1区 · 医学
Article
作者: Chen, Sujun ; Zhu, Yasheng ; Hu, Shixiu ; Zhang, Bo ; Liu, Mingyao ; Ren, Shancheng ; Chen, Huang ; Yi, Zhengfang ; Lu, Weiqiang ; Yu, Weiwei ; Chen, Weidong ; Xie, Jiayi ; Wang, Jian ; Zhang, Xiaomin ; Yang, Junjie ; Zhu, Guanghui ; Sun, Zhenliang ; Ding, Tao ; Xiao, Yu-Tian ; Wang, Ye ; Wu, Huangan ; Wang, Minna ; Peng, Shihong ; Guo, Dandan ; Yang, Yue ; Zhang, Hankun ; Hu, Pan
Purpose::Immunotherapies targeting immune checkpoint molecules have shown promising treatment for a subset of cancers; however, many “cold” tumors, such as prostate cancer, remain unresponsive. We aimed to identify a potential targetable marker relevant to prostate cancer and develop novel immunotherapy.
Experimental Design::Analysis of transcriptomic profiles at single-cell resolution was performed in clinical patients' samples, along with integrated analysis of multiple RNA-sequencing datasets. The antitumor activity of YY001, a novel EP4 antagonist, combined with anti–programmed cell death protein 1 (PD-1) antibody was evaluated both in vitro and in vivo.
Results::We identified EP4 (PTGER4) as expressed in epithelial cells and various immune cells and involved in modulating the prostate cancer immune microenvironment. YY001, a novel EP4 antagonist, inhibited the differentiation, maturation, and immunosuppressive function of myeloid-derived suppressor cells (MDSC) while enhancing the proliferation and anticancer functions of T cells. Furthermore, it reversed the infiltration levels of MDSCs and T cells in the tumor microenvironment by overturning the chemokine profile of tumor cells in vitro and in vivo. The combined immunotherapy demonstrated a robust antitumor immune response as indicated by the robust accumulation and activation of CD8+ cytotoxic T cells, with a significantly decreased MDSC ratio and reduced MDSC immunosuppression function.
Conclusions::Our study identified EP4 as a specific target for prostate cancer immunotherapy and demonstrated that YY001 inhibited the growth of prostate tumors by regulating the immune microenvironment and strongly synergized with anti–PD-1 antibodies to convert completely unresponsive prostate cancers into responsive cancers, resulting in marked tumor regression, long-term survival, and lasting immunologic memory.