Tumor necrosis factor-alpha mediates hyperthermia-induced glioma invasiveness decreases

Background: Thermotherapy has already been proved effective for the treatment of various tumors, including glioma.This study was performed to determine whether tumor necrosis factor-alpha was involved in the regulation of this biological process. Methods: RT-PCR and immunocytochemistry were used to investigate the levels of tumor necrosis factor-alpha mRNA and heat shock factor-1 protein, respectively, in glioma cells. Radioimmunoassay was used to dynamically monitor contents of TNF-α in nutrient fluid for C6 cells after hyperthermia treatment. Crystal violet staining method was used to detect glioma invasiveness. Results: The most obvious increase of heat shock factor-1 protein and tumor necrosis factor-alpha mRNA in C6cells were observed at 30 min and 60 min after hyperthermia, respectively. In addition, the radioactivity of tumor necrosis factor-alpha in C6 cells’ culture fluid also reached peak at 120 min of hyperthermia. The glioma invasiveness decreases and the concentration of tumor necrosis factor-alpha reached the maximum at 120 min of hyperthermia. Conclusion: Our results showed that the hyperthermia-mediated glioma invasiveness decreases was due to accelerated release of tumor necrosis factor-alpha,which could cause the decreases of glioma invasiveness by promoting the release heat shock factor-1 from neurospongioma cells.