Biotech company proposes stem cell production that avoids embryo destruction
Stem cell research holds promise for curing a wide range of illness such as heart disease, diabetes, and, cystic fibrosis. Stem cells are pluripotent cells that possess the ability to develop into any type of cell in the body. Early human embryos are a source of stem cells; however, significant opposition to their use exists based on moral and/or religious factors. Advanced Cell Tecnology, Inc. (ACT; Santa Monica, California) has proposed to develop a process that can grow stem cells from mature human cells from sources such as the skin; thus, negating objections based on the destruction of human embryos. The company plans to begin the process for regulatory approval as early as December 14, 2012. If approval is granted, Advanced Cell Technology will embark on the first human trial involving stem cells created by reprogramming adult cells back to an embryonic-like state.
Experiments have been conducted with other types of stem cells derived from bone marrow or umbilical cord blood; however, those cells are limited in the types of cells they can develop into. The newer approach involves reprogramming mature cells, typically from the skin, without the need to destroy embryos. Two of the researchers who developed the process shared a Nobel Prize this year for the work. Advanced Cell Technology Inc. wants to test blood-clotting particles, called platelets, made from such reprogrammed cells. Individuals with certain types of leukemia, anemia, and other blood disorders require repeat infusions of platelets to avoid hemorrhaging.
However, these people can develop resistance to the donated cells over time, making them less effective. Stem-cell derived platelets could overcome that problem because they could be derived from a patient's own cells.
Advanced Cell Technology has created proposals for clinical trials and company officials note that testing could begin as early as the end of next year if Food and Drug Administration (FDA) regulators accept the proposals. Among the challenges facing laboratories and firms that have been racing to produce induced-pluripotent-stem-cell treatments is the production of an adequate number of the cells. ACT Chief Scientific Operator Robert Lanza notes that his company has the capacity to make enough platelets for the initial clinical trials but it would take time to scale up for widespread use. Another is the prevention of genetic abnormalities to some cells that could cause tumors.
Platelets do not carry the risk of genetic defects because they do not contain DNA; however, a risk remains that some stray cells with DNA could contaminate a batch of the stem-cell derived platelets. Dr. Lanza said that his company takes multiple measures to prevent contamination of its supply, and platelets can be irradiated before use.
Advanced Cell Technology’s concept for the clinical trial would be to infuse both normal platelets and stem-cell-derived platelets into eight patients. The investigators would then compare how the cells function. A separate set of eight patients would receive normal platelets and platelets derived from human embryonic stem cells. Each of the cells would be tagged with a chemical that would allow researchers to track their presence in study subjects. Blood samples would be periodically drawn from the study subjects; the samples would be analyzed to determine if the tagged stem-cell-derived platelets are surviving and circulating like normal platelets. If the stem-cell derived platelets functioned like normal platelets, the research would have significant scientific impact.
Reference: Advanced Cell Technology