Identification of common patterns of cancer metabolic reprogramming could assist the development of new therapeutic strategies. Recent attention in this field has focused on identifying and targeting signal transduction pathways that interface directly with major metabolic control processes. In the current study we demonstrate the importance of signaling by the diphosphoinositol pentakisphosphate kinases (PPIP5Ks) to the metabolism and proliferation of the HCT116 colonic tumor cell line. We observed reciprocal cross talk between PPIP5K catalytic activity and glucose metabolism, and we show that CRISPR-mediated PPIP5K deletion suppresses HCT116 cell proliferation in glucose-limited culture conditions that mimic the tumor cell microenvironment. We conducted detailed, global metabolomic analyses of wild-type and PPIP5K knockout (KO) cells by measuring both steady-state metabolite levels and by performing isotope tracing experiments. We attribute the growth-impaired phenotype to a specific reduction in the supply of precursor material for de novo nucleotide biosynthesis from the one carbon serine/glycine pathway and the pentose phosphate pathway. We identify two enzymatic control points that are inhibited in the PPIP5K KO cells: serine hydroxymethyltransferase and phosphoribosyl pyrophosphate synthetase, a known downstream target of AMP-regulated protein kinase, which we show is noncanonically activated independently of adenine nucleotide status. Finally, we show the proliferative defect in PPIP5K KO cells can be significantly rescued either by addition of inosine monophosphate or a nucleoside mixture or by stable expression of PPIP5K activity. Overall, our data describe multiple, far-reaching metabolic consequences for metabolic supervision by PPIP5Ks in a tumor cell line.

识别癌症代谢重编程的常见模式可以帮助开发新的治疗策略。该领域最近的注意力集中在识别和靶向直接与主要代谢控制过程相互作用的信号转导通路上。在当前的研究中，我们证明了二磷酸肌醇五磷酸激酶 (PPIP5Ks) 信号转导对 HCT116 结肠肿瘤细胞系的代谢和增殖的重要性。我们观察到 PPIP5K 催化活性和葡萄糖代谢之间的相互串扰，并且我们表明 CRISPR 介导的 PPIP5K 缺失在模拟肿瘤细胞微环境的葡萄糖限制培养条件下抑制 HCT116 细胞增殖。我们进行了详细的，通过测量稳态代谢物水平和进行同位素示踪实验，对野生型和 PPIP5K 敲除 (KO) 细胞进行全局代谢组学分析。我们将生长受损的表型归因于单碳丝氨酸/甘氨酸途径和磷酸戊糖途径的从头核苷酸生物合成的前体材料供应的特定减少。我们确定了在 PPIP5K KO 细胞中被抑制的两个酶促控制点：丝氨酸羟甲基转移酶和焦磷酸磷酸核糖合成酶，这是 AMP 调节蛋白激酶的已知下游靶标，我们显示其非经典激活，与腺嘌呤核苷酸状态无关。最后，我们显示 PPIP5K KO 细胞的增殖缺陷可以通过添加肌苷一磷酸或核苷混合物或通过稳定表达 PPIP5K 活性来显着挽救。总的来说，我们的数据描述了肿瘤细胞系中 PPIP5K 代谢监督的多重、深远的代谢后果。