Browsing by Author "Maeda, Dean Y."

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    Targeting T cell checkpoints 41BB and LAG3 and myeloid cell CXCR1/CXCR2 results in antitumor immunity and durable response in pancreatic cancer
    (Springer Nature, 2023) Gulhati, Pat; Schalck, Aislyn; Jiang, Shan; Shang, Xiaoying; Wu, Chang-Jiun; Hou, Pingping; Hernandez Ruiz, Sharia; Solis Soto, Luisa; Parra, Edwin; Ying, Haoqiang; Han, Jincheng; Dey, Prasenjit; Li, Jun; Deng, Pingna; Sei, Emi; Maeda, Dean Y.; Zebala, John A.; Spring, Denise J.; Kim, Michael; Wang, Huamin; Maitra, Anirban; Moore, Dirk; Clise-Dwyer, Karen; Wang, Y. Alan; Navin, Nicholas E.; DePinho, Ronald A.; Medicine, School of Medicine
    Pancreatic ductal adenocarcinoma (PDAC) is considered non-immunogenic, with trials showing its recalcitrance to PD1 and CTLA4 immune checkpoint therapies (ICTs). Here, we sought to systematically characterize the mechanisms underlying de novo ICT resistance and to identify effective therapeutic options for PDAC. We report that agonist 41BB and antagonist LAG3 ICT alone and in combination, increased survival and antitumor immunity, characterized by modulating T cell subsets with antitumor activity, increased T cell clonality and diversification, decreased immunosuppressive myeloid cells and increased antigen presentation/decreased immunosuppressive capability of myeloid cells. Translational analyses confirmed the expression of 41BB and LAG3 in human PDAC. Since single and dual ICTs were not curative, T cell-activating ICTs were combined with a CXCR1/2 inhibitor targeting immunosuppressive myeloid cells. Triple therapy resulted in durable complete responses. Given similar profiles in human PDAC and the availability of these agents for clinical testing, our findings provide a testable hypothesis for this lethal disease.
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    Targeting the chromatin effector Pygo2 promotes cytotoxic T cell responses and overcomes immunotherapy resistance in prostate cancer
    (American Association for the Advancement of Science, 2023) Zhu, Yini; Zhao, Yun; Wen, Jiling; Liu, Sheng; Huang, Tianhe; Hatial, Ishita; Peng, Xiaoxia; Al Janabi, Hawraa; Huang, Gang; Mittlesteadt, Jackson; Cheng, Michael; Bhardwaj, Atul; Ashfeld, Brandon L.; Kao, Kenneth R.; Maeda, Dean Y.; Dai, Xing; Wiest, Olaf; Blagg, Brian S. J.; Lu, Xuemin; Cheng, Liang; Wan, Jun; Lu, Xin; Medical and Molecular Genetics, School of Medicine
    The noninflamed microenvironment in prostate cancer represents a barrier to immunotherapy. Genetic alterations underlying cancer cell-intrinsic oncogenic signaling are increasingly appreciated for their role in shaping the immune landscape. Recently, we identified Pygopus 2 (PYGO2) as the driver oncogene for the amplicon at 1q21.3 in prostate cancer. Here, using transgenic mouse models of metastatic prostate adenocarcinoma, we found that Pygo2 deletion decelerated tumor progression, diminished metastases, and extended survival. Pygo2 loss augmented the activation and infiltration of cytotoxic T lymphocytes (CTLs) and sensitized tumor cells to T cell killing. Mechanistically, Pygo2 orchestrated a p53/Sp1/Kit/Ido1 signaling network to foster a microenvironment hostile to CTLs. Genetic or pharmacological inhibition of Pygo2 enhanced the antitumor efficacy of immunotherapies using immune checkpoint blockade (ICB), adoptive cell transfer, or agents inhibiting myeloid-derived suppressor cells. In human prostate cancer samples, Pygo2 expression was inversely correlated with the infiltration of CD8+ T cells. Analysis of the ICB clinical data showed association between high PYGO2 level and worse outcome. Together, our results highlight a potential path to improve immunotherapy using Pygo2-targeted therapy for advanced prostate cancer.