title: Creatine kinase B subunit as a biomarker for small cell carcinoma of the lung: comparison with gamma-enolase.
abstract: Concentrations of creatine kinase (CK) B subunit (CK-B) in tumor tissues and in sera of patients with various lung carcinomas were determined, together with the concentrations of neuron-specific gamma-enolase (gamma subunit of a gamma and gamma gamma enolases), by the use of a sensitive enzyme immunoassay method. The CK-B and gamma-enolase levels were enhanced in tissues of small cell carcinoma of the lung. The average tissue contents of CK-B in small cell carcinoma (SCCL), adenocarcinoma (ADCL) and squamous cell carcinoma (ECCL) of the lung, and normal lung were 2320, 308, 163, and 372 ng/mg protein, respectively. The contents of gamma-enolase in those tissues were 1460, 276, 225, and 42.7 ng/mg protein, respectively. Serum CK-B concentrations in healthy adults (n = 100) were 0.53 +/- 0.22 ng/ml and ranged from 0.25 to 1.44 ng/ml, but they were significantly increased (greater than 1.5 ng/ml) in some patients with SCCL (26/42 cases, 62%), ADCL (7/36, 19%), ECCL (7/37, 19%), and large cell carcinoma of the lung (LCCL, 4/13, 31%). Serum CK-B was also enhanced in some patients with breast carcinoma and in a few cases in carcinomas of the stomach, colon and pancreas. Serum concentrations of CK-B were well correlated with those of gamma-enolase in patients with SCCL (r = 0.667, n = 83, P less than 0.01) and LCCL (r = 0.689, n = 20, P less than 0.01), but poorly in patients with ADCL and ECCL. Since serum CK-B concentrations in patients with SCCL changed in parallel with the clinical course during treatment, serum CK-B may also be a useful biomarker, as well as neuron-specific gamma-enolase, for monitoring the clinical course of patients with SCCL.
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology; D001943:Breast Neoplasms / Q000201:enzymology; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000201:enzymology*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology; D003402:Creatine Kinase / Q000032:analysis*; D005770:Gastrointestinal Neoplasms / Q000201:enzymology; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000032:analysis*; D008175:Lung Neoplasms / Q000175:diagnosis / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000032:analysis*
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase; D010751:Phosphopyruvate Hydratase