Journal: Molecular Therapy Oncology
Article Title: Fibulin-4 expressed in metastatic breast cancer is a target of peptide-based imaging probes and experimental therapeutics
doi: 10.1016/j.omton.2026.201207
Figure Lengend Snippet: BLMP6 mimics LTBP4 and binds to FBLN4 (A) AlphaFold3 (AF3) modeling of the 3D structure of BLMP6 and mouse LTBP4L (residues 716–733 shown) containing the BLMP6 similarity segment (725–730, highlighted). (B) Left, consensus docking pose predicted by AF3 and CB-Dock shows that BLMP6 interacts with the C terminus of mouse FBLN4 (residues 41–443 shown). Right, a similar binding predicted for a 106 amino acid fragment of LTBP4L (residues 675–780) containing the BLMP6 similarity segment (725–730, highlighted) using AF3 and ClusPro. (C) Biolayer interferometry assay performed with Octet to measure binding affinities. (D) Affinity purification of FBLN4 from 4T1 cell extract with biotinylated BLMP6 immobilized on streptavidin-coated beads. Immunoblotting with anti-FBLN4 antibodies identifies the expected 49 kDa protein, which is not isolated on control beads. (E) Graph: real-time PCR analysis of gene messenger RNA (mRNA) expression, relative to 18S , confirming the knockout of FBLN4 in 4T1 cells. Images: lung paraffin sections from mice that were injected with phage displaying BLMP6. Anti-phage IF demonstrates BLMP6-phage homing to 4T1 metastases but not to 4T1-FBLN4-KO metastases. Scale bars, 100 μm.
Article Snippet: Spontaneous cancer progression to metastases was modeled by injecting 2 × 10 4 4T1 cells into the mammary fat pad of 10-weeks-old female Balb/c mice (Jackson Laboratory) with a 31-gauge needle.
Techniques: Binding Assay, Affinity Purification, Western Blot, Isolation, Control, Real-time Polymerase Chain Reaction, Expressing, Knock-Out, Injection