Abstract
Chromatin modifications – including DNA methylation, modification of histones and recruitment of noncoding RNAs – are essential epigenetic events. Multiple sequential modifications converge into a complex epigenetic landscape. For example, promoter DNA methylation is recognized by MeCP2/methyl CpG binding domain proteins which further recruit SETDB1/SUV39 to attain a higher order chromatin structure by propagation of inactive epigenetic marks like H3K9me3. Many studies with new information on different epigenetic modifications and associated factors are available, but clear maps of interconnected pathways are also emerging. This review deals with the salient epigenetic crosstalk mechanisms that cells utilize for different cellular processes and how deregulation or aberrant gene expression leads to disease progression.
Papers of special note have been highlighted as: • of interest; •• of considerable interest
References
- 1. . Role of histone acetylation in the control of gene expression. Biochem. Cell Biol. 83(3), 344–353 (2005).
- 2. . Molecular marks for epigenetic identification of developmental and cancer stem cells. Clin. Epigenetics 2(1), 27–53 (2011).
- 3. Epigenetic choreography of stem cells: the DNA demethylation episode of development. Cell. Mol. Life Sci. 71(6), 1017–1032 (2014).
- 4. Histone deacetylases: a saga of perturbed acetylation homeostasis in cancer. J. Histochem. Cytochem. 62(1), 11–33 (2014).
- 5. . Histone phosphorylation: how to proceed. Methods 31(1), 40–48 (2003).
- 6. . Histone sumoylation and chromatin dynamics. Nucleic Acids Res. 49(11), 6043–6052 (2021).
- 7. . Decoding histone ubiquitylation. Front Cell Dev Biol. 10, 968398 (2022).
- 8. Chromatin dynamics: H3K4 methylation and H3 variant replacement during development and in cancer. Cell. Mol. Life Sci. 71(18), 3439–3463 (2014).
- 9. . Biology of chromatin dynamics. Annu. Rev. Plant Biol. 56, 327–351 (2005).
- 10. . Mechanistic aspects of reversible methylation modifications of arginine and lysine of nuclear histones and their roles in human colon cancer. Prog. Mol. Biol. Transl. Sci. 197, 261–302 (2023).
- 11. Active genes are tri-methylated at K4 of histone H3. Nature 419(6905), 407–411 (2002). •• One of the premier publications about H3K4 methylation status in active genes.
- 12. . DNA methylation and repressive H3K9 and H3K27 trimethylation in the promoter regions of PD-1, CTLA-4, TIM-3, LAG-3, TIGIT, and PD-L1 genes in human primary breast cancer. Clin. Epigenetics 10, 78 (2018).
- 13. . Epigenetic interplay between histone modifications and DNA methylation in gene silencing. Mutat. Res. 659(1–2), 40–48 (2008).
- 14. Critical role of the UBL domain in stimulating the E3 ubiquitin ligase activity of UHRF1 toward chromatin. Mol. Cell 72(4), 739–752.e9 (2018). • First described how RING E3 ubiquitin ligase UHRF1 controls methylation of newly replicated DNA.
- 15. Association of UHRF1 with methylated H3K9 directs the maintenance of DNA methylation. Nat. Struct. Mol. Biol. 19(11), 1155–1160 (2012).
- 16. . Structural basis for recognition of H3K4 methylation status by the DNA methyltransferase 3A ATRX-DNMT3-DNMT3L domain. EMBO Rep. 10(11), 1235–1241 (2009).
- 17. . Molecular coupling of DNA methylation and histone methylation. Epigenomics 2(5), 657–669 (2010).
- 18. In vivo targeting of de novo DNA methylation by histone modifications in yeast and mouse. Elife 4, e06205 (2015).
- 19. Dynamic changes in histone modifications precede de novo DNA methylation in oocytes. Genes Dev. 29(23), 2449–2462 (2015). •• Defined how histone modifications can configure the DNA methylation pattern.
- 20. A comprehensive analysis of 195 DNA methylomes reveals shared and cell-specific features of partially methylated domains. Genome Biol. 19(1), 150 (2018).
- 21. . Functional cooperation between HP1 and DNMT1 mediates gene silencing. Genes Dev. 21(10), 1169–1178 (2007).
- 22. . DNA modifications: function and applications in normal and disease states. Biology (Basel) 3(4), 670–723 (2014).
- 23. . MBD2 and MBD3: elusive functions and mechanisms. Front. Genet. 5, 428 (2014).
- 24. . Characterizing crosstalk in epigenetic signaling to understand disease physiology. Biochem. J. 480(1), 57–85 (2023).
