Targeting the SH2-kinase interface in Bcr-Abl inhibits leukemogenesis

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Chronic myelogenous leukemia (CML) is driven by the Bcr-Abl tyrosine kinase.
• Imatinib and other tyrosine kinase inhibitors (TKIs) are standard CML treatments.
• TKI resistance necessitates novel therapeutic strategies targeting Bcr-Abl.

Purpose of the Study:

• To investigate the role of the SH2-kinase domain interaction in Bcr-Abl activity.
• To explore the SH2-kinase interface as a potential allosteric drug target for CML.

Main Methods:

• Biochemical assays to assess Bcr-Abl kinase activity.
• In vivo studies using mouse models of CML.
• Development and testing of an engineered Abl SH2-binding monobody.

Main Results:

• An intramolecular SH2-kinase interaction is essential for Bcr-Abl catalytic activity.
• Disrupting this interface inhibits CML signaling and prevents leukemia formation in mice.
• Targeting the SH2-kinase interface resensitizes imatinib-resistant Bcr-Abl mutants to TKIs.
• An engineered monobody effectively inhibits Bcr-Abl in vitro and in primary CML cells, inducing apoptosis.

Conclusions:

• The Bcr-Abl SH2-kinase interface is a critical regulatory element and a viable allosteric target.
• Disrupting this interface offers a promising strategy for overcoming TKI resistance in CML.
• Engineered monobodies targeting this interface demonstrate therapeutic potential for CML treatment.