This project will test the effects of chemical compounds similar to conventional pills for their abilities to keep human embryonic stem cells growing and multiplying in the laboratory or to help them become one of the specialized types of cells, like spinal cord cells, found in the human body. Many of the substances currently used to accomplish these goals come from animals or animal cells. They carry a risk of transmitting diseases or making the human cells display some animal traits, either of which would make cells derived from human stem cells useless for transplantation and regenerative medicine. These animal-derived substances can also be very costly. Replacing these expensive materials will be essential to the eventual development of therapies for patients. These will be basic studies using one of the already-approved human embryonic stem cell lines. However, the molecules that are prepared in this work and discovered to have desirable properties should be applicable to human embryonic stem cell lines derived in the future by any technically and ethically appropriate method. The project therefore aims to discover new tools for embryonic stem cell research that will be useful to develop human therapies.
This work will be conducted in collaboration with leading California researchers in stem cell biology, in support of their goals to use human embryonic stem cells (hESCs) to derive tissues for regenerative medicine. Their goals are dependent on the eventual development of defined, non-biological media to support stem cell culture and differentiation, because such media would offer significant cost advantages and have no risk of biological contamination. The development of therapies that would significantly enhance the quality of life for Californians and the development of commercial ventures that would repay the tremendous investment the State is making in stem cell research are dependent on the achievement of the stated goals for this project.
This research will also train California undergraduate and graduate students in synthetic organic chemistry, one of the key scientific disciplines in biomedical research. Because chemists have not traditionally participated in stem cell research, most chemists working in industry are not familiar with it. However, these students will receive their disciplinary training in the context of stem cell research. California companies aiming to develop regenerative medicine using stem cells will require for their scientific staff synthetic chemists who can conduct the type of research described herein. This project will therefore help to meet the needs of California industry for a workforce with appropriate technical training.
SYNOPSIS: This proposal aims to identify small, organic drug-like molecules that can be used to promote the self-renewal or the directed differentiation of hES cells. This project will use chemical genetics and high-throughput screening to accomplish these two goals. Attention will be given to signal transduction pathways include Frizzled receptor, glia-derived neurotrophic factor receptor and Trk neurotrophin receptors. Organic synthesis will be used as well as chemical libraries. HSF-6, a USCF hESC line will be used.
SIGNIFICANCE AND INNOVATION: Developing improved methods for the maintenance of pluripotency and self-renewal, as well as the directed differentiation of hES cells are important goals in stem cell biology. Hence identification of novel compounds that can support these fates is significant. The project is more innovative than many other applications that propose similar goals, as the PI is an expert in chemistry and chemical genetics.
STRENGTHS: The strengths of this proposal include the chemical genetics approach with high-throughput screening, the PI's expertise, and the collaboration with others (Sato and Donovan). In total, this investigative team has a strong chemical genetics component with deep knowledge about small molecule screens, and includes well-established ES cell biologists. The PI is well-positioned to do these studies.
WEAKNESSES: There were no overriding weaknesses in this proposal, although some preliminary data would have been helpful in assessing the feasibility of the effort.
DISCUSSION: While the reviewers found no major weaknesses with the proposal, the lack of any genetic marker for neuronal differentiation in Aim 2 was mentioned.