3606

IL18

interleukin 18;IL18;interleukin 18

IFN-gamma-inducing factor|IL-1 gamma|iboctadekin|interleukin 18 (interferon-gamma-inducing factor)|interleukin-1 gamma|interleukin-18

11q22.2-q22.3

protein-coding

AIM: To explore the effect of intratumoral expressions of interleukin-12 (IL-12) and interleukin-18 (IL-18) on clinical features, angiogenesis and prognosis of gastric carcinoma. METHODS: The expressions of IL-12 and IL-18 from 50 samples of gastric cancer tissue were analyzed by immunohistochemistry, and microvessel density (MVD) was determined with microscopic imaging analysis system. RESULTS: The positive expression rates of IL-12 and IL-18 were 44% (22/50) and 26% (13/50), respectively. IL-12 was significantly associated with pathologic differentiation, depth of invasion, lymph node metastasis, distant metastasis, and TNM stage, and IL-18 was closely related to distant metastasis. Intratumoral IL-12 and IL-18 expressions were not statistically related to MVD scoring. IL-12-positive patients survived significantly longer than those with IL-12-negative tumors, but there was no significant difference between IL-18-positive patients and IL-18-negative ones. The multivariate analysis with Cox proportional hazard model revealed IL-12, MVD and T stage were independent prognostic factors. CONCLUSION: The positive expressions of IL-12 and IL-18 can play an important role in progression and metastasis of gastric cancer, and IL-12 might be an independent factor of poor prognosis in gastric carcinoma.

IL-18 is an immune-stimulating cytokine that promotes experimental melanoma metastasis via vascular endothelial growth factor (VEGF)-induced very late antigen (VLA)-4. We studied genes associated with the ability of melanoma cells to allow metastasis under IL-18 effects, and we verified their expression in metastatic lesions from patients with melanoma. Human melanoma cell lines with and without the IL-18 receptor (IL-18R)/VEGF/VLA-4-expressing phenotype were identified, and their metastatic potential was studied in nude mice. RNA from untreated and IL-18-treated melanoma phenotypes was hybridized to a cDNA microarray, and their signature genes were studied. RNA from primary and metastatic lesions from patients with melanoma was hybridized to a cDNA microarray to identify lesions with the transcript patterns of melanoma cells with and without the IL-18R/VEGF/VLA-4 phenotype. IL-18R/VEGF/VLA-4-expressing A375 and 1182 melanoma cells produced a higher metastasis number than 526 and 624.28 melanoma cells, not using this prometastatic pathway. Melanoma cells with and without the IL-18R/VEGF/VLA-4 phenotype had distinct transcript patterns. However, the type I transcriptional cluster, including cutaneous and lymph node metastases, but not the type II cluster, not including cutaneous metastases, had signature genes from IL-18-treated melanoma cells with, but not without, the IL-18R/VEGF/VLA-4 phenotype. metastatic melanoma lesions with and without IL-18-dependent genes were identified, suggesting that melanoma metastasis developed via inflammation-dependent and inflammation-independent mechanisms. Signature genes from melanomas with and without the IL-18R/VEGF/VLA-4 phenotype may serve as diagnostic biomarkers of melanoma predisposition to prometastatic effects of IL-18.

It is known that the relationship between pro-angiogenic and anti-angiogenic factors is responsible for the presence and intensity of neoangiogenesis. The angiogenic factors are produced by tumour cells and/or by tumour-infiltrating inflammatory cells such as macrophages or polymorphonuclear leukocytes (PMN). In the present study we compared VEGF secretion with IL-18 and NO release by PMN derived from oral cavity cancer patients. Knowledge of the relationship between mediators above could help in better understanding the role of PMN in angiogenesis in this patient group. The results from culture supernatants of PMN were confronted with the serum levels of parameters examined. We found an interesting relationship between VEGF and IL-18 concentrations in the culture supernatants of PMN derived from patients with oral cavity cancer. High production of VEGF was associated with low production of IL-18 by PMN derived from patients before treatment. During examinations after treatment we found lower concentrations of VEGF and higher concentrations of IL-18 than those in the study before treatment. In contrast to VEGF and IL-18, the NO production by PMN of cancer patients, before and after treatment, was unchanged. We also demonstrated markedly elevated serum levels of VEGF as well as IL-18 according to the progression of the disease. Results obtained indicate that relations between VEGF and IL-18 released by PMN may promote neoangiogenesis and may be important for benign tumour cells to acquire metastatic phenotype in the early stage of oral cavity cancer. Furthermore, our results suggest that the concentrations of VEGF and IL-18 in the serum are sensitive tumour markers in this patient group before and after treatment.