Japanese researchers develop killer cells against cancer
Japanese researchers use so-called T-lymphocyte killer cells to fight cancer cells. With the help of induced pluripotent stem cells (iPS), the scientists led by Hiroshi Kawamoto from the Riken Research Center in Yokohama have developed cancer-specific killer cells that have been used in laboratory tests to reliably kill skin cancer cells.
The previous approaches to cancer therapy, such as radiation therapy, chemotherapy and surgery, offer some considerable chances of success, but often a really reliable cure for cancer is not possible with them. Often the treatment does not work in the desired form. That is why researchers worldwide are working intensively on the development of new treatment methods for cancer. One of the particularly promising approaches is the use of reprogrammed killer cells to fight tumors. The Japanese research team has now achieved a clear success here. Hiroshi Kawamoto and colleagues created pluripotent stem cells from white blood cells, which they then converted into killer cells that act specifically against skin cancer. The study shows "an approach for cloning and expanding functionally antigen-specific CD8 + T cells that could be used in cell-based cancer therapy," the scientists write in the journal "Cell Stem Cell".
Japanese researchers develop cancer-specific killer cells from iPS Previous approaches to combating cancer with the help of cytotoxic T-lymphocytes (CTL) mainly failed due to the short lifespan and the low availability of artificially generated killer cells. The Japanese research team has now made significant progress here. They used T-lymphocytes, which were designed to fight specific skin cancer cells, reprogrammed the cells and used the iPS obtained in this way to develop new cancer-specific killer cells, which the body cannot produce itself. These had a significantly longer lifespan than ordinary CTL, but otherwise showed the properties of the original starting cells. With the receptors on their surface, they could recognize the skin cancer cells and dock onto them. In the laboratory tests, the newly developed killer cells had more than 90 percent of the properties required to fight skin cancer cells, report Hiroshi Kawamoto and colleagues.
Medical Potential of Induced Pluripotent Stem Cells The use of induced pluripotent stem cells has enormous medical potential without being burdened with ethical problems comparable to embryonic stem cell research. In this way, patient-specific cells can be generated for various applications. However, the process also involves some risks. In 2011, studies by US scientists from the University of California, the San Diego School of Medicine and the Scripps Research Institute demonstrated serious genetic changes in pluripotent stem cell lines. Accordingly, changes in the genetic material can occur during the production of iPS, which in turn cause an increased risk of cancer. Treating skin cancer with the newly developed cells from Japanese researchers would potentially cause cancer in this way. Here, further studies on the risks of iPS are required before an application in cancer therapy can be tested. Study author Hiroshi Kawamoto emphasized that "the next steps will be to investigate whether these regenerated T-lymphocytes in the human body can specifically recognize and kill tumor cells and have no effect on the other cells." In the event that all further tests are positive , the cells could in future be injected directly into the patient for cancer therapy, the doctor explained.
Increasingly critical voices on stem cell research To what extent the Japanese researchers' expectations regarding the treatment of cancer with the newly developed killer cells will be fulfilled is so far difficult to assess. Although researchers around the world are increasingly focusing on the possibilities of induced pluripotent stem cells, critical voices about the process for which Shinya Yamanaka received the 2012 Nobel Prize in Medicine from the Japanese University in Kyoto have also increased. While some scientific work has looked at the weaknesses and risks of iPS, others have criticized the premature publication of possible research success, which is due to the extreme competitive pressure among researchers. Long-term effects are often not adequately taken into account in the studies. Despite the enormous medical potential that physicians attribute to iPS, particularly in the treatment of previously incurable diseases such as cancer or Parkinson's, the results of stem cell research have so far failed to meet expectations. (fp)
Immune defense blocks cancer growth
Image: Matthias M, Wikipedia