The microscope image above shows 1 of 25 embryonic stem cell lines investigated.  The green staining shows the expression of NANOG, a marker of self-renewal in stem cells. All 25 cell lines are suitable to develop regenerative medicine therapies. Image credit: Dr Maurice Canham, University of Edinburgh.

The research – which focused on human embryonic stem cells – paves the way for clinical trials of cell therapies to treat conditions such as Parkinson’s disease (PD) and age-related degeneration of the eyes and spinal cord injury. The study also sets out a cost-effective approach for monitoring the quality of stem cell-based products and newly emerging cell therapies.

Stem cells are undifferentiated cells which have the potential to become any of the varied cell types found in the body. Researchers have been investigating how they may be used to repair or replace damaged tissues in patients. However, because the cells continuously produce copies of themselves, there are concerns that they may acquire genetic abnormalities that could lead to cancer. Scientists at the University of Edinburgh investigated the genetic make-up of human stem cells that have been grown in the laboratory from cells found in the early embryo. The 25 cell lines tested were all ‘clinical-grade’ – which means they meet the strict quality requirements for cell lines earmarked for use as therapies.

The team at the Medical Research Council Centre for Regenerative Medicine analysed each of the cell lines using a technique called molecular karyotyping, which is a highly sensitive method of detecting genetic abnormalities. More than half of the cell lines carried large but stable genetic differences, the researchers found. However, these changes are also present in healthy people without significant consequences, reflecting the genetic diversity of the human population. They found that a small number of the cell lines acquired genetic problems if they were grown in the laboratory for too long. Researchers say this highlights the need for continued genetic testing of emerging stem cell-based products to ensure they are suitable for use in patients. The study is published in the journal Scientific Reports. It was funded by The Cure Parkinson’s Trust and the Medical Research Council (MRC).

Tilo Kunath's research ... brings us far closer to being able to produce significant quantities of stem cells (that are both stable and safe) for the treatment of Parkinson's disease when these highly promising clinical trials start over the next 2-3 years.
Dr Richard Wyse - R&D Director, The Cure Parkinson's Trust

More than three-quarters of the global clinical-grade embryonic stem cell lines have been established the UK. The stem cell lines analysed in the study were established for clinical use by the Universities of Sheffield and Manchester, King’s College London, and Roslin Cells, a company that specialises in the production of clinical-grade cells for use in therapies. Dr Tilo Kunath, Senior Research Fellow at the Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, said: “This is the largest study of therapeutically useful stem cells to date and shows that we are in a good place to push forward new cell therapies into clinical trials.”

Dr Paul Colville-Nash, Programme Manager for Stem Cell, Developmental Biology and Regenerative Medicine at the MRC, said: “Collating a library of stem cells that we understand and know are fit for use in patients is vitally important if these are to be routinely used in the clinic. This work complements that of the UK Regenerative Medicine Platform that is seeking to address the key knowledge gaps needed to accelerate development, and ensure the safety and efficacy, of emerging stem cell therapies.”

For further information, please contact:
Anna Borthwick, Press and PR Office, tel 0131 650 2246; email

Our recent research meeting (April 2016) featured presentations by Professor Roger Barker (The John Van Geest Centre for Brain Repair and Neurology Dept, Cambridge) and Dr Mariah Lelos (Parkinson's UK) of their current stem cell research. These presentations can be viewed on our video channel.

Read further information about CPT's stem cell research projects.