Cantharidin suppresses HCT116 colorectal carcinoma cell proliferation and migration by changing the cytoskeleton structure

Background:Cantharidin (CTD),a natural toxin produced from Chinese blister beetles,has extensive anti-tumor activity.The present study investigated the effect of CTD on a human colon cancer cell line to elucidate potential new insights regarding the mechanism(s) through which CTD exerts its anti-tumor effects.Materials and methods:The inhibitory effect of CTD on human colon cancer HCT116 cells was evaluated using the IncuCyte ZOOMTM analyzer.Apoptotic cells were detected by Annexin V-FITC/PI assay and cell cycle was evaluated with flow cytometry following propidium iodide staining.Alterations in F-actin microfilaments were analyzed by FITC-phalloidin staining and morphological changes were evaluated with a laser scanning confocal microscope.Cell migration assay was carried out to investigate the effects of CTD on migration of HCT116 cells in vitro.Results:CTD exhibited a significant growth inhibitory effect on HCT116 cells accompanied by an increase in G2/M phase cells,without a significant effect on apoptosis.CTD-treated cells also exhibited a dramatic collapse in their microfilament network and a significant reduction in cell adhesion.Conclusion:CTD inhibits growth by increasing G2/M phase cells and decreasing S phase cells,revealing that CTD exerts a significant growth inhibitory effect primarily through an inhibition of cell cycle progression (a cytostatic effect).Moreover,a negative effect on cell migration may also constitute a contributing factor to its anti-tumor potential.These findings suggest the potential use for developing CTD as a novel anti-cancer therapy that targets metastasis Giving full play to CTD may inhibit tumor transfer.

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

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.