Immune checkpoint blockade (ICB) has demonstrated clinical success in “inflamed” tumors with substantial T-cell infiltrates, but tumors with an immune-desert tumor microenvironment (TME) fail to benefit. The tumor cell-intrinsic molecular mechanisms of the immune-desert phenotype remain poorly understood. Here, we demonstrated that inactivation of the Polycomb-repressive complex 2 (PRC2) core components, EED or SUZ12, a prevalent genetic event in malignant peripheral nerve sheath tumor (MPNST) and sporadically in other cancers, drove a context-dependent immune-desert TME. PRC2 inactivation reprogramed the chromatin landscape that led to a cell-autonomous shift from primed baseline signaling-dependent cellular responses (e.g., interferon γ) to PRC2-regulated development and cellular differentiation transcriptional programs. Further, PRC2 inactivation led to diminished tumor immune infiltrates through reduced chemokine production and impaired antigen presentation and T-cell priming, resulting in primary resistance to ICB. Intratumoral delivery of inactivated modified vaccinia virus Ankara (MVA) enhanced tumor immune infiltrates and sensitized PRC2-loss tumors to ICB. Our results provide molecular mechanisms of PRC2-inactivation-mediated context-dependent epigenetic reprogramming that underline the immune-desert phenotype in cancer. Our studies also point to intratumoral delivery of immunogenic viruses as an initial therapeutic strategy to modulate the immune-desert TME and capitalize on the clinical benefit of ICB.
Juan Yan, Yuedan Chen, Amish J. Patel, Sarah Warda, Cindy J. Lee, Briana G. Nixon, Elissa W.P. Wong, Miguel A. Miranda-Román, Ning Yang, Yi Wang, Mohini R. Pachai, Jessica Sher, Emily Giff, Fanying Tang, Ekta Khurana, Samuel Singer, Yang Liu, Phillip M. Galbo Jr., Jesper L.V. Maag, Richard P. Koche, Deyou Zheng, Cristina Antonescu, Liang Deng, Ming Li, Yu Chen, Ping Chi
Chimeric antigen receptor (CAR) T-cell therapies targeting single antigens perform poorly in clinical trials for solid tumors due to heterogenous expression of tumor-associated antigens (TAAs), limited T-cell persistence and exhaustion. Here we aimed to identify optimal CARs against Glypican-2 (GPC2) or CD276 (B7-H3), which were highly but heterogeneously expressed in neuroblastoma (NB), a lethal extracranial solid tumor of childhood. First, we examined CAR T-cell expansion in the presence of target by digital droplet PCR. Next, using Pooled Competitive Optimization of CAR by CITE-seq (P-COCC), we simultaneously analyzed protein and transcriptome expression of CAR T-cells to identify high activity CARs. Finally, we performed cytotoxicity assays to identify the most effective CAR against each target and combined them into a bicistronic “OR” CAR (BiCisCAR). BiCisCAR T-cells effectively eliminated tumor cells expressing GPC2 or CD276. Furthermore, the BiCisCAR demonstrated prolonged persistence and resistance to exhaustion comparing with single antigen targeting CARs. This study illustrated that targeting multiple TAAs with BiCisCARs may overcome heterogenous expression of target antigen in solid tumors, and identified a potent clinically relevant CAR against NB. Moreover, our multimodal approach integrating competitive expansion, P-COCC, and cytotoxicity assays is an effective strategy to identify potent CARs from a pool of candidates.
MEIJIE TIAN, Adam T. Cheuk, Jun S. Wei, Abdalla Abdelmaksoud, Hsien-Chao Chou, David Milewski, Michael C. Kelly, Young K. Song, Christopher M. Dower, Nan Li, Haiying Qin, Yong Yean Kim, Jerry T. Wu, Xinyu Wen, Mehdi Benzaoui, Katherine E. Masih, Xiaolin Wu, Zhongmei Zhang, Sherif Badr, Naomi Taylor, Brad St. Croix, Mitchell Ho, Javed Khan
An extreme chronic wound tissue microenvironment causes epigenetic gene silencing. Unbiased whole-genome methylome was studied in the wound-edge (WE) tissue of chronic wound patients. A total of 4689 differentially methylated regions (DMRs) were identified in chronic WE compared to unwounded (UW) human skin. Hypermethylation was more frequently observed (3661 DMRs) in the chronic WE compared to hypomethylation (1028 DMRs). Twenty-six hypermethylated DMRs were involved in epithelial to mesenchymal transition (EMT). Bisulfite sequencing validated hypermethylation of a predicted specific upstream regulator TP53. RNA sequencing analysis was performed to qualify findings from methylome analysis. Analysis of the downregulated genes identified the TP53 signaling pathway as being significantly silenced. Direct comparison of hypermethylation and downregulated genes identified four genes, ADAM17, NOTCH, TWIST1 and SMURF1, that functionally represent the EMT pathway. Single-cell RNA sequencing studies identified that these effects on gene expression were limited to the keratinocyte cell compartment. Experimental murine studies established that tissue ischemia potently induces WE gene methylation and that 5’-azacytidine, inhibitor of methylation, improved wound closure. To specifically address the significance of TP53 methylation, keratinocyte-specific editing of TP53 methylation at the WE was achieved by a tissue nanotransfection (TNT) based CRISPR/dCas9 approach. This work identified that reversal of methylation-dependent keratinocyte gene-silencing represents a productive therapeutic strategy to improve wound closure.
