What is Neuron-Specific Enolase (NSE)?

Neuron-Specific Enolase is a glycolytic enzyme in neuronal form which acts on the substrate Phosphoglycerate and coverts into phosphoenol pyruvate and is also known as Enolase 2. This enzyme is generally located in the peripheral and central neurons. Neuron-Specific Enolase is a soluble protein and acidic in nature and similar to bovine 14-3-2 protein. It is extensively present in mammalian tissues and has three subunits which includes alpha, beta and gamma subunits. Thus, Neuron-Specific Enolase can be used as a tool in identification of molecular markers of neurons in vitro and in vivo. Neuron-Specific Enolase was formerly found in brain tissue extracts and then after was detected in Amine Precursor uptake and Decarboxylation cells (APUD).

It has been reported that the enzyme promotes neuron survival and also neuroprotective in nature when tested on neurons under hypoxic environments.

Uses of Neuron- Specific Enolase as a Tumour marker

Presence of Neuron-Specific Enolase is usually very low in healthy people or people with diseases in benign stages, but this enzyme concentrations are elevated in people suffering from cancer patients. Patients suffering from neuroblastoma, medullary thyroid carcinoma, pancreatic islet cell carcinoma, SCLC (Small cell lung cancer) or any other neuroendocrine tumours show high concentrations of Neuron-specific enolase. There has been strong correlation demonstrated between the Neuron-specific enolase concentrations and neurological situations. Thus, Neuron-specific enolase has been used as a tool in diagnosis of various above mentioned carcinoma in patients. The levels of Neuron-specific enolase can be correlated with brain damage for predicting the extent of disease and response to the treatment. Serum NSE has shown to be useful as a tumour marker specifically in measuring the extent of disease.

Increased Neuron- specific enolase in serum is also used as a marker in patients with septic shock or sepsis but it is primarily used for lung cancer prognosis.