The D647N mutation of FGFR1 induces ligand-independent receptor activation

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• The activation loop (A-loop) of kinases is a critical regulatory region frequently altered in cancer, leading to uncontrolled kinase activity and resistance to targeted therapies.
• Fibroblast growth factor receptor 1 (FGFR1) is a receptor tyrosine kinase implicated as an oncogene in various solid and hematological malignancies, making it a significant therapeutic target.

Purpose of the Study:

• To investigate the biochemical and molecular consequences of the D647N mutation within the FGFR1 activation loop.
• To assess the impact of FGFR1^D647N on cancer cell behavior, signaling pathways, and response to the FGFR inhibitor Erdafitinib.

Main Methods:

• Expression of wild-type (WT) and D647N-mutated FGFR1 in normal and cancer cell models (in vitro).
• Analysis of FGFR1 phosphorylation, intracellular signaling activation, cell migration, invasiveness, and pro-angiogenic capacity.
• Evaluation of sensitivity to the ATP-competitive inhibitor Erdafitinib.

Main Results:

• FGFR1^D647N exhibits ligand-independent phosphorylation and activates downstream signaling pathways.
• Expression of FGFR1^D647N significantly enhances cancer cell migration (single and collective), invasiveness, and pro-angiogenic potential in vitro and in vivo.
• The D647N mutation markedly increases FGFR1 sensitivity to Erdafitinib.

Conclusions:

• The D647N substitution in FGFR1 is identified as a novel, pro-oncogenic activating mutation.
• FGFR1^D647N may serve as a predictive biomarker for a favorable response to Erdafitinib therapy in cancer patients.
• Further research is needed to fully elucidate activation mechanisms, develop more specific inhibitors, and confirm clinical relevance.