Biochemistry tumors

Despite the relative availability for chemical studies of large masses of tumor tissue, the available data is often very divergent and to date biochemical characteristics of the tumor and the body affected by the tumor, it is difficult to formulate. However, comparing different Acting between them and comparing them with normal baseline tissues, it is possible to make some generalizations.
For Acting characterized by high moisture content, the wealth of nucleic acids, soluble proteins, etc., These signs, however, is not specific for tumor growth, when compared to the original normal tissue of the chemical differences O. different histogenesis not always homogeneous. However, when comparing morphologically different tumors among themselves finds significant biochemical commonality between them. This community is evident in the relative homogeneity of enzymatic set and activity of enzymes in the comparative similarity in the amino acid composition of total protein, as well as in the contents, structure and biochemical activity of a number of other chemical components. As a rule, in O. lowered the content of those enzymes that are characteristic of specific functions of the original tissue, and strengthened the processes associated with undifferentiated growth and biosynthesis of proteins. This is a kind of chemical anaplasia (or dedifferentiate). Along with this tumor in varying degrees saves biochemical features of the original tissue, and the more O. differentiated than it less malignant, the more it retains these features.
For tumor tissue is very typical low oxidation and increased glycolysis. Especially noteworthy that, unlike most normal tissues glycolysis in the tumor continues in the presence of oxygen, i.e. is aerobic glycolysis. Although this feature is characteristic for the Acting, it still cannot be considered specific. Low oxidation may be due to the relative poverty of tumor cells mitochondria (see) and the instability of the latter.
Characterized power and undifferentiated growth of tumor cells have the ability to increased biosynthesis of proteins and nucleic acids. This ability pronounced during the incubation of cells and tissues outside the body, whereas in the body of the biosynthesis of macromolecules in tumor cells of the same order as in normal. One of the mechanisms that have value for this feature is the high ability of tumor cells to active concentration of amino acids and Sugars from the environment. As a result, the concentration of glucose in ascitic fluid surrounding the cells ascitic tumors, falls to a very low level that is insufficient to maintain the life of normal cells; however, the cancerous cells continue to grow.
The tumors also revealed violations of regulatory mechanisms of metabolism. So, unlike normal tissues, O. unable or barely able to induced synthesis of enzymes in response to the emergence of the substrate or the other coil. This phenomenon can be brought into relationship with the autonomy of tumor growth. In this connection, it should be considered violations in nuclear device tumor cells, namely changed the ratio of proteins and nucleic acids in the kernel, the accumulation of proteins sour character, especially inert and apparently ballast proteins, and increased content in the cell nucleus RNA. Violation of the regulation of glycolysis is due to damage the mitochondria, the inability of their active reduction and change of permeability.
Thus, the pathogenesis of tumor growth is connected with infringements in the apparatus of the biosynthesis of proteins, specificity and regulation of this process. The majority of researchers believe that these violations are epigenetic nature, i.e. not affect the structure of DNA molecules, but rather required changes in proteins or other substances in the kernel, perform the regulatory function.
Biochemistry tumors are very important for development of rational ways cancer chemotherapy. Modern representations are confirmed by the fact that the chemotherapy drugs used and tested for the treatment of Acting as a rule, act on the mechanisms of biosynthesis of nucleic acids and proteins.