Abstract |
Thymidine kinase 1 (TK1) is a cell cycle regulated enzyme with maximum expression during the S phase. Serum TK1 (S-TK1) is a unique biomarker for cell proliferation. Here, an optimized [(3)H]- thymidine (dThd) phosphorylation assay is described, which is as sensitive as the commercially available TK-REA and TK-Liaison assays for measurement of S-TK1 activity in dogs and humans. Serum samples from dogs (35 healthy, 32 with lymphoma, 2 with leukemia, and 35 with solid tumors) and humans (18 healthy, 9 with chronic lymphocytic leukemia, 10 with myelodysplastic syndrome) were analyzed using the [(3)H]-dThd assay. Mean S-TK1 activities were 1.11 ± 0.46 pmol/min/mL in healthy dogs and 1.15 ± 0.32 pmol/min/mL in healthy humans. S-TK1 activities in dogs with hematological malignancies were 24.2 ± 47.9 pmol/min/mL, and the receiver operating characteristic curve showed an area under the curve of 0.88. With a cut-off value of 1.9 pmol/min/mL (mean value ± 2 SD), the sensitivity was 0.94 and the specificity was 0.68. Very similar results were obtained with human samples (healthy and lymphoma cases). S-TK1 activities measured during chemotherapy of six dogs with lymphoma were drastically reduced. In one case, S-TK1 activity increased prior to relapse. S-TK1 levels in dogs with solid tumors did not differ from the healthy group. S-TK1 activities correlated with those determined with the TK-REA and TK-Liaison assays (r=0.92 and r=0.96, respectively). In conclusion, this optimized [(3)H]-dThd assay is fast, sensitive and economical for measuring S-TK1 activity and should increase its clinical use as biomarker.
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Authors | H Sharif, H von Euler, S Westberg, E He, L Wang, S Eriksson |
Journal | Veterinary journal (London, England : 1997)
(Vet J)
Vol. 194
Issue 1
Pg. 40-7
(Oct 2012)
ISSN: 1532-2971 [Electronic] England |
PMID | 22516918
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2012 Elsevier Ltd. All rights reserved. |
Chemical References |
- Biomarkers, Tumor
- PHB2 protein, human
- Prohibitins
- Thymidine Kinase
- thymidine kinase 1
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Topics |
- Animals
- Biomarkers, Tumor
- Dog Diseases
(blood, enzymology, metabolism)
- Dogs
- Female
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- Humans
- Lymphoma
(blood, metabolism, veterinary)
- Male
- Prohibitins
- Radiochemistry
(methods)
- Sensitivity and Specificity
- Thymidine Kinase
(genetics, metabolism)
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