| It is also reported that continuous ischemia–reperfusion (I/R) promotes livermetastasis of colon cancer and HCC. Hepatic I/R promotes the release of cytokinesand adhesive molecules. Toll like receptor9(TLR9) is one of TLRs. TLR9blockadein mice resulted in less hepatic I/R injury. So we want to know whether blockade ofTLR9signaling can attenuate the ischemia/reperfusion promoting the release ofcytokines and adhesive molecules, then reduces the tumor metastasia and growthafter ischemia and reperfusion.Objective: To investigate the role and mechanism of the tumor metastasis andgrowth after ischemia/referfusion with blockade of toll-like receptor9signalingpathway.Method:1. Approximately70%hepatic ischemia/reperfusion and H22intrahepatic metastasis model were estabalished. The animals were divided into fourgroups. Briefly, group1: sham operation; group2:15min ischemia; group3:30minischemia; group4:45min ischemia; tumor cell were injected after liver I/R. Tumorgrowth and metastases were evaluated with hepatic replacement area (HRA) at14days after surgery. Mice survival time was observed.2. The animals were divided into four groups. Group A: Control ODN+sham.Group B: iCpG+sham; Group C: Control ODN+I/R. Group D: iCpG+I/R; then tumorcells were injected after hepatic I/R. Tumor growth and metastases were evaluatedwith HRA at14days after surgery. Mice survival time was observed. The expressionof ICAM-1and E-selectin, HIF-1α and ROCK-2mRNA in liver tissue was tested.The activity of NF-kB was carried by EMSA. The serum levels of ALT were testedThe protein expression of E-selectin and ICAM-1in the liver tissue was examined.Serum levels of sICAM-1and TNF-α were examined.Result:1. In those mice subjected to30and45min of70%hepatic I/R, there isa significant HRA increase, lower survival time and higher ALT levels when compared with mice receiving tumor injection and laparotomy alone.2. I/Rcan increase the value of hepatic replacement area (HRA), which can beinhibited by iCpG. I/R can reduce the survival time of mice with tumor, which can beprolonged by iCpG.3.(1) mRNA and protein levels of E-selectin and ICAM-1can be up-regulatedby ischemia/reperfusion. ICpG can inhibit the mRNA and protein expression ofE-selectin and ICAM-1after ischemia/reperfusion. The levels of HIF-1α andROCK-2mRNA can be up-regulated by ischemia/reperfusion.(2) The proteinexpression of TLR9has no difference between the four groups. The proteinexpression of MyD88was up-regulated after ischemia/reperfusion and was inhibitedby iCpG. DNA binding of NF-kB increased at2hours postreperfusion and could beinhibited by iCpG.(3) The serum levels of sICAM-1were elevated after24hours ofreperfusion and could be inhibited by iCpG. The serum levels of TNF-α wereelevated after24hours of reperfusion and also could be inhibited by iCpG. Theserum levels of TNF-α in sham operation group were down-regulated by iCpG at24hours after surgery.Conclusion:1. There were significant liver injury and increased tumor metastasis andgrowth after ischemia of more than30min. The mice with tumor cell injection had alower survival time after ischemia of more than30min.2. ICpG can reduce the liver ischemia/reperfusion injury. I/R can acceleratethe liver tumor intrahepatic metastasis and growth, which can be partly inhibited byiCpG.3. The protein expression of TLR9was not changed after ischemia/reperfusionand can not be down-regulated by iCpG. However, iCpG can inhibit the increasedexpression of MyD88after ischemia/reperfusion, and then inhibit the activity ofNF-κB. Also, iCpG can down-regulated the expression of E-selectin and ICAM-1after ischemia/reperfusion. So iCpG may inhibit the tumor metastasis and growthafter ischemia/reperfusion through down-regulating the expression of adhesionmolecules.
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