Research Interests
How does a stem cell become a specialized, differentiated cell? How does a normal cell become transformed into a leukemia or tumor cell? These are the basic questions that we are addressing, using a combination of genetics, molecular biology, cell biology and biochemistry.
Hematopoietic stem cells are the immature precursors of all types of blood cells and are capable of differentiating along multiple pathways, simultaneously proliferating to produce many more cells and undergoing changes in gene expression to produce specialized cell types such as red blood cells, eosinophils, macrophages and neutrophils. The Ness laboratory studies the regulation of a transcription factor, c-Myb, which regulates the expression of lineage-specific genes in differentiating hematopoietic cells. The c-Myb protein regulates different genes in different hematopoietic cell types, so it must respond to different upstream signals in order to induce the expression of lineage-specific genes in each differentiation pathway. We are studying the post-translational modifications and protein-protein interactions that control the activity of c-Myb in order to understand the molecular basis of differentiation and the control of cell fate.
The c-Myb protein is the normal cellular counterpart to v-Myb, a transforming protein expressed by two avian leukemia viruses that transforms immature hematopoietic cells and induces leukemias in chickens and mice. The v-Myb protein is a mutated and activated version of c-Myb. Thus, the mutations in v-Myb appear to have unmasked the latent oncogenic potential in the c-Myb protein, using the ability of c-Myb to control differentiation and proliferation to transform cells and induce leukemia.
By using v-Myb as a model, and by analyzing the effects of mutations on the activity of c-Myb, we are addressing how apparently minor mutations in c-Myb, which might occur in human tumors, could have dramatic effects on the activity of c-Myb and whether such mutations might contribute to the development of human tumors.
Our laboratory uses a wide variety of different methods and techniques including molecular biology, cell biology, genetics and biochemistry. We have developed specialized adenovirus and lentivirus vectors for expressing wild type and mutant alleles of c-Myb in many different human cells, including human hematopoietic stem cells. We use microarrays and genomics approaches to study the activities of Myb proteins in human cells, and assays of differentiation, proliferation and apoptosis to assess the biological effects.
The Ness laboratory has been continuously supported by grants from NIH and ACS for over 17 years and is currently supported by two grants from the National Cancer Institute.
Please visit the NESS LAB HOMEPAGE for more information.
Information about post-doctoral positions in the Ness lab.
Information about Stem Cells and Genomics
Selected Publications
Link to PubMed
Leverson, J. D., Koskinen, P. J., Orrico, F. C., Rainio, E.-M.,
Jalkanen, K. J., Dash, A. B., Eisenman, R. N., and Ness, S. A. (1998).
Pim-1 Kinase and p100 Cooperate to Enhance c-Myb Activity. Molec. Cell
2, 417-425.
Leverson, J. D., and Ness, S. A. (1998). Point Mutations in v-Myb
Disrupt a Cyclophilin-Catalyzed Negative Regulatory Mechanism. Molec.
Cell 1, 203-211.
Ness, S. A. (1999). Myb Binding Proteins: Regulators and Cohorts in
Transformation. Oncogene 18, 3039-3046.
Bremnes, B., Rode, M., Gedde-Dahl, M., Nordeng, T. W., Jacobsen, J.,
Ness, S. A., and Bakke, O. (2000). The MHC class II-associated chicken
invariant chain shares functional properties with its mammalian
homologs. Exp Cell Res 259, 360-9.
Rushton, J. J., and Ness, S. A. (2001). The Conserved DNA Binding
Domain Mediates Similar Regulatory Interactions for A-Myb, B-Myb, and
c-Myb Transcription Factors. Blood Cells Mol Dis 27, 459-63.
Rushton JJ, Davis LM, Lei W, Mo X, Leutz A and Ness SA. (2003).
Distinct changes in gene expression induced by A-myb, B-myb and c-myb
proteins. Oncogene 2003; 22: 308-13.
Winn LM, Lei W and Ness SA. (2003). Pim-1 phosphorylates the DNA
binding domain of c-myb. Cell Cycle 2003; 2: 258-62.
Roitbak, T., Ward, C. J., Harris, P. C., Bacallao, R., Ness, S. A., and
Wandinger-Ness, A. (2004). A Polycystin-1 Multiprotein Complex is
Disrupted in Polycystic Kidney Disease Cells. Mol Biol Cell 15,
1334-1346.
Lei, W., Rushton, J. J., Davis, L. M., Liu, F., and Ness, S. A. (2004).
Positive and negative determinants of target gene specificity in Myb
transcription factors. J Biol Chem 279, 29519-29527.
Lei, W., Liu, F., and Ness, S. A. (2005). Positive and Negative
Regulation of c-Myb by Cyclin D1, Cyclin-Dependent Kinases and p27
Kip1. Blood 105, 3855-3861.
Liu, F., Lei, W., O'Rourke, J. P., and Ness, S. A. (2006). Oncogenic
mutations cause dramatic, qualitative changes in the transcriptional
activity of c-Myb. Oncogene 25, 795-805.
Ness, S.A. c-Myb. AfCS-Nature Molecule Pages (2006). (doi:
10.1038/mp.a000671.01)
Shah, VO, Dominic, EA, Moseley, P, Pickett, G, Fleet, M, Ness, S and
Raj, DSC. (2006) Hemodialysis Modulates Gene Expression Profile in
Skeletal Muscle. American Journal of Kidney Disease. 48, 816-828.
Ness, S.A. (2007) Basic Microarray Analysis: Strategies for Successful
Experiments. Methods Mol. Biol. 316, 13-33.
Pilkinton, M, Sandoval, R, Song, J, Ness, SA and Colamonici, OR (2007)
Mip/LIN-9 regulates the expression of B-Myb, and the induction of
cyclin A, cyclin B and CDK1. J. Biol. Chem. 282, 168-175.
Ness SA. (2007) Microarray analysis: basic strategies for successful
experiments. Mol Biotechnol. 2007 36(3):205-19.
O'Rourke JP, Ness SA. (2008) Alternative RNA splicing produces multiple
forms of c-Myb with unique transcriptional activities. Mol Cell Biol.
28(6):2091-101.
Quintana AM, Liu F, O’Rourke JP and Ness SA. (2011) Identification and
Regulation of c-Myb Target Genes in MCF-7 Cells. BMC Cancer, Jan 25;
11(1): 30. Identified as a “Highly Accessed” article by the publisher. View Online
Ward HH, Romero E, Welford A, Pickett G, Bacallao R, Gattone VH 2nd,
Ness SA, Wandinger-Ness A, Roitbak T. (2011) Adult human CD133/1(+)
kidney cells isolated from papilla integrate into developing kidney
tubules.Biochim Biophys Acta. 2011 Jan 19. [Epub ahead of print]
Quintana AM, Zhou YE, Pena JJ, O’Rourke JP and Ness SA (2011) Dramatic
repositioning of c-Myb to different promoters during the cell cycle
observed by combining cell sorting with chromatin immunoprecipitation.
PLoS One. 2011 Feb 22;6(2):e17362. View
Online
Quintana, A.M. and Ness, S.A. “Regulating c-Myb in real time.” Nova
Scientific Publishers, accepted for publication and in process.
Zhou Y and Ness SA “Myb proteins: angels and demons in normal and
transformed cells”, Front Biosci. 2011 Jan 1;16:1109-31.
