Efficacy of combined treatment with pirfenidone and PD-L1 inhibitor in mice bearing ectopic bladder cancer xenograft
CHEN Shoufeng
ZHANG Shuchao
FAN Weilin
SUN Wei
LIU Beibei
LIU Jianmin
GUO Yuanyuan
Abstract：Objective To assess the efficacy of pirfenidone combined with PD-L1 inhibitor for treatment of bladder cancer in a mouse model and its effect on tumor immune microenvironment modulation.Methods Forty C57BL/6 mouse models bearing ectopic human bladder cancer xenografts were randomized into control group,PD-L1 inhibitor group,pirfenidone group and combined treatment group(n=10).After successful modeling,PD-L1 inhibitor treatment was administered via intraperitoneal injection at 12.5 mg/kg every 3 days,and oral pirfenidone(500 mg/kg)was given on a daily basis.The survival rate of the mice and tumor growth rate were compared among the 4 groups.The expressions of CD3,CD8,CD45,E-cadherin and N-cadherin in the tumor tissues were detected with immunohistochemistry after the 21-day treatment,and bone marrow-derived suppressor cells(MDSCs)were observed with immunofluorescence staining;serum levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),urea nitrogen(BUN),creatinine(CRE)and lactate dehydrogenase(LDH-L)were analyzed using an automated biochemical analyzer.Results Treatment with PD-L1 inhibitor and pirfenidone alone both significantly decreased tumor growth rate and tumor volume at 21 days(P<0.05),but the combined treatment produced an obviously stronger inhibitory effect(P<0.05).PD-L1 inhibitor and pirfenidone alone significantly increased E-cadherin expression and decreased N-cadherin expression in the tumor tissue(P<0.05).The two treatments both significantly increased the percentage of CD3+,CD8 and CD45+ T cells and decreased the percentage of Ly-6G+CD11b+MDSCs in the tumor tissue,and these changes were more obvious in the combined treatment group(P<0.05).No significant differences were found in serum ALT,AST,BUN,CRE or LDH-L levels among the 4 groups(P>0.05).Conclusion Combined treatment with pirfenidone and PD-L1 inhibitor significantly inhibits the progression of bladder cancer in mice possibly by regulating tumor immune microenvironment and inhibiting epithelial-mesenchymal transition of the tumor cells.
Keywords：pirfenidonePD-L1bladder cancerimmune microenvironmentbone marrow-derived suppressor cells
Publication Date：2024-02-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 210-216 )