There are many tumor biomarkers but, they mostly reflect tumor mass or past growth, when what is more important is to obtain an indication of future growth and therapy response.

Proliferation biomarkers e.g. KI67, are mostly immunohistological biomarkers which limits their use. The ability to measure a proliferation biomarker in an easily available body fluid could reduce this problem and provide new opportunities for studying tumor growth and therapy response. 

Thymidine Kinase 1 (TK1) has the potential to be such as biomarker. 

This presentation will demonstrate how the immunoassay of TK1, using a unique monoclonal antibody directed against the TK 210 epitope (AroCell TK 210 ELISA) can provide new opportunities for the study of tumor growth, therapy response and in-vitro modelling of drug effects.

Thymidine Kinase 1 (TK1) is a key enzyme in DNA synthesis and it is up-regulated in the S phase of cell growth. It is released into the extracellular medium and, eventually, the blood during cell turnover.

TK1 enzyme activity has been used for many years as a biomarker for hematological malignancies but the complexity of the assay, plus the fact that much of serum TK1 is inactive has restricted its use, particularly for solid tumors. However, all TK1 forms express the TK 210 epitope.