Hyperthermia synergizes with tissue factor knockdown to suppress the growth and hepatic metastasis of colorectal cancer in orthotopic tumor model

Background Tissue factor (TF) is a significant risk factor for tumor growth and hepatic metastasis in patients with colorectal cancer (CRC). This study aimed to investigate whether hyperthermia has synergistic anti-tumor effects with TF knockdown in suppressing CRC progression and metastasis in vitro and in vivo. Methods Human colorectal cancer LOVO cells were treated by hyperthermia at 44 degrees C for 2?hr or/and TF siRNA. Then the cells were subjected to colony formation assay. Apoptosis was analyzed by flow cytometry, confocal microscopy, and transmission electron microscopy. The cell migration and invasion abilities were analyzed by wound healing and matrigel assay. In addition, orthotopic nude mice model of CRC was established. Results Hyperthermia synergized with TF knockdown to reduce colony formation ability, induce apoptosis, and suppress the migration and invasion of LOVO cells in vitro. Moreover, hyperthermia in combination with TF depletion inhibited the growth and hepatic metastasis of CRC in orthotopic nude mice model. Mechanistically, the synergistic effects were at least partly mediated by inducing JNK mediated apoptosis and suppressing matrix metalloproteinases (MMPs) mediated invasion. Conclusions Hyperthermia in combination with TF-targeted therapy could be a potential approach for CRC treatment. J. Surg. Oncol. 2012; 106:689695. (c) 2012 Wiley Periodicals, Inc.