Recent studies have demonstrated that CD4+ T cells can efficiently reject MHC-II–negative tumors. This requires indirect presentation of tumor-associated antigens on surrounding antigen-presenting cells. We hypothesized that intercellular transfer of proteins is not the sole consequence of cell death–mediated protein release, but depends on heat-shock cognate protein 70 (HSC70) and its KFERQ-like binding motif on substrate proteins. Using human Y chromosome antigen DBY, we showed that mutation of one of its 2 putative binding motifs markedly diminished T cell activation after indirect presentation and reduced protein-protein interaction with HSC70. Intercellular antigen transfer was shown to be independent of cell-cell contact, but relied on engulfment within secreted microvesicles. In vivo, alterations of the homologous KFERQ-like motif in murine DBY hampered tumor rejection, T cell activation, and migration into the tumor and substantially impaired survival. Collectively, we show that intercellular antigen transfer of DBY is tightly regulated via binding to HSC70 and that this mechanism influences recognition and rejection of MHC-II–negative tumors in vivo.
Sascha Kretschmann, Stefanie Herda, Heiko Bruns, Josefine Russ, Edith D. van der Meijden, Ursula Schlötzer-Schrehardt, Marieke Griffioen, Il-Kang Na, Andreas Mackensen, Anita N. Kremer
Cancer therapy is a double-edged sword, as surgery and chemotherapy can induce an inflammatory/immunosuppressive injury response that promotes dormancy escape and tumor recurrence. We hypothesized that these events could be altered by early blockade of the inflammatory cascade and/or by accelerating the resolution of inflammation. Preoperative, but not postoperative, administration of the nonsteroidal antiinflammatory drug ketorolac and/or resolvins, a family of specialized proresolving autacoid mediators, eliminated micrometastases in multiple tumor-resection models, resulting in long-term survival. Ketorolac unleashed anticancer T cell immunity that was augmented by immune checkpoint blockade, negated by adjuvant chemotherapy, and dependent on inhibition of the COX-1/thromboxane A2 (TXA2) pathway. Preoperative stimulation of inflammation resolution via resolvins (RvD2, RvD3, and RvD4) inhibited metastases and induced T cell responses. Ketorolac and resolvins exhibited synergistic antitumor activity and prevented surgery- or chemotherapy-induced dormancy escape. Thus, simultaneously blocking the ensuing proinflammatory response and activating endogenous resolution programs before surgery may eliminate micrometastases and reduce tumor recurrence.
Dipak Panigrahy, Allison Gartung, Jun Yang, Haixia Yang, Molly M. Gilligan, Megan L. Sulciner, Swati S. Bhasin, Diane R. Bielenberg, Jaimie Chang, Birgitta A. Schmidt, Julia Piwowarski, Anna Fishbein, Dulce Soler-Ferran, Matthew A. Sparks, Steven J. Staffa, Vidula Sukhatme, Bruce D. Hammock, Mark W. Kieran, Sui Huang, Manoj Bhasin, Charles N. Serhan, Vikas P. Sukhatme
Chronic myeloid leukemia (CML) results from hematopoietic stem cell transformation by the BCR-ABL kinase. Despite the success of BCR-ABL tyrosine kinase inhibitors (TKIs) in treating CML patients, leukemia stem cells (LSCs) resist elimination and persist as a major barrier to cure. Previous studies suggest that overexpression of the sirtuin 1 (SIRT1) deacetylase may contribute to LSC maintenance in CML. Here, by genetically deleting SIRT1 in transgenic CML mice, we definitively demonstrated an important role for SIRT1 in leukemia development. We identified a previously unrecognized role for SIRT1 in mediating increased mitochondrial oxidative phosphorylation in CML LSCs. We showed that mitochondrial alterations were kinase independent and that TKI treatment enhanced inhibition of CML hematopoiesis in SIRT1-deleted mice. We further showed that the SIRT1 substrate PGC-1α contributed to increased oxidative phosphorylation and TKI resistance in CML LSCs. These results reveal an important role for SIRT1 and downstream signaling mechanisms in altered mitochondrial respiration in CML LSCs.
Ajay Abraham, Shaowei Qiu, Balu K. Chacko, Hui Li, Andrew Paterson, Jianbo He, Puneet Agarwal, Mansi Shah, Robert Welner, Victor M. Darley-Usmar, Ravi Bhatia
Resistance to immunotherapy is one of the biggest problems of current oncotherapeutics. WhileT cell abundance is essential for tumor responsiveness to immunotherapy, factors that define the T cell inflamed tumor microenvironment are not fully understood. We conducted an unbiased approach to identify tumor-intrinsic mechanisms shaping the immune tumor microenvironment(TME), focusing on pancreatic adenocarcinoma because it is refractory to immunotherapy and excludes T cells from the TME. From human tumors, we identified EPHA2 as a candidate tumor intrinsic driver of immunosuppression. Epha2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy. We found that PTGS2, the gene encoding cyclooxygenase-2, lies downstream of EPHA2 signaling through TGFβ and is associated with poor patient survival. Ptgs2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy; pharmacological inhibition of PTGS2 was similarly effective. Thus, EPHA2-PTGS2 signaling in tumor cells regulates tumor immune phenotypes; blockade may represent a novel therapeutic avenue for immunotherapy-refractory cancers. Our findings warrant clinical trials testing the effectiveness of therapies combining EPHA2-TGFβ-PTGS2 pathway inhibitors with anti-tumor immunotherapy, and may change the treatment of notoriously therapy-resistant pancreatic adenocarcinoma.
