Targeted therapies used in the treatment of cancer consist of hitting a specific bullet - a drug, against malfunctioning cells (cancer cells), while sparing he althy tissue. Medicine has high hopes for targeted cancer therapy.

Molecularly targeted therapyis a major advancement in cancer treatment. Simply assuming thatcancer diseaseconsists in losing the body's control over the course of metabolic processes in the cell, potentially every element of the chain of reactions responsible for this abnormal feature of the cell may become a target for modern oncological therapy. The most important two groups of cancer drugs currently in use aremonoclonal antibodiesand small molecule tyrosine kinase inhibitors.

Cancer treatment: monoclonal antibodies

On the surface of most cancer cells, characteristic protrusions, or receptors, have been discovered, thanks to which they communicate with the environment. They can attach certain particles (e.g. growth factor), transfer chemicals and information (e.g. about division) into the cell, and send them out (e.g. by requesting food). This knowledge made it possible to design monoclonal bodies in such a way as to block the work of cancer cell receptors, making it impossible to function.

Cancer Treatment: Dual Arming

Another idea was to arm this particle with some lethal weapon. One possibility is to attach a radioactive isotope to such an antibody. For example, in a medicine called ibritumomab tiuxetan, which is effective in treating lymphoma, the antibody is linked to an isotope of yttrium. When an isotope is brought into a tumor, it not only kills the cell to which the antibody has attached, but also other cells in the area. The effect is greater than in the case of the antibody itself, because it acts on the surface and the radiation freely penetrates the tumor. The antibody can also be armed with a different isotope or with a bacterial toxin. The principle of the latter is that the toxin, after attaching to an antigen, can destroy the cell carrying the antigen. This happens without harming the body's he althy cells. Monoclonal antibodies can also be combined with drugs. This keeps the drugdelivered directly to the affected tumor. Therefore, less of it is used and its side effects are limited, which is important in the case of chemotherapy.

Important

  • Among the many receptors that have come into the focus of researchers, the epidermal growth factor receptor family is one of the best known. One of the targets that scientists have aimed at weapons is the so-called HER 2, which is responsible for proper cell growth and division. Sometimes, however, the gene that controls the production of this factor multiplies too much. As a result, there is too much of it and a cycle of incorrect divisions ensues. This is when cancer develops. Overproduction of HER 2 leads, among other things, to an aggressive form of breast cancer (25-30% of all breast cancers have a high activity of this factor). In this case, the medicine is trastuzumab, which binds to the receptor and blocks it, inhibiting growth and activating the body's own defenses. In the postoperative treatment of breast cancer, this specificity inhibits disease recurrence with an extremely high efficiency in oncology - 50%. and reduces the risk of death by 33 percent.
  • The creators of the technology received the Nobel Prize in 1984 for the technology of obtaining such antibodies.

    • Cancer treatment: tyrosine kinases

    The second group of drugs that block the activity of cancer cells are preparations that act on the intracellular domain of the receptor, inhibiting the activity of related tyrosine kinases by blocking ATP phosphate binding sites during the activation of mass mitogenic signaling. The activity of tyrosine kinases related to the receptor is necessary for its proper functioning, including the activation of proteins involved in signaling (e.g. about stimulating the receptor) inside the cell. Blocking the ATP binding sites prevents signal transmission. About 100 tyrosine kinase proteins have been identified and described in the human body, representing a potential point for targeted therapies. The action of drugs from this group is particularly effective if the activation of tyrosine kinase is a dominant phenomenon in the tumor (e.g. as a result of an activating mutation of the gene encoding it). Many drugs in this group have affinity for several tyrosine kinases. The first drug in this group approved in oncology was imatinib - a small molecule tyrosine kinase inhibitor of a protein found in chronic myeloid leukemia cells. It inhibits the activity of several kinases responsible for the development of various malignant neoplasms, mainly in chronic myeloid leukemia, but also gastrointestinal stromal tumors (GIST). Drugs from thisgroups also include gefinitib and erlotinib. The first one in 2003 was registered in Japan, Australia and the USA for the treatment of chemotherapy-resistant non-small cell lung cancer.

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