The focus of this proposal is the role of homeotic genes in human hematopoietic commitment and differentiation. This gene family determines cell fate and tissue identity during development of the Drosophila embryo. Homeobox gene products contain a highly conserved 60 amimo acid sequence (called the homeobox), which is a DNA binding domain. Homeobox-containing genes are also expressed in temporally and spacially specific patterns in human embryos. We have made the novel observation that at least 5 unique homeobox genes are expressed in lineage-restricted patterns in human hematopoietic cell lines and that expression is modulated during differentiation. This project has five major aims: 1. To demonstrate lineage-restricted patterns of expression of homeoboxcontaining genes in a survey of human leukemic cell lines representing a spectrum of hematologic phenotypes (e.g. erythroid, myeloid, monocytic, and lymphoid). We will perform Northern gel analysis of mRNA isolated from a spectrum of leukemic cell lines using our 5 homeobox probes. 2. To study the modulation of homeobox gene expression during hematopoietic differentiation. We will perform Northern gel analysis of mRNA from a range of inducible leukemic cell lines before and after exposure to a variety of differentiation induc- ers. 3. To study the expression of homeobox genes in normal blood cells and partially purified hematopoietic progenitors from human marrow, and the modulation of that expression by recombinant hematopoietic growth factors. 4. To characterize homeobox-containing cDNAs from human hematopoietic cells. We have cloned and sequenced partial cDNAs for the Hox 2.2 and 2.3 genes from an HEL cell library and a novel homeobox gene (PL1) from U-937. We propose to obtain complete sequence for these three cDNAs. 5. To express homeobox-containing proteins for the study of their intracellular distribution and turnover. Full-length cDNAs will be fused to beta-galactosidase and used to express protein in a bacterial system. Purified homeobox-proteins will be used to produce antibodies to study their role(s) in differentiating hematopoietic cells.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA047866-01A1
Application #
3191679
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1989-08-07
Project End
1992-07-31
Budget Start
1989-08-07
Budget End
1990-07-31
Support Year
1
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
Schools of Medicine
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
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Lawrence, H J; Stage, K M; Mathews, C H et al. (1993) Expression of HOX C homeobox genes in lymphoid cells. Cell Growth Differ 4:665-9
Safaei, R; Prochazka, V; Detmer, K et al. (1992) Modulation of HOX2 gene expression following differentiation of neuronal cell lines. Differentiation 51:39-47
Shen, W F; Detmer, K; Mathews, C H et al. (1992) Modulation of homeobox gene expression alters the phenotype of human hematopoietic cell lines. EMBO J 11:983-9
Lowney, P; Corral, J; Detmer, K et al. (1991) A human Hox 1 homeobox gene exhibits myeloid-specific expression of alternative transcripts in human hematopoietic cells. Nucleic Acids Res 19:3443-9
Shen, W F; Detmer, K; Simonitch-Eason, T A et al. (1991) Alternative splicing of the HOX 2.2 homeobox gene in human hematopoietic cells and murine embryonic and adult tissues. Nucleic Acids Res 19:539-45
Mathews, C H; Detmer, K; Boncinelli, E et al. (1991) Erythroid-restricted expression of homeobox genes of the human HOX 2 locus. Blood 78:2248-52