Reduced tumorigenicity of human gastric carcinoma cells engineered to produce IL-2 in SCID mice reconstituted with peripheral blood cells from cancer patients

Concise review: humanized models of tumor immunology in the 21st century: convergence of cancer research and tissue engineering

Despite positive testing in animal studies, more than 80% of novel drug candidates fail to proof their efficacy when tested in humans. This is primarily due to the use of preclinical models that are not able to recapitulate the physiological or pathological processes in humans. Hence, one of the key challenges in the field of translational medicine is to "make the model organism mouse more human." To get answers to questions that would be prognostic of outcomes in human medicine, the mouse's genome can be altered in order to create a more permissive host that allows the engraftment of human cell systems. It has been shown in the past that these strategies can improve our understanding of tumor immunology. However, the translational benefits of these platforms have still to be proven. In the 21st century, several research groups and consortia around the world take up the challenge to improve our understanding of how to humanize the animal's genetic code, its cells and, based on tissue engineering principles, its extracellular microenvironment, its tissues, or entire organs with the ultimate goal to foster the translation of new therapeutic strategies from bench to bedside. This article provides an overview of the state of the art of humanized models of tumor immunology and highlights future developments in the field such as the application of tissue engineering and regenerative medicine strategies to further enhance humanized murine model systems.

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

Interleukin-1 receptor antagonist (IL-1ra), an endogeneous inhibitor of IL-1, plays an immunosuppressive role in vivo by blocking the proinflammatory effects of IL-1. In the present study, we examined whether IL-1ra expression in human gastric carcinoma correlates with tumor progression and/or metastatic potential. The reverse transcription-polymerase chain reaction was used to compare the expression of the secreted form of IL-1ra (sIL-1ra) and the intracellular form of IL-1ra (icIL-1ra) mRNA in tumor and corresponding benign tissue obtained from 38 patients with gastric carcinoma. The incidence 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 metastasis (P = 0.008) and liver metastasis (P = 0.015). There was no association between tumor sIL-lra mRNA expression and other clinicopathologic factors. The degree of regional lymph node reaction, such as sinus histiocytosis, in tumors expressing sI-1ra mRNA was significantly weaker than that in tumors without sIL-1ra mRNA expression (5/20 vs. 12/18, P = 0.010). These results demonstrate that the altered expression of sIL-1ra by malignant tissue may be related to the progression of gastric carcinoma via modulating host immune response.