Centromere protein F (CENPF), a microtubule binding protein, modulates cancer metabolism by regulating pyruvate kinase M2 phosphorylation signaling

Prostate cancer (PC) is the most commonly diagnosed cancer in men and is the second leading cause of male cancer-related death in North America. Metabolic adaptations in malignant PC cells play a key role in fueling the growth and progression of the disease. Unfortunately, little is known regarding these changes in cellular metabolism. Here, we demonstrate that centromere protein F (CENPF), a protein associated with the centromere-kinetochore complex and chromosomal segregation during mitosis, is mechanically linked to altered metabolism and progression in PC. Using the CRISPR-Cas9 system, we silenced the gene for CENPF in human PC3 cells. These cells were found to have reduced levels of epithelial-mesenchymal transition markers and inhibited cell proliferation, migration, and invasion. Silencing of CENPF also simultaneously improved sensitivity to anoikis-induced apoptosis. Mass spectrometry analysis of tyrosine phosphorylated proteins from CENPF knockout (CENPF^KO) and control cells revealed that CENPF silencing increased inactive forms of pyruvate kinase M2, a rate limiting enzyme needed for an irreversible reaction in glycolysis. Furthermore, CENPF^KO cells had reduced global bio-energetic capacity, acetyl-CoA production, histone acetylation, and lipid metabolism, suggesting that CENPF is a critical regulator of cancer metabolism, potentially through its effects on mitochondrial functioning. Additional quantitative immunohistochemistry and imaging analyses on a series of PC tumor microarrays demonstrated that CENPF expression is significantly increased in higher-risk PC patients. Based on these findings, we suggest the CENPF may be an important regulator of PC metabolism through its role in the mitochondria.

前列腺癌（Prostate cancer, PC）是男性最常被诊断出的癌症，亦是北美地区男性癌症相关死亡的第二大诱因。恶性前列腺癌细胞的代谢适应性改变在驱动疾病生长与进展过程中发挥关键作用。遗憾的是，目前学界对这类细胞代谢的改变尚知之甚少。本研究证实，着丝粒蛋白F（centromere protein F, CENPF）——一种与有丝分裂过程中着丝粒-动粒复合物及染色体分离相关的蛋白质——与前列腺癌的代谢异常及疾病进展存在机械性关联。研究团队借助CRISPR-Cas9系统，在人前列腺癌PC3细胞中沉默了CENPF基因。实验发现，此类细胞的上皮间质转化（epithelial-mesenchymal transition）标志物水平降低，细胞增殖、迁移与侵袭能力受到抑制。同时，沉默CENPF还能提升细胞对失巢凋亡（anoikis-induced apoptosis）的敏感性。对CENPF敲除（CENPF^KO）细胞与对照细胞的酪氨酸磷酸化蛋白进行质谱分析后发现，CENPF沉默会增加丙酮酸激酶M2的非活性形式——该酶是糖酵解中不可逆反应的限速酶。此外，CENPF^KO细胞的整体生物能储备、乙酰辅酶A生成、组蛋白乙酰化及脂质代谢水平均有所降低，这表明CENPF是癌症代谢的关键调控因子，其调控作用可能与线粒体功能相关。对一系列前列腺癌肿瘤微阵列的定量免疫组织化学及成像分析显示，高风险前列腺癌患者的CENPF表达水平显著升高。基于上述发现，本研究认为CENPF可通过调控线粒体功能，成为前列腺癌代谢的重要调控因子。