Department of Medical Biology, Faculty of Medicine, Sakarya University, Sakarya, Turkey.
Department of Medical Biology, Faculty of Medicine, Gazi University, Ankara, Turkey.
Immunopharmacol Immunotoxicol. 2020 Apr;42(2):93-100. doi: 10.1080/08923973.2020.1725040. Epub 2020 Feb 12.
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. 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. 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. 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.
Toll 样受体 (TLRs) 通常在天然免疫细胞以及肿瘤细胞中表达。TLR4 具有促进肿瘤和抑制肿瘤的双重作用，TLR9 表达升高是前列腺癌 (PCa) 预后不良的重要标志物。川陈皮素 (NOB) 是一种 O-甲基化黄酮，已被证明对 PCa 细胞具有抗癌作用。然而，目前文献中尚无研究探讨 NOB 对 TLR 信号通路在癌症中的潜在抗炎作用。因此，我们旨在首次探讨 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。在本研究中，通过 WST-1 检测评估了 NOB 对 PC-3（非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 blot 和 ELISA 分析测定了 NOB 对 TLR4/TRIF/IRF3 和 TLR9/IRF7 信号通路的抑制作用。NOB 对 PCa 细胞生长具有抑制作用，并且由于雄激素受体状态，LNCaP 细胞比 PC-3 细胞对 NOB 更敏感。此外，与 LPS 或 CpG-ODN 刺激的 PCa 细胞相比，NOB 单独作用可通过下调相关途径（mRNA 和相关蛋白水平）以及 IFN-α 和 IFN-β 的释放来抑制 TLR4/TRIF/IRF3 和 TLR9/IRF7 信号通路。NOB 可能抑制 PCa 细胞中 TLR4 和 TL9 依赖性信号通路。然而，由于激素状态和侵袭性特征，NOB 在 PCa 细胞中的疗效不同。
