Mice heterozygous for CREB binding protein are hypersensitive to γ-radiation and invariably develop myelodysplastic/myeloproliferative neoplasm.

Abstract

Myelodysplastic syndrome is a complex family of preleukemic diseases in which hematopoietic stem cell defects lead to abnormal differentiation in one or more blood lineages. Disease progression is associated with increasing genomic instability and a large proportion of patients go on to develop acute myeloid leukemia. Primarily a disease of the elderly, it can also develop after chemotherapy. We have previously reported that CREB binding protein (Crebbp) heterozygous mice have an increased incidence of hematological malignancies, and others have shown that CREBBP is one of the genes altered by chromosomal translocations found in patients suffering from therapy-related myelodysplastic syndrome. This led us to investigate whether hematopoietic tumor development in Crebbp(+/-) mice is preceded by a myelodysplastic phase and whether we could uncover molecular mechanisms that might contribute to its development. We report here that Crebbp(+/-) mice invariably develop myelodysplastic/myeloproliferative neoplasm within 9 to 12 months of age. They are also hypersensitive to ionizing radiation and show a marked decrease in poly(ADP-ribose) polymerase-1 activity after irradiation. In addition, protein levels of XRCC1 and APEX1, key components of base excision repair machinery, are reduced in unirradiated Crebbp(+/-) cells or upon targeted knockdown of CREBBP levels. Our results provide validation of a novel myelodysplastic/myeloproliferative neoplasm mouse model and, more importantly, point to defective repair of DNA damage as a contributing factor to the pathogenesis of this currently incurable disease.

• Authors: Stephanie N Zimmer, Madeleine E Lemieux, Bijal P Karia, Claudia Day, Ting Zhou, Qing Zhou, Andrew L Kung, Uthra Suresh, Yidong Chen, Marsha C Kinney, Alexander J R Bishop, Vivienne I Rebel
• Journal: Experimental hematology (Exp Hematol) Vol. 40 Issue 4 Pg. 295-306.e5 (Apr 2012) ISSN: 1873-2399 [Electronic] Netherlands
• PMID: 22198154 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

Chemical References

• RNA, Small Interfering
• CREB-Binding Protein
• Crebbp protein, mouse

Topics

• Animals
• CREB-Binding Protein (genetics, physiology)
• DNA Damage
• DNA Repair (genetics)
• Disease Progression
• Gamma Rays (adverse effects)
• Gene Expression Regulation
• Gene Knockdown Techniques
• Gene Regulatory Networks
• Genomic Instability
• Heterozygote
• Mice
• Mice, Inbred C57BL
• Myelodysplastic Syndromes (genetics)
• Myeloproliferative Disorders (genetics)
• Preleukemia (genetics)
• RNA, Small Interfering (genetics, toxicity)
• Radiation Tolerance (genetics)
• Whole-Body Irradiation (adverse effects)