- 25. . Molecular mechanisms directing PRC2 recruitment and H3K27 methylation. Mol. Cell 74(1), 8–18 (2019).
- 26. . The interplay of histone modifications – writers that read. EMBO Rep. 16(11), 1467–1481 (2015).
- 27. . Crosstalk among epigenetic modifications: lessons from histone arginine methylation. Biochem. Soc. Trans. 41(3), 751–759 (2013).
- 28. . SET1/MLL family of proteins: functions beyond histone methylation. Epigenetics. 16(5), 469–487 (2021).
- 29. ASH2L regulates ubiquitylation signaling to MLL: trans-regulation of H3 K4 methylation in higher eukaryotes. Mol Cell. 49(6), 1108–1120 (2013).
- 30. Sgf29 binds histone H3K4me2/3 and is required for SAGA complex recruitment and histone H3 acetylation. EMBO J. 30(14), 2829–2842 (2011).
- 31. Spurious transcription causing innate immune responses is prevented by 5-hydroxymethylcytosine. Nat Genet. 55(1), 100–111 (2023).
- 32. Investigating crosstalk between H3K27 acetylation and H3K4 trimethylation in CRISPR/dCas-based epigenome editing and gene activation. Sci. Rep. 11(1), 15912 (2021). • Demonstrated that H3K27ac in the promoter region leads to H3K4me3 enrichment around transcription start sites and activates gene expression.
- 33. . Talk is cheap – cross-talk in establishment, maintenance, and readout of chromatin modifications. Genes Dev. 22(24), 3375–3382 (2008).
- 34. . The language of histone crosstalk. Cell 42(5), 682–685 (2010). •• Histone modifications are more like a language than a code in chromatin signaling pathways.
- 35. E2F-dependent histone acetylation and recruitment of the Tip60 acetyltransferase complex to chromatin in late G1. Mol Cell Biol. 24(10), 4546–4556 (2004).
- 36. . Epigenetics and cell cycle regulation in cystogenesis. Cell. Signal. 68, 109509 (2020).
- 37. . How the cell cycle impacts chromatin architecture and influences cell fate. Front. Genet. 6, 19 (2015).
- 38. . Epigenetic dynamics across the cell cycle. Essays Biochem. 48(1), 107–120 (2010).
- 39. The HP1alpha-CAF1-SetDB1-containing complex provides H3K9me1 for Suv39-mediated K9me3 in pericentric heterochromatin. EMBO Rep. 10(7), 769–775 (2009).
- 40. . AUF1 cell cycle variations define genomic DNA methylation by regulation of DNMT1 mRNA stability. Molecular and cellular biology 27(1), 395–410 (2007).
- 41. . The multi-functionality of UHRF1: epigenome maintenance and preservation of genome integrity. Nucleic Acids Res. 49(11), 6053–6068 (2021).
- 42. . How is epigenetic information maintained through DNA replication? Epigenetics Chromatin 6(1), 32 (2013).
- 43. . Epigenetic inheritance during the cell cycle. Nat. Rev. Mol. Cell Biol. 10(3), 192–206 (2009).
- 44. . Epigenetics- Overview and concepts. Epigenetics. Allis CDJenuwein TReinberg D (Eds). Epigenetics Cold Spring Harbor Laboratory Press, 1, 23–61 (2007).
- 45. . New insights into the regulation of heterochromatin. Trends Genet. 32(5), 284–294 (2016).
- 46. . Spreading and epigenetic inheritance of heterochromatin require a critical density of histone H3 lysine 9 tri-methylation. Proc. Natl Acad. Sci. USA 118(22), e2100699118 (2021).
- 47. . Role of non-coding RNAs in post-transcriptional regulation of lung diseases. Front. Genet. 12, 767348 (2021).
- 48. . Non-coding RNAs as regulators of gene expression and epigenetics. Cardiovasc. Res. 90(3), 430–440 (2011).
- 49. . Regulatory RNAs and control of epigenetic mechanisms: expectations for cognition and cognitive dysfunction. Epigenomics 8(1), 135–151 (2016).
- 50. . The widespread regulation of microRNA biogenesis, function and decay. Nat. Rev. Genet. 11(9), 597–610 (2010).
- 51. . Regulation of microRNA biogenesis. Nat. Rev. Mol. Cell Biol. 15(8), 509–524 (2014).
- 52. Dissecting miRNA facilitated physiology and function in human breast cancer for therapeutic intervention. Semin. Cancer Biol. 72, 46–64 (2021). •• A landmark review which highlights recent advances in miRNA function.
