Role of Heterochromatin Epigenetic Factors in CML
Abstract
During the reported period, our main goal was to test and further develop a hypothesis that structural modifications and/or interference between two heterochromatin proteins: MNEI and HP1 lead to abnormal gene regulation and impaired myeloid differentiation, CML acceleration, blast crises and/or secondary acute leukemia. In specific aim 1, we isolated monomeric and high molecular forms of MNEI by chromatography and gel electrophoresis and determined their primary structure by mass spectroscopy to identify the high molecular MNEI bands as those originating from MNEI and its complexes with a protease, neutrophil elastase. We designed peptides and raised antibodies against MNEI/elastase complex and specific peptides exposed in the modified MNEI. We found that these antibodies recognize MNEI65 expressed in a subset of CML cases including the blastic form of CML. In specific Aim 2 we conducted experiments on expressing MNEI and HP1 in leukemia cell lines. Cell cultures derived from a blastic CML cell model K562 expressing both MNEI and HP1 were raised and characterized for their chromatin structure and proliferation ability showing that expression of MNEI does not interfere with HP1 and other heterochromatin markers but significantly inhibits cell proliferation. This inhibition requires intact protease inhibitory activity of MNEI. Our results suggest that MNEI interferes with myeloid proliferation independently of heterochromatin proteins but through forming complexes with its target proteases such as neutrophil elastase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2007
- Accession Number
- ADA474571
Entities
People
- Sergei A. Grigoryev
Organizations
- Pennsylvania State University