ABSTRACT
This chapter focuses on a downstream effector gene, the product of which, cyclo-oxygenase-2 (COX-2), plays a pivotal role in tumor promotion, at the same time being a most attractive target of chemopreventive measures. Cancer is thought to result from an accumulation of irreversible genetic defects. The majority of the genes encode proteins such as receptors, protein kinases, guanosine triphosphat-ases, transcription factors, etc., which are constituents of the signal-processing network of cells. The modulation of apoptosis, differentiation, cell proliferation and angiogenesis plays a crucial role in the course of both fetal tissue development and wound repair. COX-2 is a cancer-related gene which becomes constitutively activated as a consequence of oncogene activation or tumor suppressor gene deletion as well as by tumor-promoting agents. The gross phenotype and the accumulation of prostaglandins as well as the histological changes could be prevented by treating the animals with a specific COX-2 inhibitor, starting immediately after birth.
