The history of stem cell research runs through blood transplants, frog nuclear transfer experiments, cell lines grown from human embryos and the discovery that adult cells can be reprogrammed. Each stage opened a new line of laboratory work.
This short history follows those turning points and notes what each one did and did not show. It belongs to the wider stem cell research section of this independent educational site.
Bone marrow transplants set the first precedent
The oldest clinical use of stem cells is the bone marrow transplant. The Nobel Prize organisation explains in its biography of E. Donnall Thomas that the formation of blood cells takes place in bone marrow, and that malfunctioning of bone marrow cells can lead to illnesses such as leukemia.
The same Nobel page states that from the middle of the twentieth century Thomas developed methods of providing new bone marrow cells for people through transplants. The 1990 Nobel Prize in Physiology or Medicine recognised discoveries concerning organ and cell transplantation in the treatment of human disease.
The procedure itself is described in the same biography. Using radiation and chemotherapy, the body’s own bone marrow cells are killed and the immune system’s rejection mechanism is subdued, and bone marrow cells from a donor are then provided through a blood transfusion. The steps show why this is a demanding procedure used for serious blood disorders, and why it is not comparable to a simple injection.
That work matters for the history because it showed that blood-forming cells from a donor could re-establish a recipient’s blood system. It was a medical procedure built on a specific, well-defined cell type, and it remains separate from the experimental offerings sold today as stem cell treatments.
Nuclear transfer in frogs changed the view of cell identity
For a long period, biologists assumed that development moved in one direction only. The Nobel Prize press release for 2012 describes how the journey from immature to specialised cell was previously considered to be unidirectional.
John Gurdon tested that idea in 1962 by replacing the nucleus of a frog egg with a nucleus from a mature intestinal cell of a tadpole, according to the Nobel announcement. The egg developed into a fully functional, cloned tadpole, and repeats of the experiment yielded adult frogs.
The press release adds that the discovery was initially met with scepticism but became accepted once other scientists confirmed it, and that the technique eventually led to the cloning of mammals. The lesson was conceptual: a mature cell’s genome still holds the information needed to direct development.
This finding did not produce a therapy. It changed what researchers thought was possible and set the stage for later work on reprogramming.
Human embryonic stem cell lines arrived in 1998
Embryonic stem cells were first isolated from mice. The 2012 Nobel press release credits Martin Evans, who received the Nobel Prize in 2007, with that earlier step.
In 1998, a paper indexed on PubMed described human blastocyst-derived, pluripotent cell lines. The abstract reports that, after undifferentiated proliferation in vitro for 4 to 5 months, these cells still maintained the developmental potential to form trophoblast and derivatives of all three embryonic germ layers.
The authors wrote that the lines should be useful in human developmental biology, drug discovery and transplantation medicine. Note the wording: the paper pointed to laboratory uses and a possible future, not to a proven treatment. The work also raised ethical debate, because the cells came from human embryos, a subject covered in more detail in the guide to embryonic and adult stem cells.
Reprogramming adult cells in 2006
The next landmark avoided embryos altogether. A 2006 paper, again indexed on PubMed, reported induction of pluripotent stem cells from mouse embryonic or adult fibroblasts by introducing four factors, Oct3/4, Sox2, c-Myc and Klf4.
The authors named these cells iPS (induced pluripotent stem) cells. According to the abstract, they exhibit the morphology and growth properties of embryonic stem cells, and transplanting them into nude mice produced tumors containing a variety of tissues from all three germ layers. That tumor result is a reminder that pluripotent cells carry risks that researchers must manage.
The Nobel committee gave the 2012 prize to Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent. Its press release says the findings revolutionised the understanding of how cells and organisms develop, and that reprogramming human cells created new opportunities to study diseases and develop methods for diagnosis and therapy.
The press release also describes a specific use. Skin cells can be obtained from patients with various diseases, reprogrammed and examined in the laboratory to see how they differ from the cells of healthy individuals. In other words, much of the early value of iPS cells lay in studying disease, not in treating it.
The press release notes that textbooks have been rewritten and new research fields have been established. The practical effect is a different way of framing the whole field. If a mature cell can be returned to an immature state, then the supply of pluripotent cells no longer depends only on embryos, and patient-specific cells become possible for laboratory study.
Researchers still have to show that reprogrammed cells behave safely and consistently before any clinical use is considered. Each step from a dish to a person is a separate scientific question, and the history of the field is partly a history of those questions being asked in turn.
What the history shows and what it leaves open
Looking back, the field advanced through basic biology first and clinical use later. Blood transplants are the long-established case. The newer pluripotent cell lines and reprogrammed cells mostly serve as research tools, and turning them into approved therapies requires testing in people.
It also helps to separate three kinds of claims that often get blended together: a discovery about how cells behave, a laboratory tool built from that discovery, and a treatment shown to help patients in properly controlled studies. The timeline above contains plenty of the first two and only one long-established example of the third.
That testing follows a defined path, described in the page on the phases of clinical trials. A laboratory result in cells or mice is a starting point, and many interventions fail at later stages.
The history also helps with a related question, which is how stem cells differ from other approaches that alter cells or genes. The comparison is laid out in the article on gene therapy vs cell therapy.
A timeline of discoveries does not show that any particular treatment works. Decisions about any treatment belong with a licensed physician who knows the reader’s situation.
Frequently asked questions
When were the first human embryonic stem cell lines described?
Show answer
A paper published in 1998 described human blastocyst-derived pluripotent cell lines, and its authors suggested uses in developmental biology, drug discovery and transplantation medicine.
What did the 2012 Nobel Prize recognise?
Show answer
It recognised the discovery by John Gurdon and Shinya Yamanaka that mature cells can be reprogrammed to become pluripotent.
Which stem cell procedure has the longest clinical history?
Show answer
Bone marrow transplantation, with methods developed from the middle of the twentieth century onward by E. Donnall Thomas, who shared the 1990 Nobel Prize in Physiology or Medicine.
What are iPS cells?
Show answer
Induced pluripotent stem cells are adult cells reprogrammed into an embryonic-like state. The 2006 mouse study achieved this by introducing four factors.
