54106

TLR9

toll-like receptor 9;TLR9;toll-like receptor 9

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3p21.3

protein-coding

The toll like receptor 9(TLR9) has been suggested to play an important role in the invasion and metastasis of cancer cells in vitro. However, the expression of TLR9 in human cancer specimens has never been characterized. In this study, we investigated the expression of TLR9 in breast cancer specimens and determined the association between its expression and the clinicopathological features observed. We found that TLR9 expression was significantly higher in patients with breast cancers displaying large tumor size (P = 0.040), lymph node metastasis (P < 0.001) or advanced pathological stage (P = 0.006). TLR9 expression was also increased in ER negative breast cancer specimens (P = 0.043). Logistic regression analysis revealed that pathological stage (P = 0.007) and TRL9 (P = 0.001) expression were independent factors that influenced axillary lymph node metastasis of breast cancer. Patients with positive TLR9 expression had a higher progress free survival compared with the TLR9-negative cohort (P = 0.037). Therefore we concluded that Lymph node metastasis more likely occur in breast cancer patients with a positive TLR9 status and its expression might serve as an indicator of poor prognosis in patients with breast cancer.

CpG-oligonucleotides (CpG-ODN), which induce signaling through Toll-like receptor 9 (TLR9), are widely used as adjuvants in therapy against cancer. However, tumor cells express functional TLR9 were recently reported and the immune effect of CpG ODN on tumor cells remains unclear. Here we investigated the direct effects of CpG ODN on human tumor cell line 95D cells using flow cytometric analysis and Western blotting. We found strongly high expression of TLR9 in 95D cells. Stimulation of 95D cells with CpG ODN induced significantly elevated secretion of IL-1alpha and IL-8, as well as the expression of CXCR4, ICAM-1 and MMP-2. Furthermore, the invasion of 95D cells and TLR9 modifying 95C cells were significantly enhanced by stimulation of CpG ODN, which could be abrogated by inhibitory CpG ODN and chloroquine. These results suggest that functionally active TLR9 is expressed on human tumor cell lines, and may represent a novel insight on the role of TIL9 agonist used in tumor immunotherapy.

AIM: To determine the expression of toll-like receptor 9 (TLR9) in pancreatic tumor and the effects of cytosine phosphate-guanosine oligodeoxynucleotides 2216 (CPG ODN2216) on biological behavior of pancreatic carcinoma cell line PANC-1 and explore their clinical significance. METHODS: The immunohistochemistry and Western blot were used to determine the expression of TLR9 protein in pancreatic cancer tissues, and immunofluorescence staining was performed to detect the TLR9 protein expression in pancreatic carcinoma cell line PANC-1. To assess the effects of CPG ODN2216 on the invasive property of Panc-1 cells, in vitro cell adhesion, wound-healing scrape, and invasion and cell colony formation were evaluated. RESULTS: TLR9 was highly expressed in pancreatic cancer tissues and PANC-1 cells. The percentage of positive cells expressing TLR9 protein in human pancreatic tissues, paracancerous tissues and normal tissues were 73.3%, 33.3% and 20.0%, respectively, and the protein expression level of TLR9 was gradually descending (P < 0.05). In vitro tests in wound-healing scrape, cell adhesion, colony formation and matrigel invasion showed that the adhesion and motility of PANC-1 cells in CPG ODN 2216 treatment group were significantly lower than in the control group (P < 0.05). The cell growth assay showed that the proliferative ability of PANC-1 cells in treatment group was significantly decreased and CPG ODN2216 had an inhibitive effect in the growth of Panc-1 cells in a dose and time-dependent manner (P < 0.05). CONCLUSION: The gene of TLR9 is correlated with the invasive and metastatic potential of human pancreatic carcinoma, and CPG ODN2216 induces the inhibition of migration and invasion of Panc-1 cells.

CpG-oligonucleotides (CpG-ODNs), mimicking bacterial DNA, have recently been shown to stimulate prostate cancer invasion in vitro via Toll-like receptor 9 (TLR9). Since cyclooxygenase 2 (COX-2), frequently overexpressed in multiple tumor types including prostate cancer, is a causal factor for tumor development, invasion and metastasis, an interesting question is raised whether TLR9 regulates COX-2 expression in prostate cancer cells. To address this question, herein we examined COX-2 expression in PC-3 cells stimulated with different doses and time courses of CpG-ODNs. The regulatory role of NF-kappaB in TLR9-mediated COX-2 expression was also investigated. CpG-ODN was found to up-regulate the expression of COX-2 in PC-3 cells in a dose- and time-dependent manner, but have little impact on COX-1 expression. Moreover, CpG-ODN also promoted nuclear translocation and activation of NF-kappaB, which appeared to be required for COX-2 induction by CpG-ODN. Overall, TLR9 up-regulates COX-2 expression in prostate cancer cells, at least partially through the activation of NF-kappaB, which may be implicated in tumor invasion and metastasis.