ToxReporter Cell Lines for Early, Mechanistic Drug Safety Screening

Would you like to be able to screen multiple discovery compounds for toxicity in a mechanistic way, using a simple cell-based assay? The ToxReporter cell lines allow direct measurement of induction of ten pathways linked to specific toxicological responses (e.g. oxidative stress, DNA damage, xenobiotic response) via a simple ELISA on the cell culture medium. Additionally, metabolite-mediated toxicity can be detected via transient expression of multiple human CYP450s in the cell lines.

The ToxReporter cell lines are freely available to license. For customers who have a limited number of compounds to screen or wish to perform an initial evaluation study, the cell lines can be accessed on a fee-for-service basis.

ToxReporter cell line technology

All cellular responses – both beneficial and toxic – are controlled by a complex network of signalling cascades. Effects of chemicals on these pathways can be measured in cells by developing reporter systems, where the promoter of a gene activated by one of these pathways is linked to a reporter biomarker.

In collaboration with Millipore Inc., CXR has developed a panel of novel in vitro reporter systems using a soluble reporter protein as the biomarker (Fig I). This panel can detect responses such as:

• Oxidative stress & anti-oxidant response                           Fig I 
• Inflammatory response
• Cell cycle control, DNA damage & apoptosis
• Hypoxia/angiogeneisis
• Toxic & other stress responses

The reporter cell lines can therefore be used to generate mechanistic information on the properties of a compound or series of compounds. In particular, the cell lines can be used to:

• Screen drug candidates for potential mechanisms of toxicity in a cost-effective high throughput format
• Screen anti-cancer / cytotoxic / cytoprotective compound libraries – giving a rapid & informative assessment of mechanisms of action

The easily-measured biomarker is attached to a gene promoter region in such a way that, when there is a change in expression of that particular gene, this is reflected by an increase or decrease in levels of the marker. The biomarker can be detected in the culture medium using commercially-available ELISA assays (Fig II). Ten cell lines containing promoters associated with oncogenic / cytoprotective / toxic response pathways have been developed (see below).

Fig II

What if toxicity is not mediated by the parent compound, but by toxic metabolites? Critically, CXR can add human-specific metabolism to the cell lines: multiple human CYP450s enzymes can be expressed via transient transfection with an adenoviral construct.

Reporter Cell Line Advantages

Available Reporter Cell Lines

Considerable technical expertise and experimental know-how has identified the optimal:

• Cell line for each promoter
• Promoter sequence
• Promoter repeat number

The above lines cover the major pathways of cytoprotection and cellular stress, and have been created as a result of collaborations with Millipore Inc. These lines are available for sub-licensing or fee-for-service work.

If you would like further information on these cell lines, fee-for-service prices or licensing terms, please contact CXR at info@cxrbiosciences.com  or phone +44 (0) 1382 432 163.