PDF(Pubmed)
Abstract：
Various lines of investigation support a signaling interphase shared by receptor tyrosine kinases and the DNA damage response. However, the underlying network nodes and their contribution to the maintenance of DNA integrity remain unknown. We explored MET-related metabolic pathways in which interruption compromises proper resolution of DNA damage. Discovery metabolomics combined with transcriptomics identified changes in pathways relevant to DNA repair following MET inhibition (METi). METi by tepotinib was associated with the formation of γH2AX foci and with significant alterations in major metabolic circuits such as glycolysis, gluconeogenesis, and purine, pyrimidine, amino acid, and lipid metabolism. 5\'-Phosphoribosyl-N-formylglycinamide, a de novo purine synthesis pathway metabolite, was consistently decreased in in vitro and in vivo MET-dependent models, and METi-related depletion of dNTPs was observed. METi instigated the downregulation of critical purine synthesis enzymes including phosphoribosylglycinamide formyltransferase, which catalyzes 5\'-phosphoribosyl-N-formylglycinamide synthesis. Genes encoding these enzymes are regulated through E2F1, whose levels decrease upon METi in MET-driven cells and xenografts. Transient E2F1 overexpression prevented dNTP depletion and the concomitant METi-associated DNA damage in MET-driven cells. We conclude that DNA damage following METi results from dNTP reduction via downregulation of E2F1 and a consequent decline of de novo purine synthesis.
UNASSIGNED: Maintenance of genome stability prevents disease and affiliates with growth factor receptor tyrosine kinases. We identified de novo purine synthesis as a pathway in which key enzymatic players are regulated through MET receptor and whose depletion via MET targeting explains MET inhibition-associated formation of DNA double-strand breaks. The mechanistic importance of MET inhibition-dependent E2F1 downregulation for interference with DNA integrity has translational implications for MET-targeting-based treatment of malignancies.
UNASSIGNED: Maintenance of genome stability prevents disease and affiliates with growth factor receptor tyrosine kinases. We identified de novo purine synthesis as a pathway in which key enzymatic players are regulated through MET receptor and whose depletion via MET targeting explains MET inhibition-associated formation of DNA double-strand breaks. The mechanistic importance of MET inhibition-dependent E2F1 downregulation for interference with DNA integrity has translational implications for MET-targeting-based treatment of malignancies.
摘要：
各种研究支持受体酪氨酸激酶共享的信号传导间期和DNA损伤反应。然而,底层网络节点及其对维持DNA完整性的贡献仍然未知。我们探索了MET相关的代谢途径，其中断会损害DNA损伤的正确解决。发现代谢组学结合转录组学鉴定了与MET抑制（METi）后DNA修复相关的途径的变化。Tepotinib的METi与γH2AX灶的形成以及主要代谢回路如糖酵解的显着改变有关，糖异生,嘌呤,嘧啶,氨基酸,和脂质代谢。5'-磷酸核糖基-N-甲酰甘氨酰胺（FGAR），从头嘌呤合成途径代谢产物，在体外和体内MET依赖性模型中持续下降，并观察到与METi相关的dNTPs消耗。METi引起关键嘌呤合成酶的下调,包括催化FGAR合成的磷酸核糖甘氨酰胺甲酰转移酶(GART)。编码这些酶的基因通过E2F1调节,在MET驱动的细胞和异种移植物中,E2F1的水平在METi时降低。在MET驱动的细胞中,瞬时E2F1过表达防止dNTP耗尽和伴随的METi相关DNA损伤。我们得出的结论是，METi后的DNA损伤是由于通过下调E2F1而导致的dNTP减少以及由此导致的嘌呤从头合成下降。
