e. a different Gene Regulatory Network pattern. Indeed, once "destabilized", cancer cells enter into a critical transition phase that can be adequately "oriented" by yet unidentified morphogenetic factors - acting on both cells and their microenvironment - that trigger an orchestrated array of structural and epigenetic changes. Such process can bypass genetic abnormalities, through rerouting cells toward a benign phenotype. Oocytes and embryonic tissues, obtained by animals and humans, display such "reprogramming" capability, as a number of yet scarcely identified embryo-derived factors can revert the malignant phenotype of several types of tumors. Mechanisms involved in the reversion process include the modification of cell-microenvironment cross talk (mostly through cytoskeleton reshaping), chromatin opening, demethylation, and epigenetic changes, modulation of biochemical pathways, comprising TCTP-p53, PI3K-AKT, FGF, Wnt, and TGF-β-dependent cascades. Results herein discussed promise to open new perspectives not only in the comprehension of cancer biology but also toward different therapeutic options, as suggested by a few preliminary clinical studies.
Topics: Cell Transformation, Neoplastic; Cellular Reprogramming; Cellular Reprogramming Techniques; Chromatin Assembly and Disassembly; Cytoskeleton; DNA Demethylation; Epigenesis, Genetic; Humans; Neoplasms; Tumor Microenvironment
PubMed: 32920125
DOI: 10.1016/j.semcancer.2020.09.005 -
Nucleic Acids Research Mar 2024Albeit N1-Methyladenosine (m1A) RNA modification represents an important regulator of RNA metabolism, the role of m1A modification in carcinogenesis remains enigmatic....
Albeit N1-Methyladenosine (m1A) RNA modification represents an important regulator of RNA metabolism, the role of m1A modification in carcinogenesis remains enigmatic. Herein, we found that histone lactylation enhances ALKBH3 expression and simultaneously attenuates the formation of tumor-suppressive promyelocytic leukemia protein (PML) condensates by removing the m1A methylation of SP100A, promoting the malignant transformation of cancers. First, ALKBH3 is specifically upregulated in high-risk ocular melanoma due to excessive histone lactylation levels, referring to m1A hypomethylation status. Moreover, the multiomics analysis subsequently identified that SP100A, a core component for PML bodies, serves as a downstream candidate target for ALKBH3. Therapeutically, the silencing of ALKBH3 exhibits efficient therapeutic efficacy in melanoma both in vitro and in vivo, which could be reversed by the depletion of SP100A. Mechanistically, we found that YTHDF1 is responsible for recognition of the m1A methylated SP100A transcript, which increases its RNA stability and translational efficacy. Conclusively, we initially demonstrated that m1A modification is necessary for tumor suppressor gene expression, expanding the current understandings of dynamic m1A function during tumor progression. In addition, our results indicate that lactylation-driven ALKBH3 is essential for the formation of PML nuclear condensates, which bridges our knowledge of m1A modification, metabolic reprogramming, and phase-separation events.
Topics: Humans; AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; Demethylation; DNA Methylation; Histones; Melanoma; Promyelocytic Leukemia Protein; RNA; Transcription Factors; Antigens, Nuclear; Autoantigens; Eye Neoplasms
PubMed: 38118002
DOI: 10.1093/nar/gkad1193 -
Redox Biology Aug 2023There are no effective therapeutic targets or strategies that simultaneously inhibit tumour growth and promote cardiac function recovery. Here, we analyzed targets for...
There are no effective therapeutic targets or strategies that simultaneously inhibit tumour growth and promote cardiac function recovery. Here, we analyzed targets for cancer treatments and cardiac repair, with demethylation emerging as a common factor in these candidate lists. As DNA methyltransferase 1 (DNMT1) majorly responds to methylation, a natural compound library is screened, identifying dioscin as a novel agent targeted at DNMT1, widely used for heart diseases. Dioscin was found to reduce DNMT activities and inhibits growth in breast cancer cells. Combined with analyses of RNA-seq and MeDIP-seq, the promoters of antioxidant genes were demethylated after dioscin, recruiting NRF2 and elevating their expression. In Nrf2 knockout mice, the cardiac protection role of dioscin was blocked by Nrf2-loss. Furthermore, in tumour-bearing mice with hypertrophy, dioscin was observed to inhibit tumour growth and alleviate cardiac injury simultaneously. This study is the first to identify dioscin as a novel demethylation agent with dual functions of anti-cancer and cardio-protection.
Topics: Mice; Animals; Recovery of Function; NF-E2-Related Factor 2; Neoplasms; Demethylation; DNA Methylation
PubMed: 37343447
DOI: 10.1016/j.redox.2023.102785 -
Journal of Advanced Research Dec 2023Poor wound healing is a significant complication of diabetes, which is commonly caused by neuropathy, trauma, deformities, plantar hypertension and peripheral arterial... (Review)
Review
BACKGROUND
Poor wound healing is a significant complication of diabetes, which is commonly caused by neuropathy, trauma, deformities, plantar hypertension and peripheral arterial disease. Diabetic foot ulcers (DFU) are difficult to heal, which makes patients susceptible to infections and can ultimately conduce to limb amputation or even death in severe cases. An increasing number of studies have found that epigenetic alterations are strongly associated with poor wound healing in diabetes.
