Improved hES Cell Growth and Differentiation

Improved hES Cell Growth and Differentiation

Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00110
Award Value: 
$2,381,713
Stem Cell Use: 
Embryonic Stem Cell
Status: 
Closed
Public Abstract: 
Human embryonic stem (hES) cells are pluripotent stem cells that can theoretically give rise to every cell type in the human body. Consequently, hES cells have enormous promise for the treatment of human disease. Specialized cell types derived from hES cells could be used to treat a wide variety of diseases and disorders including spinal cord injury, Parkinson’s disease, heart disease and diabetes to name just a few. Such specilaized cells, derived from either normal hES cells or hES cells derived from embryos representative of specific disease states could also be used to screen for drugs that would ameliorate the disease. Finally, the analysis of hES cell differentiation into specialized cell types could reveal important information about the embryonic and fetal development of our own species. This in turn could allow a better understanding of the factors that affect the growth of the human embryo and fetus and how these processes sometime go wrong leading to birth defects. But significant hurdles must be overcome if hES cell-derived cells are to be used in these ways. Growth and expansion of hES cells is still problematical. To overcome these problems we have developed methods for genetically manipulating hES cells with very high efficiency. These methods will be applied to studying the growth of hES cells. Improved methods for understanding how to grow and expand hES cells will allow expansion of hES cells in large quantities. This will be necessary in order that hES cells can then themselves be used to produce the numbers of specialized cells required either for transplantation or for drug screening. In addition, the ability to genetically manipulate hES cells will allow the mechanisms by which they can turn into specialized cells to be studied and developed in new ways. These studies should speed up efforts to make specialized cell types which can be used either to treat diseases directly or to develop drugs with which to treat those diseases. Understanding how hES cell grow should allow us to avoid one of the major problems with this technology, namely that the hES cells themselves can form tumors which may harm, rather than help, patients. Finally, hES cells are derived from the early embryo and are very similar to cells of the embryo. Therefore, understanding how hES cells grow could also inform us about the factors required for the growth of the early embryo. Consequently, these studies could have a major impact on our understanding of early embryo growth, the factors that cause certain types of infertility and, ultimately, lead to improved methods for treating infertile couples.
Statement of Benefit to California: 
Human embryonic stem (hES) cells are pluripotent stem cells that can theoretically give rise to every cell type in the human body. Consequently, hES cells have enormous promise for the treatment of human disease. Differentiated cell types derived from hES cells could be used to treat a wide variety of diseases and disorders. Such differentiated cells, derived from either normal hES cells or hES cells derived from embryos representative of specific disease states could also be used to screen for drugs that would ameliorate the disease phenotype. Finally, the analysis of hES cell differentiation into specialized cell types could reveal important information about the embryonic and fetal development of our own species. This proposal describes studies aimed at developing a fundamentally better understanding of how hES cells can be expanded to generate large numbers of cells either for transplantation or for drug screening. Because hES cells are derived from the early human embryo we also expect that our studies will yield new information about human development and the genetic and environmental problems that can affect embryo development. In addition the studies described in the proposal will involve the development of technology for genetically modifying hES cells with a much higher efficiency. Therefore, we expect four types of benefit to the Citizens of California. First, we expect that our work will result in the development of new cell-based treatments for a variety of human disorders and diseases. Second, we expect that our work will lead to improved methods for treating infertile couples as well as understanding the environmental risks to the early embryo. Third, we expect that our work will result in the development of technology that will form the basis of new biotech startup companies. Finally, we expect that our work will result in improved methods for drug development that could directly benefit citizens in the state.
Progress Report: 

