Interleukin-1 receptor antagonist mRNA expression and the progression of gastric carcinoma

Interleukin-l receptor antagonist (IL-1ra), an endogeneous inhibitor of IL- l, plays an immunosuppressive role in vivo by blocking the proinflammatory effects of IL-1. In the present study, we examined whether IL-1ra expressio n in human gastric carcinoma correlates with tumor progression and/or metas tatic potential, The reverse transcription-polymerase chain reaction was us ed to compare the expression of the secreted form of IL-1ra (sIL-1ra) and t he intracellular form of IL-1ra (icIL-1ra) mRNA in tumor and corresponding benign tissue obtained from 38 patients with gastric carcinoma. The inciden ce of sIL-1ra mRNA expression was significantly higher in tumor (52%) than in corresponding benign tissue (18%) (P = 0.002). On the contrary, icIL-1ra mRNA was detected in all tumors and benign tissues. The expression of sIL- 1ra mRNA by malignant tissue correlated positively with both lymph node met astasis (P = 0.008) and liver metastasis (P = 0.015). There was no associat ion between tumor sIL-1ra mRNA expression and other clinicopathologic facto rs. The degree of regional lymph node reaction, such as sinus histiocytosis , in tumors expressing sTL-1ra mRNA was significantly weaker than that in t umors without sIL-1ra mRNA expression (5/20 vs. 12/18, P = 0.010). These re sults demonstrate that the altered expression of sIL-1ra by malignant tissu e may be related to the progression of gastric carcinoma via modulating hos t immune response. (C) 1999 Elsevier Science Ireland Lid. All rights reserv ed.