Content of glucocorticoid receptor and arginase in gastric cancer and normal gastric mucosal tissues

The content of glucocorticoid receptor (GR) and arginase in human gastric cancer and the corresponding normal gastric mucosal tissues was determined. Among the 25 patients studied, the GR content in gastric cancer tissues was 33.2k10.2 fmol/mg protein versus 7.6k3.4 fmol/mg protein in gastric mucosal tissues. This difference is statistically significant (P<0.005). Of the 25 paired samples, 19 cancer tissues contained GR, whereas only seven of the normal mucosal tissues had GR. The level of arginase in gastric cancer tissues in 19 patients was assayed, it was 26.6k4.2 ng/mg protein which is also significantly higher than that in normal gastric mucosal tissues (13.5-tl.8 ng/mg protein) (P<0.005). Since glucocorticoids and arginase are potent immune suppressive agents, the increased level of GR and arginase in gastric cancer tissue suggest that these glucocorticoid-related factors in gastric cancer tissue may play a partial role in regulating cellular immunity. Cancer 64:2552-2556, 1989. LINICALLY, glucocorticoids are frequently used as C immunosuppressive agents. It was reported' that glucocorticoid reduced circulating lymphocytes and monocytes, and suppressed the production of interleukin1 and interleukin-2. These actions were mediated through glucocorticoid receptors (GR) in the cell.* Liver extract possesses a potent inhibitory activity on lymphocyte pr~liferation.~-' The effect is predominantly mediated by arginase,' which has been shown to inhibit the proliferation of both T-lymphocytes and B-lymphocytes. The inhibition was dose-related, reversible and noncytoto~ic.~ Using immunohistochemical methods, we have demonstrated that arginase existed abundantly in the cytoplasm of gastric cancer cells, as compared to that in the cells of normal gastric mucosa." This may partly account for the depressed cellular immunity in gastric cancer patients. Both glucocorticoid and arginase are immunosuppressive in nature. In this study, the possible interrelation of glucocorticoid and arginase in the gastric cancer tissue was investigated. Both the GR and arginase levels were