Synthesizing Genotoxicity Results in the MultiFlow Assay With Point-of-Departure Analysis and ToxPi Visualization...

Area of Science:

• Toxicology
• Computational Biology
• Biomarker Discovery

Background:

• In vitro genotoxicity assays traditionally provide simple binary outcomes.
• There is a growing need for quantitative data to reduce animal testing and integrate multiplexed assays.
• Holistic consideration of quantitative results from multiple biomarkers is essential for potency assessment.

Purpose of the Study:

• To explore the combined use of PROAST and Toxicological Prioritization Index (ToxPi) software for quantitative analysis of in vitro genotoxicity data.
• To demonstrate a proof-of-concept using the MultiFlow DNA damage assay with γH2AX and p53 biomarkers.
• To facilitate more quantitative analyses of multiple biomarkers and assay streams.

Main Methods:

• Employed the MultiFlow DNA damage assay focusing on γH2AX and p53 biomarkers at two time points.
• Evaluated 10 genotoxicants with and without rat liver S9 metabolic activation.
• Utilized PROAST for Benchmark Dose (BMD) calculations and ToxPi for data synthesis and visualization.

Main Results:

• PROAST calculated BMD point estimates and confidence intervals (CIs).
• ToxPi synthesized BMD results into visual, quantitative summaries of genotoxicity and metabolic properties.
• ToxPi provided insights into compound response, chemical grouping, and genotoxic mechanisms.

Conclusions:

• The combined use of PROAST and ToxPi offers a powerful approach for quantitative genotoxicity analysis.
• ToxPi enhances chemical potency analysis, particularly for complex datasets with multiple biomarkers.
• This integrated method complements traditional BMD CI graphs and supports the move towards reduced animal testing.