All of the diverse cells in the human body contain the same genetic information, and originally arose from a single cell, a fertilized egg. Embryogenesis is a result of cell division followed by differential gene expression, to selectively activate only the genes needed for development of each specialized cell type. By understanding the multiple gene activities required to either maintain stem cell pluripotency or effect cell specific differentiation, it should be possible to define conditions under which undifferentiated stem cells may be grown in large volume in culture, or induced to become mature cell types of therapeutic interest.
The experiments described in this proposal are directed at understanding the regulation of gene expression in stem cells as they self-renew, and in the conversion of adult cells back to a stem cell-like state. Our laboratory has identified three protein complexes, SCC, SCC-A and SCC-B, required for the activity of genes needed for stem cell self-renewal. Here we propose to characterize the component proteins of these complexes. SCCs are potential targets for drugs aimed at increasing or decreasing the ability of stem cells to divide. SCCs could also facilitate the production of high quality induced pluripotent stem cells for regenerative medicine and tissue replacement therapy.
The ultimate goal of these studies is the development of therapies for diseases that are the result of inappropriate levels of gene expression, cell division and differentiation. The proposed experiments will demonstrate how gene activity is controlled to maintain a renewing population of stem cells. An understanding of the gene regulatory networks will be crucial for drug development and testing.
The work described in this proposal will likely reveal gene activities that are essential for the establishment, survival and maintenance of stem cells and generation of high quality induced pluripotent stem cells that can be faithfully re-differentiated into fully functional adult cell types for tissue replacement therapy. This knowledge may potentially identify previously unknown drug targets that will allow the screening of novel classes of pharmaceuticals.
The goal of this proposal is to understand the molecular mechanisms that control the transcription of pluripotency genes in human embryonic stem cells (hESCs) as they self-renew and in cellular reprogramming. Three protein complexes that are essential to the transcription of a pluripotency gene have been identified. The applicant proposes to characterize these three protein complexes, to identify their specific targets in hESCs and to examine the role of these complexes in induced pluripotency.
Significance and Innovation
- Reviewers praised the potential significance of the proposed research.
- Successful completion of this proposal will lead to advancements in the understanding of pluripotency and reprogramming and may have a major impact on regenerative medicine.
- Reviewers were highly enthusiastic that the applicant will examine a mechanism that has not been well studied with respect to pluripotency.
Feasibility and Experimental Design
- The experimental approach is sound and supported by strong preliminary data, much of which has already been published.
- Reviewers felt that the aims were logical, well organized, and are achievable within the proposed timeframe.
- Some concern was raised that genomic studies will be performed on a single hESC line only.
- Although Aim 3 was praised for its novelty, reviewers noted that the studies were not well described in the proposal and lacked clarity.
Principal Investigator (PI) and Research Team
- The PI is a reputable scientist and a pioneer in the proposed research.
- The research team and environment are well suited to execute these studies.
Responsiveness to the RFA
- The proposal is highly responsive to the RFA.