Arthur Gutierrez-Hartmann Professor Departments of Medicine and of Biochemistry & Molecular Genetics; Member, Graduate Programs in Biochemistry & Molecular Genetics, Molecular Biology and Reproductive Sciences M.D. (1975), University of Texas Southwestern Medical School Campus Box 8106 Cancer Research Tower (RC1-South), Room 7108 S/M Endocrinology/Metabolism/Diabetes Ph: 303-724-3921 a.gutierrez-hartmann@uchsc.edu

Research Interests:

The main focus of my laboratory is to determine the role of ETS transcription factors in epithelial cell development and tumorigenesis, with a focus on pituitary, mammary and, most recently, GI epithelial cell model systems.

With regards to the pituitary project, we study how the combinatorial action of ETS factors, Ets-1 and GABP, acting in concert with the POU-homeodomain transcription factor, Pit-1, serve to regulate the lactotroph-specific basal and hormone-regulated expression of the prolactin gene. Utilizing biochemical, structural, molecular and transgenic approaches, we have discovered that ETS factors play a critical role in specifying lactotroph cell identity in pituitary ontogeny. We have expanded both the Pit-1 and Ets factor projects into transgenic mice, showing that targeting a dominant-negative ETS transgene to the pituitary lactotroph lineage abrogates pituitary lactotroph development. We are also studying the biological role of Pit-1ß, an alternative-splice form of Pit-1, which appears to act as a negative regulator of Pit-1 functions.

With regards to our breast cancer project, we study the role of the epithelial-specific ETS transcription factor, Ese-1, in human mammary epithelial cell tumorigenesis. The Ese-1 gene is an ETS member that is particularly relevant to breast cancer, since the Ese-1 chromosomal locus is amplified in 50% of early breast cancers and Ese-1 mRNA is over-expressed in human breast ductal carcinoma in situ (DCIS). We have shown that Ese-1 confers a transformed phenotype to immortalized, but nontransformed MCF-12A epithelial mammary cells. These Ese-1-transformed cells display increased motility, invasiveness, growth factor-independent growth and MAPK activation, colonies in soft agar, and that they form tumor-like colonies in a 3D organoid assay. The most exciting and significant recent contribution is our discovery that Ese-1 transforms human mammary epithelial cells via a novel cytoplasmic mechanism. We have mapped the transforming domain of Ese-1 to a unique, 40-AA serine- and aspartic rich (SAR) domain and we have shown that exclusive cytoplasmic targeting of this subdomain is both necessary and sufficient for the transformation response. These studies have not only defined a new ETS factor transformation mechanism, but they have also established a novel paradigm for cell transformation in general.

Finally, in our GI project, we have targeted a dominant-negative ETS to the proximal intestine, and these transgenic mice show abnormal radial branching morphogenesis. We have crossed these dnETS mice with APCmin mice to test whether the dnETS transgene blocks APC-induced GI tumorigenesis.

We are making a significant commitment to transgenic approaches to decipher the role of specific POU-homeodomain and ETS transcription factors in mediating the ontogeny, maintenance and tumorigenesis of epithelial cells in the pituitary, mammary and GI systems.

Surface density representations (inlays: ribbon representation in the same orientation) of the crystal structure of the Pithd bound to DNA. These fragments were taken from the crystal structure as resolved by Jacobson et al (1997). A) The results from figure 2C have been indicated by color coding. Chemical shift changes > 25 Hz are colored red, changes between 25 and 15 Hz dark red and between 15 and 10 pink. Unaffected residues are colored yellow. In green are the solvent exposed residues of the first helix, which showed a periodicity of three residues in chemical shift perturbation. The amide proton of W261, which is deeply buried, is colored in blue. B) The hydrophobic pocket around W261 formed by V257, V258, I222 and W261 itself is colored in beige. Overlaying the pocket is K226, colored in blue. The DNA has been deleted for clarity. C) Model for association of Ets-1 to the Pithd. K226 is shown in blue, the hydrophobic pocket in beige and T220 in green. Since the crystal structure does not extend beyond residue K273, an extended tail was added to represent the C-terminus of the Pithd. Ets-1 could use L288 for initial binding and subsequently, depending on the post-translational state of the Pithd, dock in the hydrophobic pocket next to W261. Additional stabilizing contacts may be made at the C-terminus of the DNA recognition helix (helix 3). These pictures were generated using MSI’s Weblab viewer Lite version (www.msi.com).

Figure 4. Mapping of chemical shift perturbations to the Pithd structure.

Selected Publications:

1. Tentler JJ, AP Bradford, RE Schweppe, Gutierrez-Hartmann A. Selective repression of prolactin gene transcription by stable expression of dominant-negative Ets in GH4 rat pituitary cells. Endocrine 20:3-12, 2003.

2. Eckel KL, Diamond SE, Tentler JJ, Cappetta GJ, Gutierrez-Hartmann A. The epithelial-specific ETS transcription factor ESX/ESE-1/Elf-3 modulates malignancy-associated gene expression and breast cell transformation. DNA & Cell Biol. 22:79-94, 2003.

3. Schweppe RE, Melton AA, Eads M, Aveline L, Resing, K, Ahn NG, Gutierrez-Hartmann A. Purification and mass spectrometric identification of GABP as the functional pituitary Ets factor binding to the basal transcription element of the prolactin promoter. J. Biol. Chem. 278:16863-16872, 2003.

4. Schedin PJ, Eckel KL, McDaniel SM, Prescott JD, Brodsky KS, Tentler JJ, Gutierrez-Hartmann A. ESX induces transformation and functional epithelial to mesenchymal transition in MCF-12A mammary epithelial cells. Oncogene 23:1766-1779, 2004.

5. Duval DL, Jean A, Gutierrez-Hartmann A. Ras signaling and transcriptional synergy at a flexible Ets-1/Pit-1 composite element is defined by the assembly of selective activation domains. J. Biol. Chem. 278:18543-18552, 2003.

6. Prescott JD, Koto K, Singh M, Gutierrez-Hartmann A. The ETS transcription factor ESE-1 transforms MCF-12A mammary epithelial cells via a novel cytoplasmic mechanism. Mol Cell Biol 24:5548-5564, 2004.

7. Coletta RD, Jedlicka P, Gutierrez-Hartmann A, Ford HL. Transcriptional control of the cell cycle in mammary gland development and tumorigenesis. J Mamm Gland Biol 9:39-53, 2004.

8. Farrow KN, Bradford AP, Tentler JJ, Gutierrez-Hartmann A. Structural and functional analysis of the differential effects of c-Jun and v-Jun on prolactin gene. Mol Endocrinol 18:2479-2490, 2004.

9. Ferry AL, Locasto DM, Meszaros L, Bailey JC, Jonsen MD, Brodsky KS, Hoon CJ, Gutierrez-Hartmann A, Diamond SE. Pit-1ß reduces transcription and CBP recruitment in a DNA context-dependent manner. J Endocrinology 185:173-185, 2005.

10. Duval DL, Diamond SE, Jonsen MD, Jean A, Murapa P, Gutierrez-Hartmann A. Differential utilization of transcription activation subdomains by distinct coactivators regulates Pit-1 basal and Ras responsiveness. J Biol Chem 21: 172-185, 2007.

11. Gutierrez-Hartmann A, Duval DL, Bradford AP. ETS transcription factors in endocrine systems. Trends Endocrinol Metab, 18(4): 150-158, 2007.

Latest Publications in PubMed