Gene networks related to the cell death elicited by hyperthermia in human oral squamous cell carcinoma HSC-3 cells

Local hyperthermia (HT) for various types of malignant tumors has shown promising antitumor effects. To confirm the detailed molecular mechanism underlying cell death induced by HT, gene expression patterns and gene networks in human oral squamous cell carcinoma (OSCC) cells were examined using a combination of DNA microarray and bioinformatics tools. OSCC HSC-3 cells were treated with HT at 44°C for 90 min or mild hyperthermia (MHT) at 42°C for 90 min, followed by culturing at 37°C for 0-24 h. Treatment of cells with HT prevented cell proliferation (62%) and induced cell death (17%), whereas these alterations were not observed in cells treated with MHT. Microarray analysis revealed substantial differences with respect to gene expression patterns and biological function for the two different hyperthermic treatments. Moreover, we identified the temperature-specific gene networks D and H that were obtained from significantly up-regulated genes in the HT and MHT conditions, respectively, using Ingenuity pathway analysis tools. Gene network D, which contains 14 genes such as ATF3, DUSP1 and JUN, was associated with relevant biological functions including cell death and cellular movement. Gene network H, which contains 13 genes such as BAG3, DNAJB1 and HSPA1B, was associated with cellular function and maintenance and cellular assembly and organization. These findings provide a basis for understanding the detailed molecular mechanisms of cell death elicited by HT in human OSCC cells.