Canadian researchers have been the first to successfully convert human skin cells directly into blood cells. The technique may help in the production of patient-specific bloods cells for the treatment of blood cancers, anaemia and individuals with a depleted or compromised blood system such as cancer patients undergoing chemotherapy.
'The pioneering findings published today are the first to demonstrate that human skin cells can be directly converted into blood cells… Producing blood from a patient's own skin cells, has the potential of making bone marrow transplant Human Leukocyte Antigen matching and paucity of donors a thing of the past', said Dr John Kelton, a haematologist and vice-president of Health Sciences at McMaster University, Canada, who was not involved in the study.
The harvested human skin cells were infected with a virus containing the gene OCT4. OCT4 protein is able to initiate the expression of genes required for the production of blood cells. The cells were then treated with cytokines, chemical messengers that stimulate the immune system. As a result, the skin cells were reprogrammed into three functional blood cell types: red blood cells, white blood cells and platelets, all of which maintained their new identities.
'This is the most encouraging result we've seen for using blood cells for cell-replacement therapy', said Dr Mick Bhatia, director of McMaster University's Stem Cell and Cancer Research Institute, Canada, and co-author of the study. I can see this blood being used for anyone undergoing cancer therapy. Chemotherapy and radiation affect the blood system, so even though the therapy is targeting a tumour, the patient usually has to withdraw because the blood system dies as an innocent bystander. We hope our technique will provide an alternative blood source that is healthy and allows them to continue therapy and eradicate the tumour', he said.
The procedure used by researchers at McMaster University negated the need for an intermediate step whereby the skin cells are first converted into a pluripotent, stem cell-like state. These cells have the potential to transform into any cell type but are also associated with the development of tumours. The current procedure is therefore believed to be simpler and safer than existing induced pluripotent stem cell-iPS (IPSCs) or embryonic stem cell (ESC) therapies.
'Bhatia's approach detours around the pluripotent stem cell stage and thus avoids many safety issues, increases efficiency, and also has the major benefit of producing adult-type l blood cells instead of fetal blood cells, a major advantage compared to the thus far disappointing attempts to produce blood cells from human ESCs or IPSCs', explained Dr Cynthia Dunbar, head of Molecular Haematopoesis at the National Heart, Lung and Blood Institute, Maryland.
'We'll now go on to work on developing other types of human cell types from skin, as we already have encouraging evidence', said Dr Bhatia. Clinical trials, which will begin in a few years, will be required before this therapy can be tested in patients. The study was published in Nature.