Epigenetic mechanisms regulate the interpretation of genetic information. Frank Lyko Epigenetics

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1 Epigenetic mechanisms regulate the interpretation of genetic information 7/19/2011 Seite 1

2 DNA methylation is a central epigenetic mechanism NH 2 NH 2 N Dnmt N CH 3 O N O N 4% of genomic C is methylated mediates epigenetic regulation 7/19/2011 Seite 2

3 The worker/queen developmental divide in honeybees: a central paradigm for developmental (epigenetic?) plasticity 7/19/2011 Seite 3

4 Indications for a functional role of DNA methylation in honeybee caste specification control (default) worker bee larvae DNA methyltransferase knockdown (sirna) queen 7/19/2011 Seite 4 Kucharski et al., Science 2008

5 Comparative whole-genome shotgun bisulfite sequencing of worker and queen methylomes DNA from adult worker and queen brains Paired-end Solexa sequencing: 131,000,000 high-quality reads 68% mapped to unique genomic regions 8.6 Gb of sequence output for workers,10.2 Gb for queens combined coverage: 20x 7/19/2011 Seite 5

6 >500 genes show caste-specific methylation differences W: worker Q: queen D: drone 7/19/2011 Seite 6

7 Conclusions: Caste-specific DNA methylation patterns in honeybees The 5-methylcytosine content of the honeybee genome is nearly three orders of magnitude below the human genome Methylation of the honeybee genome is CpG- and exon-specific and may represent a model for mammalian gene body methylation 500 genes showed significant caste-specific methylation differences and may underpin phenotypic differences 7/19/2011 Seite 7 Lyko et al., PLoS Biol. 2010

8 Epigenetic changes underpin phenotypic plasticity does reduced phenotypic plasticity in aging correspond to reduced epigenetic plasticity? young tissue old tissue adapted from Feinberg, Nature /19/2011 Seite 8

9 Primary human skin samples as a model for aging 50 primary human tissue samples = 50 million data points young : years old : years sun-protected : inner arm sun-exposed : outer forearm - keratinocytes - - fibroblasts - 7/19/2011 Seite 9

10 Illumina Infinium methylation analysis parallel analysis of 12 samples and 27,578 CpG sites located in the proximal promoter regions (1 kb upstream, 500 bp downstream) of 14,475 genes 7/19/2011 Seite 10 adapted from Bibikova et al., Epigenomics 2009

11 High interindividual similarity of epidermis methylation patterns 7/19/2011 Seite 11

12 Epidermis and dermis show substantial methylation differences 7/19/2011 Seite 12

13 Stratification according to age reveals age-associated hypermethylation 7/19/2011 Seite 13

14 Stratification according to sun exposure reveals exposure-associated hypomethylation 7/19/2011 Seite 14

15 Conclusions: Age-associated epigenetic changes in human skin Aging causes a small but significant hypermethylation shift in primary human skin samples, consistent with restricted phenotypic plasticity in aged tissue Altered methylation patterns were confirmed by bisulfite sequencing and could play a role in the phenotypic changes of aging skin Age-associated methylation changes resemble cancer-associated epigenetic mutations and might represent precursor lesions 7/19/2011 Seite 15 Grönniger et al., PLoS Genet. 2010

16 Frequent hypermethylation-associated gene silencing in human cancers 7/19/2011 Seite 16 adapted from Esteller Nat. Rev. Genet. 2007

17 Epigenetic cancer therapy: reversion of epigenetic mutations 7/19/2011 Seite 17

18 Developmental stages of DNMT inhibitors in oncology drug development inhibitor preclinical phase I phase II phase III approved 5-azacytidine decitabine zebularine procain(amide) hydralazine EGCG RG108 MG98 Azazytidine and decitabine are approved for the treatment of Myelodysplastic Syndrome Frequent off-label use for the treatment of myeloid leukemias 7/19/2011 Seite 18

19 Expression of the hent1 transporter is a limiting factor in the cellular uptake of nucleoside drugs 7/19/2011 Seite 19

20 CP-4200, an elaidic acid ester of azacytidine 7/19/2011 Seite 20

21 CP-4200 causes genome-wide DNA demethylation and reactivation of tumor suppressor genes control CP-4200 control CP-4200 control CP /19/2011 Seite 21

22 CP-4200 shows superior therapeutic efficacy in an orthotopic ALL mouse model 7/19/2011 Seite 22

23 Summary: Further development of azanucleosides as DNMT inhibitors Azacytidine and decitabine are promising epigenetic cancer drugs, but resistances are common Elaidic acid esterification of azacytidine eliminates transport-related resistance The elaidic acid ester of azacytidine, CP-4200, is a potent DNA methylation inhibitor CP-4200 shows improved in vivo efficacy in mouse models Phase I clinical trial (myelodysplastic syndrome) will start in /19/2011 Seite 23 Brueckner et al., Mol. Cancer Ther. 2010

24 Collaboration partners: Ryszard Maleszka (Canberra) Marc Winnefeld (Beiersdorf AG) Marit Sandvold (Clavis Pharma) 7/19/2011 Seite 24