New stem cell gene correction process puts time on researchers' side.
MADISON, Wis., November 12, 2015 -- Researchers from the Morgridge Institute for Research and the Murdoch Children's Research Institute (MCRI) in Australia have devised a way to significantly cut the time involved in reprogramming and genetically correcting stem cells, an important step to making future therapies possible.
The study demonstrates how genetically repaired stem cells can be derived from patient skin cells in as little as two weeks, compared to conventional multi-step approaches that take more than three months.
The key to the advance is to combine two essential steps in preparing cells for potential therapy. First, adult cells must be reprogrammed to an embryonic cell-like state in order to be differentiated into the cells of interest. Second, the cells need to undergo a sophisticated gene editing process to correct the disease-causing mutation.
The researchers combined these two steps in skin cells derived from an adult patient with retinal degeneration, and an infant patient with severe immunodeficiency.
The method may advance transplant medicine by making gene-corrected cells available to patients in a much timelier manner, and at a lower cost. It will have implications immediately for researchers working in regenerative medicine.
To conduct therapies using patient-specific iPS cells, the timeline makes it hard to accomplish. If you add correcting a genetic defect, it really looks like a non-starter. You have to make the cell line, characterize it, correct it, then differentiate it to the cells of interest.
In this new approach, the researchers combined the reprogramming and the gene correction steps using the new Cas9/CRISPR technology, greatly reducing the time required.
The faster process also means the cell culture period is greatly reduced, potentially minimizing the risks associated with culturing cells outside of the human body, such as genome instability or other epigenetic changes.
One potential next step is to adapt the protocol to work with blood samples. Not only is a blood draw less invasive than a skin biopsy, it also could further reduce the time to obtain genetically repaired iPS cells. Skin cells need to be expanded for several weeks before initiating reprogramming.
This "fast-tracked process" could be most influential in cases where urgent medical intervention is needed, said researcher Sara Howden.
One example is severe combined immunodeficiency, where children typically die within the first few years of life. However, Howden said scientists still need to derive a long-term source of blood cells from pluripotent stem cells before such treatments are viable.
Citation: Sara E. Howden et al., "Simultaneous Reprogramming and Gene Correction of Patient Fibroblasts," Stem Cell Reports, 2015; DOI: 10.1016/j.stemcr.2015.10.009
Contact: Sara E. Howden, email@example.com