Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
Elife. 2024 Apr 3;12:RP87873. doi: 10.7554/eLife.87873.
The antibiotic heliomycin (resistomycin), which is generated from , has multiple activities, including anticancer effects. Heliomycin was first described in the 1960s, but its clinical applications have been hindered by extremely low solubility. A series of 4-aminomethyl derivatives of heliomycin were synthesized to increase water solubility; studies showed that they had anti-proliferative effects, but the drug targets remained unknown. In this study, we conducted cellular thermal shift assays (CETSA) and molecular docking simulations to identify and validate that heliomycin and its water-soluble derivative, 4-(dimethylaminomethyl)heliomycin (designated compound 4-dmH) engaged and targeted with sirtuin-1 (SIRT1) in p53-functional SAS and p53-mutated HSC-3 oral cancer cells. We further addressed the cellular outcome of SIRT1 inhibition by these compounds and found that, in addition to SIRT1, the water-soluble 4-dmH preferentially targeted a tumor-associated NADH oxidase (tNOX, ENOX2). The direct binding of 4-dmH to tNOX decreased the oxidation of NADH to NAD which diminished NAD-dependent SIRT1 deacetylase activity, ultimately inducing apoptosis and significant cytotoxicity in both cell types, as opposed to the parental heliomycin-induced autophagy. We also observed that tNOX and SIRT1 were both upregulated in tumor tissues of oral cancer patients compared to adjacent normal tissues, suggesting their clinical relevance. Finally, the better therapeutic efficacy of 4-dmH was confirmed in tumor-bearing mice, which showed greater tNOX and SIRT1 downregulation and tumor volume reduction when treated with 4-dmH compared to heliomycin. Taken together, our in vitro and in vivo findings suggest that the multifaceted properties of water-soluble 4-dmH enable it to offer superior antitumor value compared to parental heliomycin, and indicated that it functions through targeting the tNOX-NAD-SIRT1 axis to induce apoptosis in oral cancer cells.
抗生素赫利霉素（雷莫司汀）由 产生，具有多种活性，包括抗癌作用。赫利霉素于 20 世纪 60 年代首次被描述，但由于其极低的溶解度，其临床应用受到阻碍。一系列赫利霉素的 4-氨甲基衍生物被合成以增加水溶性；研究表明它们具有抗增殖作用，但药物靶点仍不清楚。在这项研究中，我们进行了细胞热转移分析（CETSA）和分子对接模拟，以鉴定和验证赫利霉素及其水溶性衍生物 4-（二甲氨基甲基）赫利霉素（命名为化合物 4-dmH）与 p53 功能 SAS 和 p53 突变 HSC-3 口腔癌细胞中的 SIRT1 结合和靶向。我们进一步研究了这些化合物对 SIRT1 抑制的细胞后果，发现除了 SIRT1 之外，水溶性 4-dmH 还优先靶向肿瘤相关的 NADH 氧化酶（tNOX，ENOX2）。4-dmH 与 tNOX 的直接结合降低了 NADH 向 NAD 的氧化，从而减少了 NAD 依赖性 SIRT1 脱乙酰酶活性，最终在两种细胞类型中诱导凋亡和显著的细胞毒性，而不是亲本赫利霉素诱导的自噬。我们还观察到，与相邻正常组织相比，口腔癌患者的肿瘤组织中 tNOX 和 SIRT1 均上调，提示其具有临床相关性。最后，在荷瘤小鼠中证实了 4-dmH 的更好治疗效果，与赫利霉素相比，用 4-dmH 治疗时，小鼠的 tNOX 和 SIRT1 下调更多，肿瘤体积更小。总之，我们的体外和体内研究结果表明，水溶性 4-dmH 的多方面特性使其比亲本赫利霉素具有更高的抗肿瘤价值，并表明它通过靶向 tNOX-NAD-SIRT1 轴在口腔癌细胞中诱导凋亡发挥作用。
