Patients may soon receive blood made from their own skin cells
Patients could be treated with blood made from their own skin in just two years.
Scientists have shown that ordinary skin cells can effectively be converted into adult blood cells in the laboratory.
The Canadian team is now racing towards clinical trials, which could begin as early as 2012.
Crucially, the process misses out the ‘in-between’ stage of first reprogramming the cells into an embryonic-like state and then coaxing them to ‘differentiate’.
Previously researchers have used this approach to create poorly developed cells from ‘induced’ stem cells.
With the new technique, the transformation into cells just a small step away from being fully mature and functional adult blood cells is direct.
Dr Mick Bhatia, director of the Stem Cell and Cancer Research Institute at McMaster University in Hamilton, who led the discovery, said: “We don't envision many obstacles. It's always hard to predict exactly when it will head to the clinic, but that is our direct aim right now.
“We'll be focusing on that with several groups around the world.
“I see the first sets of patients as being patients suffering from leukaemia. Us being able to take skin cells and convert them into healthy blood, specifically adult blood, would provide a great substitute product to hopefully out-compete those leukaemic cells.”
The breakthrough arose from observations made several years ago during early work on so-called induced pluripotent stem cells. These are ordinary cells that have been genetically tweaked to make them revert to an embryonic state. They then adopt the characteristics and properties of embryonic stem cells — stem cells extracted from early human embryos.
Most importantly, they are ‘pluripotent’, having the potential ability to grow into many different kinds of cell.
During the process, a small number of skin cells seemed to jump spontaneously to the stage of being immature blood cells.
Building on these studies, Dr Bhatia's team found a genetic and chemical recipe that made it possible to generate a full range of adult blood cell progenitors from skin cells called fibroblasts.
The ‘lineages’ included different kinds of white blood cell, red cells, and the cells that generate blood clotting platelets.
The technique involves inserting a specific transcription factor (a protein that interacts with DNA to activate genes) and applying other treatment in the form of signalling molecules called cytokines. Skin cells from young and old people were used in the research to prove that age of donor made no difference to the process.
A number of the cells were successfully grafted into mice.
Dr Bhatia said: “We have shown this works using human skin. We know how it works and believe we can even improve on the process. We'll now go on to work on developing other types of human cell types from skin, as we already have encouraging evidence.”
He said the new technique was quicker than its predecessors and made “the right types of blood cells”. “It makes adult blood and not more foetal or embryonic blood that normally you would see traditionally from embryonic stem cells or induced pluripotent stem cell,” Dr Bhatia added.
Next the scientists plan to assess what kind of production capacity might be possible with the cells, and whether they can successfully be stored in deep freeze.
Professor John Hunt, a leading stem cell scientist from the University of Liverpool, said: “I think it's fantastic research, but it's not yet in the clinic and we don't know if these red blood cells are going to carry oxygen. The quantum leap for us all is going to be to get these kind of bench experiments into the patient.
“It might be two years or 10 years, but it's right to be optimistic because we're expecting breakthroughs. However it's still too early to say ‘this is it'.
“This opens a lot of doors, and if we could produce red blood cells we'd be solving a big clinical need.”