We propose that both human cancers and birth defects are caused by defects in stem cell pluripotency and self-renewal. Tumor formation is theorized to often be the result of oncogenic transformation of normal stems into cancer stem cells. Birth defects are due to disruptions of the pluripotency and self-renewal of stem cells, including inner cell mass cells that are very similar embryonic stem cells (ESC). The molecular mechanisms that cause these stem cell changes leading to human disease remain an open question, but the myc gene family is linked to both human birth defects and cancers suggesting Myc proteins may play key roles in both diseases. We are particularly interested in the specific roles that Myc proteins play in stem cells that lead to human birth defects and cancers. The proposed studies will address the issue of how a single class of proteins, the Myc family, can be so essential for stem cell biology and embryogenesis at normal levels, but in excess cause cancer and produce induced pluripotent stem (iPS) cells. Using proteomics, we have identified three novel Myc cofactors that may direct its function in ESC: histone deacetylases (HDACs);the DNA methyltransferases, DNMT3;and the ESC-specific transcription factor, UTF1. Myc proteins have no known cofactors in ESC or iPS cells, representing a serious gap in the field that our work will bridge. By analyzing the biochemical properties of these protein-protein interactions as well as the nature of how they form on DNA to regulate transcription, the proposed work will provide key insight into Myc function in maintaining pluripotency in ESC and establishing pluripotency in iPS cells. Innovative aspects of the proposal include a new model of how Myc functions as transcription factor including a widespread, repressive function, novel proteomics studies on Myc complexes in stem cells, studies on iPS cells, and analyzing the function of UTF1. When these studies are complete we will have a clearer understanding of the molecular mechanisms that control pluripotency as well as human development and how when disrupted these events lead to human disease.

Public Health Relevance

The objective of the proposed is to elucidate the stem cell-related causes of human birth defects and cancers, thereby opening the door to new treatments and preventative measures. Thus, it has great significance for human health. We also aim to facilitate the development of safe and effective regenerative medicine therapies based on embryonic and induced pluripotent stem cells (ESC, iPS cells). In this way, our studies also may advance one of the most cutting edge approaches to treating and curing human diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM100782-02
Application #
8290400
Study Section
Special Emphasis Panel (ZRG1-BDA-P (90))
Program Officer
Haynes, Susan R
Project Start
2011-07-01
Project End
2016-06-30
Budget Start
2012-07-01
Budget End
2013-06-30
Support Year
2
Fiscal Year
2012
Total Cost
$289,520
Indirect Cost
$101,520
Name
University of California Davis
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Tung, P-Y; Knoepfler, P S (2015) Epigenetic mechanisms of tumorigenicity manifesting in stem cells. Oncogene 34:2288-96
Yuen, Benjamin T K; Bush, Kelly M; Barrilleaux, Bonnie L et al. (2014) Histone H3.3 regulates dynamic chromatin states during spermatogenesis. Development 141:3483-94
Barrilleaux, Bonnie L; Burow, Dana; Lockwood, Sarah H et al. (2014) Miz-1 activates gene expression via a novel consensus DNA binding motif. PLoS One 9:e101151
Bush, Kelly M; Yuen, Benjamin Tk; Barrilleaux, Bonnie L et al. (2013) Endogenous mammalian histone H3.3 exhibits chromatin-related functions during development. Epigenetics Chromatin 6:7
Tung, Po-Yuan; Varlakhanova, Natalia V; Knoepfler, Paul S (2013) Identification of DPPA4 and DPPA2 as a novel family of pluripotency-related oncogenes. Stem Cells 31:2330-42
Barrilleaux, Bonnie L; Cotterman, Rebecca; Knoepfler, Paul S (2013) Chromatin immunoprecipitation assays for Myc and N-Myc. Methods Mol Biol 1012:117-33
Laskowski, Agnieszka I; Knoepfler, Paul S (2013) Myc binds the pluripotency factor Utf1 through the basic-helix-loop-helix leucine zipper domain. Biochem Biophys Res Commun 435:551-6
Knoepfler, Paul S (2013) Call for fellowship programs in stem cell-based regenerative and cellular medicine: new stem cell training is essential for physicians. Regen Med 8:223-5
Yuen, Benjamin T K; Knoepfler, Paul S (2013) Histone H3.3 mutations: a variant path to cancer. Cancer Cell 24:567-74
Riggs, John W; Barrilleaux, Bonnie L; Varlakhanova, Natasha et al. (2013) Induced pluripotency and oncogenic transformation are related processes. Stem Cells Dev 22:37-50