Funding opportunities

Improvement of Induced Pluripotent Stem Cell as a Tool for Clinical use in Cardiology

Funding Type: 
Tools and Technologies I
Grant Number: 
RT1-01127
Funds requested: 
$716 006
Funding Recommendations: 
Not recommended
Grant approved: 
No
Public Abstract: 
Very recently, November of 2007 , a discovery was made that could broaden the prospects of rapid development of stem cell therapies without the ethical barriers. It is called “Induced Pluripotent Stem Cells” ( iPS) or direct reprogramming of adult cells, turning them back into embryonic like cells without involving any embryos. These cells could be used as stem cells that would turn into any type of cell required to treat human diseases. However we are not there yet. iPS cells have been produced by the use of retro viruses which could induce tumors in the recipient. At least one of the transcription factors used was cancer causing. Further the iPS cells have not been compared to other studies of adult stem cells as therapy for important diseases. We need to have a reliable method to make iPS effective for human use. So far the main source of donor cells has been skin cells ( fibroblasts) . To be practical, medicine will need to obtain cels from easily available sources. The goal of our proposal is to develop iPS as a tool that can be easily produced in large quantities and used safely and effectively in human diseases. We propose to avoid tumorogenesis by delivering the necessary and sufficient transcription factors to reprogram adult cells by a non retro viral vector and two non viral delivery systems. 1) We will deliver selected transcription factors in adeno-associated viral vectors (AAV). These vectors have been used in human trials and are safe and non cancerous. 2) We will test a cell membrane penetrating protein ( VP22) to deliver the factors effectively. These novel methods could allow us to produce a large quanity of the critical factors and then mix them in the appropriate cocktail to produce many iPS cells ready for use in humans. Further, we will apply the techniques to three different sources of human cells that are easily obtained by standard methods, skin fibroblasts, adipocytes ( fat cells ) and bone marrow stromal stem cells. To test that the stem cells derived from iPS made by these methods are therapeutic and clinically relevant we will test the human stem cells in a model of heart failure. The proposal could have several benefits. First we will define a way of safely producing pluripotent stem cells for human use. Second we will test them in cardiovascular disease.
Statement of Benefit to California: 
The State of California and its citizens have led the world in investing in stem cell research. They are looking for benefits both to patients health and to business in creating new industries that provide employment and reap the economic benefits of their investment. Originally CIRM addressed research on human embryonic stem cells because of the federal government ban on federal funding for stem cell research. Very recently, November of 2007 , a discovery was made that could change this focus and broaden the prospects of rapid development of stem cell therapies without the ethical barriers. It is called ìInduced Pluripotent Stem Cellsî ( iPS) or direct reprogramming of adult cells turning them back into embryonic like cells without involving any embryos. These cellscould be used as stem cells that would turn into any type of cell required to treat human diseases. However we are not there yet. iPS cells have been produced by the use of retro viruses which could induce tumors in the recipient. At least one of the transcription factors used was cancer causing. Further the iPS cells have not been compared to other studies of adult stem cells as therapy for important diseases. We need to have a reliable method to make iPS effective for human use. So far the main source o donor cells has been skin cells ( fibroblasts) . To be practical, medicine will need to obtain cells from easily available sources. The goal of our proposal is to develop iPS as a tool that can be easily produced in large quantities and used safely and effectively in human diseases. We propose to avoid tumorogenesis by delivering the necessary and sufficient transcription factors to reprogram adult cells by a non retro viral vector and two non viral delivery systems. 1) We will deliver selected transcription factors in adeno-associated viral vectors (AAV). These vectors have been used in human trials and are safe and non cancerous. 2) We will test a cell membrane penetrating protein ( VP22) to deliver the factors effectively. The VP-22 combined with AAV could allow us to produce a lage quantitiy of these critical factors and then mix them in the appropriate cocktail to produce many iPS cells ready for use in humans. Further, we will apply the techniques to three different sources of human cells that are easily obtained by standard methods, skin fibroblasts, adipocytes ( fat cells ) and bone marrow stromal stem cells. To test that the stem cells derived from iPS made by these methods are therapeutic and clinically relevant we will test the human stem cells in an animal model of heart ailure. The proposal could have several benefits for California. First we will define a way of safely producing pluipotent stem cells for human use. Second we will test them in cardiovascular disease . Third we may develop a new business in California working with such companies as [REDACTED] to produce stem cells.
Review Summary: 
This application is focused on improving methods for generating human induced pluripotent stem (iPS) cells for possible clinical use. To achieve this goal, the applicant proposes to use two non-retroviral delivery systems to introduce activators of pluripotency into fibroblasts, adipocytes, and bone marrow stromal cells. The efficiency and validity of these methods will be evaluated by assessing cardiac differentiation and activity in a rodent model of heart failure. The proposed technology could have a substantial impact on the field, as it addresses a key roadblock in stem cell biology: the need for safer and more efficient methods for iPS cell generation. Current approaches rely on the use of retroviral vectors, which are potentially carcinogenic due to insertional mutagenesis. If effective, the proposed alternatives, i.e. use of adeno-associated viral vectors (AAV) to deliver reprogramming genes or delivery of reprogramming factors as membrane-permeable proteins, could eliminate the need for integrating vectors and lead to the generation of iPS cell lines that are safer for clinical use. Furthermore, improvements in reprogramming efficiency could significantly benefit basic, translational and clinical research. Reviewers found the proposed study to be rationally designed with appropriate experimental milestones and to be supported by some promising preliminary data. Reviewers appreciated the comparison of cardiac differentiation capacity amongst iPS cell lines generated by different methods, but at the same time felt that this goal was not directly related to the focus of this RFA. Overall, reviewers had serious concerns about the proposal’s feasibility. The proposal lacked adequate consideration of improving reprogramming efficiency when compared to existing methods, or of limitations associated with producing sufficient quantity of recombinant proteins in a cell free system. Moreover, for the protein delivery experiments, the applicant did not provide adequate details relating to protein half life and effects of simultaneous delivery of multiple proteins, and did not discuss whether subsets of transcription factors might be sufficient for iPS generation using different starting cell types. Although the applicant recognized as a potential problem the differential uptake of the various AAV vectors, there was no discussion as to how this would be addressed. Concerns were also raised about the complexity of producing conditioned media that could be difficult to control and successfully reproduce. Finally, the reviewers felt that the project was understaffed as not a single team member committed 100% effort, thus limiting its chance for success. Reviewers judged the proposed team as very well qualified to conduct the described research. The principal investigator has strong publications in relevant areas and the collaborators appear well qualified with complementary expertise.
Conflicts: 

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