[Development of prediction models for three in vitro embryotoxicity tests which are evaluated in an ECVAM validation...

Area of Science:

• Toxicology
• Developmental Biology
• In Vitro Assays

Background:

• The European Centre for the Validation of Alternative Methods (ECVAM) funded a study to pre-validate and validate three in vitro embryotoxicity tests.
• These tests included the whole embryo culture (WEC) test, the micromass (MM) test, and the embryonic stem cell (EST) test.

Purpose of the Study:

• To evaluate and validate three in vitro embryotoxicity tests under blind conditions across multiple laboratories.
• To improve prediction models (PM) for WEC and MM tests for accurate identification of chemical embryotoxic potential.
• To assess the existing PM for the EST using initial validation study results.

Main Methods:

• Blind testing of 20 chemicals with varying embryotoxic potential using WEC, MM, and EST assays.
• Development and refinement of prediction models (PM) for each test based on initial results.
• Incorporation of 3T3 cytotoxicity data into the WEC test's PM (PM2) for enhanced accuracy.

Main Results:

• The EST's existing PM achieved 80% correct classification of in vivo embryotoxic potential.
• Newly developed PMs for MM and WEC tests yielded 79% correct classifications.
• The enhanced WEC test PM (PM2), including cytotoxicity data, achieved a 96% correct classification rate.

Conclusions:

• The validated in vitro embryotoxicity tests show promise for predicting chemical developmental toxicity.
• Integrating cytotoxicity data significantly improves the predictive accuracy of the whole embryo culture test.
• These refined methods offer a more reliable alternative for assessing chemical safety during development.