Disruption of FGF2-Heparin-FGFR1 Complex Formation by Antiangiogenic Small Molecule Found In Silico

Background: Basic fibroblast growth factor (FGF2), is one of the most potent proangiogenic proteins involved in tumor angiogenesis. Interaction of heparin with FGF2 and FGF2 receptor (FGFR1) form a ternary complex that is prerequisite for FGF2 proangiogenic activity. Therefore, this interaction can be an important target for inhibition of angiogenesis. Methods: In this study, we performed screening studies by computer-aided techniques to find a small molecule interfering with this interaction. Based on ionic interactions, we found seventeen small molecules to have possiblity of angiogenic inhibition effect. According to important negative charge distances, benzene-1,2,4-tricarboxylic acids, known as Trimellitic acid (TMLA), was chosen. MTT viability test, Real Time PCR, Tube Formation assay and Flowcytometry technique were used to evaluate TMLA effect. Results: Here we demonstrated viability of HUVECs was decreased after exposure to TMLA only at high concentrations. Real time PCR revealed that gene expression was dramatically decreased in comparison to negative control that indicates TMLA is an effective agent on reduction of CD31 expression. At half maximal inhibitory concentration (13mM), TMLA inhibited HUVEC tube formation process. Annexin V-FITC / PI flow cytometry technique revealed that TMLA inhibitory effect was via apoptosis. Conclusion: The present work demonstrates that it is possible to extend the FGF2 inhibitors with much specificity based on ionic interactions strategy