Expression of tight-junction-associated proteins in human gastric cancer: downregulation of claudin-4 correlates with tumor aggressiveness and survival.

Background: Claudin, occludin, and zonula occludens (ZO)-1 are known as tight-junction-associated proteins. The aim of this study was to examine the expression of these proteins in gastric carcinoma.

Methods: Gastric cancer tissues (n = 124) were obtained from 124 patients who underwent gastrectomy at our hospital between January 2000 and December 2004.

Ornithine decarboxylase activity as a prognostic marker for colorectal cancer.

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthesis of polyamines, which are essential for cell proliferation. ODC activity was measured in 47 colorectal cancer patients, 5 patients with adenoma of colorectum and 4 healthy volunteers. Mean ODC activities of cancer tissue, non-cancerous mucosa from cancer-bearing colorectum, adenoma tissue, and normal mucosa from healthy volunteers were 435+/-392, 154+/-173, 295+/-202, 103+/-60 pmol CO2/h/mg protein, respectively.