Toll-Like Receptor 9 Mediates CpG Oligonucleotide–Induced Cellular Invasion
| Autor: | Sonja C. Brooks, David E. Graves, Arja Jukkola-Vuorinen, Savita Wakchoure, Eeva Rahko, Li Li, Katri S. Selander, Kevin W. Harris, Joanna M. Ilvesaro, Katri S. Vuopala, Melinda A. Merrell |
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| Rok vydání: | 2008 |
| Předmět: |
Cancer Research
Molecular Sequence Data Breast Neoplasms chemical and pharmacologic phenomena Biology Mice Breast cancer medicine Animals Humans Neoplasm Invasiveness Molecular Biology Genes Dominant TNF Receptor-Associated Factor 6 Base Sequence Nucleic Acid Heteroduplexes TLR9 Cancer hemic and immune systems Methylation DNA Methylation medicine.disease Molecular biology Toll-Like Receptor 9 Oligodeoxyribonucleotides Oncology CpG site Knockout mouse Cancer research Nucleic Acid Conformation Female Tumor necrosis factor alpha |
| Zdroj: | Molecular Cancer Research. 6:1534-1543 |
| ISSN: | 1557-3125 1541-7786 |
| Popis: | Toll-like receptor 9 (TLR9) belongs to the innate immune system and recognizes microbial and vertebrate DNA. We showed previously that treatment with the TLR9-agonistic ODN M362 (a CpG sequence containing oligonucleotide) induces matrix metalloproteinase-13–mediated invasion in TLR9-expressing human cancer cell lines. Here, we further characterized the role of the TLR9 pathway in this process. We show that CpG oligonucleotides induce invasion in macrophages from wild-type C57/B6 and MyD88 knockout mice and in human MDA-MB-231 breast cancer cells lacking MyD88 expression. This effect was significantly inhibited in macrophages from TLR9 knockout mice and in human MDA-MB-231 breast cancer cells stably expressing TLR9 small interfering RNA or dominant-negative tumor necrosis factor receptor-associated factor 6 (TRAF6). Sequence modifications to the CpG oligonucleotides that targeted the stem loop and other secondary structures were shown to influence the invasion-inducing effect in MDA-MB-231 cells. In contrast, methylation of the cytosine residues of the parent CpG oligonucleotide did not affect the TLR9-mediated invasion compared with the unmethylated parent CpG oligonucleotide. Finally, expression of TLR9 was studied in clinical breast cancer samples and normal breast epithelium with immunohistochemistry. TLR9 staining localized in epithelial cells in both cancer and normal samples. The mean TLR9 staining intensity was significantly increased in the breast cancer cells compared with normal breast epithelial cells. In conclusion, our results suggest that TLR9 expression is increased in breast cancer and CpG oligonucleotide–induced cellular invasion is mediated via TLR9 and TRAF6, independent of MyD88. Further, our findings suggest that the structure and/or stability of DNA may influence the induction of TLR9-mediated invasion in breast cancer. (Mol Cancer Res 2008;6(10):1534–43) |
| Databáze: | OpenAIRE |
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