- 53. Crosstalk between miRNAs and DNA methylation in cancer. Genes 14(5), 1075 (2023).
- 54. . The roles of microRNAs in epigenetic regulation. Curr. Opin. Chem. Biol. 51, 11–17 (2019).
- 55. . Complex cross-talk between EZH2 and miRNAs confers hallmark characteristics and shapes the tumor microenvironment. Epigenomics 14(11), 699–709 (2022).
- 56. Regulation of microRNAs by epigenetics and their interplay involved in cancer. J. Exp. Clin. Cancer Res. 32(1), 96 (2013).
- 57. . On the road to reading the RNA-interference code. Nature 457(7228), 396–404 (2009).
- 58. Discrete small RNA-generating loci as master regulators of transposon activity in Drosophila. Cell 128(6), 1089–1103 (2007).
- 59. A slicer-mediated mechanism for repeat-associated siRNA 5′ end formation in Drosophila. Science 315(5818), 1587–1590 (2007).
- 60. The epigenetic regulatory mechanism of PIWI/piRNAs in human cancers. Mol Cancer. 22(1), 45 (2023).
- 61. UHRF1 suppresses retrotransposons and cooperates with PRMT5 and PIWI proteins in male germ cells. Nat. Commun. 10(1), 4705 (2019).
- 62. . piRNA pathway targets active LINE1 elements to establish the repressive H3K9me3 mark in germ cells. Genes Dev. 28(13), 1410–1428 (2014).
- 63. 3′ UTR seed matches, but not overall identity, are associated with RNAi off-targets [published correction appears in Nat. Methods 2007 Jun; 4(6): 533]. Nat. Methods 3(3), 199–204 (2006).
- 64. Neutralization of the positive charges on histone tails by RNA promotes an open chromatin structure. Cell Chem. Biol. 26(10), 1436–1449.e5 (2019).
- 65. Molecular interplay of the noncoding RNA ANRIL and methylated histone H3 lysine 27 by polycomb CBX7 in transcriptional silencing of INK4a. Mol. Cell 38(5), 662–674 (2010).
- 66. . Mutually exclusive sense–antisense transcription at FLC facilitates environmentally induced gene repression. Nat. Commun. 7, 13031 (2016).
- 67. . Antisense COOLAIR mediates the coordinated switching of chromatin states at FLC during vernalization. Proc. Natl Acad. Sci. USA 111(45), 16160–16165 (2014).
- 68. . Interaction of noncoding RNA with the rDNA promoter mediates recruitment of DNMT3b and silencing of rRNA genes. Genes Dev. 24(20), 2264–2269 (2010).
- 69. . Gene regulation by long non-coding RNAs and its biological functions. Nat. Rev. Mol. Cell Biol. 22(2), 96–118 (2021).
- 70. . De novo formation and epigenetic maintenance of centromere chromatin. Curr. Opin. Cell Biol. 58, 15–25 (2019).
- 71. . Epigenetic regulation of centromeric chromatin: old dogs, new tricks? Nat. Rev. Genet. 9(12), 923–937 (2008).
- 72. . The elusive structure of centro-chromatin: molecular order or dynamic heterogenetity? J. Mol. Biol. 433(6), 166676 (2021).
- 73. . HACking the centromere chromatin code: insights from human artificial chromosomes. Chromosome Res. 20(5), 505–519 (2012).
- 74. . Ten principles of heterochromatin formation and function. Nat. Rev. Mol. Cell Biol. 19(4), 229–244 (2018).
- 75. . Epigenetic codes for heterochromatin formation and silencing: rounding up the usual suspects. Cell 108(4), 489–500 (2002). •• Histone hypoacetylation, histone H3K9 methylation and CpG methylation are three important epigenetic bases for spreading of heterochromatin for stable epigenetic inheritance of the silent state.
- 76. . Constitutive heterochromatin formation and transcription in mammals. Epigenetics Chromatin 8, 3 (2015).
- 77. . The epigenetic regulation of centromeres and telomeres in plants and animals. Comp. Cytogenet. 14(2), 265–311 (2020).
- 78. . Epigenetic centromere propagation and the nature of CENP-a nucleosomes. Cell 144(4), 471–479 (2011).
- 79. . The centromere: epigenetic control of chromosome segregation during mitosis. Cold Spring Harb. Perspect. Biol. 7(1), a015818 (2014).
- 80. Breaking the HAC barrier: histone H3K9 acetyl/methyl balance regulates CENP-A assembly. EMBO J. 31(10), 2391–2402 (2012). •• Demonstrated the role of H3K9 acetyl/methyl modifications in kinetochore assembly and maintenance.
