Glioblastoma as a Novel Drug Repositioning Target: Updated State

Vortioxetine: A Potential Drug for Repurposing for Glioblastoma Treatment via a Microsphere Local Delivery System

Drug repurposing is an attractive route for finding new therapeutics for brain cancers such as glioblastoma. Local administration of drugs to brain tumors or the postsurgical resection cavity holds promise to deliver a high dose to the target site with minimal off-target effects. Drug delivery systems aim to sustain the release of the drug at the target site but typically exhibit drawbacks such as a poor safety profile, uncontrolled/rapid drug release, or poor control over synthesis parameters/material dimensions. Herein, we analyzed the antidepressant vortioxetine and showed in vitro that it causes a greater loss of viability in glioblastoma cells than it does to normal primary human astrocytes. We developed a new droplet microfluidic-based emulsion method to reproducibly produce vortioxetine-loaded poly(lactic-co-glycolic) acid (PLGA) microspheres with tight size control (36.80 ± 1.96 μm). The drug loading efficiency was around 90% when 9.1% (w/w) drug was loaded into the microspheres, and drug release could be sustained for three to 4 weeks. The vortioxetine microspheres showed robust antiglioblastoma efficacy in both 2D monolayer and 3D spheroid patient-derived glioblastoma cells, highlighting the potential of combining an antidepressant with sustained local delivery as a new therapeutic strategy.

Repurposing Therapeutic Drugs Complexed to Vanadium in Cancer

Repurposing drugs by uncovering new indications for approved drugs accelerates the process of establishing new treatments and reduces the high costs of drug discovery and development. Metal complexes with clinically approved drugs allow further opportunities in cancer therapy-many vanadium compounds have previously shown antitumor effects, which makes vanadium a suitable metal to complex with therapeutic drugs, potentially improving their efficacy in cancer treatment. In this review, covering the last 25 years of research in the field, we identified non-oncology-approved drugs suitable as ligands to obtain different vanadium complexes. Metformin-decavanadate, vanadium-bisphosphonates, vanadyl(IV) complexes with non-steroidal anti-inflammatory drugs, and cetirizine and imidazole-based oxidovanadium(IV) complexes, each has a parent drug known to have different medicinal properties and therapeutic indications, and all showed potential as novel anticancer treatments. Nevertheless, the precise mechanisms of action for these vanadium compounds against cancer are still not fully understood.