Related Experiment Video
Updated: Jul 1, 2025
Comprehensive Analysis of Drug Response using the FLICK Assay
Published on: June 6, 2025
Functional genomic screens with death rate analyses reveal mechanisms of drug action
Megan E Honeywell1, Marie S Isidor2,3, Nicholas W Harper1
1Department of Systems Biology, UMass Chan Medical School, Worcester, MA, USA.
Abstract:
A common approach for understanding how drugs induce their therapeutic effects is to identify the genetic determinants of drug sensitivity. Because 'chemo-genetic profiles' are performed in a pooled format, inference of gene function is subject to several confounding influences related to variation in growth rates between clones. In this study, we developed Method for Evaluating Death Using a Simulation-assisted Approach (MEDUSA), which uses time-resolved measurements, along with model-driven constraints, to reveal the combination of growth and death rates that generated the observed drug response. MEDUSA is uniquely effective at identifying death regulatory genes. We apply MEDUSA to characterize DNA damage-induced lethality in the presence and absence of p53. Loss of p53 switches the mechanism of DNA damage-induced death from apoptosis to a non-apoptotic death that requires high respiration. These findings demonstrate the utility of MEDUSA both for determining the genetic dependencies of lethality and for revealing opportunities to potentiate chemo-efficacy in a cancer-specific manner.
Insights
We developed a new method, MEDUSA, to accurately measure drug effects by analyzing gene function and cell death rates. This approach helps identify new cancer drug targets and improve existing therapies.
Area of Science:
- Genetics
- Molecular Biology
- Cancer Research
Background:
- Understanding drug mechanisms requires identifying genetic factors influencing drug sensitivity.
- Pooled chemo-genetic profiling presents challenges due to variations in clone growth rates, confounding gene function inference.
Purpose of the Study:
- To develop a novel computational method, MEDUSA, for precise analysis of drug response.
- To accurately determine gene function and identify genetic dependencies of drug-induced cell death.
- To investigate the role of p53 in DNA damage-induced cell death.
Main Methods:
- Developed the Method for Evaluating Death Using a Simulation-assisted Approach (MEDUSA).
- Utilized time-resolved measurements and model-driven constraints to differentiate growth and death rates.
- Applied MEDUSA to analyze DNA damage-induced lethality with and without p53.
Main Results:
- MEDUSA accurately deconvolutes growth and death rates, overcoming limitations of pooled profiling.
- Identified key death regulatory genes, particularly in the context of DNA damage.
- Demonstrated that p53 loss alters DNA damage-induced cell death from apoptosis to a respiration-dependent non-apoptotic pathway.
Conclusions:
- MEDUSA is a powerful tool for dissecting genetic determinants of drug sensitivity and cell death.
- Revealed a p53-dependent switch in DNA damage response pathways.
- Highlights potential strategies for enhancing cancer chemotherapy efficacy based on specific genetic profiles.
