Cyclooxygenase-2 in cancer and angiogenesis.

Tumor angiogenesis is a process where new blood vessels are formed from preexisting ones, resulting in several pathologies. Solid tumors induce angiogenesis to obtain the required nutrients and oxygen. Otherwise, tumors do not grow beyond 2 to 3 mm in diameter. Cyclooxygenase-2, an inducible enzyme important in inflammation, catalyzes the production of prostanoids from arachidonic acid. Cyclooxygenase-2 plays an important role in several cancer types, including colorectal, gastric, prostate, breast, lung, and endometrial cancer. Besides, cyclooxygenase-2 has been implicated in the progression and angiogenesis of cancers. Cyclooxygenase-2 inhibitors have been used to block angiogenesis and tumor proliferation. In this review, the recent studies related to the role of cyclooxygenase-2 in several cancer types and tumor-induced angiogenesis were compiled.