Vismodegib regulates microenvironment of basal cell carcinoma via BRD9-mediated Hedgehog and PD-L1 signaling
10.16016/j.2097-0927.202508025
- VernacularTitle:维莫德吉通过BRD9介导的PD-L1调控基底细胞癌微环境
- Author:
Hao WANG
1
;
Lei ZHANG
;
Junlong LI
;
Xintong LI
;
Meiyan SUN
Author Information
1. 吉林医药学院检验学院
- Keywords:
basal cell carcinoma;
vismodegib;
BRD9;
PD-L1;
tumor microenvironment
- From:
Journal of Army Medical University
2025;47(21):2641-2651
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate how vismodegib(Vis)influences the pathogenesis of basal cell carcinoma(BCC)via a chromatin remodeling factor,bromodomain containing protein 9(BRD9),and to analyze the expression profile of BRD9 in BCC and its relationship with the immune checkpoint,programmed cell death-1 ligand 1(PD-L1)and the Hedgehog(Hh)signaling pathway.Methods ① A UVB-induced BCC model was established in SKH-1 hairless background Ptch1+/-;LacZ reporter mice.Then the mice were treated with Vis,and those without treatment served as control.X-gal staining,immunohistochemistry(IHC)staining,immunofluorescence(IF)assay,and Western blotting were used to assess the expression and localization of BRD9 and PD-L1 in tumor tissues and to evaluate immune-cell infiltration.② In vitro,mouse BCC cell line ASZ001(ASZ cells)were treated with Vis or a BRD9 degrader(dBRD9),and BRD9-overexpressing cells were generated.Cell viability and the protein and mRNA levels of BRD9,PD-L1,Gli1,and cyclin D1(Ccnd1)were measured.ChIP-qPCR was performed to examine BRD9 and H3K27ac enrichment at the PD-L1 promoter,including the promoter-proximal site(P1)and an upstream active segment(P2).Results ① At the tissue level,BRD9 was highly expressed in BCC,and co-localization of BRD9 and PD-L1 was observed within tumor regions,with evident immune-cell infiltration.Vis markedly suppressed UVB-induced BCC formation,reduced the probability of large-volume tumors(by probability-density analysis),decreased the X-gal-positive lesion area(P<0.000 1),down-regulated BRD9(P=0.024 9),and attenuated immune-cell infiltration.② At the cellular level,Vis treatment reduced cell viability and down-regulated BRD9,Gli1,and Ccnd1 in ASZ cells(P<0.000 1).dBRD9 inhibited ASZ cell viability in a dose-dependent manner and decreased PD-L1,Gli1,and Ccnd1(P<0.000 1),whereas its overexpression increased the expression of these molecules(P<0.000 1).In ASZ cells,BRD9 and H3K27ac were enriched at the PD-L1 promoter P1/P2 regions.Treatment with dBRD9 or Vis reduced BRD9 and H3K27ac enrichment at P1/P2 regions(P<0.000 1).Conclusion In BCC,BRD9 maintains chromatin activation at the proximal PD-L1 promoter and modulates Hh/Gli1 signaling,thereby promoting immune evasion.Vis remodels the tumor immune microenvironment by inhibiting the Hh-BRD9-PD-L1 axis.
