Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
Nat Commun. 2024 Jun 11;15(1):4969. doi: 10.1038/s41467-024-49221-0.
Metabolic remodeling is a strategy for tumor survival under stress. However, the molecular mechanisms during the metabolic remodeling of colorectal cancer (CRC) remain unclear. Melanocyte proliferating gene 1 (MYG1) is a 3'-5' RNA exonuclease and plays a key role in mitochondrial functions. Here, we uncover that MYG1 expression is upregulated in CRC progression and highly expressed MYG1 promotes glycolysis and CRC progression independent of its exonuclease activity. Mechanistically, nuclear MYG1 recruits HSP90/GSK3β complex to promote PKM2 phosphorylation, increasing its stability. PKM2 transcriptionally activates MYC and promotes MYC-medicated glycolysis. Conversely, c-Myc also transcriptionally upregulates MYG1, driving the progression of CRC. Meanwhile, mitochondrial MYG1 on the one hand inhibits oxidative phosphorylation (OXPHOS), and on the other hand blocks the release of Cyt c from mitochondria and inhibits cell apoptosis. Clinically, patients with KRAS mutation show high expression of MYG1, indicating a high level of glycolysis and a poor prognosis. Targeting MYG1 may disturb metabolic balance of CRC and serve as a potential target for the diagnosis and treatment of CRC.
代谢重编程是肿瘤在应激下生存的一种策略。然而,结直肠癌(CRC)代谢重编程过程中的分子机制尚不清楚。黑素瘤增殖基因 1(MYG1)是一种 3'-5' RNA 外切酶,在线粒体功能中发挥关键作用。在这里,我们发现 MYG1 的表达在 CRC 进展中上调,高表达的 MYG1 促进糖酵解和 CRC 进展,而不依赖其外切酶活性。在机制上,核 MYG1 募集 HSP90/GSK3β 复合物以促进 PKM2 磷酸化,增加其稳定性。PKM2 转录激活 MYC 并促进 MYC 介导的糖酵解。相反,c-Myc 也转录上调 MYG1,驱动 CRC 的进展。同时,线粒体 MYG1 一方面抑制氧化磷酸化(OXPHOS),另一方面阻止 Cyt c 从线粒体中释放并抑制细胞凋亡。临床上,KRAS 突变患者表现出 MYG1 的高表达,表明糖酵解水平较高,预后较差。靶向 MYG1 可能会扰乱 CRC 的代谢平衡,可作为 CRC 诊断和治疗的潜在靶点。