Institut für Pharmakologie und Klinische Pharmakologie, Universitätsklinikum der Heinrich-Heine-Universität, Düsseldorf, Germany.
Br J Pharmacol. 2019 Dec;176(23):4474-4490. doi: 10.1111/bph.14808. Epub 2019 Dec 9.
Aerobic glycolysis is a unique feature of tumour cells that entails several advantages for cancer progression such as resistance to apoptosis. The low MW compound, dichloroacetate, is a pyruvate dehydrogenase kinase inhibitor, which restores oxidative phosphorylation and induces apoptosis in a variety of cancer entities. However, its therapeutic effectiveness is limited by resistance mechanisms. This study aimed to examine the role of the anti-apoptotic hyaluronan (HA) matrix in this context and to identify a potential add-on treatment option to overcome this limitation.
The metabolic connection between dichloroacetate treatment and HA matrix augmentation was analysed in vitro by quantitative PCR and affinity cytochemistry. Metabolic pathways were analysed using Seahorse, HPLC, fluorophore-assisted carbohydrate electrophoresis, colourimetry, immunoblots, and immunochemistry. The effects of combining dichloroacetate with the HA synthesis inhibitor 4-methylumbelliferone was evaluated in 2D and 3D cell cultures and in a nude mouse tumour xenograft regression model by immunoblot, immunochemistry, and FACS analysis.
Mitochondrial reactivation induced by dichloroacetate metabolically activated HA synthesis by augmenting precursors as well as O-GlcNAcylation. This process was blocked by 4-methylumbelliferone, resulting in enhanced anti-tumour efficacy in 2D and 3D cell culture and in a nude mouse tumour xenograft regression model.
The HA rich tumour micro-environment represents a metabolic factor contributing to chemotherapy resistance. HA synthesis inhibition exhibited pronounced synergistic actions with dichloroacetate treatment on oesophageal tumour cell proliferation and survival in vitro and in vivo suggesting the combination of these two strategies is an effective anticancer therapy.
有氧糖酵解是肿瘤细胞的一个独特特征，为癌症进展带来了多种优势，例如抗细胞凋亡。低分子量化合物二氯乙酸盐是一种丙酮酸脱氢酶激酶抑制剂，可恢复氧化磷酸化并诱导多种癌症实体发生细胞凋亡。然而，其治疗效果受到耐药机制的限制。本研究旨在探讨抗凋亡透明质酸（HA）基质在这种情况下的作用，并确定一种潜在的附加治疗选择以克服这种局限性。
通过定量 PCR 和亲和细胞化学，在体外分析二氯乙酸盐处理与 HA 基质扩增之间的代谢联系。使用 Seahorse、HPLC、荧光染料辅助的碳水化合物电泳、比色法、免疫印迹和免疫组织化学分析代谢途径。通过免疫印迹、免疫组织化学和 FACS 分析，在 2D 和 3D 细胞培养以及裸鼠肿瘤异种移植消退模型中评估二氯乙酸盐与 HA 合成抑制剂 4-甲基伞形酮联合使用的效果。
二氯乙酸盐诱导的线粒体再激活通过增加前体以及 O-GlcNAc 化来代谢性地激活 HA 合成。该过程被 4-甲基伞形酮阻断，导致 2D 和 3D 细胞培养以及裸鼠肿瘤异种移植消退模型中的抗肿瘤疗效增强。
富含 HA 的肿瘤微环境是导致化疗耐药的代谢因素。HA 合成抑制与二氯乙酸盐治疗在体外和体内对食管肿瘤细胞增殖和存活表现出显著的协同作用，表明这两种策略的联合是一种有效的抗癌疗法。