Kanhaiya Singh, Yashika Rustagi, Ahmed S. Abouhashem, Saba Tabasum, Priyanka Verma, Edward Hernandez, Durba Pal, Dolly K. Khona, Sujit K. Mohanty, Manishekhar Kumar, Rajneesh Srivastava, Poornachander R Guda, Sumit S. Verma, Sanskruti Mahajan, Jackson A. Killian, Logan A. Walker, Subhadip Ghatak, Shomita S. Mathew-Steiner, Kristen Wanczyk, Sheng Liu, Jun Wan, Pearlly Yan, Ralf Bundschuh, Savita Khanna, Gayle M. Gordillo, Michael P. Murphy, Sashwati Roy, Chandan K. Sen
Targeted protein degradation is a rapidly advancing and expanding therapeutic approach. Drugs that degrade GSPT1 via the CRL4CRBN ubiquitin ligase are a new class of cancer therapy in active clinical development with evidence of activity against acute myeloid leukemia in early phase trials. However, other than activation of the integrated stress response, the downstream effects of GSPT1 degradation leading to cell death are largely undefined, and no murine models are available to study these agents. We identified the domains of GSPT1 essential for cell survival and show that GSPT1 degradation leads to impaired translation termination, activation of the integrated stress response pathway, and TP53-independent cell death. CRISPR-Cas9 screens implicated decreased translation initiation as protective to GSPT1 degradation, suggesting that cells with higher levels of translation are more susceptible to GSPT1 degradation. We defined two Crbn amino acids that prevent Gspt1 degradation in mice, generated a knock-in mouse with alteration of these residues, and demonstrated the efficacy of GSPT1-degrading drugs in vivo with relative sparing of numbers and function of long-term hematopoietic stem cells. Our results provide a mechanistic basis for the use of GSPT1 degraders for the treatment of cancer, including TP53-mutant AML.
Rob S. Sellar, Adam S. Sperling, Mikołaj Słabicki, Jessica A. Gasser, Marie E. McConkey, Katherine A. Donovan, Nada Mageed, Dylan N. Adams, Charles Zou, Peter G. Miller, Ravi Kumar Dutta, Steffen Boettcher, Amy E. Lin, Brittany E. Sandoval, Vanessa A. Quevedo Barrios, Veronica Shkolnik, Jonas Koeppel, Elizabeth K. Henderson, Emma C. Fink, Lu Yang, Anthony K.N. Chan, Sheela Pangeni Pokharel, Erik J. Bergstrom, Rajan Burt, Namrata D. Udeshi, Steven A. Carr, Eric S. Fischer, Chun-Wei Chen, Benjamin L. Ebert
Poly(ADP-ribose) polymerase inhibitors (PARP inhibitors) have had an increasing role in the treatment of ovarian and breast cancers. PARP inhibitors are selectively active in cells with homologous recombination DNA repair deficiency caused by mutations in BRCA1/2 and other DNA repair pathway genes. Cancers with homologous recombination DNA repair proficiency respond poorly to PARP inhibitors. Cancers that initially respond to PARP inhibitors eventually develop drug resistance. We have identified salt-inducible kinase 2 (SIK2) inhibitors, ARN3236 and ARN3261, which decreased DNA double-strand break (DSB) repair functions and produced synthetic lethality with multiple PARP inhibitors in both homologous recombination DNA repair deficiency and proficiency cancer cells. SIK2 is required for centrosome splitting and PI3K activation and regulates cancer cell proliferation, metastasis, and sensitivity to chemotherapy. Here, we showed that SIK2 inhibitors sensitized ovarian and triple-negative breast cancer (TNBC) cells and xenografts to PARP inhibitors. SIK2 inhibitors decreased PARP enzyme activity and phosphorylation of class-IIa histone deacetylases (HDAC4/5/7). Furthermore, SIK2 inhibitors abolished class-IIa HDAC4/5/7–associated transcriptional activity of myocyte enhancer factor-2D (MEF2D), decreasing MEF2D binding to regulatory regions with high chromatin accessibility in FANCD2, EXO1, and XRCC4 genes, resulting in repression of their functions in the DNA DSB repair pathway. The combination of PARP inhibitors and SIK2 inhibitors provides a therapeutic strategy to enhance PARP inhibitor sensitivity for ovarian cancer and TNBC.
