Effect and mechanism of HER2 antibody-drug conjugate combined with anti-PD-1 antibody in mouse bladder cancer models
10.16016/j.2097-0927.202504097
- VernacularTitle:抗HER2抗体偶联药物联合抗PD-1单抗对小鼠膀胱肿瘤的作用及机制研究
- Author:
Shuo HE
1
;
Lu TAO
;
Yue WU
;
Mengting SHI
;
Tiantian ZHANG
;
Yuanyuan GUO
;
Rui WANG
Author Information
1. 蚌埠医科大学第一附属医院肿瘤内科
- Keywords:
urinary bladder neoplasms;
HER2 antibody-drug conjugate;
anti-PD-1 antibody;
tumor microenvironment
- From:
Journal of Army Medical University
2025;47(14):1623-1631
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the synergistic therapeutic effects of HER2 antibody-drug conjugate(HER2-ADC)combined with anti-PD-1 antibody(anti-PD-1)on HER2-expressing bladder cancer and elucidate its regulatory mechanisms on the tumor immune microenvironment.Methods Orthotopic tumor models were established in 40 female C57BL/6 mice(6～8 weeks old,body mass 18～22 g)using MB49 bladder cancer cells overexpressing human HER2.When tumors reached 100 mm3,the mice were randomized into(n=10)control(intraperitoneal injection of 1.0 mL PBS),anti-PD-1(200 μg per mouse every 3 d),HER2-ADC(2.5 mg/kg once weekly),and combination groups(same regimens as above monotherapy).Tumor volume and body mass were measured every 3 d during 28-day treatment.Tumor growth kinetics and survival rates were analyzed.Post-treatment survival was monitored until natural death to determine median survival time(n=5).At day 28,blood and tumor samples(n=5)were collected to detect myeloid-derived suppressor cells(MDSCs;CD11b?Gr1?)and regulatory T cells(Tregs;CD4?CD25?FOXP3?)with flow cytometry,tumor-infiltrating CD3?T,CD8?T,and FOXP3?T cells with immunohistochemical assasy,and liver/kidney functions[alanine aminotransferase(ALT),aspartate aminotransferase(AST),blood urea nitrogen(BUN),creatinine(CRE)]and tissue damage indicators[lactate dehydrogenase isoenzyme(LDH-L)].Results In 28 d after treatment,the combination group obtained significantly smallest tumor volume than the control group and the 2 monotherapy groups(all P<0.01).The longest median survival was observed in the combination group(65 d,P<0.01),followed by the HER2-ADC group(55 d),anti-PD-1 group(53 d)and control group(41 d).After 28 d of treatment,the combination group exhibited obviously the smallest peripheral proportions of MDSCs/Tregs,most tumor-infiltrating CD3?T/CD8?T cells,and less FOXP3?T cells when compared with the 2 monotherapy groups and control group(all P<0.05).While,the 2 monotherapy groups had smaller MDSCs/Tregs proportions than the control group(P<0.05).No significant differences were observed among the 4 groups in serum ALT,AST,BUN,CRE,or LDH-L levels,and all of them were within normal ranges.Conclusion HER2-ADC combined with anti-PD-1 suppresses the growth of orthotopic bladder tumor,probably through their synergic effects on down-regulating MDSCs/Treg and enhancing CD8?T cell infiltration.
