1. Academic Validation
  2. Reprogramming immunosuppressive myeloid cells facilitates immunotherapy for colorectal cancer

Reprogramming immunosuppressive myeloid cells facilitates immunotherapy for colorectal cancer

  • EMBO Mol Med. 2021 Jan 11;13(1):e12798. doi: 10.15252/emmm.202012798.
Weiqiang Lu 1 Weiwei Yu 1 Jiacheng He 1 Wenjuan Liu 1 Junjie Yang 1 Xianhua Lin 1 Yuanjin Zhang 1 Xin Wang 1 Wenhao Jiang 1 Jian Luo 1 Qiansen Zhang 1 Huaiyu Yang 1 Shihong Peng 1 Zhengfang Yi 1 Shancheng Ren 2 Jing Chen 3 Stefan Siwko 4 Ruth Nussinov 5 6 Feixiong Cheng 7 8 9 Hankun Zhang 1 Mingyao Liu 1
Affiliations

Affiliations

  • 1 Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China.
  • 2 Department of Urology, Changhai Hospital, Second Military University, Shanghai, China.
  • 3 School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, China.
  • 4 Department of Molecular and Cellular Medicine, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA.
  • 5 Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research Sponsored by the National Cancer Institute, Frederick, MD, USA.
  • 6 Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
  • 7 Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
  • 8 Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
  • 9 Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
Abstract

Immune checkpoint blockade (ICB) has a limited effect on colorectal Cancer, underlining the requirement of co-targeting the complementary mechanisms. Here, we identified prostaglandin E2 (PGE2 ) receptor 4 (EP4) as the master regulator of immunosuppressive myeloid cells (IMCs), which are the major driver of resistance to ICB therapy. PGE2 -bound EP4 promotes the differentiation of immunosuppressive M2 macrophages and myeloid-derived suppressor cells (MDSCs) and reduces the expansion of immunostimulated M1 macrophages. To explore the immunotherapeutic role of EP4 signaling, we developed a novel and selective EP4 antagonist TP-16. TP-16 effectively blocked the function of IMCs and enhanced cytotoxic T-cell-mediated tumor elimination in vivo. Cell co-culture experiments revealed that TP-16 promoted T-cell proliferation, which was impaired by tumor-derived CD11b+ myeloid cells. Notably, TP-16 and anti-PD-1 combination therapy significantly impeded tumor progression and prolonged mice survival. We further demonstrated that TP-16 increased responsiveness to anti-PD-1 therapy in an IMC-related spontaneous colorectal Cancer mouse model. In summary, this study demonstrates that inhibition of EP4-expressing IMCs may offer a potential strategy for enhancing the efficacy of immunotherapy for colorectal Cancer.

Keywords

colorectal cancer; immunosuppressive myeloid cells; immunotherapy; prostaglandin E2 receptor 4.

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