Nune Markosyan, Jinyang Li, Yu H. Sun, Lee P. Richman, Jeffrey H. Lin, Fangxue Yan, Liz Quinones, Yogev Sela, Taiji Yamazoe, Naomi Gordon, John W. Tobias, Katelyn T. Byrne, Andrew J. Rech, Garret A. FitzGerald, Ben Z. Stanger, Robert H. Vonderheide
Poroma is a benign skin tumor exhibiting terminal sweat gland duct differentiation. The present study aimed to explore the potential role of gene fusions in the tumorigenesis of poromas. RNA sequencing and reverse transcription PCR identified highly recurrent YAP1-MAML2 and YAP1-NUTM1 fusions in poromas (92/104 lesions, 88.5%) and their rare malignant counterpart, porocarcinomas (7/11 lesions, 63.6%). A WWTR1-NUTM1 fusion was identified in a single lesion of poroma. Fluorescent in-situ hybridization confirmed genomic rearrangements involving these genetic loci. Immunohistochemical staining could readily identify the YAP1 fusion products as nuclear expression of the N-terminal portion of YAP1 with a lack of the C-terminal portion. YAP1 and WWTR1, also known as YAP and TAZ, respectively, encode paralogous transcriptional activators of TEAD, which are negatively regulated by the Hippo signaling pathway. The YAP1 and WWTR1 fusions strongly transactivated a TEAD reporter and promoted anchorage-independent growth, confirming their tumorigenic roles. Our results demonstrate the frequent presence of transforming YAP1 fusions in poromas and porocarcinomas and suggest YAP1/TEAD-dependent transcription as a candidate therapeutic target against porocarcinoma.
Shigeki Sekine, Tohru Kiyono, Eijitsu Ryo, Reiko Ogawa, Susumu Wakai, Hitoshi Ichikawa, Koyu Suzuki, Satoru Arai, Koji Tsuta, Mitsuaki Ishida, Yuko Sasajima, Naoki Goshima, Naoya Yamazaki, Taisuke Mori
Gliomas account for approximately 80% of primary malignant tumors in the central nervous system. Despite aggressive therapy, the prognosis of patients remains extremely poor. Glioma stem cells (GSCs) which considered as the potential target of therapy for their crucial role in therapeutic resistance and tumor recurrence, are believed to be key factors for the disappointing outcome. Here, we took advantage of GSCs as the cell model to perform high-throughput drug screening and the old antibiotic, clofoctol, was identified as the most effective compound, showing reduction of colony-formation and induction of apoptosis of GSCs. Moreover, growth of tumors was inhibited obviously in vivo after clofoctol treatment especially in primary patient-derived xenografts (PDXs) and transgenic xenografts. The anticancer mechanisms demonstrated by analyzing related downstream genes and discovering the targeted binding protein revealed that clofoctol exhibited the inhibition of GSCs by upregulation of Kruppel-like factor 13 (KLF13), a tumor suppressor gene, through clofoctol’s targeted binding protein, Upstream of N-ras (UNR). Collectively, these data demonstrated that induction of KLF13 expression suppressed growth of gliomas and provided a potential therapy for gliomas targeting GSCs. Importantly, our results also identified the RNA-binding protein UNR as a drug target.
Yan Hu, Meilian Zhang, Ningyu Tian, Dengke Li, Fan Wu, Peishan Hu, Zhixing Wang, Liping Wang, Wei Hao, Jingting Kang, Bin Yin, Zhi Zheng, Tao Jiang, Jiangang Yuan, Boqin Qiang, Wei Han, Xiaozhong Peng
The presence of tumor-infiltrating T cells is associated with favorable patient outcomes, yet most pancreatic cancers are immunologically silent and resistant to currently available immunotherapies. Here we show using a syngeneic orthotopic implantation model of pancreatic cancer that Pik3ca regulates tumor immunogenicity. Genetic silencing of Pik3ca in KrasG12D/Trp53R172H-driven pancreatic tumors resulted in infiltration of T cells, complete tumor regression, and 100% survival of immunocompetent host mice. By contrast, Pik3ca-null tumors implanted in T cell-deficient mice progressed and killed all of the animals. Adoptive transfer of tumor antigen-experienced T cells eliminated Pik3ca-null tumors in immunodeficient mice. Loss of PIK3CA or inhibition of its effector, AKT, increased the expression of MHC Class I and CD80 on tumor cells. These changes contributed to the increased susceptibility of Pik3ca-null tumors to T cell surveillance. Our results indicate that tumor cell PIK3CA-AKT signaling limits T cell recognition and clearance of pancreatic cancer cells. Strategies that target this pathway may yield an effective immunotherapy for this cancer.
