This revised application proposes to compare the activities of the wild type and variant versions of c-Myb expressed by normal cells and leukemias, and to determine their relevance to human disease. The c-myb proto-oncogene encodes a DNA binding transcription factor with latent transforming activity. Relatively minor changes to the c-Myb protein unleash its ability to cause leukemias in birds and rodents and microarray assays have shown that even minor changes to its C-terminal domains result in dramatic changes in transcriptional activity. Alternative RNA splicing generates multiple c-myb mRNAs that encode proteins with altered C-terminal domains and the alternative splicing is more abundant and more varied in leukemias than in normal cells, suggesting that variants of c-Myb may participate in leukemogenesis.
In Aim 1, the structures of the most abundant variant c-myb mRNAs expressed in a representative group of normal hematopoietic cells and leukemias will be determined. To compare their activities, the normal and variant forms of c-Myb will be expressed in human monocytes and microarray assays will be used to identify telltale changes in gene expression.
Aim 2 will test the biological relevance of the variant c-Myb proteins. First, alternative splicing of c-myb gene products will be studied in differentiating hematopoietic cells, then wild type and variant c-Myb proteins will be expressed in normal hematopoietic progenitors, to see if changes in differentiation or proliferation are induced.
In Aim 3, quantitative assays will be used to follow the expression of normal and variant c-myb RNAs in a defined cohort of adult AML samples, and then statistical analyses will determine whether specific variants correlate with clinical parameters, prognosis or gene expression patterns in AML patient samples. The proposed experiments build on our expertise and extensive preliminary and published data and have great relevance to the study of alternative RNA splicing, the activity of Myb proteins and human leukemia.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
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Hematopoiesis Study Section (HP)
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Mufson, R Allan
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University of New Mexico
Schools of Medicine
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Quintana, Anita M; Zhou, Ye E; Pena, Janeth J et al. (2011) Dramatic repositioning of c-Myb to different promoters during the cell cycle observed by combining cell sorting with chromatin immunoprecipitation. PLoS One 6:e17362
Zhou, Ye E; O'Rourke, John P; Edwards, Jeremy S et al. (2011) Single molecule analysis of c-myb alternative splicing reveals novel classifiers for precursor B-ALL. PLoS One 6:e22880
Ward, Heather H; Romero, Elsa; Welford, Angela et al. (2011) Adult human CD133/1(+) kidney cells isolated from papilla integrate into developing kidney tubules. Biochim Biophys Acta 1812:1344-57
Zhou, Ye; Ness, Scott A (2011) Myb proteins: angels and demons in normal and transformed cells. Front Biosci (Landmark Ed) 16:1109-31
Quintana, Anita M; Liu, Fan; O'Rourke, John P et al. (2011) Identification and regulation of c-Myb target genes in MCF-7 cells. BMC Cancer 11:30
O'Rourke, John P; Ness, Scott A (2008) Alternative RNA splicing produces multiple forms of c-Myb with unique transcriptional activities. Mol Cell Biol 28:2091-101
Ness, Scott A (2007) Microarray analysis: basic strategies for successful experiments. Mol Biotechnol 36:205-19