Immuno-expression of Smac/Diablo, AIF, cytochrome c, cleaved caspase 3 and Ki-67 in gastric cancer tissue by tissue micro array (TMA)

Abstract

The processes of proliferation and cell death are important in tumor development. Both are crucial for both biological activities and pathological physiological processes. Apoptosis plays a key role in maintaining the integrity of gastrointestinal mucosa and its deregulation is associated with the occurrence of lesions such as atrophic gastritis, peptic ulcer, intestinal metaplasia, dysplasia and eventually gastric cancer. Increased rate of apoptosis may be stimulus for compensatory hyperproliferative response in an attempt to maintain the gastric mucosal cell mass. It is suggested that, since the proliferation is established, an increase in the rate of cell cycle may predispose the gastric epithelium to genotoxic and mutagenic damage. The protein Smac / Diablo is present in the inner mitochondrial membrane where after being released has the function to inhibit the IAPS (apoptosis inhibitory protein), cytochrome c is released after the destabilization of the mitochondrial membrane to form the apoptosome function to connect with the Apaf-1 and caspase 9, and these two proteins induce apoptosis, since the AIF (apoptosis inducing factor) is also present in the mitochondrial membrane and released after their destabilization induces apoptosis independent of caspases. Study these proteins and cleaved caspase-3 and Ki-67 may predict levels of proliferation and cell death rate during gastric carcinogenesis. (AU)