Nithya Sivaram, Patrick A. McLaughlin, Han V. Han, Oleksi Petrenko, Ya-Ping Jiang, Lisa M. Ballou, Kien Pham, Chen Liu, Adrianus W.M. van der Velden, Richard Z. Lin
Oncolytic virotherapy has been proposed as an ablative and immunostimulatory treatment strategy for solid tumors that are resistant to immunotherapy alone; however, there is a need to optimize host immune activation using preclinical immunocompetent models in previously untested common adult tumors. We studied a modified oncolytic myxoma virus (MYXV) that shows high efficiency for tumor-specific cytotoxicity in small-cell lung cancer (SCLC), a neuroendocrine carcinoma with high mortality and modest response rates to immune checkpoint inhibitors. Using an immunocompetent SCLC mouse model, we demonstrated the safety of intrapulmonary MYXV delivery with efficient tumor-specific viral replication and cytotoxicity associated with induction of immune cell infiltration. We observed increased SCLC survival following intrapulmonary MYXV that was enhanced by combined low-dose cisplatin. We also tested intratumoral MYXV delivery and observed immune cell infiltration associated with tumor necrosis and growth inhibition in syngeneic murine allograft tumors. Freshly collected primary human SCLC tumor cells were permissive to MYXV and intratumoral delivery into patient-derived xenografts resulted in extensive tumor necrosis. We confirmed MYXV cytotoxicity in classic and variant SCLC subtypes as well as cisplatin-resistant cells. Data from 26 SCLC human patients showed negligible immune cell infiltration, supporting testing MYXV as an ablative and immune-enhancing therapy.
Patrick Kellish, Daniil Shabashvili, Masmudur M. Rahman, Akbar Nawab, Maria V. Guijarro, Min Zhang, Chunxia Cao, Nissin Moussatche, Theresa Boyle, Scott Antonia, Mary Reinhard, Connor Hartzell, Michael Jantz, Hiren J. Mehta, Grant McFadden, Frederic J. Kaye, Maria Zajac-Kaye
The mesenchymal (MES) subtype of glioblastoma (GBM) stem cells (GSCs) represents a subpopulation of cancer cells that are notorious for their highly aggressive nature and resistance to conventional therapy. Aldehyde dehydrogenase 1A3 (ALDH1A3) has been recently suggested as a key determinant for the maintenance of MES features of GSCs. However, the mechanisms underpinning aberrant ALDH1A3 expression remain elusive. Here, we identified ubiquitin-specific protease 9X (USP9X) as a bona fide deubiquitinase of ALDH1A3 in MES GSCs. USP9X interacted with, depolyubiquitylated, and stabilized ALDH1A3. Moreover, we showed that FACS-sorted USP9Xhi cells were enriched for MES GSCs with high ALDH1A3 activity and potent tumorigenic capacity. Depletion of USP9X markedly downregulated ALDH1A3, resulting in a loss of self-renewal and tumorigenic capacity of MES GSCs, which could be largely rescued by ectopic expression of ALDH1A3. Furthermore, we demonstrated that the USP9X inhibitor WP1130 induced ALDH1A3 degradation and showed marked therapeutic efficacy in MES GSC–derived orthotopic xenograft models. Additionally, USP9X strongly correlated with ALDH1A3 expression in primary human GBM samples and had a prognostic value for patients with the MES subgroup. Collectively, our findings unveil USP9X as a key deubiquitinase for ALDH1A3 protein stabilization and a potential target for GSC-directed therapy.
Zhengxin Chen, Hong-Wei Wang, Shuai Wang, Ligang Fan, Shuang Feng, Xiaomin Cai, Chenghao Peng, Xiaoting Wu, Jiacheng Lu, Dan Chen, Yuanyuan Chen, Wenting Wu, Daru Lu, Ning Liu, Yongping You, Huibo Wang
Intrinsically disordered proteins (IDPs) are emerging as attractive drug targets by virtue of their prevalence in various diseases including cancer. Drug development targeting IDPs is challenging because they have dynamical structure features and conventional drug design is not applicable. NUPR1 is an IDP playing an important role in pancreatic cancer. We previously reported that Trifluoperazine (TFP), an antipsychotic agent, was capable of binding to NUPR1 and inhibiting tumors growth. Unfortunately, TFP showed strong central nervous system side-effects. In this work, we undertook a multidisciplinary approach to optimize TFP, based on the synergy of computer modeling, chemical synthesis, and a variety of biophysical, biochemical and biological evaluations. A family of TFP-derived compounds was produced and the most active one, named ZZW-115, showed a dose-dependent tumor regression with no neurological effects and induced cell death mainly by necroptosis. This study opens a new perspective for drug development against IDPs, demonstrating the possibility of successful ligand-based drug design for such challenging targets.
Patricia Santofimia-Castaño, Yi Xia, Wenjun Lan, Zhengwei Zhou, Can Huang, Ling Peng, Philippe Soubeyran, Adrian Velazquez-Campoy, Olga Abian, Bruno Rizzuti, Jose L. Neira, Juan Iovanna