Background: Glioblastoma is a frequently encountered central nervous system malignancy. Calycosin, a bioactive compound extracted from dried Radix astragali root has exhibited anticancer activity across several different types of cancers, including glioma, but the therapeutic mode of action has yet to be clarified. One ubiquitous inflammatory chemokine implicated in cancer biology is the C-X-C chemokine ligand 10 (CXCL10). The current study seeks to investigate CXCL10 as a likely calycosin target in aiding its inhibitory effects on glioblastoma progression.
Method: The clinical significance of CXCL10 including pathologic grade and survival rate in GBM patients were accessed from TCGA database and our clinical samples. CCK-8 experiments and clone formation assay were performed to detect the cell proliferation. Transwell assay was conducted to examined cell migration and invasion. Western blotting and immunofluorescence staining was used to analyze protein expression levels. Xenograft mouse model was used to evaluate the effect of CA in vivo.
Results: Firstly, we demonstrated that CXCL10 expression is positively associated with glioma and correlated negatively to patient prognosis, supporting our hypothesis that CXCL10 was a potential target for GBM treatment. Additionally, U251 and U87 glioma cell lines were found to demonstrate inhibited invasive, migratory and proliferative abilities upon exposure to calycosin. Calycosin was then found to downregulate CXCL10 expression in a manner that increased with increasing doses, resulting in reduced downstream inflammatory cytokines including NLRP3, NF-κB, IL-1β. Moreover, we demonstrated that overexpressing CXCL10 abolished the inhibitory impact of calycosin on cellular invasion, migration and proliferation in glioma cell lines. Meanwhile, CXCL10 knockdown enhanced calycosin effects on GBM cells. We also used in vivo xenograft mice models to determine the impact of calycosin on glioma growth and obtained results similar to our in vitro experiments.
Conclusions: The current investigation underscores the role of CXCL10 as a promising therapeutic target for treating GBM, with calycosin functioning as a future treatment modality.