DNA Methyltransferase Inhibition by Intercalating Agents

Summary

Principal Investigator: KEITH ROBERTSON
Abstract: Anti-cancer drugs of the DNA intercalator class, which includes doxorubicin (adriamycin), are among the most effective and widely used agents in systemic cancer chemotherapy. Numerous mechanisms have been proposed to be responsible for intercalator-mediated cytotoxicity, including inhibition of DNA topoisomerase II and DNA replication, yet none of these can completely account for the myriad effects these agents have seen shown to exert on cells. Our incomplete understanding of the molecular mechanism of action of DNA intercalators prevents them from being used as effectively as possible. Epigenetic genome modifications, in particular DNA methylation, have now been recognized as major regulators of gene activity and genomic stability. Indeed, the DNA methylation machinery and cellular DNA methylation patterns are disrupted in nearly all tumor cells. Emerging evidence indicates that chemotherapeutic drugs can alter DNA methylation patterns. How anti-cancer drugs such as DNA intercalators alter the efficacy of the DNA methylation machinery - and vice versa - has been largely unexplored. The central hypothesis we plan to test in this application is that inhibition of DNA methyltransferases (DNMTs) by DNA intercalating agents leads to alterations in genomic DNA methylation patterns and contributes directly to intercalator-mediated cell growth inhibition and apoptosis of human cancer cells. The three aims of this proposal are designed to test this hypothesis. In aim 1, the inhibition properties of a group of DNA intercalating agents on the major DNMTs will be characterized in vitro using both DNA and chromatin substrates. Our second aim entails characterizing the effects of DNA intercalating agents on both DNA methylation patterns (global and gene-specific) and the DNMTs in vivo in tumor cell lines. Lastly, we aim to determine whether cellular DNA methyltransferase levels influence the capacity of DNA intercalating drugs to induce cell cycle arrest and apoptosis in human tumor cell lines. Addressing these questions will advance our understanding of how DNA intercalating agents exert their powerful anticancer effects and how their inhibition of DNA methylation affects this process. This is expected to positively affect human health by allowing for the development of new therapies that maximize the anti-tumor properties of DNA intercalating agents and minimize their side-effects. Cancer is one of the leading causes of death in the United States and chemotherapy is frequently employed to treat cancer patients, however the success rate is variable and our current repertoire of drugs is limited. It is therefore critical to understand how these drugs function to kill tumor cells and determine how they can be used more effectively. Elucidating the molecular mechanism of a widely utilized class of anticancer drugs known as DNA intercalators is the focus of this proposal.
Funding Period: ----------------2006 - ---------------2011-
more information: NIH RePORT

Top Publications

  1. pmc DNA methylation inhibitor 5-Aza-2'-deoxycytidine induces reversible genome-wide DNA damage that is distinctly influenced by DNA methyltransferases 1 and 3B
    Stela S Palii
    Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Box 100245, 1600 SW Archer Rd, Gainesville, FL 32610, USA
    Mol Cell Biol 28:752-71. 2008
  2. pmc DNA methylation in development and human disease
    Suhasni Gopalakrishnan
    Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
    Mutat Res 647:30-8. 2008
  3. pmc Molecular modeling of inhibitors of human DNA methyltransferase with a crystal structure: discovery of a novel DNMT1 inhibitor
    Jakyung Yoo
    Torrey Pines Institute for Molecular Studies, Port St Lucie, Florida, USA
    Adv Protein Chem Struct Biol 87:219-47. 2012
  4. pmc DNA methyltransferases, DNA damage repair, and cancer
    Bilian Jin
    Department of Biochemistry and Molecular Biology, Georgia Health Sciences University Cancer Center, CN 2151, 1410 Laney Walker Blvd, Augusta, GA 30912, USA
    Adv Exp Med Biol 754:3-29. 2013
  5. pmc Linking DNA methyltransferases to epigenetic marks and nucleosome structure genome-wide in human tumor cells
    Bilian Jin
    Cancer Research Center, Georgia Health Sciences University, Augusta, GA 30912, USA
    Cell Rep 2:1411-24. 2012
  6. pmc Rapid and transient recruitment of DNMT1 to DNA double-strand breaks is mediated by its interaction with multiple components of the DNA damage response machinery
    Kyungsoo Ha
    Cancer Center, Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, GA 30912, USA
    Hum Mol Genet 20:126-40. 2011
  7. pmc Modulation of Dnmt3b function in vitro by interactions with Dnmt3L, Dnmt3a and Dnmt3b splice variants
    Beth O Van Emburgh
    Department of Biochemistry and Molecular Biology, Cancer Research Center, CN 2151, Georgia Health Sciences University, 1410 Laney Walker Blvd, Augusta, GA 30912, USA
    Nucleic Acids Res 39:4984-5002. 2011
  8. pmc DNA methylation: superior or subordinate in the epigenetic hierarchy?
    Bilian Jin
    Department of Biochemistry and Molecular Biology, Medical College of Georgia Cancer Center, Augusta, GA, USA
    Genes Cancer 2:607-17. 2011

