Background: Toll-like receptors (TLRs) are often expressed in natural immune cells as well as in tumor cells. TLR4 exhibits both tumor promoting and tumor-suppressing roles and higher TLR9 expression is an important marker of poor prognosis in prostate cancer (PCa). Nobiletin (NOB) is an O-methylated flavonoid and NOB has been proven to have anti-cancer effect in PCa cells. However, there is no study in the literature investigating the potential anti-inflammatory effects of NOB on the TLR signaling pathways in cancer. Therefore, we aimed to explore the potential anti-inflammatory effects of NOB on the TLR4/TRIF/IRF3 and TLR9/IRF7 signaling pathways in different types of PCa cell lines, for the first time.Material and methods: In the current study, the cytotoxic effect of NOB PC-3 (hormone-independent and metastatic) and LNCaP cells (hormone-dependent) was evaluated by WST-1 assay. Furthermore, the inhibitory effects of NOB on TLR4/TRIF/IRF3 and TLR9/IRF7signaling pathway were determined by RT-PCR, western blotting and ELISA analysis.Results: NOB demonstrated an inhibitory effect on PCa cell growth and LNCaP cells were more sensitive to NOB than PC-3 cells due to androjen receptor status. Furthermore, NOB alone could suppress TLR4/TRIF/IRF3 and TLR9/IRF7 signaling pathways through the downregulation of their associated pathways (mRNA and related protein levels) and the release of IFN-α and IFN-β compared to LPS or CpG-ODN stimulated PCa cells.Conclusions: NOB potentially inhibited TLR4 and TL9-dependent signaling pathway in PCa cells. However, the efficacy of NOB was different in PCa cells due to the hormone status and aggressive features.

中文翻译：

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诺比列汀对前列腺癌细胞中TLR4 / TRIF / IRF3和TLR9 / IRF7信号通路的抗炎作用。

背景：Toll样受体（TLR）通常在天然免疫细胞以及肿瘤细胞中表达。TLR4同时具有促进肿瘤和抑制肿瘤的作用，而较高的TLR9表达是前列腺癌（PCa）预后不良的重要标志。Nobiletin（NOB）是一种O-甲基化的类黄酮，NOB已被证明对PCa细胞具有抗癌作用。但是，没有文献研究NOB对癌症中TLR信号通路的潜在抗炎作用。因此，我们旨在首次探索NOB对不同类型PCa细胞系中TLR4 / TRIF / IRF3和TLR9 / IRF7信号通路的潜在抗炎作用。材料与方法：在本研究中，通过WST-1分析评估NOB PC-3（激素依赖性和转移性）和LNCaP细胞（激素依赖性）的细胞毒性作用。此外，通过RT-PCR，western blotting和ELISA分析，确定了NOB对TLR4 / TRIF / IRF3和TLR9 / IRF7信号通路的抑制作用。结果：NOB对PCa细胞的生长具有抑制作用，而LNCaP细胞对NOB的敏感性更高。由于雄激素受体状态，PC-3细胞比PC-3细胞多。此外，与LPS或CpG-ODN刺激相比，单独的NOB可以通过下调其相关途径（mRNA和相关蛋白水平）以及释放IFN-α和IFN-β来抑制TLR4 / TRIF / IRF3和TLR9 / IRF7信号传导途径。结论：NOB可能抑制PCa细胞中TLR4和TL9依赖性信号通路。然而，