Cancer cells prefer to utilizing aerobic glycolysis to generate energy and anabolic metabolic intermediates for cell growth. However, whether the activities of glycolytic enzymes can be regulated by specific posttranslational modifications, such as SUMOylation, in response to oncogenic signallings, thereby promoting the Warburg effect, remain largely unclear. Here, we demonstrate that phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a key glycolytic enzyme, interacts with SUMO-conjugating enzyme UBC9 and is SUMOylated at K302 in glioblastoma cells. Expression of UBC9, which competitively prevents the binding of ubiquitin E3 ligase APC/C to PFKFB3 and subsequent PFKFB3 polyubiquitination, increases PFKFB3 stability and expression. Importantly, EGFR activation increases the interaction between UBC9 and PFKFB3, leading to increased SUMOylation and expression of PFKFB3. This increase is blocked by inhibition of EGFR-induced AKT activation whereas expression of activate AKT by itself was sufficient to recapitulate EGF-induced effect. Knockout of PFKFB3 expression decreases EGF-enhanced lactate production and GBM cell proliferation and this decrease was fully rescued by reconstituted expression of WT PFKFB3 whereas PFKFB3 K302R mutant expression abrogates EGF- and UBC9-regulated lactate production and GBM cell proliferation. These findings reveal a previously unknown mechanism underlying the regulation of the Warburg effect through the EGFR activation-induced and UBC9-mediated SUMOylation and stabilization of PFKFB3.

癌细胞更喜欢利用有氧糖酵解来产生能量和合成代谢中间体以促进细胞生长。然而，糖酵解酶的活性是否可以通过特定的翻译后修饰（例如 SUMOylation）来调节，以响应致癌信号，从而促进 Warburg 效应，目前仍不清楚。在这里，我们证明磷酸果糖-2-激酶/果糖-2,6-双磷酸酶 3 (PFKFB3)（一种关键的糖酵解酶）与 SUMO 结合酶 UBC9 相互作用，并在胶质母细胞瘤细胞中在 K302 处被 SUMO 化。UBC9 的表达竞争性地阻止泛素 E3 连接酶 APC/C 与 PFKFB3 的结合以及随后的 PFKFB3 多泛素化，从而增加 PFKFB3 的稳定性和表达。重要的是，EGFR 激活增加了 UBC9 和 PFKFB3 之间的相互作用，导致 PFKFB3 的 SUMO 化和表达增加。这种增加可以通过抑制 EGFR 诱导的 AKT 激活来阻断，而激活 AKT 本身的表达足以重现 EGF 诱导的效果。PFKFB3表达的敲除降低了EGF增强的乳酸产生和GBM细胞增殖，并且这种降低通过WT PFKFB3的重建表达完全挽救，而PFKFB3 K302R突变体表达消除了EGF和UBC9调节的乳酸产生和GBM细胞增殖。这些发现揭示了一种以前未知的机制，该机制通过 EGFR 激活诱导和 UBC9 介导的 SUMO 化以及 PFKFB3 的稳定来调节 Warburg 效应。