Department of Medicinal Chemistry, University of Florida, Gainesville, FL 32610, United States; Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610, United States.
Smithsonian Marine Station, Fort Pierce, FL 34949, United States.
Biochem Pharmacol. 2023 Jul;213:115608. doi: 10.1016/j.bcp.2023.115608. Epub 2023 May 16.
Lagunamide D, a cyanobacterial cyclodepsipeptide, exhibits potent antiproliferative activity against HCT116 colorectal cancer cells (IC 5.1 nM), which were used to probe the mechanism of action. Measurements of metabolic activity, mitochondrial membrane potential, caspase 3/7 activity and cell viability indicate the rapid action of lagunamide D on mitochondrial function and downstream cytotoxic effects in HCT116 cells. Lagunamide D preferentially targets the G cell cycle population and arrests cells in G/M phase at high concentration (32 nM). Transcriptomics and subsequent Ingenuity Pathway Analysis identified networks related to mitochondrial functions. Lagunamide D induced mitochondrial network redistribution at 10 nM, suggesting a mechanism shared with the structurally related aurilide family, previously reported to target mitochondrial prohibitin 1 (PHB1). Knockdown and chemical inhibition of ATP1A1 sensitized the cells to lagunamide D, as also known for aurilide B. We interrogated potential mechanisms behind this synergistic effect between lagunamide D and ATP1A1 knockdown by using pharmacological inhibitors and extended the functional analysis to a global level by performing a chemogenomic screen with a siRNA library targeting the human druggable genome, revealing targets that modulate susceptibility to lagunamide D. In addition to mitochondrial targets, the screen revealed hits involved in the ubiquitin/proteasome pathway, suggesting lagunamide D might exert its effects by additionally affecting proteostasis. Our analysis illuminated cellular processes of lagunamide D that can be modulated in parallel to mitochondrial functions. The identification of potential synergistic drug combinations that can alleviate undesirable toxicity may open possibilities to resurrect this class of compounds for anticancer therapy.
Lagunaamide D，一种来源于蓝藻的环二肽，对 HCT116 结直肠癌细胞（IC50 为 5.1 nM）表现出很强的增殖抑制活性，我们用它来研究其作用机制。代谢活性、线粒体膜电位、半胱天冬酶 3/7 活性和细胞活力的测量表明， Lagunaamide D 能快速作用于线粒体功能，并对 HCT116 细胞产生下游细胞毒性效应。Lagunamide D 优先靶向 G 期细胞周期群体，并在高浓度（32 nM）时将细胞阻滞在 G2/M 期。转录组学和随后的 Ingenuity 通路分析确定了与线粒体功能相关的网络。Lagunamide D 在 10 nM 时诱导线粒体网络重新分布，这表明其作用机制与结构相关的 aurilide 家族相似，此前有报道称 aurilide 家族靶向线粒体抑素 1（PHB1）。ATP1A1 的敲低和化学抑制使细胞对 Lagunaamide D 敏感，这与 aurilide B 相同。我们通过使用药理学抑制剂来研究 Lagunaamide D 与 ATP1A1 敲低之间协同作用的潜在机制，并通过使用靶向人类可药物基因组的 siRNA 文库进行化学基因组筛选，将功能分析扩展到全局水平，揭示了调节 Lagunaamide D 敏感性的靶标。除了线粒体靶标外，该筛选还揭示了参与泛素/蛋白酶体途径的命中靶点，表明 Lagunaamide D 可能通过另外影响蛋白质稳态来发挥作用。我们的分析阐明了 Lagunaamide D 可以平行于线粒体功能进行调节的细胞过程。确定可能缓解不良毒性的潜在协同药物组合可能为复活这类化合物用于癌症治疗开辟可能性。
