Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) hold great promise for biomedicine as an unlimited source of cells for generating differentiated progenies for transplantation-based therapies, studying the etiology of various diseases, and developing new drug treatments. In my previous work published in Cell Stem Cell and Nature Protocols, I discovered a novel role for the Aurka-p53 signaling pathway in regulating ESC/iPSC identity and somatic cell programming. A single phosphorylation event mediated by Aurka on p53 shifts ESCs from differentiating to a self-renewal state. Through genome-wide analysis of direct p53 binding target genes in ESCs, I revealed a unique p53 function in negatively controlling ESC self-renewal by regulating mesodermal and ectodermal lineage gene expression and functioning as a differentiation activator. Collectively recent studies, including my own, revealed the unappreciated role of p53 in regulating cell differentiation instead of cell apoptosis and cell cycle. To build on my previous finding that p53 serves as a guardian of differentiation and expand our knowledge into the critical role of p53 as a both tumor suppressor and differentiation activator, I propose to establish the first cancer-related Li-Fraumeni Syndrome (LFS) iPSC model to study this p53 mutation-associated disorder. LFS is a genetically heterogeneous inherited cancer syndrome characterized by Mendelian autosomal dominant inheritance of germline p53 mutations that cause early onset of multiple tumors in individual patients. In contrast to other inherited cancers that are predominantly tissue-specific, LFS patients present with a variety of tumors. The p53 protein plays critical roles in regulating normal physiological homeostasis and mutations in p53 not only abolish its normal tumor suppressor activity but convert this function to oncogenic potential. The objectives of this proposal are first to model human LFS-associated osteosarcomas by using osteoblasts derived from patient-specific iPSCs and creating a disease in a dish platform to elucidate the underlying pathogenesis caused by these p53 mutations. Correction of the LFS-linked mutation in LFS patient-derived iPSCs by Transcription Activation-Like Effector Nuclease (TALEN)-mediated precise gene targeting is expected to reverse the disease-associated dedifferentiation phenotype. The following proposal will use systematical analyses to identify the molecular mechanisms involved in p53 mutant-associated osteosarcoma and further provide therapeutic targets for treating future osteosarcomas or other cancers with p53 mutations. Successful completion of the proposed experiment will significantly advance our understanding of the role of mutant p53 in osteosarcoma development. In addition, these proposed studies will potentially lead to identifying novel therapeutic targets to improve clinical outcomes for osteosarcoma patients.

Public Health Relevance

Modeling human disease in vitro has become possible due to induced pluripotent stem cell (iPSC) technology. We propose a Li-Fraumeni Syndrome (LFS) iPSC model to study osteosarcoma, one type of bone cancer, caused by p53 mutation. The results may not only provide a new experimental approach to study cancer disease but also help us to better understand the relationship between dysregulation of p53 signals and cancer development.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Transition Award (R00)
Project #
5R00CA181496-05
Application #
9437572
Study Section
Special Emphasis Panel (NSS)
Program Officer
Watson, Joanna M
Project Start
2014-03-03
Project End
2019-02-28
Budget Start
2018-03-01
Budget End
2019-02-28
Support Year
5
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Biology
Type
Schools of Medicine
DUNS #
800771594
City
Houston
State
TX
Country
United States
Zip Code
77030
Kim, Huensuk; Yoo, Seungyeul; Zhou, Ruoji et al. (2018) Oncogenic role of SFRP2 in p53-mutant osteosarcoma development via autocrine and paracrine mechanism. Proc Natl Acad Sci U S A 115:E11128-E11137
Liu, Mo; Tu, Jian; Gingold, Julian A et al. (2018) Cancer in a dish: progress using stem cells as a platform for cancer research. Am J Cancer Res 8:944-954
Zhou, Ruoji; Xu, An; Tu, Jian et al. (2018) Modeling Osteosarcoma Using Li-Fraumeni Syndrome Patient-derived Induced Pluripotent Stem Cells. J Vis Exp :
Xu, An; Zhou, Ruoji; Tu, Jian et al. (2018) Establishment of a human embryonic stem cell line with homozygous TP53 R248W mutant by TALEN mediated gene editing. Stem Cell Res 29:215-219
Tu, Jian; Huo, Zijun; Liu, Mo et al. (2018) Generation of human embryonic stem cell line with heterozygous RB1 deletion by CRIPSR/Cas9 nickase. Stem Cell Res 28:29-32
Zhou, Ruoji; Xu, An; Wang, Donghui et al. (2018) A homozygous p53 R282W mutant human embryonic stem cell line generated using TALEN-mediated precise gene editing. Stem Cell Res 27:131-135
Jewell, Brittany E; Liu, Mo; Lu, Linchao et al. (2018) Generation of an induced pluripotent stem cell line from an individual with a heterozygous RECQL4 mutation. Stem Cell Res 33:36-40
Freire, Ana G; Waghray, Avinash; Soares-da-Silva, Francisca et al. (2017) Transient HES5 Activity Instructs Mesodermal Cells toward a Cardiac Fate. Stem Cell Reports 9:136-148
Zhou, Ruoji; Xu, An; Gingold, Julian et al. (2017) Li-Fraumeni Syndrome Disease Model: A Platform to Develop Precision Cancer Therapy Targeting Oncogenic p53. Trends Pharmacol Sci 38:908-927
Lin, Yu-Hsuan; Jewell, Brittany E; Gingold, Julian et al. (2017) Osteosarcoma: Molecular Pathogenesis and iPSC Modeling. Trends Mol Med 23:737-755

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