CXCR4/SDF-1 pathway is crucial for TLR9 agonist enhanced metastasis of human lung cancer cell.

Accumulating data suggested that CXCR4/SDF-1 pathway may play an important role in the metastasis of tumor. We previously demonstrated that CpG ODN could enhance the metastasis of human lung cancer cell via TLR9. Here we further evaluated the possible role of CXCR4/SDF-1 pathway in the enhanced metastasis of human lung cancer 95D cells induced by CpG ODN. Our data showed down-regulation of CXCR4 expression using siRNA against CXCR4 could significantly reduce the enhanced metastasis of 95D cells induced by CpG ODN both in vitro and in vivo. These results suggested that TLR9 agonist might promote the metastasis of human lung cancer cells via CXCR4/SDF-1 pathway.