TK 1 in breast and prostate cancer: early detection of tumor proliferation and cell turnover is important for therapeutic outcome.
The AroCell TK 210 ELISA kit is a serum biomarker for cell turnover, and the only CE marked TK1 immunoassay on the market. The TK 210 ELISA kit can be used to study malignancies of many forms but it may be particularly useful to measure TK1 protein in serum samples from subjects with solid tumors, for instance breast and prostate cancer. TK1 monitoring offers a step towards individualized cancer therapy.
High cell turnover is a sign that a tumor is growing …
Designed specifically for measuring TK1 protein
TK1 leaks into the blood from tumors during cell growth and turnover and elevated serum levels are a sign of increased tumor growth.
However, TK1 forms in sera from subjects with breast or prostate tumors may have reduced enzyme activity with the effect that current enzyme activity assays show poor discrimination between TK1 levels in healthy subjects and those with cancer.
The AroCell TK 210 ELISA kit measures total TK 1 protein rather than TK1 activity, and utilizes a special sample pre-treatment buffer that frees TK1 from complexes and makes it more available for assay.
Together this results in better discrimination between TK1 levels in healthy subjects and those with cancer. More advanced disease is associated with increased serum TK1 levels as measured with AroCell TK 210 ELISA. Furthermore, the great stability of TK1 protein at 4C and in frozen samples facilitates shipping of samples and research based on archived material.
The AroCell TK 210 ELISA is a new, unique and sensitive sandwich ELISA test designed to measure total TK1 protein. All that is needed is a standard blood sample from patients with solid tumors and standard laboratory immunoassay equipment.
Structure of TK1 XPA-210 Welin M et al 2004
Quality by design
The AroCell TK 210 ELISA kit was developed based on monoclonal antibodies selected by a three-step screening process: towards the peptide antigen, recombinant TK1 and TK1, and finally, positive-negative serum samples. This has resulted in uniquely sensitive and well-controlled monoclonal antibodies.
TK1 protein: prostate and breast cancer
TK1 activity assays have been available for over 30 years as a biomarker for tumor cell proliferation in haematological malignancies. Recent studies by Professor Staffan Eriksson and his colleagues have expanded on this earlier work, and defined the relationship of TK1 protein levels to TK1 activity in different tumour groups. Total TK1 protein assays showed significantly better sensitivity and specificity in distinguishing blood donors and those from subjects with prostate or breast cancer sera (K Jagarlamudi et al; BMC Cancer, 2015; 15:66).
Furthermore, the research group showed significant correlations between TK1 activity and protein levels in blood samples and sera from patients with different types of malignancies. Serum samples included patients with the hematologic pre-malignancy myelodysplastic syndrome, breast cancer, prostate cancer and healthy blood donors.
In another study, compared with an established biomarker of tumor mass, Ca 15-3, the AroCell TK 210 ELISA serum biomarker showed better discrimination between healthy and subjects with stage 2 breast cancer. Even more importantly, the combination of Ca 15-3 and the AroCell TK 210 ELISA biomarker increased the diagnostic accuracy still more, demonstrating the value of combining biomarkers that monitor different aspects of tumor growth (Kumar JK et al 2016 Tumor Biology).
Mean STK1 enzyme activities in sera from MDS, breast and prostate cancer were 11 ± 17.5, 6.7 ± 19 and 1.8 ± 1.4 pmol/min/mL, (mean ± standard deviation (SD), differing significantly from blood donors (mean ± standard deviation (SD) = 1.1 ± 0.6 pmol/min/mL).
Serum TK1 protein concentration levels were also significantly higher in MDS, breast, prostate cancer compared to blood donors (mean ± SD = 19 ± 9, 22 ± 11, 20 ± 12, and 5 ± 3.5 ng/mL, respectively).
Note that TK1 protein concentrations differed more between serum from healthy individuals and subjects with cancer than TK1 enzyme activities.
This has several important implications for the use of STK1 as a tumor biomarker. One is that STK1 protein assays may differentiate early-stage tumour progression in breast and prostate cancer more effectively than STK1 activity assays.