Kitabı oku: «DNA Reveals Its Secret», sayfa 5
During methylation, the repulsive forces between adjacent base pairs change: they force the DNA to twist more, the voltage increases, and after the transition of the final product of demethylation to cytosine, the number of electrons decreases sharply. And the previously tightly twisted DNA, after losing electrons, begins to unwind, forming energy. From this it can be assumed that, along with the fact that DNA is the keeper of hereditary information, it also performs an energetic function.
The first nitrogenous base in the demethylation process
is 5-methylcytosine (C5H7N3O – 66). The number of electrons of this molecule in DNA is 65. In total with complementary guanine we get: 77 + 65 = 142, therefore the repulsive forces F'1> F1 (RM number – 134), thereby changing the angle of rotation between the planes of complementary nitrogenous bases, and this leads to tighter twisting of DNA.
With an equal ratio of q, the repulsive forces along the entire DNA chain are balanced: F1 = F2 = F3 = F4 = Fn, and the layers are rotated at a certain angle relative to each other, creating a helical structure of DNA and giving stability to the molecule.
Hypothesis
Possible mechanism of malignant neoplasms occurrence
Cytosine methylation in the promoter part of the genes of the intermediate demethylation process leads to the activation of these genes, which leads to the start of the demethylation process.
It can be assumed that the transformation of a healthy cell into a cancerous one is associated with the activation of enzymes involved in methylation and demethylation, and primarily methyltransferase. The target of methylation in DNA is the G-C sequence.
The reason for the primary methylation of genes encoding proteins can be caused by viral etiology, the action of a carcinogen, radiation, etc. Thus, the concept that viruses can cause cancer is being confirmed. If a virus is inserted into the promoter part of the genes involved in the demethylation processes, and contains a significant amount of G-C dinucleotides, then it further activates these genes. Ultimately, the DNA unwinds, generating the energy necessary for further DNA duplication. Then this process is repeated in the cells, and the immature DNA molecules are doubled again, that is; the activation of the promoter part of the genes can be one of the causes of cancer.
It turns out a closed process, where DNA is in an active state.
Thus, in malignant neoplasms, DNA regions that encode genes that ferment methylation and demethylation are affected. In tumor cells, demethylation first occurs, followed by hypermethylation.
Perspectives
1. Knowledge of the mechanism of cancer formation makes it possible to develop new methods of treating this disease and diagnose the promoter part of genes involved in the processes of methylation and demethylation, followed by removal of pathological changes.
2. DNA also performs an energetic function, which makes it possible to use this molecule in the field of nanoenergy.
Sources
1. Tet proteins can convert 5-methylcytosine to 5-formylcytosine and 5-carboxylcytosine. Ito S, Shen L, Dai Q, Wu SC, Collins LB, Swenberg JA, He C, Zhang Y Science, 2011 Sep 2;333(6047)61300–3. doi: 10.1126/ science.1210597. Epub 2011 Jul 21.
2. Уотсон, Джеймс Д. Двойная спираль Воспоминания об открытии структуры ДНК: [Пер. с англ.: Брухнов, М.; Иорданский, А.] = Watson, James D. The Double Helix. A Personal Account of the Discovery of the Structure of DNA. Atheneum: New York, 1968. – М.: Мир, 1969. – 152 с.
