1. Delivery of SiRNA-PD-L1 by attenuated Salmonella in combination with oxaliplatin in a hepatocellular carcinoma mouse model.
- Author
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Chen P, Chen J, Li B, Zhang Y, Li K, Shao C, Guo P, Yang T, Liu H, Jia X, Duan X, Zhao T, Jia H, and Ren J
- Subjects
- Animals, Mice, Humans, Antineoplastic Agents therapeutic use, Antineoplastic Agents pharmacology, Macrophages immunology, Macrophages drug effects, Macrophages metabolism, Cell Line, Tumor, Apoptosis drug effects, Salmonella, Mice, Inbred BALB C, Male, Combined Modality Therapy, Disease Models, Animal, T-Lymphocytes immunology, T-Lymphocytes drug effects, Oxaliplatin therapeutic use, Oxaliplatin pharmacology, B7-H1 Antigen metabolism, B7-H1 Antigen genetics, B7-H1 Antigen antagonists & inhibitors, RNA, Small Interfering genetics, Carcinoma, Hepatocellular drug therapy, Carcinoma, Hepatocellular immunology, Liver Neoplasms drug therapy, Liver Neoplasms immunology
- Abstract
Oxaliplatin is currently used for chemotherapy in patients with hepatocellular carcinoma, but its increasing tolerance to tumours over time limits its clinical application. Studies have shown that high PD-L1 expression promotes the polarization of M2 macrophages. The increased infiltration of M2 macrophages, including those in HCC, is positively correlated with poor prognosis in various solid tumours. We found that oxaliplatin promoted the expression of PD-L1 in liver cancer cells, which might be attributed partly to the tolerance of tumours to oxaliplatin. Therefore, in this study, we explored the antitumour effect of attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin via Western blotting, immunohistochemistry, immunofluorescence, and flow cytometry. The results revealed that attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin more significantly inhibited tumour growth in tumour-bearing mice, suppressed the expression of PD-L1 in tumour tissue, increased the apoptosis of tumour cells and the expression of the tumour-related protein cleaved-caspase3, and increased the infiltration of M1 macrophages and T lymphocytes in tumour tissues. Moreover, the combination therapy increased the activation of T cells and the number of T lymphocytes and NK cells in the spleens of the mice and improved the overall antitumour immune response in the mice. Our results confirmed that attenuated Salmonella harbouring siRNA-PD-L1 combined with oxaliplatin had a significant antitumour effect and did not increase the incidence of toxic side effects, providing a theoretical reference for addressing oxaliplatin tolerance in the treatment of hepatocellular carcinoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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