AP BIOLOGY

Detailed explanation-1: -Angiogenesis is stimulated when tumor tissues require nutrients and oxygen. Angiogenesis is regulated by both activator and inhibitor molecules. However, up-regulation of the activity of angiogenic factors is itself not sufficient for angiogenesis of the neoplasm.

Detailed explanation-2: -Angiogenesis plays a critical role in the growth of cancer because solid tumors need a blood supply if they are to grow beyond a few millimeters in size. Tumors can actually cause this blood supply to form by giving off chemical signals that stimulate angiogenesis.

Detailed explanation-3: -Angiogenesis is how the body forms new blood vessels. This is a normal part of growth and healing. But sometimes angiogenesis can play a role in diseases such as cancer. To grow, a tumor needs nutrients and oxygen from your blood.

Detailed explanation-4: -With cancer, this formation of new blood vessels (angiogenesis) is what allows tumors to grow. Angiogenesis means essentially the same thing as neovascularization, though neovascularization refers to any type of blood vessel (artery, vein, capillary, lymph vessel).

Detailed explanation-5: -Increased angiogenesis in tumor tissues can increase the supply of nutrients to tumor cells, and facilitate tumor growth, invasion, and metastasis. Recent studies have showed that several cytokines in the tumor microenvironment and some conventional anticancer agents exhibit a pro-angiogenic effect.