Dual targeting of EphAs and KDR axis hampers VEGF-induced angiogenesis and glioma stem cell replication

Area of Science:

• Neuro-oncology
• Molecular biology
• Cancer therapeutics

Background:

• Glioblastoma multiforme (GBM) is an aggressive brain tumor with poor prognosis, driven by glioma stem-like cells (GSCs) responsible for tumor progression, recurrence, and angiogenesis.
• Eph receptor tyrosine kinases (EphAs and EphBs) are implicated in GBM; EphA receptors are crucial for GSC maintenance and interact with the VEGF/VEGFR-2 pathway, while EphB receptors may promote invasion.
• Selective targeting of EphA receptors presents a promising therapeutic strategy due to their direct role in GSC maintenance and GBM biology.

Purpose of the Study:

• To characterize UniPR1449, a novel selective EphA receptor inhibitor.
• To evaluate the efficacy of UniPR1449 in inhibiting GSC proliferation and angiogenesis relevant to GBM.
• To assess the therapeutic potential of targeting EphA signaling and VEGFR-2-mediated angiogenesis in GBM.

Main Methods:

• UniPR1449 was characterized as a protein-protein interaction inhibitor (PPI-i) blocking ephrin-A1-induced EphA2 signaling in GBM cell lines.
• The compound's effects on patient-derived GSCs were assessed, measuring proliferation and cell cycle progression (S-phase entry).
• Angiogenesis was evaluated using the chick chorioallantoic membrane (CAM) assay to assess inhibition of VEGF-induced vascularization.

Main Results:

• UniPR1449 effectively blocks ephrin-A1-induced EphA2 phosphorylation, internalization, and degradation in GBM cells.
• The compound significantly reduces proliferation and S-phase entry in patient-derived GSCs.
• UniPR1449 impairs VEGF-induced angiogenesis in the CAM assay but does not affect FGF2-mediated vascularization.

Conclusions:

• UniPR1449 exhibits a dual mechanism of action, targeting both EphA signaling in GSCs and VEGFR-2-mediated angiogenesis.
• The selectivity of UniPR1449 for EphA receptors may offer a safety advantage over pan-Eph inhibitors.
• UniPR1449 represents a promising lead compound for developing multitarget therapies against glioblastoma multiforme.