Scientific Experts

  • Keith D Robertson
  • Bilian Jin
  • Beth O Van Emburgh
  • Stela S Palii
  • Jakyung Yoo
  • Kyungsoo Ha
  • Kevin D Brown
  • Suhasni Gopalakrishnan
  • Jeong Hyeon Choi
  • Rochelle L Tiedemann
  • Stephen Dalton
  • Manolis Kellis
  • Jose L Medina-Franco
  • Hongyan Xu
  • Joo Hee Kim
  • Jason Ernst
  • Chen Liu
  • Suhas Sureshchandra
  • Kapil N Bhalla
  • Kebin Liu
  • Yajun Li
  • Gun Eui Lee
  • Yoshihiko Takeda
  • Umesh T Sankpal

Detail Information

Publications9

  1. pmc DNA methylation inhibitor 5-Aza-2'-deoxycytidine induces reversible genome-wide DNA damage that is distinctly influenced by DNA methyltransferases 1 and 3B
    Stela S Palii
    Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Box 100245, 1600 SW Archer Rd, Gainesville, FL 32610, USA
    Mol Cell Biol 28:752-71. 2008
    ....
  2. pmc DNA methylation in development and human disease
    Suhasni Gopalakrishnan
    Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
    Mutat Res 647:30-8. 2008
    ....
  3. pmc Molecular modeling of inhibitors of human DNA methyltransferase with a crystal structure: discovery of a novel DNMT1 inhibitor
    Jakyung Yoo
    Torrey Pines Institute for Molecular Studies, Port St Lucie, Florida, USA
    Adv Protein Chem Struct Biol 87:219-47. 2012
    ..4 μM. This chapter illustrates the synergy from integrating molecular modeling and experimental methods to further advance the discovery of novel candidates for epigenetic therapies...
  4. pmc DNA methyltransferases, DNA damage repair, and cancer
    Bilian Jin
    Department of Biochemistry and Molecular Biology, Georgia Health Sciences University Cancer Center, CN 2151, 1410 Laney Walker Blvd, Augusta, GA 30912, USA
    Adv Exp Med Biol 754:3-29. 2013
    ..This chapter is focused on reviewing the links between DNA methylation and the DNA damage response...
  5. pmc Linking DNA methyltransferases to epigenetic marks and nucleosome structure genome-wide in human tumor cells
    Bilian Jin
    Cancer Research Center, Georgia Health Sciences University, Augusta, GA 30912, USA
    Cell Rep 2:1411-24. 2012
    ..Taken together, these results shed important light on the determinants of DNA methylation and how it may become disrupted in cancer cells...
  6. pmc Rapid and transient recruitment of DNMT1 to DNA double-strand breaks is mediated by its interaction with multiple components of the DNA damage response machinery
    Kyungsoo Ha
    Cancer Center, Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, GA 30912, USA
    Hum Mol Genet 20:126-40. 2011
    ..Taken together, our studies provide compelling additional evidence for DNMT1 acting as a regulator of genome integrity and as an early responder to DNA DSBs...
  7. pmc Modulation of Dnmt3b function in vitro by interactions with Dnmt3L, Dnmt3a and Dnmt3b splice variants
    Beth O Van Emburgh
    Department of Biochemistry and Molecular Biology, Cancer Research Center, CN 2151, Georgia Health Sciences University, 1410 Laney Walker Blvd, Augusta, GA 30912, USA
    Nucleic Acids Res 39:4984-5002. 2011
    ..Our studies therefore suggest that seemingly 'inactive' DNMT3B isoforms may influence genomic methylation patterns in vivo...
  8. pmc DNA methylation: superior or subordinate in the epigenetic hierarchy?
    Bilian Jin
    Department of Biochemistry and Molecular Biology, Medical College of Georgia Cancer Center, Augusta, GA, USA
    Genes Cancer 2:607-17. 2011
    ....