In a world-beating medical breakthrough, Hamilton researchers have created human blood directly from adult skin cells.

Efficient enough to produce usable amounts of blood for transfusions, the technique also opens the possibility of creating other transplant tissues without the arduous and time-consuming step of making embryonic stem cells first.

“We have taken very young patients’ skin cells and patients as old as 80,” says Mick Bhatia, director of McMaster University’s Stem Cell and Cancer Research Institute.

“And we can convert the cells always to blood,” says Bhatia, the senior study author.

The new discovery holds out hope for all kinds of transfusion advancements, especially for cancer patients whose blood systems are often badly compromised by chemotherapy.

The finding, released Sunday by the journal Nature, could also help stock overburdened blood banks.

While the technique is not yet producing blood for clinical use, study calculations show that, even in the worst cases, it could create enough for successful transfusions.

Bhatia says a patch of skin as small as 12 square centimetres – a size routinely removed during grafting operations – would generate sufficient blood for transfusions.

The technique also circumvents a major roadblock that has developed in the embryonic stem cell field.

Formed just after conception, embryonic stem cells are the building blocks for every organ and tissue in our bodies. Since Japanese scientist Shinya Yamanaka rocked the medical world five years ago by showing adult cells could be turned back into the embryonic state, researchers around the globe have been in a heated race to create better methods to make them.

They have devised ingenious new recipes that have produced more robust embryonic cells more efficiently, but have had little luck coaxing them to grow into usable transplant tissues.

“However you get them (embryonic cells) and the technology and techniques and methods involved, you still have to make a cell that you want to use for transplantation,” Bhatia says. “This (transformation) problem really persists no matter how you generate (the stem cells).”

Bhatia’s team has skipped that embryonic step altogether and gone straight from one adult tissue type to another.

The method they used may well be able to produce other types of tissues in a similar direct fashion. “We haven’t published it, but yes, we have evidence to that effect,” he says.

Those transplant tissues would be ideal because, coming from a patient’s own body they would pose no rejection risks.

Such direct tissue creation has created pancreatic and neural cells in the recent past, but only in mice, says Dr. Cynthia Dunbar, a senior investigator at the U.S. National Institutes of Health.

“This has been done with human cells, which is very exciting,” says Dunbar, who edits the scientific journal Blood.

“And we really do know that people are not mice . . . and starting right away with human cells was definitely admirable because they are much harder to work with,” she says.

Loading... Loading... Loading... Loading... Loading... Loading...

Dunbar cautions that it will be beyond five years before the Hamilton technique would create any clinically useful blood.

To create his embryonic cells, Yamanaka introduced three simple “transcription factors” into the skin cells’ DNA, and cultured them in special growth factors. Other scientists have subsequently used different recipes with alternate types and numbers of transcription factors.

But Bhatia’s method, achieved by trial and error, employed just one transcription factor and a precisely timed basting of two different growth factors.

The resulting blood cells actually emerge at a “progenitor” stage where they have not transformed into the final variety of red or white products, Bhatia says. This makes them ideal for transfusion, especially in cancer patients, whose blood supply systems are often compromised or destroyed by chemotherapies.

“Leukemic patients are certainly one of the primary visions we have for the use of this technology,” Bhatia says.

Christine Williams, research director at the Canadian Cancer Society Research Institute, says the technique offers huge advantages for leukemia and lymphoma patients.

She says current methods to replace blood-creating stem cells in destroyed marrow in these patients either utilize donor material or stem cells that have been harvested from the patient beforehand.

But in the former case, suitable donors often cannot be found, and in the latter, patients’ own stem cells are likely to bear the same genetic mutation that caused the disease in the first place.

Blood progenitors made from skin cells, however, would not have the disease mutation and would eliminate the need for donor searches, Williams says.

She says they would also allow doctors to increase and lengthen chemotherapy treatments for other types of cancers. These are currently curtailed in many cases because the drugs used can destroy blood-producing cells.

“It is very exciting for people working in cancers,” Williams says.

Bhatia’s team will be looking at the conversion of abundant and often unwanted fat cells into blood using the same method.