The tumor-enriched small molecule gambogic amide suppresses glioma by targeting WDR1-dependent cytoskeleton remodeling

Abstract

Glioma is the most prevalent brain tumor, presenting with limited treatment options, while patients with malignant glioma and glioblastoma (GBM) have poor prognoses. The physical obstacle to drug delivery imposed by the blood‒brain barrier (BBB) and glioma stem cells (GSCs), which are widely recognized as crucial elements contributing to the unsatisfactory clinical outcomes. In this study, we found a small molecule, gambogic amide (GA-amide), exhibited the ability to effectively penetrate the blood-brain barrier (BBB) and displayed a notable enrichment within the tumor region. Moreover, GA-amide exhibited significant efficacy in inhibiting tumor growth across various in vivo glioma models, encompassing transgenic and primary patient-derived xenograft (PDX) models. We further performed a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) knockout screen to determine the druggable target of GA-amide. By the combination of the cellular thermal shift assay (CETSA), the drug affinity responsive target stability (DARTS) approach, molecular docking simulation and surface plasmon resonance (SPR) analysis, WD repeat domain 1 (WDR1) was identified as the direct binding target of GA-amide. Through direct interaction with WDR1, GA-amide promoted the formation of a complex involving WDR1, MYH9 and Cofilin, which accelerate the depolymerization of F-actin to inhibit the invasion of patient-derived glioma cells (PDCs) and induce PDC apoptosis via the mitochondrial apoptotic pathway. In conclusion, our study not only identified GA-amide as an effective and safe agent for treating glioma but also shed light on the underlying mechanisms of GA-amide from the perspective of cytoskeletal homeostasis.

Unlocking Glioblastoma Vulnerabilities with CRISPR-Based Genetic Screening

“…CRISPR screening has also been employed to identify targets of chemotherapy drugs. For example, Qu et al developed gambogic amide (GA-amide), a potential new chemotherapy drug for GBM that can effectively penetrate the blood–brain barrier and inhibit tumor growth [ 64 ]. They conducted a genome-wide CRISPRn screen to identify the target of GA-amide.…”

Liver sinusoidal endothelial cell: An important yet often overlooked player in the liver fibrosis

“…LSEC fenestrae were restructured by administering cytochalasin D (Cyto D), an F-actin-depolymerizing agent, which predominantly dispelled the formation of large stress fibers in LSEC dedifferentiation , leading to fenestrae reformation and consequently mitigating liver fibrosis [ 23 ]. Besides, the dynamic remodeling of the cellular cytoskeleton is intricately linked to cellular destiny, encompassing apoaptosis, aging and oxidative states [ 24 ]. Oxidative stress-induced injury mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) is also documented to exacerbate LSEC defenestration through premature senescence related to progestin.…”

Cellular Components of the Tumor Environment in Gliomas—What Do We Know Today?

“…An important example of the targeting of elements of the TEM by SMs is the small molecule gambogic amide (GA-amide), which shows good penetration through the BBB. GA-amide promotes the formation of a protein complex involving WD repeat domain 1 (WDR1) and cofilin, leading to the inhibition of migration and tumor-sphere formation involving tumor cells and glioma stem cells [154]. Another example is the delivery of two SMs by nanoparticles targeting the canonical and non-canonical NF-kB signaling pathway in myeloid cells from TEM.…”