AIM OF REVIEW
This work provides significant insights into the development of therapeutics for improving chronic diabetic wound healing, particularly by targeting and regulating DNA methylation and demethylation in DFU. Key scientific concepts of review: DNA methylation and demethylation play an important part in diabetic wound healing, via regulating corresponding signaling pathways in different breeds of cells, including macrophages, vascular endothelial cells and keratinocytes. In this review, we describe the four main phases of wound healing and their abnormality in diabetic patients. Furthermore, we provided an in-depth summary and discussion on how DNA methylation and demethylation regulate diabetic wound healing in different types of cells; and gave a brief summary on recent advances in applying cellular reprogramming techniques for improving diabetic wound healing.
Topics: Humans; Diabetic Foot; DNA Methylation; Endothelial Cells; Wound Healing; Demethylation; Diabetes Mellitus
PubMed: 36706989
DOI: 10.1016/j.jare.2023.01.009 -
Scientific Reports Apr 2023Role of DNA damage and demethylation on anticancer activity of DNA methyltransferase inhibitors (DNMTi) remains undefined. We report the effects of DNMT1 gene...
Role of DNA damage and demethylation on anticancer activity of DNA methyltransferase inhibitors (DNMTi) remains undefined. We report the effects of DNMT1 gene deletion/disruption (DNMT1) on anticancer activity of a class of DNMTi in vitro, in vivo and in human cancers. The gene deletion markedly attenuated cytotoxicity and growth inhibition mediated by decitabine, azacitidine and 5-aza-4'-thio-2'-deoxycytidine (aza-T-dCyd) in colon and breast cancer cells. The drugs induced DNA damage that concurred with DNMT1 inhibition, subsequent G/M cell-cycle arrest and apoptosis, and upregulated p21 in DNMT1 versus DNMT1 status, with aza-T-dCyd the most potent. Tumor growth and DNMT1 were significantly inhibited, and p21 was upmodulated in mice bearing HCT116 DNMT1 xenograft and bladder PDX tumors. DNMT1 gene deletion occurred in ~ 9% human colon cancers and other cancer types at varying degrees. Decitabine and azacitidine demethylated CDKN2A/CDKN2B genes in DNMT1 and DNMT1 conditions and increased histone-H3 acetylation with re-expression of p16/p15 in DNMT1 state. Thus, DNMT1 deletion confers resistance to DNMTi, and their anti-cancer activity is determined by DNA damage effects. Patients with DNMT1 gene deletions may not respond to DNMTi treatment.
Topics: Humans; Mice; Animals; Decitabine; DNA (Cytosine-5-)-Methyltransferases; DNA (Cytosine-5-)-Methyltransferase 1; Azacitidine; DNA Damage; Demethylation; DNA; DNA Methylation; Cell Line, Tumor
PubMed: 37045940
DOI: 10.1038/s41598-023-32509-4 -
Clinical Epigenetics Jul 2022SLC5A7 (solute carrier family 5 member 7), also known as choline transporter 1 (CHT1), is downregulated in colorectal cancer (CRC) and functions as a tumor suppressor....
BACKGROUND
SLC5A7 (solute carrier family 5 member 7), also known as choline transporter 1 (CHT1), is downregulated in colorectal cancer (CRC) and functions as a tumor suppressor. However, the mechanisms underlying the inactivation of SLC5A7 in CRC remain to be elucidated.
RESULTS
In the present study, two broad-spectrum demethylation agents (azacitidine and decitabine) employed to treat CRC cells significantly upregulated SLC5A7 expression. Further results based on the CRC cohort and TCGA database indicated that SLC5A7 promoter methylation inversely correlated with SLC5A7 expression, and the status of SLC5A7 promotor methylation showed a promising prognostic value for patients with CRC. Next, the dCas9-multiGCN4/scFv-TET1CD-based precision demethylation system was constructed, which could significantly and specifically promote SLC5A7 expression in CRC cells through sgRNA targeting the SLC5A7 promoter. Both in vitro and in vivo experiments demonstrated that targeted demethylation of SLC5A7 by dCas9-multiGCN4/scFv-TET1CD-sgSLC5A7 inhibited tumor growth by stabilizing p53 and regulating downstream targets.
CONCLUSIONS
Collectively, DNA promoter methylation caused inactivation of SLC5A7 in CRC, and targeted demethylation of SLC5A7 might be a therapeutic target for CRC and other cancers.
Topics: Azacitidine; Cell Line, Tumor; Colorectal Neoplasms; DNA Methylation; Demethylation; Gene Expression Regulation, Neoplastic; Humans; Promoter Regions, Genetic; Symporters
PubMed: 35858918
DOI: 10.1186/s13148-022-01308-5 -
Neuro-oncology May 2022
Topics: DNA; Demethylation; Glioma; Humans; Isocitrate Dehydrogenase; Tretinoin
PubMed: 35239963
DOI: 10.1093/neuonc/noac056