In medicine, there are many obscure terms for a simple person. One of them is neuron-specific enolase (enolase). In this article, the definition of the term will be disclosed, issues related to the content of NSE in the blood are raised, and the diseases that are associated with it are discussed. We will also consider a general description of enolase as an enzyme.
general information
Enolase (phosphopyruvate hydratase) is an enzyme that is involved in the final stage of the glycolysis process. Enolase is a biological catalyst that affects the conversion of 2-phospho-D-glyceric acids to phosphoenolpyruvate. In this case, acids lose one molecule of water during cleavage.
There are 3 genes responsible for encoding the enolase isoenzyme:
- G. ENO 1. Encrypts data on alpha enolase consisting of 2 alpha subunits. An alternative type of translation leads to the formation of the Myc-binding protein, which can reduce the efficiency of the c-myc proto-oncogen. It is found in the thickness of the cytoplasm of many cells.
- G. ENO 2. Encrypts data on enolase 2, or gamma enolase, an enzyme consisting of 2 gamma subunits. It is also called a neuron-specific enolase. Most often, they are found in neuronal cells.
- G. ENO 3. Encrypts data on enolase 3, or beta-enolase, an enzyme consisting of 2 subunits. Over 90% of the activity of the enolase type, which is observed in human muscles after 23-25 years, provides this type of enzyme. Beta-enolase, respectively, is located in muscle tissue.
Enolases are a superfamily, a group of enzymes that have been linked by evolution. They perform a similar series of functions in various processes of biochemical nature.
NSE in the blood
The rates of neuron-specific enolase can vary within small limits. However, in blood serum its level should not exceed 13.2 ng / ml.
NSE is an enzyme of the glycolytic type. It is exploited as a marker of neuroendocrine tumors. NSE is located in the cytoplasm of cells of neuroectodermal origin, in neuronal cells of the brain and PNS. An increase in the concentration of this enzyme can occur during the formation of small cell lung cancer or neuroblastoma, leukemia, after a radiation therapy session, and after x-ray medical tests and studies. If the neuron-specific enolase is increased to 20 ng / ml, then a benign lung disease is possible. Due to this, the clinical diagnosis of malignant tumors registers them with a value of 25 ng / ml. Due to the fact that NSE is present in red blood cell cells, hemolysis increases its value and overestimates the results of experiments.
Diagnostics
Tests to check the level of neuron-specific enolase (NSE) are prescribed for the diagnosis and monitoring of the effectiveness of the treatment sessions in the treatment of small cell lung cancer. When combined with the use of NSE with CYFRA-21-1, it becomes possible to increase the sensitivity of diagnostic tools (when determining carcinoma in the lung) to 62%. The use of NSE together with CEA allows increasing the sensitivity of analyzes by 57%.
Neuron-specific enolase is a valuable indicator in the diagnosis of neuroblastoma. With a separation point of 25 ng / ml, the sensitivity to this marker in a similar tumor can be 85%.
Biochemistry
Neurospecific enolase is a glycolytic enzyme. Its molecular weight is 80 kDa. Its three types mentioned above are also called dimers. The difference in forms is manifested at the level of properties, however, they all have an immunological beginning. It is important to know that λ-λ and α-λ isoforms of gamma-enolase are classified as neurospecific enolase. Initially, it was found in nerve and neuroendocrine cells. NSE is also found in neoplasms.
Onomarker concept
NSE is a serum substance that serves as an onomarker for the diagnosis of neoplasms from cells, the APUD system, which are found in various types of tissues. It is also used in the search for neuroendocrine sources of the disease. The category of such neoplasias includes retinoblastomas, neuroblastomas, medullary thyroid cancer , pheochromocytomas, carcinoids, as well as small cell lung cancer (MRL) and pancreatic islet cell cancer. The enzyme activity index correlates with the clinical situation and finds its application in monitoring pathologies, as well as in predicting. It can rarely be used in special cases with neuroblastoma and MRL.
The history of the discovery and study of NSE is closely related to the study of the structure of the brain of rodents, because the biochemistry of, for example, white mice is very similar to ours, human.
Isoform concept
Neuron-specific enolase (NSE) is an enzyme necessary for the stages of glycolysis. Therefore, it is found in all cells of a multicellular organism. It is important to know that NSE is tissue specific.
Specifically, NSE is characteristic of neural cells that possess some features of their structure. These features affect the normal functioning of this enzyme with an increased concentration of Cl ions (chlorine). In addition to the neural cytoplasm, NSEs are found, for example, in the chromaffin cells of the adrenal medulla, in the parafollicular cells of the thyroid gland.
In the tumor cell, there is an increase in the synthesis of this enzyme, which allows for a high rate of glycolysis. Because of this, there is an active growth of the tumor itself, its spread over the surrounding tissues.
NSE and children
If a neuron-specific enolase is elevated in a child, this does not mean that it is necessary to sound the alarm. Often in medical practice there are cases when caring parents resort to researching the level of NSE in the blood serum on their own initiative. For this, there may be certain prerequisites and causes, for example, frequent diseases associated with the lungs. But this type of research is not specific, which is important to remember. The term “non-specific” means that the measurement of the indicators of the desired onomarker can vary greatly. It depends on many conditions that are associated both with the physiological characteristics of the body, and with certain diseases.
Most importantly, this diagnostic measure will not be correct in relation to the child. This is due to the "atypical" presence of many diseases that could lead to an increase in neuron-specific enolase. The exception is congenital ailments that are inherited or formed during a random mutation. If your child often suffers from diseases affecting the lungs, you should first make a tank. inoculation from the oral cavity. You may need antibiotic treatment. The use of methods with detecting the level of NSE may be justified if they are prescribed by a qualified doctor.