Derivation and Epigenomic Analysis of hES Cells
We propose to derive new human embryonic stem (hES) cell lines, and begin an investigation of epigenetic abnormalities in these lines. Epigenetics refers to changes in the behavior of genes that are not caused by changes in the DNA itself (i.e. mutations) but rather by alterations to protein and chemical (methyl) groups bound to the DNA. The overall goals of this project are to develop the capacity to derive hES cell lines, and to perform pilot projects on the natural history of epigenetic marks in hES cells and the body cells derived from them. The project builds on our efforts to establish the capacity to derive hES lines in collaboration with an IVF facility. In keeping with the goals of CIRM, this proposal is intended to serve as the nucleus for a program of ES cell research; we think that it is important that this program have the ability to derive ES cells. It is often assumed that ES cells do not retain epigenetic marks acquired in previous generations. Some evidence indicates that epigenetic marks can arise in the human germline and cause a disease syndrome; they may also be inherited. Epigenetic inheritance requires that an epigenetic mark be retained in cells of the inner cell mass, and thus presumably in ES cells as well. This raises the possibility that individual ES cell lines carry epigenetic marks, either inherited from the parent or acquired in the derivation process, that are capable of affecting the phenotype of their progeny somatic cells. We propose a pilot project to investigate this hypothesis. To prepare for the derivation of hES cell lines, we have established a collaboration with an IVF facility, which provides us with access to extensive expertise in human embryo manipulation. We have recruited a technician with substantial ES cell experience, which we have extended by further training, and are ready to begin derivation of hES cell lines. We propose to derive new hES cell lines from spare embryos by established methods; these will be used in our own studies, and will also be made available to the wider research community. In the hES lines we derive, we will study the occurrence and natural history of epigenetic abnormalities. We will identify epigenetic marks using antibodies, then choose likely candidates for further analysis. We will study several such marks in multiple hES lines. Because there is a new area of study, it is difficult to predict just what we will find; this is entirely appropriate for a pilot study.
Human embryonic stem (hES) cells hold tremendous promise for the alleviation of human suffering, because they are able to form new cells that can be used to replace cells that are defective due to inherited or other types of disease, and because by studying them we may learn how to change the behavior of cells within the human body. If cells derived from hES cells are to be useful, we must develop ways to assess not just their efficacy, but their safety, because cellular therapies may require implanted cells to survive indefinitely in a patient’s body. We are aware that one possible source of defects in ES cells are epigenetic changes, which alter the behavior of genes without changing the DNA of those genes. Epigenetic defects can predispose to diseases such as cancer. We need methods to assess hES cells for such defects and understand their natural history and consequences; we are proposing a pilot project that begins to explore ways of detecting and analyzing them. As part of this effort, we also propose to derive new hES cell lines from spare embryos donated for research. These new hES lines will be made available to other investigators for their projects. Thus this project will benefit California by producing new hES lines, which are badly needed to advance stem cell research generally, and by exploring methods to assess the integrity of existing hES cell lines.