Year 1

Human embryonic stem (hES) cells are pluripotent stem cells that can theoretically give rise to every cell type in the human body. Consequently, hES cells have enormous promise for the treatment of human disease. Differentiated cell types derived from hES cells could be used to treat a wide variety of diseases and disorders or used to develop drugs that would ameliorate disease. Finally, the analysis of hES cell differentiation into specialized cell types could reveal important information about the embryonic and fetal development of our own species. But significant hurdles must be overcome if hES cell-derived cells are to be used in these ways. The goals of this project are to gain a fundamentally better understanding of the mechanisms controlling hES cell growth and differentiation. We discovered a unique role for neurotrophins (NTs), acting through their receptors, the Tropomyosin-related kinases (TRKs), in mediating hES cell survival. NTs improve both hES survival and the ability to genetically manipulate the cells. But both the role of the NTs and the other factors regulating hES cell growth remain largely obscure. The goals of the grant take advantage of our improved ability to genetically manipulate hES cells and are designed to fill gaps in our knowledge about factors regulating their growth. In the second year of studies we have carried out studies that have defined the role of key stem cell regulatory genes, including, SOX2, OCT4 and NANOG, in regulating the growth of hES cells via regulation of the TRKs. We have found that SOX2, OCT4 and NANOG likely control the expression of the TRKs in hES cells. We have also carried out further studies on the pathways downstream of the TRKs that are activated in hES cells and have identified a key role for the Forkhead transcription factors in this process. In addition, we have developed tools for identifying new genes that regulate stem cell growth, especially kinases and phosphatases that are known regulators of growth of other cell types. These studies should aid in growth and expansion of hES cells as normal healthy cells for cell-based transplantation and other uses of hES cells in the development of new treatments for human disease.

Year 2

Human embryonic stem cells have the potential to proliferate indefinitely in culture while at the same time have the ability to give rise to any cell type present in the human body. As such they represent an important new tool for understanding the underlying causes of disease, for developing new, safer drugs to treat disease and for cell-based therapy for treating a wide range of human diseases and disorders. But the molecular mechanisms regualting human embryonic stem cell growth are still poorly understood.In our studies we have begun to understand how a core group of transcription factors acts to regulate the growth and survival of embryonic stem cells. In adittion we have begun to understand how those factors act through distinct pathways to control the so-called stem cell state. Improvingour understanding of how the stem cell state is regulated will improve our ability to grow stem cells for all of the possible uses of the cells described above. That in turn will accelerate the development of our understanding of human disease and the development of new treatments for human diseases, disorders and injuries.

Year 3

Human embryonic stem cells have the potential to proliferate indefinitely in culture while at the same time have the ability to give rise to any cell type present in the human body. As such they represent an important new tool for understanding the underlying causes of disease, for developing new, safer drugs to treat disease and for cell-based therapy for treating a wide range of human diseases and disorders. But the molecular mechanisms regulating human embryonic stem cell growth are still poorly understood. In our studies we have begun to understand how a key growth factor signaling pathway acts to regulate the growth and survival of embryonic stem cells. In adittion we have begun to understand how that factor acts through distinct pathways to control the so-called stem cell state. So far our studies have elucidated how this growth factor signaling pathway is controlled and how it itself controls events within the stem cell. Several of these results have been published. Improving our understanding of how the stem cell state is regulated will improve our ability to grow stem cells for all of the possible uses of the cells described above. That in turn will accelerate the development of our understanding of human disease and the development of new treatments for human diseases, disorders and injuries.

Year 4

Human embryonic stem cells have the potential to proliferate indefinitely in culture while at the same time have the ability to give rise to any cell type present in the human body. As such they represent an important new tool for understanding the underlying causes of disease, for developing new, safer drugs to treat disease and for cell-based therapy for treating a wide range of human diseases and disorders. But the molecular mechanisms regulating human embryonic stem cell growth are still poorly understood. In our studies we have begun to understand how a key growth factor signaling pathway acts to regulate the growth and survival of embryonic stem cells. Importantly we have shown that one of the key factors controlling the stem cell state acts in part to control the expression of growth factor receptors on the stem cell membrane. In addition we have begun to understand how that growth factor signaling pathway acts through distinct pathways to control the so-called stem cell state. So far our studies have elucidated how this growth factor signaling pathway is controlled and how it itself controls events within the stem cell. Our studies suggest that signaling from growth factor receptors acts through factors in the cell nucleus to feedback on regulatory machinery to conrtol the stem cell state. Several of these results have been published. Improving our understanding of how the stem cell state is regulated will improve our ability to grow stem cells for all of the possible uses of the cells described above. That in turn will accelerate the development of our understanding of human disease and the development of new treatments for human diseases, disorders and injuries.

Publications

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