Adult Stem Cell Quality Control Methods Devised

Stem cells (National Science Foundation)

27 February 2015. A European research team developed a process for testing the safety and quality of adult stem cells before being used in gene therapy treatments on patients. The team led by stem cell scientist Yann Barrandon at the Swiss Federal Institute of Technology in Lausanne published its findings today in the journal EMBO Molecular Medicine.

Barrandon and colleagues sought a way to prevent serious problems with gene therapies using regenerated skin cells from adult stem cells, even stem cells taken from the patient needing the therapy. The problems occur when mutations develop in the cloned or regenerated cells that lead to irreversible transformations in the cells, and more complications for patients rather than cures.

The authors designed and tested the concept of assessing potential effectiveness and safety of cultured adult stem cells before transplanting into patients, in this case with recessive dystrophic epidermolysis bullosa, an inherited skin condition. The condition occurs when individuals do not produce a specific type of collagen protein that anchors the epidermal or outer layers of skin to underlying tissue, resulting in blistering of the skin, and can range from mild to serious, causing disfigurement and vision loss.

The researchers cultured adult skin stem cells with recessive dystrophic epidermolysis bullosa with the gene that encodes the protein missing from people with the condition. The team then produced modified cells for replacement, but first submitted the replacement cells to a series of quality tests.

The tests included the ability to regenerate new outer-layer skin cells, produce the missing protein, anchor the outer skin layer to underlying tissue, and renew themselves over the long term. The researchers also submitted the cells to a series of safety tests, including genomic sequencing. The results indicate only a few of the replacement cells could pass both the quality and safety tests.

Barrandon and colleagues tested the cells passing both quality and safety steps by transplanting these cells into lab mice with weakened immune systems and bred to express the recessive dystrophic epidermolysis bullosa condition. The mice receiving the transplanted cells were able to produce the missing protein and regenerate new skin that did not blister.

The authors believe the findings point to measures that can improve outcomes for patients needing stem cell transplants, as well as newer types of gene therapies. “Until now there has not been a systematic way to ensure that adult epidermal stem cells meet all the necessary requirements for safety before use as treatments for disease,” says Barrandon in an EMBO statement, adding their techniques “should make it possible to integrate some of the more recent technologies for targeted genome editing that offer more precise ways to change genes in ways that may further benefit the treatment of disease.”

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• Novartis Licensing Biotechs’ Gene-Editing Technologies
• Stem Cells Engineered to Produce Insulin-Making Cells

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