- 81. . Centromere formation: from epigenetics to self-assembly. Trends Cell Biol. 16(2), 70–78 (2006).
- 82. A genetic memory initiates the epigenetic loop necessary to preserve centromere position. EMBO J. 39(20), e105505 (2020). • Genetic memory governed by CENP proteins initiates the epigenetic modification necessary for centromere formation.
- 83. . Epigenetics of X chromosome inactivation. Handbook of Epigenetics. Academic Press, 341–351 (2011).
- 84. . X-chromosome inactivation: a crossroads between chromosome architecture and gene regulation. Annu. Rev. Genet. 52, 535–566 (2018).
- 85. . Mechanistic insights in X-chromosome inactivation. Philos. Trans. R. Soc. Lond. B Biol. Sci. 372(1733), 20160356 (2017).
- 86. . X inactivation and escape: epigenetic and structural features. Front Cell Dev Biol. 7, 219 (2019).
- 87. The implication of early chromatin changes in X chromosome inactivation. Cell 176(1–2), 182–197.e23 (2019).
- 88. The Xist lncRNA interacts directly with SHARP to silence transcription through HDAC3. Nature 521(7551), 232–236 (2015).
- 89. . The Polycomb group protein Eed protects the inactive X-chromosome from differentiation-induced reactivation. Nat. Cell Biol. 8(2), 195–202 (2006). •• PRC complexes repress the inactive X chromosome from reactivation by stably silencing gene expression.
- 90. . Locked nucleic acids (LNAs) reveal sequence requirements and kinetics of Xist RNA localization to the X chromosome. Proc. Natl Acad. Sci. USA 107(51), 22196–22201 (2010).
- 91. hnRNPK Recruits PCGF3/5-PRC1 to the Xist RNA B-repeat to establish Polycomb-mediated chromosomal silencing. Mol. Cell 68(5), 955–969.e10 (2017).
- 92. . YY1 tethers Xist RNA to the inactive X nucleation center. Cell 146(1), 119–133 (2011).
- 93. . The matrix protein hnRNP U is required for chromosomal localization of Xist RNA. Dev. Cell. 19(3), 469–476 (2010).
- 94. The non-canonical SMC protein SmcHD1 antagonises TAD formation and compartmentalisation on the inactive X chromosome. Nat. Commun. 10(1), 30 (2019).
- 95. Mechanistic view of hnRNPA2 low-complexity domain structure, interactions, and phase separation altered by mutation and arginine methylation. Mol. Cell 69(3), 465–479.e7 (2018).
- 96. . Epigenetic crosstalk in chronic infection with HIV-1. Semin. Immunopathol. 42(2), 187–200 (2020).
- 97. Transcription regulation of CDKN1A (p21/CIP1/WAF1) by TRF2 is epigenetically controlled through the REST repressor complex. Sci. Rep. 7(1), 11541 (2017).
- 98. EZH2 promotes gastric cancer cells proliferation by repressing p21 expression. Pathol. Res. Pract. 215(6), 152374 (2019).
- 99. EZH2 inhibition: a promising strategy to prevent cancer immune editing. Epigenomics 12(16), 1457–1476 (2020).
- 100. Phosphorylation of EZH2 at T416 by CDK2 contributes to the malignancy of triple negative breast cancers. Am. J. Transl. Res. 7(6), 1009–1020 (2015).
- 101. CDK2-mediated site-specific phosphorylation of EZH2 drives and maintains triple-negative breast cancer [published correction appears in Nat. Commun. 2020 Jan 29; 11(1): 673]. Nat. Commun. 10(1), 5114 (2019).
- 102. DNA methylation and not H3K4 trimethylation dictates the expression status of miR-152 gene which inhibits migration of breast cancer cells via DNMT1/CDH1 loop. Exp. Cell Res. 346(2), 176–187 (2016). •• A landmark article which described the epigenetic command of DNA methylation for gene silencing over H3K4me3, a strong histone mark for active genes.
- 103. H3K4/H3K9me3 bivalent chromatin domains targeted by lineage-specific DNA methylation pauses adipocyte differentiation. Mol. Cell 60(4), 584–596 (2015).
- 104. Distinct features of H3K4me3 and H3K27me3 chromatin domains in pre-implantation embryos. Nature 537(7621), 558–562 (2016).
- 105. Hypoxia increases genome-wide bivalent epigenetic marking by specific gain of H3K27me3. Epigenetics Chromatin 9, 46 (2016).
