Abstract
Background It has been reported lately that Toll-like receptors (TLRs) play an essential role in the activation of innate immunity, and TLRs are expressed in a large number of immune cells like B-lymphocytes, monocytes, plasmacytoid dendritic cells and at low levels in human respiratory cells as well as epithelial cells. In the present study, we investigated whether there is a relationship between the expression of TLR4 or TLR9 and the clinical or pathological changes in human lung cancer. Method Protein expression of TLR4 and TLR9 was assessed by using immunohistochemistry and western blotting. mRNA expressions of TLR4 and TLR9 were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results High TLR4 and TLR9 mRNA signal intensity was found in the majority of lung cancer specimens. In contrast, tumor-free lung tissue showed lower signal intensity. Consistently, the low amount of TLR4 and TLR9 protein expression was found in tumor-free lung tissue, while they were strongly expressed in lung cancer tissue. In addition, we found for the first time that the differentiation degree of tumor cells was positively correlated with the expression level of TLR4. There was no relationship between the expressions of TLR4 or TLR9 and patients’ age, gender, smoking, the histological type of tumor, lymph node metastasis, and tumor node metastases (TNM) stage. Conclusions We found that both mRNA and protein levels of TLR4 and TLR9 were strongly expressed in lung cancer tissue. In addition, we reported for the first time a positive correlation between the expression level of TLR4 and malignancy of lung cancer. These results suggested that TLR4 and TLR9 may be involved in the development of lung cancer which may have the potentials for the treatment of this malignant tumor.
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Abbreviations
- TLR:
-
Toll-like receptor
- TNM:
-
Tumor node metastases
- LRR:
-
Leucine-rich repeat
- TIR:
-
Toll/IL-1 receptor
- PAMP:
-
Pathogen associated molecular patterns
- dsRNA:
-
Double-stranded RNA
- AP-1:
-
Activator protein-1
- NF-κB:
-
Nuclear factor-κB
- LPS:
-
Lipopolysaccharide
- CpG-ODN:
-
Cytidylyl phosphate guanosine oligodeoxynucleoside
- CXCR:
-
CXC chemokine receptor
- IL-8:
-
Interleukin-8
- CTL:
-
Cytotoxicity lymphocyte
- DC:
-
Dendritic cells
- NSCLC:
-
Non-small cell lung carcinoma
References
Hashimoto C, Hudson KL, Anderson KV (1988) The Toll gene of Drosophila, required for dorsal-ventral embryonic polarity, appears to encode a transmembrane protein. Cell 52:269–279. doi:10.1016/0092-8674(88)90516-8
Lemaitre B, Nicolas E, Michaut L, Reichhart JM, Hoffmann JA (1996) The dorsoventral regulatory gene cassette spatzle/Toll/cactus controls the potent antifungal response in Drosophila adults. Cell 86:973–983. doi:10.1016/S0092-8674(00)80172-5
Beutler B, Rehli M (2002) Evolution of the TIR, tolls and TLRs: functional inferences from computational biology. Curr Top Microbiol Immunol 270:1–21
Bell JK, Mullen GE, Leifer CA, Mazzoni A, Davies DR, Segal DM (2003) Leucine-rich repeats and pathogen recognition in Toll-like receptors. Trends Immunol 24:528–533. doi:10.1016/S1471-4906(03)00242-4
O’Neill LA (2002) Signal transduction pathways activated by the IL-1 receptor/Toll-like receptor super family. Curr Top Microbiol Immunol 270:47–61
Takeda K, Kaisho T, Akira S (2003) Toll-like receptors. Annu Rev Immunol 21:335–376. doi:10.1146/annurev.immunol.21.120601.141126
Alexopoulou L, Holt AC, Medzhitov R, Flavell RA (2001) Recognition of double-stranded RNA and activation of NF-kappaB by Toll-like receptor 3. Nature 413:732–738. doi:10.1038/35099560
Hayashi F, Smith KD, Ozinsky A, Hawn TR, Yi EC, Goodlett DR et al (2001) The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature 410:1099–1103. doi:10.1038/35074106
