Dissecting Polypharmacology in Phenotypic Screening to Resolve Ferroptotic and Necrotic Cell-Death Mechanisms

Area of Science:

• Molecular Biology
• Chemical Biology
• Drug Discovery

Background:

• Small molecules often induce complex, heterogeneous cell-death programs.
• Understanding these diverse death pathways is crucial for mechanistic interpretation and therapeutic optimization.
• Ferroptosis and necrosis are distinct, chemically induced cell-death modalities.

Purpose of the Study:

• To investigate the ferroptotic and necrotic activities of the small molecule CIL56 and its analogs.
• To identify distinct molecular targets associated with ferroptosis and necrosis induced by small molecules.
• To enhance the interpretability of small-molecule phenotypic screens.

Main Methods:

• Phenotypic screening of small molecules, including CIL56 and related analogs.
• Utilizing a phenotypic suppressor screen to identify compounds that selectively attenuate ferroptotic or necrotic death.
• Applying ligand-based target prediction to classify suppressor compounds and infer candidate protein targets.

Main Results:

• Structurally similar small molecules, CIL56 and analogs, induced chemically separable cell-death phenotypes (ferroptosis and necrosis).
• Distinct sets of suppressor compounds were identified for ferroptosis and necrosis.
• Target prediction analysis suggested non-overlapping candidate protein targets for each death modality.

Conclusions:

• Integrating phenotypic screening with suppressor classification and target prediction improves the interpretability of small-molecule screens.
• This approach prioritizes candidate proteins and pathways involved in specific cell-death responses.
• The findings provide a framework for dissecting complex small-molecule-induced cell death.