- 106. Epigenetic silencing of genes enhanced by collective role of reactive oxygen species and MAPK signaling downstream ERK/Snail axis: ectopic application of hydrogen peroxide repress CDH1 gene by enhanced DNA methyltransferase activity in human breast cancer. Biochim. Biophys. Acta Mol. Basis Dis. 1865(6), 1651–1665 (2019).
- 107. Clusterin gene is predominantly regulated by histone modifications in human colon cancer and ectopic expression of the nuclear isoform induces cell death. Biochim. Biophys. Acta 1852(8), 1630–1645 (2015).
- 108. . Mechanisms of Hedgehog, calcium and retinoic acid signalling pathway inhibitors: plausible modes of action along the MLL–EZH2–p53 axis in cellular growth control. Arch. Biochem. Biophys. 742, 109600 (2023).
- 109. Targeting bivalency de-represses Indian Hedgehog and inhibits self-renewal of colorectal cancer-initiating cells. Nat. Commun. 10(1), 1436 (2019).
- 110. . Epigenetics, cardiovascular disease, and cellular reprogramming. J. Mol. Cell. Cardiol. 128, 129–133 (2019).
- 111. Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials. Signal Transduct. Target. Ther. 7(1), 200 (2022).
- 112. Class I HDACs regulate angiotensin II-dependent cardiac fibrosis via fibroblasts and circulating fibrocytes. J. Mol. Cell. Cardiol. 67, 112–125 (2014).
- 113. Inhibition of DYRK1A, via histone modification, promotes cardiomyocyte cell cycle activation and cardiac repair after myocardial infarction. EBioMedicine 82, 104139 (2022).
- 114. Histone H3K27 methyltransferase EZH2 and demethylase JMJD3 regulate hepatic stellate cells activation and liver fibrosis. Theranostics 11(1), 361–378 (2021).
- 115. HDAC7 is overexpressed in human diabetic islets and impairs insulin secretion in rat islets and clonal beta cells. Diabetologia 60(1), 116–125 (2017).
- 116. . Epigenetics and type 1 diabetes: mechanisms and translational applications. Transl. Res. 185, 85–93 (2017).
- 117. . JMJD3 in the regulation of human diseases. Protein Cell 10(12), 864–882 (2019).
- 118. . Epigenetic regulation in neurodegenerative diseases. Trends Neurosci. 41(9), 587–598 (2018).
- 119. . Neurodegeneration, and epigenetics: a review. Neurologia (Engl. Ed.) 38(6), e62–e68 (2023).
- 120. . Epigenetic signaling in psychiatric disorders. J. Mol. Biol. 426(20), 3389–3412 (2014).
- 121. H2B ubiquitylation enhances H3K4 methylation activities of human KMT2 family complexes. Nucleic Acids Res. 48(10), 5442–5456 (2020).
- 122. Research progress of dual inhibitors targeting crosstalk between histone epigenetic modulators for cancer therapy. Eur. J. Med. Chem. 222, 113588 (2021). • Highlights the recent advancements in dual inhibitors in epigenetic crosstalk.
- 123. . Epigenetic mechanisms in breast cancer therapy and resistance. Nat. Commun. 12(1), 1786 (2021).
- 124. . Histone modifications: insights into their influence on gene expression. Cell 175(1), 6–9 (2018).
- 125. Dopaminylation of histone H3 in ventral tegmental area regulates cocaine seeking. Science 368(6487), 197–201 (2020).
- 126. Histone serotonylation is a permissive modification that enhances TFIID binding to H3K4me3. Nature 567(7749), 535–539 (2019).
- 127. . Emerging histone glutamine modifications mediated gene expression in cell differentiation and the VTA reward pathway. Gene 768, 145323 (2021).
- 128. . Epigenetic perspectives of COVID-19: virus infection to disease progression and therapeutic control. Biochim Biophys Acta Mol Basis Dis. 1868(12), 166527 (2022).
- 129. . Epigenetic mechanisms regulating COVID-19 infection. Epigenetics 16(3), 263–270 (2021).
- 130. The ORF8 protein of SARS-CoV-2 mediates immune evasion through down-regulating MHC-I. Proc. Natl Acad. Sci. USA 118(23), e2024202118 (2021).
- 131. SARS-CoV-2 disrupts host epigenetic regulation via histone mimicry. Nature 610(7931), 381–388 (2022).
- 132. . Structure of SARS-CoV-2 ORF8, a rapidly evolving immune evasion protein. Proc. Natl Acad. Sci. USA 118(2), e2021785118 (2021).