Department of Urology, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
Department of Surgery, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
PLoS One. 2019 Jun 27;14(6):e0218737. doi: 10.1371/journal.pone.0218737. eCollection 2019.
Bladder cancer is a "Warburg-like" tumor characterized by a reliance on aerobic glycolysis and expression of pyruvate kinase M2 (PKM2). PKM2 oscillates between an active tetramer and an inactive dimer. We aim to further characterize PKM2, in particular PKM2 dimer, as a urinary biomarker of bladder cancer and a potential target for treatment.
HTB-9, HTB-5, and UM-UC3 bladder cancer cells were assessed for proliferation under differential glucose levels using the hexosaminidase assay. Western blot and Blue-native analysis was performed for protein expression of PKM2. Shikonin, an herb that is known to bind and inhibit PKM2, was utilized to determine if PKM2 has a role in glucose usage and cellular proliferation in bladder cancer cells by caspase activity assay. Institutional review board approval was obtained to collect healthy control and bladder cancer patient urine samples. The ScheBo M2-PK EDTA Plasma Test was performed on urine samples to assess urine Tumor M2-PK values.
The three bladder cancer cell lines tested all demonstrate statistically significant increases in proliferation when exposed to higher level of glucose (200mg/dL). Similarly, low doses of glucose (25mg/dL) result in reduced proliferation. Increased cell growth in higher glucose concentration correlated with up-regulation of PKM2 protein expression. Shikonin, a PKM2 inhibitor, reduced cell proliferation and switched PKM2 isoforms from the dimer to tetramer. Lastly, dimer PKM2 (Tumor-M2PK) levels were assessed in the urine samples from bladder cancer (Bca) patients and healthy controls. Tumor M2-PK significantly correlated with the presence of BCa in our subjects.
Our studies demonstrate the potential of PKM2, specifically the dimer (Tumor-M2PK) as a target of drug therapy and as a urinary marker for bladder cancer.
膀胱癌是一种“Warburg 样”肿瘤，其特征是依赖有氧糖酵解和丙酮酸激酶 M2（PKM2）的表达。PKM2 在活性四聚体和非活性二聚体之间振荡。我们旨在进一步表征 PKM2，特别是 PKM2 二聚体，作为膀胱癌的尿生物标志物和潜在的治疗靶点。
使用己糖胺酶测定法评估 HTB-9、HTB-5 和 UM-UC3 膀胱癌细胞在不同葡萄糖水平下的增殖情况。进行 Western blot 和 Blue-native 分析以检测 PKM2 的蛋白表达。利用已知能结合和抑制 PKM2 的紫草素，通过半胱天冬酶活性测定来确定 PKM2 是否在膀胱癌细胞的葡萄糖利用和细胞增殖中发挥作用。获得机构审查委员会的批准以收集健康对照者和膀胱癌患者的尿液样本。在尿液样本上进行 ScheBo M2-PK EDTA 血浆测试，以评估尿液肿瘤 M2-PK 值。
测试的三种膀胱癌细胞系在暴露于更高水平的葡萄糖（200mg/dL）时均显示增殖的统计学显着增加。同样，低剂量的葡萄糖（25mg/dL）导致增殖减少。更高葡萄糖浓度下的细胞生长增加与 PKM2 蛋白表达的上调相关。紫草素，一种 PKM2 抑制剂，可减少细胞增殖并将 PKM2 同工型从二聚体转换为四聚体。最后，在膀胱癌（Bca）患者和健康对照者的尿液样本中评估二聚体 PKM2（肿瘤-M2PK）水平。肿瘤 M2-PK 与我们研究对象中的 BCa 存在显着相关。
我们的研究表明 PKM2，特别是二聚体（肿瘤-M2PK）作为药物治疗靶点和膀胱癌的尿标志物具有潜力。
