Tumor M2-PK: A novel urine marker of bladder cancer.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Urinary enzyme analysis in renal allograft transplantation.

The urinary excretion of four enzymes (fructose-1,6-bisphosphatase, glutathione S-transferase, N-acetyl-beta-D-glucosaminidase and pyruvate kinase) was assayed daily in 59 patients following renal cadaveric allografting. 51 patients were given cyclosporin A (CyA group) as an immunosuppressive, 8 patients were treated conventionally with azathioprine and prednisolone (CON-group). Urinary enzyme output was evaluated by two different mathematical models. Model A follows single enzyme excretion, whereas model B also analyzes enzyme patterns. The best results were obtained by a combined analysis of all four enzymes with model B. In the CON-group the sensitivity was 1.00, the specificity 0.85, the predictive values of positive test 0.45 and all 12 graft rejections were diagnosed correctly. In the CyA group the sensitivity was 0.40, the specificity 0.99, the predictive value of positive test 0.33, and 6 out of 9 rejections were recognized. The evaluation of the single enzymes did not produce similarly good results with either model.

[Urinary enzymes in the non-invasive diagnosis of kidney epithelial lesions in acute kidney failure]. / Harnenzyme zur nichtinvasiven Diagnostik von Nierenepithelschäden im akuten Nierenversagen.

The present investigation describes the urinary output of four different enzymes localized within nephron cells in two models of experimental acute renal failure. The activities of fructose-1,6-diphosphatase (FDP), glutathione-S-transferase (GST), N-acetyl-beta-D-glucosaminidase (NAG) and pyruvate kinase (PK) were determined in the urine of rats after maleate or HgCl2 intoxication. 2 hours after maleate intoxication the urinary output of FDP, GST and NAG was significantly increased above control values. 6 hours after HgCl2 poisoning FDP, GST and NAG showed increased urinary enzyme activities. The urinary activity of each enzyme was significantly increased 24 hours after intoxication. These results are in good accordance with the damage observed on light and electron microscopic investigations carried out with both experimental models. Furthermore, general problems of urinary enzyme measurements are discussed in this paper.