Genetic integrity of human induced pluripotent stem cells.

Funding Type: 
Basic Biology II
Grant Number: 
RB2-01645
ICOC Funds Committed: 
$0
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Public Abstract: 
One of the most potentially powerful aspects of regenerative medicine is stem cell therapy. In this therapy, healthy tissues derived from stem cells will be implanted into patients with damaged tissue in order to restore function. However, there is currently a risk of immune rejection. Induced pluripotent stem cells (iPS) have the potential to revolutionize regenerative medicine. By reprogramming a patient's own cells into pluripotent stem cells, stem cell therapies can be performed with little to no risk of rejection. However, this nuclear reprogramming process is not well understood at a mechanistic level. Also, all procedures developed to date use cancer-related genes. This has raised fears that current iPS cells could potentially have a high cancer risk if used therapeutically. In this proposed research, we intend to study the reprogramming process and determine if and when deleterious mutations are occurring. We will use the obtained knowledge to develop safer methods of generating iPS cells. We will perform large-scale screening of mutations that have potential deleterious effects in iPS cells reprogrammed with a number of different methods. For the mutations found, we will also use a highly sensitive assay to quantify the frequencies of these mutations in the intermediate stages of the reprogramming. These information will help us to understand how do the mutations occur and propagate. Finally, we seek to develop a method for deriving genetically safe iPS cells by manipulating the activities of the mutated genes during the reprogramming process. This proposed project will not only help us to gain additional mechanistic insights on nuclear reprogramming, but also allow great progress towards functional stem cell therapy, as safe IPS cells will be available for therapeutic use.
Statement of Benefit to California: 
Over the past decade, California has made great progress in stem cell research thanks to Proposition 71. Research into stem cell properties and applications has made the promise of regenerative cell therapies almost a reality. Induced pluripotent stem (iPS) cells offer the promise of treatments or cures for diseases that affect millions of people without a risk of immune rejection, including Alzheimer's disease, heart disease, organ failure, and spinal cord injury. However, before these cells can be used therapeutically in the clinic, a better understanding of the mechanisms of generating iPS and the safety of the resultant cells must be gained. Our work will greatly improve understanding of the reprogramming process with respect to genomic mutations and integrity by determining the relative safety of a variety of available iPS reprogramming techniques. We will work towards creating iPS reprogramming methods that have been proven to be non-tumorigenic. Through this research, we hope to clear one of the biggest hurdles stopping iPS cells: the risk of cancer. Due to the huge potential of stem cell therapies in regenerative medicine, this work has applications to a large number of diseases and genetic disorders that affect Californians, from infants to senior citizens.
Progress Report: 
  • The ultimate goal of the proposed study is to identify approaches to increase the production of therapeutically useful blood cells from human ESCs and patient-specific iPSCs. Currently, bone marrow transplantation is the best way to cure many blood-related disorders, such as sickle cell anemia, thalassemia, and blood cancers like leukemia. Furthermore, blood transfusion is an effective way to rapidly counteract blood cell loss due to ablative treatments, such as chemotherapy and radiation therapy. Unfortunately, the limiting factor in transplantation and transfusion treatments is the lack of matched donors. The ability to producing unlimited numbers of blood stem cells and/or functioning differentiated blood cells from human ESCs and patient-derived iPSCs will greatly improve the opportunity of such treatments. Transcription factors play important roles in regulating cell proliferation and differentiation. RUNX1 is a transcription factor that is expressed in blood cells and regulates the expression of many blood cell related genes. Therefore, the specific aim of our studies is to examine the effect of RUNX1 on blood cell formation, expansion, and differentiation from human embryonic stem cells and induced pluripotent stem cells. During the first year of funding period, we have established the cell culture and differentiation systems in our laboratory, generated necessary DNA constructs for the proposed studies, and produced transcription factors for testing the effect.
  • The ultimate goal of the proposed study is to identify approaches to increase the production of therapeutically useful blood cells from human ESCs and patient-specific iPSCs. Currently, bone marrow transplantation is the best way to cure many blood-related disorders, such as sickle cell anemia, thalassemia, and blood cancers like leukemia. Furthermore, blood transfusion is an effective way to rapidly counteract blood cell loss due to ablative treatments, such as chemotherapy and radiation therapy. Unfortunately, the limiting factor in transplantation and transfusion treatments is the lack of matched donors. The ability to producing unlimited numbers of blood stem cells and/or functioning differentiated blood cells from human ESCs and patient-derived iPSCs will greatly improve the opportunity of such treatments. Transcription factors play important roles in regulating cell proliferation and differentiation. RUNX1 is a transcription factor that is expressed in blood cells and regulates the expression of many blood cell related genes. Therefore, the specific aim of our studies is to examine the effect of RUNX1 on blood cell formation, expansion, and differentiation from human embryonic stem cells and induced pluripotent stem cells. During the second year of funding period, we have performed hematopoietic cell differentiation using both human ESCs and iPSCs in the presence and absence of this transcription factor. Our results indicate that this factor promotes the production of blood stem cells and progenitors. We will make additional amount of this factor and further confirm our initial finding.
  • The ultimate goal of the proposed study is to identify approaches to increase the production of therapeutically useful blood cells from human ESCs and patient-specific iPSCs. Currently, bone marrow transplantation is the best way to cure many blood-related disorders, such as sickle cell anemia, thalassemia, and blood cancers like leukemia. Furthermore, blood transfusion is an effective way to rapidly counteract blood cell loss due to ablative treatments, such as chemotherapy and radiation therapy. Unfortunately, the limiting factor in transplantation and transfusion treatments is the lack of matched donors. The ability to producing unlimited numbers of blood stem cells and/or functioning differentiated blood cells from human ESCs and patient-derived iPSCs will greatly improve the opportunity of such treatments. Transcription factors play important roles in regulating cell proliferation and differentiation. RUNX1 is a transcription factor that is expressed in blood cells and regulates the expression of many blood cell related genes. Therefore, the specific aim of our studies is to examine the effect of RUNX1 on blood cell formation, expansion, and differentiation from human embryonic stem cells and induced pluripotent stem cells. During the second year of funding period, we have performed hematopoietic cell differentiation using both human ESCs and iPSCs in the presence and absence of this transcription factor. Our results indicate that this factor promotes the production of blood stem cells and progenitors. We will make additional amount of this factor and further confirm our initial finding.

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