Major Breakthrough: “Killer” Stem Cells Can Kill Cancer Cells

Japanese scientists say they have managed to artificially create in the laboratory killer T cells, able to fight cancer. This is the first successful attempt to create such cells, in the context when all previous attempts have failed because these cells have a very short life, which limits their use. The so-called killer T cells, or killer stem cells, are a special class of immune cells involved in defending the body from pathogenic microorganisms or cancerous cells, which are abnormal.

T lymphocytes are produced in small numbers in the body, but it is thought that injecting them in large quantities may enhance the basic immune functions and thus lead to the destruction of cancer. Japanese experts from the Center for Research in Allergy and Immunology RIKEN say they have used induced pluripotent stem cells (iPS) to create killer T lymphocytes capable of destroying tumor cells.

They reprogrammed T lymphocytes specialized in destroying a type of skin cancer, transforming them into iPS. This process of generating iPS later led to fully active T lymphocytes capable of destroying cancer cells. Previous attempts to produce T cells in the laboratory by conventional methods were unsuccessful because these cells have a very short life, and therefore could not be used to treat cancer. Dr. Hiroshi Kawamoto, who led the research, believes that this strategy can solve the problems they face today in immunotherapy and this could also represent a major breakthrough in terms of cancer treatment. The next step will be testing the T cells obtained to determine if they selectively attack cancer cells and not other cells. If it turns out that their action is selective (only on tumor cells), then, in a not too distant future, they could be injected directly into the body, as a treatment for patients suffering from cancer, said Dr. Kawamoto. Some experts argue, however, that there are other similar treatment methods that have failed and that this new discovery is far from being used in practice in present.

British oncologists and specialist Japanese researchers consider that the results are encouraging and represent a step forward in the relatively new field of this type of therapy that involves stimulating the body’s immune defense system to make it attack and destroy only cancer cells. But they warned it oculd be some time before the method could be put into practice, because so far they have achieved only some minor results under laboratory conditions and it is unknown whether killer T cells thus obtained are indeed capable of destroying cancer in animals and humans and their use is without risk. A similar method has been studied adoptive T cells as part of a special form of therapy that involves removal of T cells from patients and increasing their ability to “attack” and then be reinjected into patients. It remains to be seen whether this discovery is indeed the one all the patients suffering from cancer have been looking for or not.