Molecular Haematopoiesis and Epigenetics

runxGroup Leader: Professor Constanze Bonifer

Overview

Our main research interest is to study the mechanism of cell fate decisions at the level of gene regulation. All blood cells arise from pluripotent stem cells of the bone marrow. We want to understand in mechanistic detail how different genetic programs are activated and silenced at specific stages of blood cell development and which factors are involved in this process. In addition, we study how this finely balanced process is subverted in leukaemic cells.

Our research group

In our work, we address the question of how the regulators of transcription, the sequence-specific DNA binding proteins or transcription factors, interact with the chromatin template and change its structure. We know from genetic studies that chromatin modification complexes play essential roles in all phases of the development of multicellular organisms.

We also know that transcription factors bring these epigenetic regulatory proteins to specific genes. Together, they are responsible for the expression of different genes. Our research has shown that even the process of expressing one gene at the right time and in the right cell is a breathtakingly complex process that involves the coordinate action of hundreds of different molecules. We have also made progress in understanding how these intricately balanced processes are disturbed in leukaemia.

We have now taken these studies one step further. One of the great challenges for future biological and medical research will be to understand how all genes and all molecules in a cell work together to generate different cells that each express only one set of genes. This means that we will have to study all genes simultaneously. To this end, we employ sophisticated genome-wide methods such as ChIP-sequencing and DNaseI-sequencing to generate such data.

We also collaborate with computational biologists to reconstruct models of the molecular interactions driving blood cell development. However, we also study the global consequences of expression of aberrant transcription factors in form of nuclear oncogenes on how the epigenetic landscape is altered in leukaemic cells. The outcome of such studies will shed light on the complex deregulation processes that turn normal into leukaemic cells and will uncover novel therapeutic targets to combat a disease with a high death toll, in particular amongst the elderly.

The results of our experiments are therefore not only important for our understanding of how blood cells form, but are extremely important for how we may diagnose and treat patients in the future.exphaem2

Current projects

1. Establishment of the Haematopoietic Transcriptional Programme: From Systems Approaches to Molecular Mechanisms (together with B.Göttgens, Cambridge; G.Lacaud and V.Kouskoff, Manchester; D.Westhead, Leeds). BBSRC LoLa grant.

Postdocs: Monika Lichtinger, Nadine Obier. Technician: Laura Noailles. BBSRC student: Liam Redgrave

This project studies how the ordered interplay of transcription factors and specific chromatin states leads to the stable expression of lineage specific genetic programs. We use haemopoiesis as a model to identify the molecular mechanisms and dynamics of cell differentiation in a system-wide fashion. To this end we have formed a consortium consisting of experimental researchers and computational biologists to study haemopoietic development as particularly powerful system for the reconstruction of dynamic and global models of the molecular interactions governing an entire developmental pathway.

2. Mechanistic insights into the interplay between transcription factors and the epigenetic regulatory machinery in normal and leukaemic cells (together with Peter Cockerill). Leukemia Lymphoma Research Specialist Programme.

Postdocs: Anetta Ptasinska, Pierre Cauchy, So Yeon Kwon, Joaquin Zacarias, Maria Rosaria Imparato. PhD student: Anna Pickin. Collaborators: Olaf Heidenreich, University of Newcastle, Dan Tenen, Harvard Stem Cell Institute and National University of Singapore, David Westhead, University of Leeds.

In this program, we examine the molecular mechanisms underlying how normal and aberrant leukaemic transcription factors interact with the epigenetic regulatory machinery, reprogram the epigenetic landscape of normal human precursor cells and initiate the vast deregulation phenomena that we observe in malignant cells. We are also developing methods and computational tools that will allow us to model how the human epigenome swings back to normal, once we eliminate specific leukaemia-initiating oncogenes and/or block aberrant signalling through therapy.

3. The role of the transcription factor Sp1 in embryonic macrophage development. MRC.

Postdocs: Jane Gilmour, Salam Assi, in collaboration with Sjaak Philipsen, Erasmus University Rotterdam, and David Westhead, University of Leeds.

Macrophages fulfil multiple important functions in the mammalian organism and each macrophage type is tailored to specific functions within the tissues where they reside. Besides their function in the innate immune system, they also have other roles. These functions are particularly important during embryonic development where phagocytes are involved in tissue remodeling via the removal of cells undergoing programmed cell death. Using the differentiation of mouse ES cells as a model, we have recently demonstrated that embryonic macrophages are uniquely dependent on the presence of the transcription factor Sp1. This project studies the molecular basis of this finding.

4. Mechanistic insights into the deregulation of haematopoietic development by mutated forms of the RUNX1 transcription factor. Kay Kendall Leukaemia Fund.

Postdoc: Regha Kakkad, in collaboration with Georges Lacaud, Paterson Institute of Cancer Research, Manchester

The transcription factor RUNX1 is crucial for the establishment of haemopoiesis and mutation of this gene plays an important role in myeloid leukemia. However, little is known about the mechanistic details of how mutant versions of RUNX1 subvert normal haemopoietic development and counteract normal RUNX1 activity. Using the differentiation of mouse embryonic stem (ES) cells as model we address this question.

