Liquid Biotech’s Technology Platform
Liquid Biotech’s assay relies on an adenoviral-based vector that expresses green fluorescent protein (GFP) with amplification of the GFP signal driven by the human telomerase promoter. Telomerase is an enzyme that protects the ends of chromosomes to forestall senescence, and is up regulated in almost all tumor cells to help confer immortality. In contrast, telomerase is not expressed in the majority of normal cells, which thus are susceptible to senescence. It has been demonstrated that this vector is effective in generating a signal in cultured mammalian cancer cells in vitro as well as circulating tumor cells isolated from the blood of cancer patients. Figure 1 below shows an outline of the process and steps used in the assay. For a more detailed description see Ju et al., Cancer Biology & Therapy 15:6, 683-687 (2014).
Figure 1. The process outlined in this figure describes measuring circulating tumor cells (CTCs) from blood samples (liquid biopsy) by employing Liquid Biotech’s telomerase-based adenovirus vector to measure CTCs. The three step process incudes: (1) blood draw and CTC monolayer collection, then (2) incubation of the probe followed by fluorescent imaging and the last steps include (3) assembly of tiled images, filtering and enumeration as highlighted in the flow diagram above.