engleski

Cyclooxygenase isoforms in tumorigenesis

Cyclooxygenases (COXs) are the key enzymes in prostanoid biosynthetic pathway. Prostanoids act as local hormones and they are involved in numerous normal physiological proceses but also in the development of various diseases. COXs are present in three isoforms: COX1, COX2 and COX3. COX1 is usually involved in maintaining the physiological conditions of the healthy tissues while COX2 is mainly related with various malignancies. COX3 is a functional splice variant of COX1 and its role is still controversial. COX1 has a housekeeping role while COX2 has been implicated in tumorigenesis.COX2 overexpression has been detected in premalignant and malignant lesions in different tissues. Numerous experiments confirmed its role in all stages of tumor development. It was reported that COX2 participates in promotion of angiogenesis and inhibition of apoptosis and immunosurveillance. The exact mechanisms of its activity in these processes are not fully clarified. Expression of COX2 has been proposed to be an early event in colorectal tumorigenesis. Different drugs were developed to target COX and they were effective in preventing cancer but they also exhibited adverse effects. There is extensive research conducted in order to develop the drug that wouldn’t cause severe toxicities and to define the polymorphisms that affect the patients response to a certain drug but also to define the cancer risk polymorphisms.

COX-1 ; COX-2 ; cancer

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