Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
Oncol Res. 2010;18(11-12):529-35. doi: 10.3727/096504010x12767359113721.
NF-kappaB is a transcription factor that induces the expression of inflammatory cytokines and antiapoptotic proteins. Earlier we designed a new NF-kappaB inhibitor, (-)-DHMEQ, and showed that it had potent anticancer and anti-inflammatory activities in various animal models without any toxicity. In the present research, we studied whether (-)-DHMEQ could be efficiently taken by cultured cells and irreversibly inhibit NF-kappaB by short time application to cultured cells. Even after mouse monocytic leukaemia RAW264.7 cells had been washed free of (-)-DHMEQ, lipopolysacharide (LPS)-induced activation of NF-kappaB in these cells was still inhibited. Moreover, topical application for 15 min was found to induce dormancy of the cells against LPS for 2-8 h. When it was topically added to RAW264.7 cells in which NF-kappaB was activated by LPS, the inhibition lasted at least for 2 h. NF-kappaB derectly upregulates expression of iNOS that produces NO. Short time application of (-)-DHMEQ also inhibited the function of cells in terms of NO production and iNOS induction in RAW264.7 cells. Thus, the fast incorporation of (-)-DHMEQ into the cells and irreversible inhibition of NF-kappaB by it were demonstrated, and this observation would explain its effective inhibition of certain functions in cellular and animal disease models.
NF-κB 是一种转录因子，可诱导炎症细胞因子和抗凋亡蛋白的表达。我们之前设计了一种新型 NF-κB 抑制剂（-）-DHMEQ，并在各种动物模型中证明其具有强大的抗癌和抗炎活性，且无任何毒性。在本研究中，我们研究了（-）-DHMEQ 是否可以被培养的细胞有效摄取，并通过短时间应用于培养的细胞来不可逆地抑制 NF-κB。即使在去除（-）-DHMEQ 后，脂多糖（LPS）仍能诱导 RAW264.7 细胞中的 NF-κB 激活。此外，我们发现 15 分钟的局部应用可诱导细胞对 LPS 的休眠 2-8 小时。当将其局部添加到 LPS 激活的 RAW264.7 细胞中时，抑制作用至少持续 2 小时。NF-κB 直接上调诱导型一氧化氮合酶（iNOS）的表达，从而产生 NO。（-）-DHMEQ 的短时间应用也抑制了 RAW264.7 细胞中 NO 产生和 iNOS 诱导的细胞功能。因此，证明了（-）-DHMEQ 快速掺入细胞并不可逆地抑制 NF-κB 的功能，这一观察结果可解释其在细胞和动物疾病模型中有效抑制某些功能的原因。