Schmaußer B, Andrulis M, Endrich S, Müller-Hermelink HK, Eck M (2005) Toll-like receptors TLR4, TLR5 and TLR9 on gastric carcinoma cells: an implication for interaction with Helicobacter pylori. Int J Med Microbiol 295:179–185. doi:10.1016/j.ijmm.2005.02.009
Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193(1):265–275
Hemmi H, Takeuchi O, Kawai T, Kaisho T, Sato S, Sanjo H et al (2000) A Toll-like receptor recognizes bacterial DNA. Nature 408:740–745. doi:10.1038/35047123
Muzio M, Natoli G, Saccani S, Levrero M, Mantovani A (1998) The human toll signaling pathway: divergence of nuclear factor-kappaB and JNK/SAPK activation upstream of tumor necrosis factor receptor-associated factor 6 (TRAF6). J Exp Med 187:2097–2101. doi:10.1084/jem.187.12.2097
Coussens LM, Werb Z (2002) Inflammation and cancer. Nature 420:860–867. doi:10.1038/nature01322
Li L (2004) Regulation of innate immunity signaling and its connection with human diseases. Curr Drug Targets Inflamm Allergy 3:81–86. doi:10.2174/1568010043483863
Barton GM, Medzhitov R (2002) Toll-like receptors and their ligands. Curr Top Microbiol Immunol 270:81–92
Takeda K, Akira S (2001) Roles of Toll-like receptors in innate immune responses. Genes Cells 6:733–742. doi:10.1046/j.1365-2443.2001.00458.x
Akira S, Hemmi H (2003) Recognition of pathogen-associated molecular patterns by TLR family. Immunol Lett 85:85–95. doi:10.1016/S0165-2478(02)00228-6
Droemann D, Albrecht D, Gerdes J, Branscheid D, Vollmer E (2005) Human lung cancer cells express functionally active Toll-like receptor 9. Respir Res 6:1. doi:10.1186/1465-9921-6-1
Diamond G, Legarda D, Ryan LK (2000) The innate immune response of the respiratory epithelium. Immunol Rev 173:27–38. doi:10.1034/j.1600-065X.2000.917304.x
Medzhitov R (2001) Toll-like receptors and innate immunity. Nat Rev Immunol 1:135–145. doi:10.1038/35100529
Alexopoulou L, Holt AC, Medzhitov R, Flavell RA (2001) Recognition of double-stranded RNA and activation of NF-kappaB by Toll-like receptor 3. Nature 413:732–738. doi:10.1038/35099560
Yamamoto M, Takeda K, Akira S (2004) TIR domain-containing adaptors define the specificity of TLR signaling. Mol Immunol 40:861–868. doi:10.1016/j.molimm.2003.10.006
Bohnhorst J, Rasmussen T, Moen SH, Fløttum M, Knudsen L, Børset M et al (2006) Toll-like receptors mediate proliferation and survival of multiple myeloma cells. Leukemia 20:1138–1144. doi:10.1038/sj.leu.2404225
Guillot L, Medjane S, Le-Barillec K, Balloy V, Danel C, Chignard M et al (2004) Response of human pulmonary epithelial cells to lipopolysaccharide involves Toll-like receptor 4 (TLR4)-dependent signaling pathways. J Biol Chem 279:2712–2718. doi:10.1074/jbc.M305790200
Platz J, Beisswenger C, Dalpke A, Koczulla R, Pinkenburg O, Vogelmeier C et al (2004) Microbial DNA induces a host defense reaction of human respiratory epithelial cells. J Immunol 173:1219–1223
Oshikawa T, Okamoto M, Tano T, Sasai A, Kan S, Moriya Y, Ryoma Y, Saito M, Akira S, Sato M (2006) Antitumor effect of OK-432-derived DNA: one of the active constituents of OK-432, a streptococcal immunotherapeutic agent. J Immunother 29(2):143–150
Acknowledgments
This work was supported by foundations. We would like to thank Mr. J Liu and D-B Wang for their excellent technical assistants. We would like to thank Dr. Jiang-Ning Zhou from University of Science and Technology of China for support. We also would like to thank Charlean Luellen from University of Tennessee Health Science Center, Memphis Department of Medicine.
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Zhang, YB., He, FL., Fang, M. et al. Increased expression of Toll-like receptors 4 and 9 in human lung cancer. Mol Biol Rep 36, 1475–1481 (2009). https://doi.org/10.1007/s11033-008-9338-9
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DOI: https://doi.org/10.1007/s11033-008-9338-9