Basic Biology IV
Embryonic stem cells can be expanded indefinitely in a culture dish and have the potential to make any cell type in the adult body. These properties make them a remarkable tool to study and even potentially treat human disease. However, most of what we know about embryonic stem cells is based on the mouse model. Human embryonic stems are inferior to their mouse counterparts in a number of ways including more complex culture conditions, increased genetic instability, diminished manipulability, and likely diminished developmental potential. Much work has suggested that the differences between human and mouse embryonic stem cells is their developmental maturity. Therefore, there is a push to find ways to induce these cells to a less mature state, more similar to that of mouse. This application presents preliminary data showing novel means to do exactly that. Here we propose to characterize the resulting cells and find additional means that could synergize to further induce a stable immature embryonic stem cell fate. Such cells will be tested for all the desired properties one normally finds in the equivalent cells in mouse. Successful completion of these aims would have a dramatic impact on the stem cell field as it would provide more robust means for laboratories and companies around the world to grow and differentiate human embryonic stem cells into genetically sound adult cell types for the study and treatment of a wide range of human diseases.
Statement of Benefit to California:
The proposed research aims to improve the utility of human embryonic stem cells through a deeper understanding of the mechanisms that control their growth and their potential to make all adult tissue types. Successful completion of the research would lead to more robust methods of expanding, manipulating, and differentiating the cells. Such advances are critical to extending the promise of embryonic stem cells in both the study and treatment of disease. Therefore, it will benefit the State of California by making human embryonic stem cells more experimentally accessible to both academics and industrialists. The knowledge learned is expected to provide insights useful to the development of new technologies by California laboratories and companies. Such technologies would have major implications for the development of new commercial endeavors and for the improvement of human health, both major goals of the California Institute of Regenerative Medicine.
Human embryonic stem cells (hESC) differ from their murine counterparts (mESC) by a variety of criteria including increased genetic instability, difficulty of culture and maintenance, and reduced ability to be genetically manipulated. These observations are thought to reflect differences in developmental maturity between the cell types, with mESC representing a “naïve” state, and hESC representing a “primed” one. The applicant hypothesizes that a deeper understanding of such differences could lead to methods for pushing hESC into a more naïve state, thereby improving their utility and imparting them with mESC-like properties. Towards this end, two aims have been proposed, each focusing on the role of a specific signaling pathway (Aim 1) or microRNA cluster (Aim 2) in the transition from naïve to primed pluripotency. Significance and Innovation - The proposed research is not likely to have a significant impact on the field. Other methods to convert hESC to a naïve state have already been published, and there is no compelling evidence to suggest that this study would lead to superior outcomes. - The system employed to produce developmentally staged hESC is highly artificial, calling into question the relevance of the resulting cell lines and what can be learned from them. - The rationale for addressing technical hurdles by converting hESC to a naive state is not convincing. Use of mechanical passaging techniques, along with recent progress in gene modification approaches, suggest that key challenges are rapidly being overcome. Feasibility and Experimental Design - The proposal did not include sufficient data to convince reviewers that the microRNA cluster to be studied plays a fundamental role in hESC pluripotency. - The research plan does not include convincing experiments to demonstrate that the novel hESC lines would better serve the needs of the regenerative medicine community. - The experimental plan is feasible and includes a meaningful discussion of potential pitfalls and alternative approaches. Principal Investigator (PI) and Research Team - Both the PI and partner PI are highly experienced investigators with complementary expertise encompassing genomics, embryonic stem cells, signaling and microRNA/epigenetics. Each has an outstanding track record of success. - The research team comprises an impressive international collaboration that is integral to the success of the project. Responsiveness to the RFA No relevant concerns were highlighted by reviewers under this review criterion.