Research Centre of Siyuan Natural Pharmacy and Biotoxicology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China.
Joint Centre of Zhejiang University and the Chinese University of Hong Kong on Natural Products and Toxicology Research, Zhejiang University, Hangzhou, People's Republic of China.
Apoptosis. 2017 Mar;22(3):381-392. doi: 10.1007/s10495-016-1331-5.
3,5-Dimethyl-H-furo[3,2-g]chromen-7-one (DMFC) is a coumarin derivative with anti-cancer activity against human hepatoma cells, but the mechanisms underlying DMFC function in cancer suppression is unknown. In this study, we aimed at elucidating the molecular mechanisms underlying DMFC anti-cancer activity and determining whether DMFC is effective in suppression of drug-resistant human hepatocellular carcinoma. We show here that DMFC effectively suppresses both the parent and the multidrug-resistant hepatoma cell growth in vitro and DMFC suppresses hepatoma cell growth at least in part through inducing tumor cell apoptosis. In the molecular level, we observed that DMFC treatment decreases Bcl-2 level by a post-transcriptional mechanism and activates Bim transcription to increase Bim mRNA and protein level in hepatoma cells. Furthermore, co-immunoprecipitation studies revealed that DMFC-induced Bim interrupts interactions between Bcl-2 and Bax and between Mcl-1 and Bak, resulting in dissociation of Bax from Bcl-2 and Bak from Mcl-1 and subsequent activation of both Bax and Bak. Activation of Bax and Bak leads to mitochondrial outer membrane permeabilization and cytochrome c release. Consistent with its potent apoptosis-inducing activity, DMFC exhibited potent activity against the multidrug-resistant hepatoma xenograft growth in vivo. Therefore, we determine that DMFC suppresses hepatoma growth through decreasing Bcl-2 and increasing Bim to induce tumor cell apoptosis and hold great promise for further development as a therapeutic agent to treat chemoresistant hepatoma.
3,5-二甲基-H-呋喃并[3,2-g]色烯-7-酮（DMFC）是一种具有抗癌活性的香豆素衍生物，可抑制人肝癌细胞的生长，但 DMFC 抑制癌症的作用机制尚不清楚。在本研究中，我们旨在阐明 DMFC 抗癌活性的分子机制，并确定 DMFC 是否对耐药性人肝癌的抑制有效。我们的研究结果表明，DMFC 能有效抑制亲本和多药耐药肝癌细胞的体外生长，DMFC 至少部分通过诱导肿瘤细胞凋亡来抑制肝癌细胞的生长。在分子水平上，我们观察到 DMFC 通过转录后机制降低 Bcl-2 水平，并激活 Bim 的转录，增加肝癌细胞中 Bim mRNA 和蛋白水平。此外，共免疫沉淀研究表明，DMFC 诱导的 Bim 中断了 Bcl-2 和 Bax 之间以及 Mcl-1 和 Bak 之间的相互作用，导致 Bax 从 Bcl-2 解离，Bak 从 Mcl-1 解离，随后 Bax 和 Bak 被激活。Bax 和 Bak 的激活导致线粒体膜通透性增加和细胞色素 c 释放。与 DMFC 诱导细胞凋亡的强大活性一致，DMFC 对体内多药耐药肝癌异种移植的生长具有强大的抑制活性。因此，我们确定 DMFC 通过降低 Bcl-2 和增加 Bim 来抑制肝癌生长，诱导肿瘤细胞凋亡，为进一步开发治疗耐药性肝癌的治疗剂提供了广阔的前景。
