The Possible Relationship between Gastric Cancer and Angiogenesis (Mide Kanseri ve Anjiyogenez Arasindaki Olasi Iliski)

Abstract Cancer, which occurs when cells proliferate in an uncontrolled manner, is one of the greatest health problems of our times.  Stomach cancer is one of the commonest causes of cancer death in the world, and it is highly resistant to treatment.  Cancers spread by infiltrating the blood vessels and lymphatic system, and research has shown that this invasion is made easier by angiogenesis, the process by which new capillaries and blood vessels develop from pre-existing blood vessels in the vascular system which provides oxygen and nutrients and takes away waste.  Angiogenesis plays a part in beneficial processes such as the healing of injuries, growth and development, but can at the same time open the way to tumor growth and metastasis.  There are many factors which influence these processes.  The most important of these are angiogenesis system activators and inhibitors.  One of the most important activators in the angiogenic system is vascular endothelial growth factor (VEGF).  This increases blood vessel permeability and stimulates the secretion of matrix metalloproteinase (MMP), which is responsible for the breakdown of the extracellular matrix, and in this way facilitates metastasis and invasion.  Endostatin is a powerful inhibitor of angiogenesis.  It directly prevents endothelial call growth and migration, and inhibits the angiogenic effect of VEGF.  Thrombospondin-1 is a five-member extracellular protein from the family of heparin-binders secreted by many normal cells.  In this review, we aimed to investigate the relation between stomach cancer and angiogenesis, and present it to the reader in a broad perspective. Key Words: Gastric cancer, anjiogenezis,VEGF,MMP, endostatin, TSP-1 Ozet Hucrelerin kontrolsuz bir sekilde cogalmasiyla meydana gelen kanser, cagimizin en onemli saglik sorunlarindan birisidir. Mide kanseri ise, dunyada en yaygin kanser olumleri arasinda yer almakta olup, ilac tedavilerine oldukca direnclidir. Kanser, kan damarlari ve lenfatik sisteme nufuz ederek yayilir. Bu invazyonun anjiogenez ile kolaylastigi yapilan arastirmalarla saptanmistir. Anjiyogenez; oksijen ve besin saglayan, atiklari uzaklastiran bir sistem olan damar yapilanmasinda, onceden var olan damarlardan yeni kapiller kan damarlari olusmasi olayidir. Yaralarin iyilesmesi, buyume gelisme gibi yararli olaylarda yer alan anjiyogenez, ayni zamanda tumor buyumesi ve metastazina da yol acabilir. Kanserin progresyonunu ve metastazini etkileyen cok sayida etken vardir. Bu etkenlerden en onemlisi anjiyogenez sisteminin aktivator/inhibitorleridir. Anjiyogenik sistemin en onemli aktivatorlerinden biri vaskuler endotelyal buyume faktoru (VEGF)’dur. VEGF, damar gecirgenligini artirir ve hucre disi matriks yikimindan sorumlu olan matrix metalloproteinaz (MMP) salinimini uyarir, boylece metastaz ve invazyon kolaylasir. Anti-anjiyogenik ajanlardan en onemlileri endostatin ve trombospondindir. Endostatin, anjiogenezin kuvvetli bir inhibitorudur. Direkt olarak endotelial hucre buyumesi ve gocunu engeller ve VEGF’in anjiogenez etkisini inhibe eder. Trombospondin -1, bircok normal hucre tarafindan salgilanan heparin baglayici 5 uyeli bir ekstraselluler protein ailesindendir. Biz bu derlemede, mide kanseri ile anjiogenez arasindaki iliskileri arastirmayi ve genis bir perspektifle okuyucuya sunmayi hedefledik. Key Words: Mide kanseri, anjiyogenez, VEGF, MMP, endostatin, TSP-1