1. Academic Validation
  2. PARP inhibitors accumulate B7-H3 on fibroblasts via blocking autophagic flux to potentiate immune evasion in ovarian cancer

PARP inhibitors accumulate B7-H3 on fibroblasts via blocking autophagic flux to potentiate immune evasion in ovarian cancer

  • Oncoimmunology. 2025 Dec;14(1):2516294. doi: 10.1080/2162402X.2025.2516294.
Tian Fang 1 2 3 Yu Xia 1 2 Ying Li 1 2 Sen Xu 1 2 Huayi Li 1 2 Siyuan Wang 1 2 Pu Huang 1 2 4 Yiyu Qian 1 2 4 Ping Jin 1 2 Ning Jin 1 2 Cheng Xu 1 2 Zhen Wang 1 2 Xiaoming Xiong 1 2 Mengjie Wang 1 2 Dongchen Zhou 1 2 Ya Wang 1 2 Xiaoting Li 1 2 Tao Xu 5 Qi Zhang 6 Dan Liu 1 2 Yong Fang 1 2 Guang-Nian Zhao 1 2 Qinglei Gao 1 2
Affiliations

Affiliations

  • 1 Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 2 Key Laboratory of Cancer Invasion and Metastasis (Ministry of Education), Hubei Key Laboratory of Tumor Invasion and Metastasis, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 3 Department of Obstetrics and Gynecology, Academician Expert Workstation, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 4 Department of Obstetrics and Gynecology, The Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China.
  • 5 Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 6 Department of Plastic and Cosmetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Abstract

Besides targeting tumor cells via canonical synthetic lethality, poly(ADP-ribose) polymerase inhibitors (PARPis) can remodel tumor immune microenvironment (TIME), which then affects PARPis' anti-tumor capabilities. However, exact function of PARPis on TIME remains insufficiently explored. Here, by leveraging paired samples during neoadjuvant PARPi Niraparib treatment derived from a prospective clinical trial, we discovered that the expression of immune checkpoint ligand B7-H3 was induced by PARPis in cancer-associated fibroblasts (CAFs) of ovarian Cancer. Depletion of B7-H3 in CAFs by using host cd276 (coding B7-H3) knockout mice or B7-H3 deficient fibroblast cells both boosted T cell functions and enhanced the anti-tumor capacities of PARPis in immunocompetent mouse models. Besides, increased B7-H3 on CAFs also attenuated the anti-tumor potentials of T cells in co-culture system. Mechanistically, PARPis blocked autophagic flux by inhibiting PIP4K2A expression, a critical regulator of autophagosome and lysosome fusion, and therefore dampening the lysosomal degradation of B7-H3. Importantly, neutralizing B7-H3 antibodies had synergistic effects with PARPis and achieved superior therapeutic efficacy than PARPis plus PD-1 blockade in a syngeneic mouse ovarian Cancer model. Collectively, this study revealed an autophagy-mediated pathway by which PARPis contribute to immune evasion via enhanced B7-H3 accumulation on CAFs, highlighting the complexity of the regulation of PARPis on TIME and the potential application of combining PARPis with B7-H3 blockade in the treatment of ovarian Cancer.

Keywords

Autophagy; B7-H3; PARP inhibitor; cancer-associated fibroblast; ovarian cancer.

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