A high throughput screening system for predicting chemically-induced reproductive organ deformities

• We used a mechanistic approach to validate a panel of high throughput tests.
• The battery was challenged with two sets of chemicals addressing two major apical effect classes in developmental toxicity.
• We found selectivity in this battery in that neural tube defects were predicted correctly in 47% of the cases only while 82% of compounds inducing reproductive organ deformities were predicted correctly.
• Estrogenicity and androgen receptor antagonism were the most informative pathways.
• The assays assessing estrogenicity and antagonistic effects on the androgen receptor were the most informative in the current approach.

There is a great need for alternative testing methods for reproductive toxicants that are practical, fast, cost-effective and easy to interpret. Previously we followed a pragmatic approach using readily available tests, which was successful in predicting reproductive toxicity of chemicals [13]. This initial battery still contained apical tests and is fairly complex and low in its throughput. The current study aimed to simplify this screening battery using a mechanistic approach and a panel of high throughput CALUX reporter gene assays. A mechanistic approach was taken to validate this high throughput test battery. To this end it was challenged with two preselected sets of chemicals addressing two major apical effect classes relevant in reproductive toxicity. We found selectivity in this battery in that 82% of the compounds inducing reproductive organ deformities were predicted correctly, while for compounds inducing neural tube defects this was the case in 47% only. This is consistent with the mechanisms of toxicity covered in the battery. The most informative assays in the battery were ERalpha CALUX to measure estrogenicity and the AR-anti CALUX assay to measure androgen receptor antagonism.