DDR2/STAT3 Positive Feedback Loop Mediates the Immunosuppressive Microenvironment by Upregulating PD-L1 and Recruiting MDSCs in Oxaliplatin-Resistant HCC
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引用次数: 0
Abstract
Background and Aims
Transcriptome sequencing revealed high expression of DDR2 in oxaliplatin-resistant hepatocellular carcinoma (HCC). This study aimed to explore the role of DDR2 in oxaliplatin resistance and immune evasion in HCC.
Methods
Oxaliplatin-resistant HCC cell lines were established. The interaction between DDR2 and STAT3 was investigated, along with the mechanisms involved in DDR2/STAT3-mediated PD-L1 upregulation and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) accumulation both in vitro and in vivo.
Results
DDR2 was found to induce the phosphorylation of STAT3, leading to its nuclear translocation. Conversely, the activation of STAT3 enhanced DDR2 expression. A positive feedback loop involving DDR2/STAT3 was identified in oxaliplatin-resistant HCC, which was associated with PD-L1 upregulation and PMN-MDSCs accumulation. Knockdown of DDR2 and STAT3 sensitized oxaliplatin-resistant HCC cells to oxaliplatin and resulted in decreased PMN-MDSCs and increased CD8+ T cells in the tumor microenvironment. Enzyme-linked immunosorbent array and MDSC transwell migration assays indicated that oxaliplatin-resistant HCC cells recruited PMN-MDSCs through CCL20. Dual luciferase reporter assays demonstrated that STAT3 can directly enhance the transcription of PD-L1 and CCL20. Furthermore, treatment with a PD-L1 antibody in combination with CCL20 blockade had significant antitumor effects on oxaliplatin-resistant HCC.
Conclusions
Our findings revealed a positive feedback mechanism involving DDR2 and STAT3 that mediates the immunosuppressive microenvironment and promotes oxaliplatin resistance and immune evasion via PD-L1 upregulation and PMN-MDSC recruitment. Targeting the DDR2/STAT3 pathway may be a promising therapeutic strategy to overcome immune escape and chemoresistance in HCC.
期刊介绍:
"Cell and Molecular Gastroenterology and Hepatology (CMGH)" is a journal dedicated to advancing the understanding of digestive biology through impactful research that spans the spectrum of normal gastrointestinal, hepatic, and pancreatic functions, as well as their pathologies. The journal's mission is to publish high-quality, hypothesis-driven studies that offer mechanistic novelty and are methodologically robust, covering a wide range of themes in gastroenterology, hepatology, and pancreatology.
CMGH reports on the latest scientific advances in cell biology, immunology, physiology, microbiology, genetics, and neurobiology related to gastrointestinal, hepatobiliary, and pancreatic health and disease. The research published in CMGH is designed to address significant questions in the field, utilizing a variety of experimental approaches, including in vitro models, patient-derived tissues or cells, and animal models. This multifaceted approach enables the journal to contribute to both fundamental discoveries and their translation into clinical applications, ultimately aiming to improve patient care and treatment outcomes in digestive health.