5. Geneome-wide maps of transcription factor binding in the human epigenome.

PhD student: Jason Piper, in collaboration with Sascha Ott, Systems Biology Institute, University of Warwick.

In this project we are employing nuclease digestion followed by high-throughput sequencing at high read depth to probe the chromatin fine structure of normal and malignant cells. This tells us how the epigenetic landscape differs between normal and cancer cells, and which transcription factor biding sites are occupied and which ones are not.

6. Consequences of Pax5 deregulation in acute myeloid leukaemia.

PhD student: Debleena Ray. Leukemia Lymphoma Research Gordon Piller student, together with Anetta Ptasinska, So Yeon Kwon and Olaf Heidenreich, University of Newcastle.

The master regulator of B cell development PAX5 is aberrantly expressed in a specific type of acute myeloid leukaemia carrying the t(8;21) translocation. The expression of this factor is one of the reasons why differentiation of cells is blocked in these cells. This project studies this gene locus in detail to determines why this is the case. Our research has uncovered that this aberrant activation is governed by the interplay of polycomb complexes and aberrant signalling.

7. Mechanistic insights into CpG island promoter regulation by the histone methyltransferase Mll2. EU Framework 6 studentship

PhD student: Vasileios Ladopoulos, in collaboration with Francis Stewart, University of Dresden and Arthur Riggs, Beckman Institute of City of Hope

Mll2 is a H3K4 specific histone methyltransferase which is vital for normal embryonic development in the mouse. In this project we conduct an in depth analysis of the molecular mechanism by which MLL2 regulates CpG island promoters.

Recent publications

  • Lichtinger, M., Ingram, R.M., Hannah, R., Clarke, D., Müller, D., Lie-A-Ling, M., Noailles, L., Zhang, P., Wu, M., Tenen, D.G., Assi, S., Westhead, D.R., Kouskoff, V., Lacaud, G., Göttgens, B., and Bonifer, C. (2012) RUNX1 reshapes the epigenetic landscape at the onset of haematopoietic development. EMBO J. In press.
  • Ptasinska, A.; Assi, S.A., James, S.R.,Williamson, D.,Hoogenkamp, M., Mengchu, W., Care, M., McNeill, H., Cullen, M., Tooze, R., Tenen, D.G., Cockerill, P.N. Westhead, D.R.,Heidenreich, O. and Bonifer, C. (2012). Reversible genome-wide epigenetic reprogramming by the leukemia-initiating fusion protein RUNX1/ETO. Leukemia 26:1829-41
  • Leddin, M., Perrod, C. , Hoogenkamp, M., Ghani, S., Ass, S., Heinz,S., Wilson, N.K., Follows, G., Schönheit,J., Vockentanz,L., Mosamam,A., Chen, W., Tenen, D.G., Westhead, D.R., Göttgens, B., Bonifer, C*. and Rosenbauer, F*. (2011) (*joint corr. authors). Two distinct auto-regulatory loops operate at the Pu.1 locus in B cells and myeloid cells. Blood. Mar 10;117(10):2827-38
  • Lamprecht, B., Walter, K., Kreher, S., Kumar, R., Hummel, M., Lenze, D., Köchert, K., Bouhlel, M.A., Richter, J., Soler, E., Stadhouders, R., Jöhrens, C., Wurster, K.D., Callen, C., Harte, M.F., Giefing, M., Barlow, R., Stein, H., Anagnostopoulos, I., Janz, M., Cockerill, P.N., Siebert, R., Dörken, B., Bonifer, C.*, and Mathas, S.* (2010). (*Joint corresponding authors). De–repression of an endogenous long terminal repeat activates the CSF1R proto–oncogene in human lymphoma. Nature Medicine. 16, 571 – 579
  • Hoogenkamp, M.; Lichtinger, M.; Krysinska, H.; Lancrin, C.; Clarke, D.; Williamson, A.; Mazzarella,L.; Ingram, R.; H. Jorgensen, A. Fisher, D,G. Tenen, Kouskoff, V.; G.Lacaud, and C.Bonifer (2009). Early chromatin unfolding by Runx1 - a molecular explanation for differential requirements during specification versus maintenance of the hematopoietic gene expression program. Blood 114; 299-309
  • Lefevre, P., Lacroix, C., Witham, J.,Cockerill, P.N. and Bonifer, C (2008). The LPS-induced transcriptional upregulation of the chicken lysozyme locus involves CTCF eviction and non-coding RNA transcription. Molecular Cell 32, 129 - 139.

Staff

Principle Investigator:
Professor Contsanze Bonifer

Postdocs:
Monika Lichtinger
Nadine Obier
Anetta Ptasinska
Pierre Cauchy
So Yeon Kwon
Joaquin Zacarias
Maria Rosario Imparato
Regha Kakkad Jane Gilmour

PhD Students:
Debleena Ray
Vasileios Ladopulos
Anna Pickin
Liam Redgrave
Jason Piper

Intercalated BsC student:
Sarah Burgin

Technical staff:
Laura Noailles