Stem cells grown in the lab could represent a breakthrough in cancer treatment

For the first time, human blood stem cells have been produced in the laboratory, which could significantly improve the way we treat certain types of diseases. cancer.

So far, the lab-grown cells have only been tested in mice, but when infused into the animals, the cells became functional bone marrow at levels similar to those seen after umbilical cord blood. blood cell transplants.

Treating cancers such as leukemia and lymphoma with radiation and chemotherapy can destroy blood-forming cells in the bone marrow. A stem cell transplant means that new, healthy bone marrow and blood cells can grow. Umbilical cords are a particularly rich source of stem cells, but donations are limited and the transplant can be rejected by the body.

The new method would allow researchers to produce stem cells by the patient himself, eliminating the problem of supply and reducing the risk of rejection by the body.

First, human blood or skin cells were transformed into so-called pluripotent stem cells through a process called reprogramming. “This involves temporarily turning on four genes, resulting in the patient’s cells returning to an early stage of development where they can become any cell in the body,” he says. Andrew Elephant at the Murdoch Children’s Research Institute in Melbourne.

The second step involved transforming the pluripotent cells into blood stem cells. “We first create thousands of little floating spheres of cells, a few hundred cells in each sphere, and direct them to transform from stem cells into blood vessels and then blood cells,” Elefanty says. This process, called differentiation, takes about two weeks and creates millions of blood cells, he says.

These cells were then infused into mice lacking a immune system and became functional bone marrow in up to 50 percent of cases. That means it produced the same oxygen-carrying, infection-fighting cells as healthy human bone marrow, Elefanty says. “It’s this unique ability to produce all types of blood cells over an extended period of time that defines the cells as blood stem cells,” he says.

Abbas Shafie at the University of Queensland in Brisbane says the work is a “wonderful breakthrough” toward new therapies for blood cancers. “It’s never been done before and has great potential for the future.” But even once animal testing is complete, much more research needs to be done in humans before the approach can be used in the clinic, he says.

Simone Conn at Flinders University in Adelaide, Australia, says a key advantage of the team’s approach is that it could be scaled up to produce “an essentially infinite supply” of blood stem cells. But he adds that the work was based on blood or skin cells, with the success rate and diversity of blood cells depending on the starting cell type.

“This suggests that the treatment, even in the preclinical stage in mice, is not consistent, and this will need to be addressed before any clinical trials in human patients,” he says.