Crenolanib-Derived Probes Suitable for Cell- and Tissue-Based Protein Profiling and Single-Cell Imaging

Area of Science:

• Pharmacology
• Molecular Biology
• Biochemistry

Background:

• Crenolanib is a potent inhibitor of FLT3 and PDGFRα/β, currently in Phase III trials for acute myeloid leukemia.
• The precise protein targets of Crenolanib within cancer cells are not fully understood, hindering comprehension of its mechanism and side effects.

Purpose of the Study:

• To identify unknown cellular targets of Crenolanib.
• To develop tools for visualizing drug distribution and understanding drug action.

Main Methods:

• Synthesis of a Crenolanib-based photoaffinity probe and two fluorescent probes.
• Competitive protein profiling using pull-down assays combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Bioimaging studies using fluorescent probes for single-cell level analysis.

Main Results:

• Identification of several previously unknown protein targets, including MAPK1, SHMT2, SLC25A11, and HIGD1A.
• Successful characterization of cellular targets through proteomic analysis.
• Demonstration of fluorescent probes' utility for imaging drug distribution in single cells.

Conclusions:

• The identified protein targets offer insights into Crenolanib's mechanism of action and potential toxicities.
• Developed chemical probes are valuable tools for further research into Crenolanib's cellular interactions and distribution.