Mohan Chakrabhavi Dhananjaya, Bharathkumar Hanumantharayappa, Rangappa Shobith, Shanmugam Muthu K, Chinnathambi Arunachalam, Alharbi Sulaiman Ali, Alahmadi Tahani Awad, Bhattacharjee Atanu, Lobie Peter E, Deivasigamani Amudha, Hui Kam Man, Sethi Gautam, Rangappa Kanchugarakoppal S, Kumar Alan Prem
Department of Studies in Molecular Biology, University of Mysore, Mysore, India.
Laboratory of Chemical Biology, Department of Chemistry, Bangalore University, Bangalore, India.
Front Pharmacol. 2018 Nov 5;9:1125. doi: 10.3389/fphar.2018.01125. eCollection 2018.
Hepatocellular carcinoma (HCC) is a fatal disease and ranked fifth in cancer related mortality. Persistent activation of NF-κB is responsible for the oncogenesis, metastasis, tumor evasion, anti-apoptosis, angiogenesis and proliferation in HCC. Therefore, designing of chemically novel, biologically potent small molecules that target NF-κB signaling cascade have gained prominent clinical interest. Herein we synthesized a novel class of 4-(substituted)-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one by reacting 2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one with various alkyl halides by using combustion derived bismuth oxide. We evaluated the antiproliferative efficacy of newly synthesized compounds against HCC cells and identified 4-(4-nitrobenzyl)-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one (NPO) as lead anticancer agent. In addition, we investigated the effect of NPO on the DNA binding ability of NF-κB and NF-κB regulated luciferase expression in HCC cells. The results demonstrated that NPO can induce significant growth inhibitory effects in HepG2, HCCLM3 and Huh-7 cells in dose and time-dependent manner. Interestingly, NPO induced significant downregulation in p65 DNA binding ability, p65 phosphorylation and subsequent expression of NF-κB dependent luciferase gene expression in diverse HCC cell lines. Further, docking analysis suggested that NPO can show direct physical interaction with NF-κB. Finally, NPO was found to significantly abrogate tumor growth at a dose of 50 mg/kg in an orthotopic mouse model. Thus, we report the potential anticancer effects of NPO as a novel inhibitor of NF-κB signaling pathway in HCC.
肝细胞癌（HCC）是一种致命疾病，在癌症相关死亡率中排名第五。NF-κB的持续激活与HCC的肿瘤发生、转移、肿瘤逃逸、抗凋亡、血管生成和增殖有关。因此，设计针对NF-κB信号级联的化学结构新颖、生物活性强的小分子已引起了显著的临床关注。在此，我们通过燃烧衍生的氧化铋使2H-吡啶并[3,2-b][1,4]恶嗪-3(4H)-酮与各种卤代烃反应，合成了一类新型的4-(取代)-2H-吡啶并[3,2-b][1,4]恶嗪-3(4H)-酮。我们评估了新合成化合物对HCC细胞的抗增殖效果，并确定4-(4-硝基苄基)-2H-吡啶并[3,2-b][1,4]恶嗪-3(4H)-酮（NPO）为主要抗癌剂。此外，我们研究了NPO对HCC细胞中NF-κB的DNA结合能力和NF-κB调节的荧光素酶表达的影响。结果表明，NPO能以剂量和时间依赖性方式在HepG2、HCCLM3和Huh-7细胞中诱导显著的生长抑制作用。有趣的是，NPO在多种HCC细胞系中诱导p65 DNA结合能力、p65磷酸化以及随后NF-κB依赖性荧光素酶基因表达的显著下调。此外，对接分析表明NPO可与NF-κB表现出直接的物理相互作用。最后，在原位小鼠模型中发现NPO在50 mg/kg剂量下能显著抑制肿瘤生长。因此，我们报道了NPO作为HCC中NF-κB信号通路的新型抑制剂的潜在抗癌作用。
