Interleukin-6 overexpression as a marker of malignancy in human gliomas

Object. Glioblastomas multiforme (GBMs) grow rapidly and are highly resista nt to treatment compared with other glioma types and grades. Consequently, it is of major interest to identify markers of aggressiveness in these tumo rs that could represent new therapeutic targets. Interleukin (IL)-6 is freq uently produced in gliomas and, given its manifold properties, could be con sidered as a candidate marker. Expression of IL-6 may be involved in cell g rowth, resistance to chemotherapy and radiotherapy (via an antiapoptotic pa thway), and angiogenesis. This study was conducted to test this hypotheses and to evaluate the suitability of IL-6 as a target in the treatment of GBM s. Methods. The authors studied the relationship between the level of IL-6 gen e expression as assessed using semiquantitative reverse transcription-polym erase chain reaction and by determining various histological types and grad es in a series of 59 gliomas. It was found that GBMs displayed a significan tly higher level of IL-6 expression than other types of glioma (p < 0.001). Immunohistochemical analysis revealed that IL-6 was produced mainly by mal ignant cells and a few vascular endothelial cells. Conclusions. It can be i nferred from these findings that IL-6 gene expression is related to glioma aggressiveness and that IL-6 may play a central role in GEM behavior. Inter leukin-6, therefore, could be considered as a new potential target in the t reatment of GBMs.