ABSTRACT
This chapter discusses and describes the novel aspects about the physiological and pathophysiological roles of Glutathione peroxidase 2 (GPx2). GPx2 has first been described in 1993 as an enzyme of the gastrointestinal tract. During early embryonic development of mice, GPx2 messenger RNA is mainly located in extra-embryonic tissues including placenta. GPx2 expression levels can indeed be adapted to food intake. Major differences have been observed in the intestinal epithelium upon loss of GPx2, which affect the intestinal homoeostasis and integrity. The GPx2 expression is enhanced under conditions of inflammation, for example, in the intestine of patients with inflammatory bowel disease. Chronic inflammation substantially contributes to the proliferation of established cancer cells and, thus, is part of a tumor-promoting microenvironment. The upregulation in many tumor types and the obvious growth supporting properties of GPx2 are the reasons for an increasing number of studies analyzing the value of GPx2 as a prognostic marker for the survival of patients.
