EXPERIMENTAL DRUG DISCOVERY AND REPURPOSING VIA DRUGREP AND PYRX PREDICATED UPON THE GLIOBLASTOMA INfiLTRATIVE MARGIN

Abstract

AIMS The infiltrative margin of GBM, a critical region indicative of residual disease, can be identified using 5- aminolevulinic acid (5ALA). This facilitates the detection of differentially expressed genes which potentially predict GBM recurrence a priori. RNAseq analyses of resected tissue identified six genes (MRGPRX3, RENBP, SUN3, FOSL1, and KRT79, ZNF185) exhibiting high expression and conferring poor prognoses in 5ALA+ infil- trative margin, relative to 5ALA- subpopulations. We aimed to identify FDA-approved and experimental drugs, predicated upon these 5ALA+ gene targets. METHODS A bioinformatics approach leveraging DrugRep and PyRx analysed 3D crystallographic structures retrieved for each gene. Binding pockets with a volume ≥ 200 ų were subjected to screening against a library of FDA- approved and experimental drugs. For each gene and its corresponding binding pocket, drugs were filtered based on binding energy scores of ≤ -7 kcal/mol and rotatable bonds between 5-15. Shortlisted candidates were cross-referenced with small molecule databases and 2D ligand structures inputted into PyRx for molecular dock- ing. RESULTS DrugRep identified novel binding pockets for all six GBM infiltrative margin genes except KRT79. MRGPRX3 ex- hibited four binding pockets, with volumes ranging from 2613 to 427 ų, RENBP was found to have five binding pockets (1032 to 324 ų) and SUN3 contained three binding pockets (289 to 255 ų). Both FOSL1 and ZNF185 dis- played a single binding pocket (201 ų and 4668 ų respectively). All 14 binding pockets were screened against a library of FDA-approved drugs and experimental compounds, identifying >2,800 drugs, which are being further filtered to identify those with potential antiproliferative effects on 5ALA+ cells. CONCLUSION Expanding upon these analytical methods illustrates the power of computational molecular docking techniques to integrate diverse datasets, revealing promising avenues to identify therapeutics specifically targeting the GBM infiltrative margin.