Dynamics of repurposing synthetic and natural compounds against WNT/β-Catenin signaling in glioma- An in vivo approach

Background Glioblastomas arise from multistep tumorigenesis of the glial cells and are associated with poor prognosis. Despite the current state-of-art treatment, tumor recurrence is inevitable. Thus, there exists a desperate need for effective therapeutic alternatives to improve glioblastoma outcome. Among the innovations blooming up, drug repurposing could provide a profound premises for glioblastoma treatment enhancement. While considering this strategy, the efficacy of the repurposed drugs as monotherapies were not up to par; hence, the focus has now shifted to investigate the multi-drug combinations to target glioblastomas. In line with this concept, we investigated the efficacy of a quadruple-combinatorial treatment comprising temozolomide (the benchmark drug) along with chloroquine (a synthetic drug), naringenin (a flavonoid) and phloroglucinol (a marine derivative) in an orthotopic glioma-induced xenograft model. Methods Anti-proliferative effect of the drugs was assessed by immunostaining. The expression profiles of WNT/β-catenin and apoptotic markers were evaluated by qRT-PCR, immunoblotting and ELISA. Patterns of mitochondrial depolarization was determined by flow cytometry. TUNEL assay was performed to affirm apoptosis induction. In vivo drug detection study was carried out by ESI-Q-TOF MS analysis. Results The quadruple-drug treatment had significantly hampered GB proliferation and had induced apoptosis by modulating the WNT/β-catenin signalling. Flow cytometric analysis revealed that the induction of apoptosis was associated with mitochondrial depolarization. Further the quadruple-drug cocktail, had breached the blood brain barrier and was detected in the brain tissue and plasma samples from various experimental groups. Conclusion The quadruple-drug combination served as a promising adjuvant therapy to combat glioma lethality in vivo and can be probed for translation from bench to bedside.