Zhen Lu, Weiqun Mao, Hailing Yang, Janice M. Santiago-O’Farrill, Philip J. Rask, Jayanta Mondal, Hu Chen, Cristina Ivan, Xiuping Liu, Chang-Gong Liu, Yuanxin Xi, Kenta Masuda, Eli M. Carrami, Meng Chen, Yitao Tang, Lan Pang, David S. Lakomy, George A. Calin, Han Liang, Ahmed A. Ahmed, Hariprasad Vankayalapati, Robert C. Bast Jr.
The discovery of microRNAs and their role in diseases was a breakthrough that inspired research into microRNAs as drug targets. Cardiovascular diseases are an area in which limitations of conventional pharmacotherapy are highly apparent and where microRNA-based drugs have appreciably progressed into preclinical and clinical testing. In this Review, we summarize the current state of microRNAs as therapeutic targets in the cardiovascular system. We report recent advances in the identification and characterization of microRNAs, their manipulation and clinical translation, and discuss challenges and perspectives toward clinical application.
Bernhard Laggerbauer, Stefan Engelhardt
Charcot-Marie-Tooth disease type 1A (CMT1A), the most common inherited demyelinating peripheral neuropathy, is caused by PMP22 gene duplication. Over-expression of wild-type PMP22 in Schwann cells destabilizes the myelin sheath, leading to demyelination and ultimately to secondary axonal loss and disability. No treatments currently exist that modify the disease course. The most direct route to CMT1A therapy will involve reducing PMP22 to normal levels. To accomplish this, we developed a gene therapy strategy to reduce PMP22 using novel artificial microRNAs targeting human and mouse PMP22/Pmp22 mRNAs. Our lead therapeutic microRNA, miR871, was packaged into an AAV9 vector and delivered by lumbar intrathecal injection into C61-het mice, a model of CMT1A. AAV9-miR871 efficiently transduced Schwann cells in C61-het peripheral nerves and reduced human and mouse PMP22/Pmp22 mRNA and protein levels. Treatment at early and late stages of the disease significantly improved multiple functional outcome measures and nerve conduction velocities. Furthermore, myelin pathology in lumbar roots and femoral motor nerves was ameliorated. Treated mice also showed reductions in circulating biomarkers of CMT1A. Taken together, our data demonstrate that AAV9-miR871-driven silencing of PMP22 rescues a CMT1A model and provides proof of principle for treating CMT1A using a translatable gene therapy approach.
Marina Stavrou, Alexia Kagiava, Sarah G. Choudury, Matthew J. Jennings, Lindsay M. Wallace, Allison M. Fowler, Amanda Heslegrave, Jan Richter, Christina Tryfonos, Christina Christodoulou, Henrik Zetterberg, Rita Horvath, Scott Q. Harper, Kleopas A. Kleopa
Molecularly targeted cancer therapy has improved outcomes for cancer patients with targetable oncoproteins, such as mutant epidermal growth factor receptor (EGFR) in lung cancer. Yet, long-term patient survival remains limited because treatment responses are typically incomplete. One potential explanation for the lack of complete and durable responses is that oncogene-driven cancers with activating mutations in the EGFR often harbor additional co-occurring genetic alterations. This hypothesis remains untested for most genetic alterations that co-occur with mutant EGFR. Here, we report the functional impact of inactivating genetic alteration of the mRNA splicing factor RBM10 that co-occur with mutant EGFR. RBM10 deficiency decreased EGFR inhibitor efficacy in patient-derived EGFR mutant tumor models. RBM10 modulated mRNA alternative splicing of the mitochondrial apoptotic regulator Bcl-x to regulate tumor cell apoptosis during treatment. Genetic inactivation of RBM10 diminished EGFR inhibitor-mediated apoptosis by decreasing the ratio of Bcl-xS-(pro-apoptotic)-to-Bcl-xL(anti-apoptotic) Bcl-x isoforms. RBM10 deficiency was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Co-inhibition of Bcl-xL and mutant EGFR overcame resistance induced by RBM10 deficiency. This study sheds light on the role of co-occurring genetic alterations, and on the impact of splicing factor deficiency in the modulation of sensitivity to targeted kinase inhibitor cancer therapy.
