Most cancer cells carry unique receptors on their surface. Because the receptors extend into the cell's interior, they act as intermediaries between the outside and the inside. Chemotherapeutic drugs that dock on the exterior trigger a cascade of biochemical reactions inside the cell. At the end of this process, the cancer cells should die off. Researchers at the Paul Scherrer Institute PSI are now investigating a new method that would not only attach radioactive substances to the outside of a cancer cell, but also would channel them right into the cell's nucleus. Thus the radiation source would remain inside the cell and work in a more targeted way, by getting closer to the genetic information. If the suitable radioactive compounds can be found, this method has the potential to help with several kinds of cancer in the future.
One of the most important goals in cancer therapy is to strike at the
heartof the camouflaged cancer cells – that is, in the nucleus. In cancer cells, pathologically mutated DNA ensures that cell division occurs more rapidly and more frequently than in normal cells. Many cytotoxins used in chemotherapy against cancer manage to penetrate to the cell nucleus and attack precisely those processes that are important for cell division. Others interfere with the metabolism of tumour cells, thereby impeding their growth. Thus they all operate within the cell, and particularly at the time when it is dividing. Many cytotoxins, however, are non-specific and also attack other tissues of the body that renew themselves frequently, such as hair or mucous membranes.