Shigeki Nanjo, Wei Wu, Niki Karachaliou, Collin M. Blakely, Junji Suzuki, Yu-Ting Chou, Siraj M. Ali, D. Lucas Kerr, Victor R. Olivas, Jonathan Shue, Julia Rotow, Manasi K. Mayekar, Franziska Haderk, Nilanjana Chatterjee, Anatoly Urisman, Jia Chi Yeo, Anders J. Skanderup, Aaron C. Tan, Wai Leong Tam, Oscar Arrieta, Kazuyoshi Hosomichi, Akihiro Nishiyama, Seiji Yano, Yuriy Kirichok, Daniel S.W. Tan, Rafael Rosell, Ross A. Okimoto, Trever G. Bivona
The inability of CD8+ T effectors (Teff) to reach tumor cells is an important mechanism of tumor resistance to cancer immunotherapy. The recruitment of these cells to the tumor microenvironment (TME) is regulated by integrins, a family of adhesion molecules that is expressed on T cells. Here we show that 7HP349, a small molecule activator of Lymphocyte function–associated antigen-1 (LFA-1) and very late activation antigen-4 (VLA-4) integrin-cell-adhesion receptors, facilitated the preferential localization of tumor-specific T cells to the tumor and improve antitumor response. 7HP349 monotherapy had modest effects on anti- programmed death 1 (PD-1)–resistant tumors, whereas combinatorial treatment with anti- T-lymphocyte-associated protein 4 (CTLA-4) therapy increased CD8+ Teff intratumoral sequestration and synergized in inducing cancer regression, in cooperation with neutrophils. 7HP349 intratumoral CD8+ Teff enrichment activity depended on CXCL12. We analyzed gene expression profiles using RNA from baseline and on treatment tumor samples of 14 melanoma patients. We identified baseline CXCL12 gene expression may improve response likelihood to anti-CTLA-4 therapies. Our results provided a proof-of-principle demonstration that LFA-1 activation could convert a T cell-exclusionary TME to a T-cell enriched TME through mechanisms involving cooperation with innate immune cells.
Amber Hickman, Joost Koetsier, Trevin Kurtanich, Michael C. Nielsen, Glenn Winn, Yunfei Wang, Salah-Eddine Bentebibel, Leilei Shi, Simone Punt, Leila Williams, Cara Haymaker, Charles B. Chesson, Faisal Fa'ak, Ana Dominguez, Richard Jones, Isere Kuiatse, Amy R. Caivano, Sayadeth Khounlo, Navin D. Warier, Upendra Marathi, Robert V. Market, Ronald J. Biediger, John W. Craft Jr, Patrick Hwu, Michael A. Davies, Darren G. Woodside, Peter Vanderslice, Adi Diab, Willem W. Overwijk, Yared Hailemichael
Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder whose most debilitating pathology is progressive and cumulative heterotopic ossification (HO) of skeletal muscles, ligaments, tendons, and fascia. FOP is caused by mutations in the type I BMP receptor gene ACVR1, which enable ACVR1 to utilize its natural antagonist, Activin A, as an agonistic ligand. The physiological relevance of this property is underscored by the fact that HO in FOP is exquisitely dependent on activation of FOP-mutant ACVR1 by Activin A, an effect countered by inhibition of Activin A via monoclonal antibody treatment. Hence, we surmised that ACVR1 antibodies that block activation of ACVR1 by ligand should also inhibit HO in FOP and provide an additional therapeutic option for this condition. Therefore, we generated ACVR1 monoclonal antibodies that block ACVR1’s activation by its ligands. Surprisingly, in vivo, these ACVR1 antibodies stimulate HO and activate signaling of FOP-mutant ACVR1. This property is restricted to FOP-mutant ACVR1 and results from ACVR1 antibody-mediated dimerization of ACVR1. Conversely, wild type ACVR1 is inhibited by ACVR1 antibodies. These results uncover an additional novel property of FOP-mutant ACVR1 and indicate that ACVR1 antibodies should not be considered as therapeutics for FOP.
Senem Aykul, Lily Huang, Lili Wang, Nanditha M. Das, Sandra Reisman, Yonaton Ray, Qian Zhang, Nyanza J. Rothman, Kalyan C. Nannuru, Vishal Kamat, Susannah Brydges, Luca Troncone, Laura Johnsen, Paul B. Yu, Sergio Fazio, John Lees-Shepard, Kevin Schutz, Andrew J. Murphy, Aris N. Economides, Vincent Idone, Sarah J. Hatsell
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